@article{abdellah_eletmany_el-shafei_2023, title={Exploring the impact of electron acceptor tuning in D-π-A′-π-A photosensitizers on the photovoltaic performance of acridine-based DSSCs: A DFT/TDDFT perspective}, volume={35}, ISSN={2352-4928}, url={http://dx.doi.org/10.1016/j.mtcomm.2023.106170}, DOI={10.1016/j.mtcomm.2023.106170}, abstractNote={Nine novel organic molecules with D-π-A′-π-A motifs, designated as (Ac-T-Qs-T-CA) and (Ac-T-Bx-T-CA), were proposed as potential photosensitizers for use in dye-sensitized solar cells (DSSCs). These novel organic photosensitizers are comprised of an acridine electron donor (Ac) and a thiophene π-spacer (T), while the electron acceptor unit (A′) is either a substituted quinoxaline (Qs) or a benzo[2,5]diazole-1-heteroatom (Bx), and the anchoring group (A) is 2-cyanoacrylic acid (CA). The influence of electron acceptor (A′) moieties on the electronic, photophysical, thermodynamic and photovoltaic properties of the photosensitizers was analyzed using DFT and TD-DFT calculations. The MM3 force field and CONFLEX conformational search methods were employed to study all possible structural conformations of the photosensitizers. The goal was to identify the lowest energy conformer and gain a better understanding of how the structure conformation and torsional angles of (Ac-T-Qs-T-CA) and (Ac-T-Bx-T-CA) compared to the reference photosensitizer RK1 affect electron injection ability and overall performance of DSSCs. The thermodynamic analysis revealed that the photosensitizers (Ac-T-Q2,3-diOMe-T-CA) and (Ac-T-BtA-T-CA), which contain a 2,3-dimethoxyquinoxaline (Q2,3-diOMe) and a benzo[d][1,2,3]triazole (BtA) acceptor moieties, respectively, exhibit a noteworthy enhancement in their electron-injection free energy (ΔGinj) and a reduction in their recombination-free energy (ΔGrec) values, leading to an improvement in the overall photovoltaic properties of the solar cell when compared to the other photosensitizers. The photovoltaic characteristics of the photosensitizers showed that the photosensitizer (Ac-T-Q2,3-diOMe-T-CA) demonstrated the highest values of open-circuit photovoltage (Voc = 1.41 eV) and light harvesting efficiency (LHE = 0.80 eV) compared to the other (Ac-T-Qs-T-CA) photosensitizers. Similarly, (Ac-T-BtA-T-CA) photosensitizer demonstrated the highest Voc (1.08 eV) and LHE (0.75 eV) among (Ac-T-Bx-T-CA) photosensitizers. The photovoltaic performance of these new photosensitizers outperformed the reference RK1 photosensitizer, which only achieved a Voc of 1.2 eV and LHE of 0.61 eV. Finally, the electronic structures and optical properties of photosensitizers adsorbed on the TiO2 surface were studied to provide more accurate information about their adsorption on the semiconductor surface.}, journal={Materials Today Communications}, publisher={Elsevier BV}, author={Abdellah, Islam M. and Eletmany, Mohamed R. and El-Shafei, Ahmed}, year={2023}, month={Jun}, pages={106170} }
 @article{abdellah_yildirim_el-shafei_2023, title={Low-cost novel X-shaped hole transport materials for efficient perovskite solar cells: Molecular modelling of the core and schiff base effects on photovoltaic and photophysical properties}, volume={296}, ISSN={["1879-3312"]}, url={https://doi.org/10.1016/j.matchemphys.2022.127188}, DOI={10.1016/j.matchemphys.2022.127188}, abstractNote={Eight molecules with D-π-D molecular motifs coded HTM(1-4)a,b were designed as efficient symmetric hole transporting materials for perovskite solar cells. These HTMs are composed of different core moieties, such as spiro [fluorene-9,9′-xanthene]-diol (SFO), spiro [fluorene-9,9′-xanthene]-dimethoxy (SFM), benzo [c][1,2,5]thiadiazole (BTD), and biphenyl (BP) and are gaining lot of attention because of their low-cost, reproducible electrical and optical properties in device performance. Detailed information about the energetic of molecular levels (GSOP/ESOP), first singlet excitation energy (E0-0), equilibrium molecular geometry, charge separation, charge transfer, reorganization energies, polarizability and hyperpolarizability, density of states (DOS), solubility and stability of these molecules was attained by systematically performing molecular modeling calculations using density functional theory (DFT) and time dependent-DFT calculations utilizing hybrid density functional B3LYP using the basis set 6–31g(d,p) level of theory as a successful method for predicting the photophysical and photovoltaic properties of these conjugated systems. The results showed that not only the core moieties, but also Schiff-base linkage extended conjugation, have an effect on the photophysical and photovoltaic properties of the proposed HTMs. It was demonstrated that HTMs incorporating SFO (HTM1a,b), SFM (HTM2a,b), and BP (HTM4a,b) achieved better charge transport, high stability values (η a = 2.11–2.40 eV), low electron-hole binding energy (Eb = 0.16–0.21 eV) than HTM3a,b with BTD core, which improves hole mobility and decreases recombination, all of which improved device photocurrent, which can be attributed to the extended π-conjugation in SFO, SFM and BP cores. These findings are strikingly similar to those of Spiro-OMeTAD (η a = 2.45 eV, Eb = 0.16 eV), indicating that these HTMs are promising candidates for efficient and cost-effective PSCs. Interestingly, when the stability of HTM(1-4)a and HTM(1-4)b was compared, it was clear that HTM(1-4)a has lower stability than HTM(1-4)b, which could be attributed to the presence of Schiff base CN bonds in HTM(1-4)b, which reduces the molecules stability when compared to HTM(1-4)b, owing to a strong C–C linkage. Meanwhile, HTM(1-4)a outperforms HTM(1-4)b in terms of electronic performance and hole mobility.}, journal={MATERIALS CHEMISTRY AND PHYSICS}, author={Abdellah, Islam M. and Yildirim, Erol and El-Shafei, Ahmed}, year={2023}, month={Feb} }
 @article{el-shafei_2023, title={Nomination and commentary on 'Smart textiles: an overview of recent progress on chromic textiles, by Ramlow H., Andrade K. L. & Immich A. P. S., Journal of the Textile Institute, 112:1, 152-171, 2021, and published online 29 Jun 2020. https://doi.org/10.1080/00405000.2020.1785071'}, volume={114}, ISSN={["1754-2340"]}, DOI={10.1080/00405000.2023.2207343}, abstractNote={The paper I would like to nominate that stimulated my color chemistry passion and had constructive impact on me in teaching dye chemistry classes and in my research on functional dyes is entitled: ‘Smart textiles: an overview of recent progress on chromic textiles’ by Ramlow, Andrade and Immich. The paper provides a comprehensive and a state-of-theart review of different types of chromic textiles including photochromic, thermochromic, electrochromic, halochromic, solvatochromic and ionochromic along with the reaction mechanisms showing color change as a result of an external stimulus. It also provides a good coverage of performance characterization, challenges and future directions of chromic textiles, and it is one of the highly cited papers in the JTI with 31 citations so far. Photochromic textiles undergo reversible color change when they are subjected to electromagnetic radiation. The most common photochromic dyes are based on spiropyrans, spirooxazines, naphthopyrans, azobenzene, fulgids and diaryltenenes. The most desired photochromic textiles are those that demonstrate excellent color resistance properties with excellent washfastness and lightfastness after exposure to UV irradiation, which can be used in the manufacture of innovative and smart materials for smart UV-blocker garments, sensing environmental changes, military camouflage, brand protection, security printing, sports clothing and clothing for special services such as fire brigades and police, fabric-based electronic image displays, security barcodes, sensor systems, solar heat and light management. Due to constant exposure to UV, photochromic compounds undergo photodegradation. Microencapsulation of photochromic dyes is one of the approaches for reducing the photodegradation of photochromic compounds as a result of repetitive cycles of UV irradiation. Thermochromic textiles undergo reversible color change due to changes in their molecular structures as a result of changes in the environmental temperature. A thermochromic system is a mixture of a leuco dye, a developer and a solvent in specific ratios. Reversible thermochromic microencapsulated phase change materials with good stability were developed in 2018 by Geng et al. in thermal protective textiles for thermal energy storage application. Electrochromic textiles undergo color changes upon applying an electrical potential. The optical properties of electrochromic textiles are governed by its oxidation state, which can be controlled by the oxidation-reduction process. For example, wool with electrochromic properties was developed by Koc et al (2017) using indium tin oxide (ITO) and tungsten oxide. There are other types of chromic textiles including halochromic, changing color as a function of pH, solvatochromic, changing absorption or emission spectrum as a function of solvent polarity, and ionochromism, which changes color due to a change in the absorption or emission spectra of the molecule as it interacts with ionic species.}, number={6}, journal={JOURNAL OF THE TEXTILE INSTITUTE}, author={El-Shafei, Ahmed}, year={2023}, month={Jun}, pages={895–895} }
 @article{kobaisy_elkady_abdel-moneim_yildirim_el-shafei_el-khouly_2023, title={Optical Properties of Cationic Perylenediimide Nanowires in Aqueous Medium: Experimental and Computational Studies}, ISSN={["1573-4994"]}, DOI={10.1007/s10895-023-03253-9}, abstractNote={Abstract}, journal={JOURNAL OF FLUORESCENCE}, author={Kobaisy, Ahmed M. M. and Elkady, Marwa F. F. and Abdel-Moneim, Ahmed A. A. and Yildirim, Erol and El-Shafei, Ahmed and El-Khouly, Mohamed E. E.}, year={2023}, month={Jun} }
 @article{zafar_ashraf_iqbal_yousuf_siddiqi_liaqat_rehman_akhtar_el-shafei_shahzad_2023, title={Synthesis of new benzimidazole based ruthenium (II) dyes for application in dye-sensitized solar cells with detailed spectroscopic and theoretical evaluation}, volume={1289}, ISSN={["1872-8014"]}, DOI={10.1016/j.molstruc.2023.135860}, abstractNote={In this work, four ancillary ligands named SL-1 to SL-4, having core nucleus of 2-(2-pyridyl) benzimidazole, augmented with electron donating and electron withdrawing groups were successfully synthesized in good yields. The characterization of ligands was assured by FTIR, 1HNMR, 13CNMR, and X-ray crystallographic analysis. The as-synthesized ligands were subjected to complexation with 2,2′-bipyridyl-4,4′-dicarboxylic acid and potassium thiocyanate to prepare four new ruthenium (II) dyes. All the synthesized ruthenium (II) dyes were characterized by infrared spectroscopy and their photophysical and electrochemical studies were compared to the benchmarked dye (N719). Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) were performed to gain deep insights and better understanding of the quantitative structure-property relationships of the named ruthenium dyes (SL1–4). Results showed excellent correlation between the experimental and theoretical results; all the four new dyes exhibited narrow band gap and low singlet excitation energies (1.33 – 1.72 eV) indicating good light harvesting ability in DSSCs. Mulliken charge analysis reveals the intramolecular charge transfer between the highly electronegative nitrogen and oxygen donor centers and the strongly electropositive ruthenium acceptor in the synthesized dyes.}, journal={JOURNAL OF MOLECULAR STRUCTURE}, author={Zafar, Sidrah and Ashraf, Saba and Iqbal, Urooj and Yousuf, Sammer and Siddiqi, Humaira Masood and Liaqat, Faroha and Rehman, Hafiza Maria and Akhtar, Zareen and El-Shafei, Ahmed and Shahzad, Nadia}, year={2023}, month={Oct} }
 @article{lyu_su_el-shafei_2022, title={Highly Efficient Rigidified Quinoxaline-based Co-Sensitizers Carrying Long Alkyl Chains for Ruthenium-Complex-Sensitized DSSCs}, volume={7}, ISSN={["2365-6549"]}, DOI={10.1002/slct.202202183}, abstractNote={Abstract}, number={33}, journal={CHEMISTRYSELECT}, author={Lyu, Luping and Su, Rui and El-Shafei, Ahmed}, year={2022}, month={Sep} }
 @article{badawy_su_fadda_abdel-latif_el-shafei_elmorsy_2022, title={Highly efficient (N-benzothiazolyl)-cyanoacetamide based co-sensitizers for high efficiency dye-sensitized solar cells}, volume={249}, ISSN={["1618-1336"]}, DOI={10.1016/j.ijleo.2021.168274}, abstractNote={Four novels (N-benzothiazolyl)-cyanoacetamide-based metal-free dyes SA17–20 with D-π-A architecture were designed and synthesized as co-sensitizers for HD-2 for dye-sensitized solar cells (DSSCs). They contain strong donating moieties of trimethoxybenzene and N,N-dimethylaniline conjugated with the nitrile function of cyanoacetamide part (NHCOCH2CN) as an anchoring group. The role of donor/acceptor in the cyanoacetamide-based structure motifs of SA17–20 in the co-adsorption properties was characterized and their influence on the optical and electrochemical properties was discussed. Consistent with the experimental results, the equilibrium molecular geometries calculated using density functional theory (DFT), at the B3LYP/ 6–31 G (d, p) level, demonstrated the effect of (N-benzothiazolyl)-cyanoacetamide structures on the photovoltaic performance. Co-sensitization technique mainly depends on the uniqueness of the donor-acceptor unit of the co-sensitizer being used. Using (N-benzothiazolyl)-cyanoacetamide co-sensitizers with HD-2 showed improved power conversion efficiency (PCE) than HD-2 alone. HD-2 was used because of its high efficiency, molar extinction coefficient and photocurrent densities. While HD-2 sensitizer alone displayed PCE of (7.46%), among the co-sensitizers, SA20, containing methoxythiazole and trimethoxybenzene as a donor part attached to (CN) and (CO) as anchoring components, exhibited the best PCE of (8.27%) with Jsc (19.25 mA/cm2) and Voc (0.68 V). These results demonstrated that (N-benzothiazolyl)-cyanoacetamide dyes SA17–20 are promising candidates for efficient DSSCs.}, journal={OPTIK}, author={Badawy, Safa A. and Su, Rui and Fadda, Ahmed A. and Abdel-Latif, Ehab and El-Shafei, Ahmed and Elmorsy, Mohamed R.}, year={2022}, month={Jan} }
 @article{ding_szymczyk_mehraban_lim_parrillo-chapman_el-shafei_freeman_2022, title={Molecular and excited state properties of photostable anthraquinone red and violet dyes for hydrophobic fibers}, volume={1248}, ISSN={["1872-8014"]}, DOI={10.1016/j.molstruc.2021.131349}, abstractNote={The molecular, spectroscopic, and excited state properties of synthetic dyes for fiber-based outdoor materials continue to be of commercial interest. Early developments in this area were reported in the 1980s, when the need for dyes for polyester (PET)-based automobile interiors gave rise to commercially viable nitrodiphenylamine yellow, anthraquinone red and blue, and azo red dyes. To augment that initial knowledge base, the present study involved the use of experimental and theoretical methods to help establish the molecular structures and excited state properties of some more recent dyes for producing photostable colors on PET fibers. Having completed the characterization of present-day scarlet, blue, and yellow disperse dyes for PET-based fibers used outdoors, our attention turned to commercially available red and violet dyes. In this regard, HPLC analysis showed that the red product was a mixture containing four components, while the violet product contained only one component. Results from 1H NMR, HRMS, and single crystal X-ray diffraction analyses indicated that the principal components were dyes having a 1-amino-4-hydroxyanthraquinone base structure. The presence of an –OH group alpha to an anthraquinone C=O moiety provides for intramolecular H-bonding and a subsequent opportunity for intramolecular proton transfer in the excited state – as a photostabilizing mechanism. Further, for both dyes, results from the analysis of Frontier HOMO and LUMO isosurfaces indicated strong HOMO-LUMO overlap without molecular gaps and were consistent with strong excited state energy dissipation in a non-destructive way.}, journal={JOURNAL OF MOLECULAR STRUCTURE}, author={Ding, Yi and Szymczyk, Malgorzata and Mehraban, Nahid and Lim, Jihye and Parrillo-Chapman, Lisa and El-Shafei, Ahmed and Freeman, Harold S.}, year={2022}, month={Jan} }
 @article{wang_hamedi_zhang_el-shafei_brown_gluck_king_2022, title={Plasma-Induced Diallyldimethylammonium Chloride Antibacterial Hernia Mesh}, volume={11}, ISSN={["2576-6422"]}, url={https://doi.org/10.1021/acsabm.2c00695}, DOI={10.1021/acsabm.2c00695}, abstractNote={A hernia is a pathological condition caused by a defect or opening in the muscle wall, which leads to organs pushing through the opening or defect. Hernia recurrence, seroma, persistent pain, tissue adhesions, and wound infection are common complications following hernia repair surgery. Infection after hernia mesh implantation is the third major complication leading to hernia recurrence. In order to reduce the incidence of late infections, we developed a polypropylene mesh with antibacterial properties. In this study, knitted polypropylene meshes were exposed to radio-frequency plasma to activate their surfaces. The antibacterial monomer diallyldimethylammonium chloride (DADMAC) was then grafted onto the mesh surface using pentaerythritol tetraacrylate as the cross-linker since it is able to engage all four functional groups to form a high-density cross-linked network. The subsequent antibacterial performance showed a 2.9 log reduction toward Staphylococcus aureus and a 0.9 log reduction for Escherichia coli.}, journal={ACS APPLIED BIO MATERIALS}, author={Wang, Ziyu and Hamedi, Hamid and Zhang, Fan and El-Shafei, Ahmed and Brown, Ashley C. and Gluck, Jessica M. and King, Martin W.}, year={2022}, month={Nov} }
 @article{altay_yildirim_gursoy_hauser_el-shafei_2022, title={Synthesis of a Novel and More Sustainable Cationic Bleach Activator,N-[4-(N,N,N)-Triethylammoniumchloride-butanoyl] Butyrolactam, for Cotton: Optimization and Theoretical Limitations br}, volume={10}, ISSN={["2168-0485"]}, DOI={10.1021/acssuschemeng.1c07233}, abstractNote={Activated bleach systems have the potential to produce more efficient kinetically potent bleaching systems through increased oxidation rates with reduced energy cost and less time, hence causing less cellulose polymer chain damage or degradation than conventional hot peroxide bleaching. This article presents a study at the molecular level of a novel and more sustainable cationic bleach activator for cotton than aromatic-based cationic bleach activators using combined experimental and first-principles density functional theory (DFT) calculations. In this study, a novel and aliphatic-based cationic bleach activator, N-[4-(N,N,N)-triethylammoniumchloride-butanoyl] butyrolactam (TBUCB), was synthesized and applied for hot peroxide-cotton bleaching to optimize the bleaching conditions at lower temperatures. To improve the bleaching efficiency in the presence of TBUCB, the limitations of TBUCB, namely, the limitations of peracid generation in situ, have been identified using DFT calculations. First-principles density functional theory (DFT) calculations were performed to elucidate the reaction mechanism via identifying plausible transition state(s) of the nucleophilic attack of perhydroxyl anion (HOO–) at different carbonyl carbons and the advantages and limitations of the TBUCB activator for hydrogen peroxide bleaching for cotton. The results obtained showed that a whiteness index greater than 80 for cellulose can be achieved using an activated H2O2-TBUCB bleaching system at a lower temperature, providing reduced energy costs while maintaining the integrity of cellulose polymer chains.}, number={14}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Altay, Pelin and Yildirim, Erol and Gursoy, Nevin Cigdem and Hauser, Peter J. and El-Shafei, Ahmed}, year={2022}, month={Apr}, pages={4415–4424} }
 @article{kim_danilov_yoon_el-shafei_freeman_2021, title={Characterization of the photophysics of a mixed system of red disperse dyes using experimental and theoretical methods}, volume={184}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85090416933&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2020.108745}, abstractNote={While many disperse dyes have been studied in a variety of scientific fields, from textiles to biochemistry, most studies have been conducted on individual dyes having specific chromogens. However, bearing in mind that dyes are often used in combinations, in order to produce target colors for outdoor environments, an understanding of the photophysics of mixed system of dyes is important. As an extension of our previous work pertaining to scarlet and blue disperse dyes developed for use in outdoor applications, we investigated the photophysics of two commercial colorants and their various components (azo and anthraquinone red disperse dyes) to help account for their photostability when used in combinations. In this regard, experimental and modeling studies were performed to get insight into excited-state properties following light absorption. Transient absorption spectroscopy (TAS) showed that the dye mixtures dissipated excited-state energy much faster than the main component (an anthraquinone disperse red dye), which emphasized the benefit of multiple components in a commercial dye. The reduced excited-state lifetime clearly showed that the presence of additional dyes can play an important role in the photophysics and improving photostability.}, journal={DYES AND PIGMENTS}, author={Kim, Bo Hyung and Danilov, Evgeny and Yoon, Seog Joon and El-Shafei, Ahmed and Freeman, Harold}, year={2021}, month={Jan} }
 @article{abdellah_chowdhury_lee_islam_nazeeruddin_graetzel_el-shafei_2021, title={Facile and low-cost synthesis of a novel dopant-free hole transporting material that rivals Spiro-OMeTAD for high efficiency perovskite solar cells}, volume={5}, ISSN={["2398-4902"]}, url={https://doi.org/10.1039/D0SE01323D}, DOI={10.1039/d0se01323d}, abstractNote={A Spiro fluorene-based dopant-free hole-transporting material named Spiro-IA has been designed and developed as an alternative to commercial Spiro-OMeTAD for more effective perovskite solar cells (PSCs).}, number={1}, journal={SUSTAINABLE ENERGY & FUELS}, publisher={Royal Society of Chemistry (RSC)}, author={Abdellah, Islam M. and Chowdhury, Towhid H. and Lee, Jae-Joon and Islam, Ashraful and Nazeeruddin, Mohamad K. and Graetzel, Michael and El-Shafei, Ahmed}, year={2021}, month={Jan}, pages={199–211} }
 @article{ashraf_su_akhtar_shuja_siddiqi_el-shafei_2021, title={Molecular engineering of ruthenium-based photosensitizers with superior photovoltaic performance in DSSCs: novel N-alkyl 2-phenylindole-based ancillary ligands}, ISSN={["1369-9261"]}, DOI={10.1039/d1nj04362e}, abstractNote={In this work, we report the design and successful synthesis of two new heteroleptic polypyridyl Ru(ii) complexes (SD-5 and SD-6), by incorporating hetero-aromatic electron-donating N-alkyl-2-phenylindole moieties into the ancillary ligand.}, journal={NEW JOURNAL OF CHEMISTRY}, author={Ashraf, Saba and Su, Rui and Akhtar, Javeed and Shuja, Ahmed and Siddiqi, Humaira M. and El-Shafei, Ahmed}, year={2021}, month={Dec} }
 @article{arangdad_yildirim_detwiler_cleven_burk_shamey_pasquinelli_freeman_el-shafei_2021, title={X-ray photoelectron spectroscopy study on the photodegradation of copolyester model compounds}, volume={138}, ISSN={["1097-4628"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85088566956&partnerID=MN8TOARS}, DOI={10.1002/app.49661}, abstractNote={Abstract}, number={2}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={Arangdad, Kiarash and Yildirim, Erol and Detwiler, Andrew and Cleven, Curtis D. and Burk, Christopher and Shamey, Renzo and Pasquinelli, Melissa A. and Freeman, Harold and El-Shafei, Ahmed}, year={2021}, month={Jan} }
 @article{elmorsy_lyu_su_abdel-latif_badawy_el-shafei_fadda_2020, title={Co-sensitization of the HD-2 complex with low-cost cyanoacetanilides for highly efficient DSSCs}, volume={19}, ISSN={["1474-9092"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85081142495&partnerID=MN8TOARS}, DOI={10.1039/c9pp00381a}, abstractNote={The photophysical and electrochemical properties of new targeted 2-cyanoacetanilide-based dyes are illustrated. New cyanoacetanilides SA7 –10 were synthesized and employed as co-sensitizers in DSSCs. The chemical structures of these 2-cyanoacetanilides differ according to the substituent at the benzene ring (–H, –Me, –OMe and –NEt_2), with the anchoring moiety being the same, a –COOH group. Furthermore, a density functional theory (DFT) calculation has shown an effective intermolecular charge transfer character, the HOMOs of SA7 –10 are mainly located on the corresponding donor part, and their LUMOs are located on carboxylic acid moieties as the acceptor. Interestingly, using photosensitizers SA7 –10 as co-sensitizers with HD-2 dye causes an improvement in their photovoltaic performances. Among the dyes, SA10 co-sensitized with HD-2 displayed an overall efficiency of 8.25%, a J _SC of 19.5 mA cm^−2, a V _OC of 0.65 V and an FF of 64.35 compared to 7.46%, 19 mA cm^−2, 0.64 V and 60.54, respectively, of HD-2 only. Moreover, the electrochemical impedance spectroscopy (EIS) data of SA7 –10 and HD-2 were found to be in accordance with the obtained photovoltaic parameters. Finally, the results indicated that 2-cyanoacetanilide-based dyes were utilized as promising co-sensitizers due to their easy preparation methods and their relatively small size}, number={2}, journal={PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES}, author={Elmorsy, Mohamed R. and Lyu, Luping and Su, Rui and Abdel-Latif, Ehab and Badawy, Safa A. and El-Shafei, Ahmed and Fadda, Ahmed A.}, year={2020}, month={Feb}, pages={281–288} }
 @article{ashraf_su_akhtar_siddiqi_shuja_el-shafei_2020, title={Effect of fluoro-substituted acceptor-based ancillary ligands on the photocurrent and photovoltage in dye-sensitized solar cells}, volume={199}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85079154469&partnerID=MN8TOARS}, DOI={10.1016/j.solener.2020.02.016}, abstractNote={Herein, we report four novel heteroleptic ruthenium (II) complexes, namely SD-7 to SD-10, containing fluoro- and trifluoro- methyl antennas as substituents on the ancillary ligands for dye-sensitized solar cells, and were compared to the benchmark dye N719. Photosensitizers (dyes) SD-7 to SD-10 were synthesized according to a typical one-pot three-step procedure with the corresponding ancillary ligands (LS-7 to LS-10). All the dyes were characterized by ATR-FTIR, 1H NMR and mass spectrometry. Furthermore, the photophysical, electrochemical and photovoltaic performances were compared with N719. The band gaps, ground and excited state oxidation potentials were measured. The photovoltaic performance of the dyes showed that SD-7 with five fluorine atoms and SD-8 with CF3 at the –ortho position of the phenyl moiety outperformed the benchmark dye N719 with the efficiencies of 8.03% and 8.17%, respectively, with current density of 19.57 and 19.46 mA∙cm−2, respectively, and open-circuit voltages of 0.65 V and 0.69 V, respectively, under optimized conditions. The fabricated solar devices at lab-scale showed a systematic trend of decreasing JSC when the fluoro-substituted dyes were sensitized on TiO2: SD-7 (with five –F) > SD-8 (with one CF3 at ortho position) > SD-9 (with one CF3 at para position) > SD-10 (with two CF3, one at ortho and one at para position). This can be attributed to the greater number of fluorine atoms directly attached to sp2 hybridized carbon atoms, which greatly enhanced the dipole moment and intimate electronic coupling of SD-7 with TiO2 nanoparticles leading to better photocurrent density.}, journal={Solar Energy}, author={Ashraf, S. and Su, R. and Akhtar, J. and Siddiqi, H.M. and Shuja, A. and El-Shafei, A.}, year={2020}, pages={74–81} }
 @article{abdellah_el-shafei_2020, title={Efficiency enhancement of ruthenium-based DSSCs employing A–π–D–π–A organic Co-sensitizers}, volume={10}, ISSN={2046-2069}, url={http://dx.doi.org/10.1039/d0ra03916k}, DOI={10.1039/d0ra03916k}, abstractNote={The role of metal-free organic sensitizers (IMA1-4) in the improvement of photocurrent efficiency and the overall performance of the DSSCs when used as a co-sensitizer with a Ru(ii) sensitizer (IMA5).}, number={47}, journal={RSC Advances}, publisher={Royal Society of Chemistry (RSC)}, author={Abdellah, Islam M. and El-Shafei, Ahmed}, year={2020}, pages={27940–27953} }
 @article{ahmad_mohamed_el-shafei_al-qaradawi_aljaber_2020, title={Facile one-step synthesis of supportless porous AuPtPd nanocrystals as high performance electrocatalyst for glucose oxidation reaction}, volume={45}, ISSN={["1879-3487"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85085334005&partnerID=MN8TOARS}, DOI={10.1016/j.ijhydene.2020.05.020}, abstractNote={Direct glucose fuel cells (DGFCs) received great interest due to non-toxicity, low cost, and renewability. Herein, we demonstrated the synthesis of novel porous AuPtPd nanocrystals (NCs) via plausible one-pot synthesis route. This was implemented by reduction of the metal precursors with l-ascorbic acid in the presence of polyvinylpyrrolidone (PVP) as a structure-directing agent. TEM (transmission electron microscopy) images of the as-synthesized nanocrystals depicted porous nanodendritic morphology with particle size ranging from 20 to 30 nm. The catalytic performance of AuPtPd NCs was investigated towards glucose oxidation reaction (GOR) in alkaline medium compared to AuPt, PtPd, and Pt/C. The delivered maximum oxidation current density over AuPtPd was 10.1 mA cm−2, which is nearly 1.4, 1.8, and 3.5 times greater than AuPt, PtPd, and Pt/C, respectively. Additionally, the ternary electrocatalyst exhibited higher electrochemical stability compared to binary alloys and Pt/C counterparts. Furthermore, AuPtPd revealed lower Tafel slope for GOR compared to binary alloys and Pt/C which affirm enhanced GOR kinetics. The outstanding catalytic performance of AuPtPd NCs was attributed to the synergistic effect of the alloying elements and the high anti-poisoning effect of Au and Pd metals which facilitates the adsorption of surface hydroxyls (OH)ads on the catalyst active sites and enhances the oxidation kinetics.}, number={38}, journal={INTERNATIONAL JOURNAL OF HYDROGEN ENERGY}, author={Ahmad, Yahia H. and Mohamed, Assem T. and El-Shafei, Ahmed and Al-Qaradawi, Siham Y. and Aljaber, Amina S.}, year={2020}, month={Jul}, pages={19163–19173} }
 @article{ahmad_mohamed_alashraf_matalqeh_el-shafei_al-qaradawi_aljaber_2020, title={Highly porous PtPd nanoclusters synthesized via selective chemical etching as efficient catalyst for ethanol electro-oxidation}, volume={508}, ISSN={["1873-5584"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85077437176&partnerID=MN8TOARS}, DOI={10.1016/j.apsusc.2019.145222}, abstractNote={Direct ethanol fuel cells (DEFCs) have received great interest owing to their high power density and environmental friendness. Nevertheless, the designing of active, durable, and efficient anode for DEFCs is a profound challenge. In this context, we reported the synthesis of PtPd porous nanoclusters (PtPd PNCs) as electrocatalyst for ethanol oxidation reaction (EOR). This was implemented through two-step synthesis. Firstly, ternary AgPtPd nanodendrites (NDs) were synthesized via ultrasound-assisted co-reduction of the metal precursors using ascorbic acid (AA) as a mild reductant and Pluronic F127 as structure-directing agent. Thereafter, PtPd PNCs were created by selective chemical etching of AgPtPd nanocrystals in 1 M HNO3. The textural properties, morphology, and elemental composition of the studied electrocatalysts were investigated, and their catalytic activities towards ethanol electrooxidation were examined. PtPd PNCs revealed a high surface area of 83.0 m2 g−1 and high porosity compared to its counterparts. Additionally, it depicted enhanced catalytic performance towards ethanol electrooxidation in 1 M KOH with mass activity of 1.8 A mg−1 compared to PtPd NDs (0.97 A mg−1), Pt NDs (0.51 A mg−1), and Pt/C (0.33 A mg−1). The enhanced catalytic performance of PtPd PNCs was ascribed to high surface area, high porosity, and increased active sites.}, journal={APPLIED SURFACE SCIENCE}, author={Ahmad, Yahia H. and Mohamed, Assem T. and Alashraf, Abdullah and Matalqeh, Maha and El-Shafei, Ahmed and Al-Qaradawi, Siham Y. and Aljaber, Amina S.}, year={2020}, month={Apr} }
 @article{abdellah_el-shafei_2020, title={Influence of carbonyl group on photocurrent density of novel fluorene based D-π-A photosensitizers: Synthesis, photophysical and photovoltaic studies}, volume={387}, ISSN={1010-6030}, url={http://dx.doi.org/10.1016/j.jphotochem.2019.112133}, DOI={10.1016/j.jphotochem.2019.112133}, abstractNote={Herein, we developed novel and promising low-cost metal free organic dyes 7a-c and 10a-c via a simple, highly efficient, and high yield through two-step methodology based on Suzuki coupling reaction. These new dyes characterized with D-π-A architecture, utilized a binary π-conjugated spacer comprised of fluorenone and thiophene or spiro fluorene and thiophene. This construction would help in studying the impact of π-spacers on the photovoltaic (PV) parameters of fabricated DSSCs. The highest photocurrent efficiency (PCE) of 3.5%, JSC (7.80 mA cm−2), VOC (0.62 V) and FF (69.11%) was achieved by photosensitizer 10b incorporating spiro fluorene π-spacers moiety compared to PCE of 2.70%, JSC (6.45 mA cm−2), VOC (0.57 V) and FF (71.50%) for dye 7b with fluorenone π-spacers at the AM1.5 G conditions and using a volatile redox electrolyte (iodide/triiodide). DFT/TD-DFT calculations were used to clarify the relation between the molecular structure, photophysical and photoelectrochemical properties utilizing GAUSSIAN 09 programming. Interestingly, DFT results showed a distribution of a frontier LUMO isosurface between the carbonyl group of fluorenone and the acceptor part in case of photosensitizers 7a-c compared to 10a-c, which shows a complete frontier LUMO shift to the acceptor part only. This confirms the effect of carbonyl group on trapping the electrons. This causes a weak electron injection into TiO2 surface, which lowered the photocurrent conversion efficiency of 7a-c dyes compared to 10a-c. The dyes structures were confirmed by UV–vis, emission spectrophotometry, FT-IR, ESI-MS and 1H-NMR.}, journal={Journal of Photochemistry and Photobiology A: Chemistry}, publisher={Elsevier BV}, author={Abdellah, Islam M. and El-Shafei, Ahmed}, year={2020}, month={Jan}, pages={112133} }
 @article{ashraf_su_akhtar_siddiqi_shuja_al-saad_al-qaradawi_el-shafei_2020, title={Investigations into structure-property relationships of novel Ru(II) dyes with N,N '-Diethyl group in ancillary ligand for dye-sensitized solar cells (vol 171, 107754, 2019)}, volume={173}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85073031853&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2019.107955}, journal={DYES AND PIGMENTS}, author={Ashraf, Saba and Su, Rui and Akhtar, Javeed and Siddiqi, Humaira M. and Shuja, Ahmed and Al-Saad, Khalid A. and Al-Qaradawi, Siham Y. and El-Shafei, Ahmed}, year={2020}, month={Feb} }
 @article{ding_szymczyk_mehraban_lim_parrillo-chapman_el-shafei_freeman_2020, title={Molecular and excited state properties of photostable yellow disperse dyes}, volume={1207}, ISSN={["1872-8014"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85078970244&partnerID=MN8TOARS}, DOI={10.1016/j.molstruc.2020.127815}, abstractNote={Textile dyes with high resistance to UV light induced fading on poly (ethylene terephthalate) (PET) fibers are important for textile substrates used in applications such as automobile interiors and outdoor furniture. Dye photostability influenced the development of dye structures for automobile fabrics dating back to the 1980s but the nature of currently used disperse dyes is less widely known. As part of a study designed to provide updates on this subject, the current investigation employed experimental and theoretical methods to determine the nature and properties of commercial dyes used to produce lightfast colors on PET fibers. Having completed the characterization of scarlet and blue disperse dyes for PET-based fabrics used outdoors, our attention turned to the characterization of commercially available lightfast yellow dyes. HPLC analysis showed that a pair of yellow products were mixtures containing three or four dyes, and the use of 1NMR, HRMS and single crystal X-ray diffraction analyses indicated that they were homologous azo–anthraquinone based dyes with or without a 1,8-bis(phenylthio)anthraquinone dye. Results from calculating Frontier HOMO and LUMO isosurfaces indicated strong HOMO/LUMO overlap, and the E0-0 for the homologous anthraquinone-based azo dyes was exactly the same (2.37 eV) which contributes to their photostability.}, journal={JOURNAL OF MOLECULAR STRUCTURE}, author={Ding, Yi and Szymczyk, Malgorzata and Mehraban, Nahid and Lim, Jihye and Parrillo-Chapman, Lisa and El-Shafei, Ahmed and Freeman, Harold S.}, year={2020}, month={May} }
 @article{elmorsy_su_abdel-latif_badawy_el-shafei_fadda_2020, title={New cyanoacetanilides based dyes as effective co-sensitizers for DSSCs sensitized with ruthenium (II) complex (HD-2)}, volume={31}, ISSN={["1573-482X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85083047076&partnerID=MN8TOARS}, DOI={10.1007/s10854-020-03337-3}, number={10}, journal={JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS}, author={Elmorsy, Mohamed R. and Su, Rui and Abdel-Latif, Ehab and Badawy, Safa A. and El-Shafei, Ahmed and Fadda, Ahmed A.}, year={2020}, month={May}, pages={7981–7990} }
 @article{abdellah_chowdhury_lee_islam_el-shafei_2020, title={Novel dopant-free hole-transporting materials for efficient perovskite solar cells}, volume={206}, ISSN={0038-092X}, url={http://dx.doi.org/10.1016/j.solener.2020.06.016}, DOI={10.1016/j.solener.2020.06.016}, abstractNote={Two novel highly conjugated small organic molecules as hole transporting materials (HTMs) coded T(EDOT-TPA)2 and DBT(QT-TPA)2 were designed and developed by utilizing facile synthetic procedures with high yields. The fabricated perovskite solar cells (PSCs) utilizing these HTMs without any dopants under 1 sun illumination (100 mW cm−2, AM 1.5G) and surface area of 1.02 cm2 achieved a short circuit current (JSC = 19.23), open circuit voltage (VOC = 1.042), fill factor (FF = 0.679) and overall power conversion efficiency (PCE = 13.61%) for DBT(QT-TPA)2. While, T(EDOT-TPA)2 exhibited (JSC = 20.25, VOC = 1.04, FF = 0.583, and PCE = 12.27%). These dopant free HTM based PSCs achieved superior PCEs compared to that of undoped Spiro-OMeTAD (PCE = 9.34%) based PSCs and a comparable photovoltaic performance to the PSCs using doped Spiro-OMeTAD (JSC = 20.37, VOC = 1.057, FF = 0.74, and PCE = 15.93) as the HTM under same fabrication conditions. Noticeably, the absence of additives is of significant importance, as DBT(QT-TPA)2 and T(EDOT-TPA)2 based PSCs still produces a Jsc up to 20.25 mA cm−2 and a comparable PCE of 13.61%, which reduces the fabrication cost of cm sized PSCs.}, journal={Solar Energy}, publisher={Elsevier BV}, author={Abdellah, Islam M. and Chowdhury, Towhid H. and Lee, Jae-Joon and Islam, Ashraful and El-Shafei, Ahmed}, year={2020}, month={Aug}, pages={279–286} }
 @article{keremane_abdellah_naik_el-shafei_adhikari_2020, title={Simple thiophene-bridged D–π–A type chromophores for DSSCs: a comprehensive study of their sensitization and co-sensitization properties}, volume={22}, ISSN={1463-9076 1463-9084}, url={http://dx.doi.org/10.1039/d0cp02781b}, DOI={10.1039/d0cp02781b}, abstractNote={DSSCs were fabricated using new dyes T1–4 as sensitizers/co-sensitizers along with the MH-12 dye. This work highlights the optimization of various factors involved in the cell as well as a complete analysis on their structure-performance behaviour.}, number={40}, journal={Physical Chemistry Chemical Physics}, publisher={Royal Society of Chemistry (RSC)}, author={Keremane, Kavya S. and Abdellah, Islam M. and Naik, Praveen and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2020}, pages={23169–23184} }
 @article{su_lyu_elmorsy_el-shafei_2020, title={Structural studies and photovoltaic investigation of indolo[2,3-b]quinoxaline-based sensitizers/co-sensitizers achieving highly efficient DSSCs}, volume={44}, ISSN={["1369-9261"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85082978601&partnerID=MN8TOARS}, DOI={10.1039/c9nj04456f}, abstractNote={Novel organic sensitizers were designed and synthesized by employing indolo[2,3-b]quinoxaline (IQ) as the main building block. IPCE graphs indicated that both competition and compensation of photon harvesting co-exist during the co-sensitization.}, number={7}, journal={NEW JOURNAL OF CHEMISTRY}, author={Su, Rui and Lyu, Luping and Elmorsy, Mohamed R. and El-Shafei, Ahmed}, year={2020}, month={Feb}, pages={2797–2812} }
 @article{abdellah_el-shafei_2020, title={Synthesis and characterization of novel tetra anchoring A2-D-D-D-A2 architecture sensitizers for efficient dye-sensitized solar cells}, volume={198}, ISSN={0038-092X}, url={http://dx.doi.org/10.1016/j.solener.2020.01.040}, DOI={10.1016/j.solener.2020.01.040}, abstractNote={Novel metal free organic dyes coded TET(RA)4, TET(CA)4, and TET(QA)4 were designed, synthesized, and characterized as effective sensitizers for dye sensitized solar cells (DSSCs). These new push-pull sensitizers used a strong electron donor consisting of 3,4-ethylenedioxythiophene and two triphenylamine molecules connected together to form a TPA-EDOT-TPA (TET) motif, which is directly connected to tetra anchoring groups (A) without any π-spacers to construct A2-D-D-D-A2 architecture, three different anchoring series, viz. rhodanine-3-acetic acid (RA), cyanoacetic acid (CA), and 2-methyl quinoline-6-carboxylic acid (QA) were employed to investigate the influence of anchoring moieties on the electrochemical, thermodynamic, kinetics, and photovoltaic efficiency of DSSCs. The DSSCs devices showed a maximum overall power conversion efficiency (PCE) = 5.13%, short-circuit current density (JSC) = 12.71 mA.cm−2, open circuit voltage (VOC) = 0.62 V, and fill factor (FF) = 65.36% with a maximum incident photon conversion efficiency (IPCE) = 75% for TET(QA)4. The optical and electrochemical studies showed that TET(QC)4 achieved higher electron injection free energy (ΔG°inj) into CB edge of TiO2 as well as high recombination resistance (Rrec) compared to TET(RA)4, and TET(CA)4, which explains the outstanding charge separation and superior power conversion efficiency (PCE) of TET(QC)4 possessing quinoline-6-carboxylic acid (QC) anchoring group. Molecular modeling calculations using DFT and TD-DFT showed effective charge separation, where HOMO is delocalized over the donor scaffold (TPA-EDOT-TPA), and the LUMO is delocalized over only two anchoring groups on the same side of the donor system, which provides strong HOMO-LUMO overlap as well as intimate electronic coupling with TiO2 nanoparticle surface for electron injection. Further, the calculated values of the energy gaps (E0-0) and ground/excited stated oxidation potentials were in perfect agreement with the experimental results.}, journal={Solar Energy}, publisher={Elsevier BV}, author={Abdellah, Islam M. and El-Shafei, Ahmed}, year={2020}, month={Mar}, pages={25–35} }
 @article{su_ashraf_lyu_el-shafei_2020, title={Tailoring dual-channel anchorable organic sensitizers with indolo[2,3-b] quinoxaline moieties: Correlation between structure and DSSC performance}, volume={206}, ISSN={["0038-092X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85086470512&partnerID=MN8TOARS}, DOI={10.1016/j.solener.2020.06.020}, abstractNote={Two new metal-free heteroaromatic organic dyes, FS13 and FS14, with D-D|A-(π-A)2 structural configuration were tailored and synthesized as effective dual-channel anchorable sensitizers in DSSCs. The new entities consist of indolo[2,3-b]quinoxaline (IQ) as the constructing unit containing merged donor–acceptor system (D|A) connected to two cyanoacetic acids as anchoring groups via phenylene as π-linker at 2- and 3- positions of IQ rings. Their experimental properties together with theoretical modeling using density functional theory (DFT) are studied to understand their achievability as feasible sensitizers. The photovoltaic performance and charge transfer properties were assessed with illumination condition as 1.5 AM standard. The DFT study revealed that the isodensity of FS13 and FS14 has been slightly shifted towards di-anchors compared to the mono-anchoring FS08, leading to more distinguished charge separation; however, the closely paralleled anchoring branches bring out high spatial hindrance, turning into the less conjugated system and the lower photocurrent. For the study of co-sensitization effect employing dual-channel dyes with HD-2 ruthenium sensitizer, FS14 displayed the most positive co-sensitization effect and enhanced the overall efficiency by 9.2% from 7.50% to 8.67%. For both novel dyes, the considerably improved photovoltage and fill factor are ascribed to the improved coverage percentage on TiO2 surface and the enhancement of dye anti-aggregation and charge recombination resistance, which in turn corroborates the superior affinity of di-anchors. Furthermore, the dark current resistance estimated from impedance graphs employing co-sensitization methodology coincided with the observed photovoltage, indicating the enormous potential of di-anchoring dyes in ameliorating the photovoltaic performance.}, journal={SOLAR ENERGY}, author={Su, Rui and Ashraf, Saba and Lyu, Luping and El-Shafei, Ahmed}, year={2020}, month={Aug}, pages={443–454} }
 @article{zidan_el-shafei_noshy_salim_2020, title={The effectiveness of aqueous and nonaqueous magnesium hydroxide nanopowder on the color stability of dyed cotton paper pulp}, volume={11}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85092239302&partnerID=MN8TOARS}, number={3}, journal={International Journal of Conservation Science}, author={Zidan, Y. and El-Shafei, A. and Noshy, W. and Salim, E.}, year={2020}, pages={657–668} }
 @article{abdellah_el-shafei_2020, title={The molecular engineering, synthesis and photovoltaic studies of a novel highly efficient Ru(ii) complex incorporating a bulky TPA ancillary ligand for DSSCs: donor versus π-spacer effects}, volume={10}, ISSN={2046-2069}, url={http://dx.doi.org/10.1039/C9RA06150A}, DOI={10.1039/c9ra06150a}, abstractNote={The IA-7 complex was applied in DSSCs.}, number={1}, journal={RSC Advances}, publisher={Royal Society of Chemistry (RSC)}, author={Abdellah, Islam M. and El-Shafei, Ahmed}, year={2020}, pages={610–619} }
 @article{lyu_su_al-qaradawi_al-saad_el-shafei_2020, title={Three-component one-pot reaction for molecular engineering of novel cost-effective highly rigid quinoxaline-based photosensitizers for highly efficient DSSCs application: Remarkable photovoltage (vol 171, 107683, 2019)}, volume={173}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85073544248&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2019.107962}, journal={DYES AND PIGMENTS}, author={Lyu, Luping and Su, Rui and Al-Qaradawi, Siham Y. and Al-Saad, Khalid and El-Shafei, Ahmed}, year={2020}, month={Feb} }
 @article{kesavan_attia_su_anees_el-shafei_adhikari_2019, title={Asymmetric Dual Anchoring Sensitizers/Cosensitizers for Dye Sensitized Solar Cell Application: An Insight into Various Fundamental Processes inside the Cell}, volume={123}, ISSN={["1932-7455"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85072953120&partnerID=MN8TOARS}, DOI={10.1021/acs.jpcc.9b06525}, abstractNote={To study the various fundamental processes occurring inside the dye sensitized solar cell (DSSC), we have fabricated devices employing newly synthesized diphenylamine-based organic dyes with A-D-π-A configuration, carrying four different anchoring groups, namely, cyanoacetic acid (DDC), rhodanine acetic acid (DDR), 4-hydrazinylbenzoic acid (DDH), and barbituric acid (DDB), as effective sensitizers/cosensitizers. In the present work, all the bianchoring dyes were subjected to photophysical, electrochemical, thermodynamic, photoelectrochemical, and theoretical studies. All of them displayed characteristic λabs and λemi in the range of 415–480 and 570–680 nm, respectively. Their optical and electrochemical band gaps were calculated to be in the order of 2.1 to 2.3 eV. The calculated driving forces for electron injection (ΔGinj), recombination (ΔGinj), and regeneration (ΔGreg) processes were found to be negative, showing the feasibility of these processes, while their DFT studies clearly indicated the directi...}, number={40}, journal={JOURNAL OF PHYSICAL CHEMISTRY C}, author={Kesavan, Rajalakshmi and Attia, Fathy and Su, Rui and Anees, P. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2019}, month={Oct}, pages={24383–24395} }
 @inproceedings{zha_nakod_he_el-shafei_brown_hudson_king_2019, title={Designing an antimicrobial knitted wound dressing for vacuum assisted wound closure}, volume={40}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85065387853&partnerID=MN8TOARS}, booktitle={Transactions of the Annual Meeting of the Society for Biomaterials and the Annual International Biomaterials Symposium}, author={Zha, D. and Nakod, P. and He, T. and El-Shafei, A. and Brown, A. and Hudson, S. and King, M.W.}, year={2019}, pages={603} }
 @article{altay_hauser_gursoy_el-shafei_2019, title={Facile synthesis of a novel, highly effective, more sustainable and cost-effective cationic bleach activator for cotton: N-[4-(N,N,N)-triethylammoniumchloride-butyryl] caprolactam}, volume={26}, ISSN={["1572-882X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85060697399&partnerID=MN8TOARS}, DOI={10.1007/s10570-018-02224-9}, number={4}, journal={CELLULOSE}, author={Altay, Pelin and Hauser, Peter J. and Gursoy, Nevin Cigdem and El-Shafei, Ahmed}, year={2019}, month={Mar}, pages={2849–2860} }
 @article{arangdad_yildirim_detwiler_cleven_burk_shamey_pasquinelli_freeman_el-shafei_2019, title={Influence of UV stabilizers on the weathering of PETG and PCTT films}, volume={136}, ISSN={["1097-4628"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85069911866&partnerID=MN8TOARS}, DOI={10.1002/app.48198}, abstractNote={ABSTRACT}, number={47}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, publisher={Wiley}, author={Arangdad, Kiarash and Yildirim, Erol and Detwiler, Andrew and Cleven, Curtis D. and Burk, Christopher and Shamey, Renzo and Pasquinelli, Melissa A. and Freeman, Harold S. and El-Shafei, Ahmed}, year={2019}, month={Dec} }
 @article{ashraf_su_akhtar_siddiqi_shuja_al-saad_al-qaradawi_el-shafei_2019, title={Investigations into structure-property relationships of novel Ru(II) dyes with N,N '-Diethyl group in ancillary ligand for dye-sensitized solar cells}, volume={171}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85073088390&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2019.107754}, abstractNote={Structure-property relationships of four novel bipyridyl Ru(II) complexes, denoted as SD-22, SD-24, SD-26 and SD-28, are reported herein. The molecular structures of all four photosensitizers were confirmed using FT-IR, 1H NMR and mass spectrometry. Photovoltaic characteristics of the photosensitizers were evaluated under 1.5 a.m. standard illumination condition, in presence of deoxycholic acid as co-adsorbent, and subsequently compared to the performance of the benchmark, Z907. SD-22 showed an IPCE of 52% and 50% at 440 nm and 550 nm, respectively, a short-circuit photocurrent density (JSC) of 17.37 mA cm−2, open-circuit photovoltage (VOC) of 0.63 V and fill factor (FF) of 0.66, producing an overall conversion efficiency (η) of 7.31%, which outperformed Z907 (7.02%) under the same experimental device conditions. The η of the other photosensitizers is in the following order: SD-22 > SD-28 > SD-26 > SD-24. Photosensitizer SD-22 has N,N′-dialkyl group attached to a benzene ring while SD-24 has N,N′-dialkyl without a benzene ring. The extended conjugation in SD-22 translated into higher overall solar-to-electric conversion efficiency. Substitution of dialkylamino-based ancillary ligands of Ru(II) dyes SD-26 and SD-28 with –OCH3 and –OC6H13 also demonstrated that the photovoltaic performance of polypyridyl ruthenium photosensitizers is a function of the donating power of ancillary ligands as well as the steric effect of alkoxy auxochromes at –ortho position.}, journal={DYES AND PIGMENTS}, author={Ashraf, Saba and Su, Rui and Akhtar, Javeed and Siddiqi, Humaira M. and Shuja, Ahmed and Al-Saad, Khalid A. and Al-Qaradawi, Siham Y. and El-Shafei, Ahmed}, year={2019}, month={Dec} }
 @article{abdel-shakour_el-said_abdellah_su_el-shafei_2019, title={Low-cost Schiff bases chromophores as efficient co-sensitizers for MH-13 in dye-sensitized solar cells}, volume={30}, ISSN={0957-4522 1573-482X}, url={http://dx.doi.org/10.1007/s10854-019-00806-2}, DOI={10.1007/s10854-019-00806-2}, number={5}, journal={Journal of Materials Science: Materials in Electronics}, publisher={Springer Science and Business Media LLC}, author={Abdel-Shakour, M. and El-Said, Waleed A. and Abdellah, Islam M. and Su, Rui and El-Shafei, Ahmed}, year={2019}, month={Feb}, pages={5081–5091} }
 @article{ding_mehraban_szymczyk_parrillo-chapman_el-shafei_freeman_2019, title={Molecular and excited state properties of photostable anthraquinone blue dyes for hydrophobic fibers}, volume={1181}, ISSN={0022-2860}, url={http://dx.doi.org/10.1016/J.MOLSTRUC.2018.12.070}, DOI={10.1016/j.molstruc.2018.12.070}, abstractNote={Abstract Synthetic dyes having high photostability on hydrophobic fibers such as poly(ethylene terephthalate) (PET) are of interest for use on textile substrates for outdoor applications. While much is known about photostable dyes developed for PET in the 1980s, owing to their viability for use in automobile interiors, little has been published on currently viable photostable disperse dyes. As part of an effort to help fill this void and to facilitate future photostable disperse dye design, the present study involved the use of experimental measurements and modelling studies to help characterize the molecular structures of commercially viable dyes for producing photostable colors on PET fibers, beginning with a pair of blue dyes. With the aid of HR-MS, 500 MHz 1H NMR, and X-ray crystallography, it was established that the two dyes are structural isomers having 1,5-(OH)2-anthraquinone (AQ) and 1,8-(OH)2-AQ base structures. It is proposed that the photostability of these dyes arises from the presence of multiple OH/NH groups ortho to the AQ C O groups which enables them to dissipate excited state energy through intramolecular proton transfer. Further, using DFT-based molecular modelling studies, it was shown that the dye having the 1,5-(OH)2-AQ base structure has a lower ESOP than the isomeric dye having the 1,8-(OH)2-AQ base structure. Similarly, results from calculating Frontier HOMO and LUMO isosurfaces indicated that the LUMO lobes of the latter dye are larger, suggesting that this dye undergoes excitation faster than the 1,5-(OH)2-AQ isomer.}, journal={Journal of Molecular Structure}, publisher={Elsevier BV}, author={Ding, Yi and Mehraban, Nahid and Szymczyk, Malgorzata and Parrillo-Chapman, Lisa and El-Shafei, Ahmed and Freeman, Harold S.}, year={2019}, month={Apr}, pages={109–117} }
 @article{abdellah_koraiem_el-shafei_2019, title={Molecular engineering and investigation of new efficient photosensitizers/co-sensitizers based on bulky donor enriched with EDOT for DSSCs}, volume={164}, ISSN={0143-7208}, url={http://dx.doi.org/10.1016/j.dyepig.2019.01.035}, DOI={10.1016/j.dyepig.2019.01.035}, abstractNote={Herein, we report design, synthesis and photovoltaic performance of four novel metal-free heteroaromatic photosensitizers coded IA 1-4 with (D-D)2-D-A architecture carrying electron donating triphenylamine coupled with EDOT core which is directly connected to four different electron withdrawing/anchoring groups, viz. rhodamine-3-acetic acid, cyano acetic acid, 2-methyl quinoline-6-carboxylic acid and 1-phenyl-pyrazol-5-one-3-carboxylic acid without any π-spacer. The newly designed IA 1-4 were applied as sensitizers and co-sensitizers in DSSCs. Their structures were confirmed by FT-IR, 1H NMR, MS and elemental analyses. The photosensitizers were subjected to optical and electrochemical studies in order to investigate their absorption/emission behavior as well as HOMO/LUMO energies. The UV–Vis revealed that IA 1-4 exhibited at 464, 497, 531 and 412 nm,λmax respectively. Their optical band gap is in the range of 1.95–2.28 eV. From the energy level diagram of the named photosensitizer, it is clear that all the dyes have good thermodynamically favorable ground and excited state oxidation potentials for electron injection into CB edge of TiO2 as well as dye regeneration. The photovoltaic performance studies indicate that, dye IA-1 anchored with cyanoacetic acid displayed the highest IPCE (61.5%), resulting in PCE of 5.92% (JSC = 12.3 mA cm−2, VOC = 0.68 V, FF = 70.29%). Furthermore, when IA-1 was used as a co-sensitizer with MH-13, a total PCE of 8.43% (JSC = 22.8 mA cm−2, VOC = 0.66 V, FF = 54.1%) was achieved to gain more insights into the equilibrium molecular geometry (EMG), thermodynamic parameters and vertical electronic excitation, DFT studies were performed using GAUSSIAN 09 software to calculate the EMG of each photosensitizer, its and electron cloud delocalization of HOMO/LUMO levels and vertical electronic excitation. Results from FMO revealed that dyes IA 1-4 showed effective charge separation, which translated into greater ICT behavior with IA-1 being the highest in photovoltaic performance.}, journal={Dyes and Pigments}, publisher={Elsevier BV}, author={Abdellah, Islam M. and Koraiem, Ahmed I. and El-Shafei, Ahmed}, year={2019}, month={May}, pages={244–256} }
 @article{sun_lyu_elmorsy_el-shafei_2019, title={Novel metal-free organic dyes constructed with the D-D vertical bar A-pi-A motif: Sensitization and co-sensitization study}, volume={194}, ISSN={["0038-092X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85074473045&partnerID=MN8TOARS}, DOI={10.1016/j.solener.2019.10.061}, abstractNote={A new structural motif, D-D|A-π-A, was suggested for the design of novel metal-free organic sensitizers, where “D|A” represents a fused donor-acceptor conjugated building block. Three organic dyes, coded FS07, FS08 and FS09, were synthesized accordingly with the incorporation of indolo [2,3-b] quinoxaline (IQ) as the main building block but different additional donors. The synthesized dyes were well-characterized and their photophysical and electrochemical properties were well-studied. Additionally, molecular modeling via DFT method was employed to probe their photovoltaic behaviors as sensitizers/co-sensitizers. The isodensity of the molecular orbitals displays the distinguished intramolecular charge delocalization in the IQ moiety, even though its donor and acceptor sections are coplanar-fused. In the photovoltaic characterization, FS08 exhibited the best DSSC performance. Moreover, FS07, FS08 and FS09 were co-sensitized along with a typical high efficient bipyridyl Ru(II) sensitizer, HD-2, in order to induce the light harvesting over expanded spectral region and hence improve the efficiency. The solar cell co-sensitized with FS08 displayed improved efficiency of 7.94% with JSC of 19.37 mA⋅cm−2, VOC of 0.654 V and FF of 62.7%, which outperformed the device employing HD-2 alone (efficiency of 7.46%). Owing to the appropriate dye loading of FS08 in the presence of HD-2 and CDCA mixed dye solution, the benign coordination for light harvesting was guaranteed and the photoexcitation was maximized, the co-sensitized JSC was improved; due to the well-modified TiO2 surface coverage with the tight attachment of FS08 and HD-2, the dye aggregation was diminished and the undesired charge recombination was suppressed, the co-sensitized VOC was improved.}, journal={SOLAR ENERGY}, author={Sun, Rui and Lyu, Luping and Elmorsy, Mohamed R. and El-Shafei, Ahmed}, year={2019}, month={Dec}, pages={400–414} }
 @article{arangdad_detwiler_cleven_burk_shamey_pasquinelli_freeman_el-shafei_2019, title={Photodegradation of copolyester films: A mechanistic study}, volume={136}, ISSN={0021-8995}, url={http://dx.doi.org/10.1002/APP.47148}, DOI={10.1002/APP.47148}, abstractNote={ABSTRACT}, number={10}, journal={Journal of Applied Polymer Science}, publisher={Wiley}, author={Arangdad, Kiarash and Detwiler, Andrew and Cleven, Curtis D. and Burk, Christopher and Shamey, Renzo and Pasquinelli, Melissa A. and Freeman, Harold and El-Shafei, Ahmed}, year={2019}, month={Mar}, pages={47148} }
 @article{kesavan_abdellah_singh_el-shafei_adhikari_2019, title={Simple diphenylamine based D–π–A type sensitizers/co-sensitizers for DSSCs: a comprehensive study on the impact of anchoring groups}, volume={21}, ISSN={1463-9076 1463-9084}, url={http://dx.doi.org/10.1039/C9CP01032G}, DOI={10.1039/c9cp01032g}, abstractNote={Three new diphenylamine based metal-free dyes were designed and developed as efficient sensitizers as well as co-sensitizers along with N3 in DSSCs. Their detailed photophysical, electrochemical, theoretical and photovoltaic properties have been explored.}, number={20}, journal={Physical Chemistry Chemical Physics}, publisher={Royal Society of Chemistry (RSC)}, author={Kesavan, Rajalakshmi and Abdellah, Islam M. and Singh, Surya Prakash and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2019}, pages={10603–10613} }
 @article{abdellah_koraiem_el-shafei_2019, title={Structure-property relationship of novel monosubstituted Ru (II) complexes for high photocurrent and high efficiency DSSCs: Influence of donor versus acceptor ancillary ligand on DSSCs performance}, volume={177}, ISSN={0038-092X}, url={http://dx.doi.org/10.1016/j.solener.2018.11.047}, DOI={10.1016/j.solener.2018.11.047}, abstractNote={Two novel high molar extinction coefficient monosubstituted-bipy Ru (II) complexes, IA-5 and IA-6, based on D-D-π and π-A-π-A ancillary ligands were synthesized with the aid of Knoevenagel reaction, to study the influence of the electron donor and electron acceptor ancillary ligand and number of anchoring group (COOH) on the light harvesting efficiency (LHE), ground and excited state oxidation potentials, incident-photon-to-current conversion efficiency (IPCE), short-circuit photocurrent density (J), and total solar-to-electric conversion efficiency (%η) for DSSCs, and their device performances were studied and showed a maximum of PCE of 7.81% (JSC = 17.61 mA cm−2, VOC = 0.69 V and FF = 64.05%) for dye IA-6 compared to PCE of 7.74% (JSC = 15.83 mA cm−2, VOC = 0.74 V and FF = 65.37%) for N719 dye. The photophysical and photoelectrochemical properties discussed herein addressed the significant impact of the electron donor and electron acceptor ancillary ligand and the number of anchoring groups on JSC and %η in DSSCs. The molecular structures of IA-5 and IA-6 were characterized using UV–Vis, emission spectrophotometry, FT-IR, ESI-MS, and 1H NMR. To probe the interrelationship between the chemical structure, photophysical and photoelectrochemical properties, molecular modeling studies, implemented in Gaussian, were employed. DFT/TD-DFT calculations were used to calculate the thermodynamics and electronic properties of IA-5 and IA-6 including HOMO and LUMO isosurfaces, lowest singlet-singlet electronic transitions (E0-0), ground and excited states oxidation potentials, GSOP and ESOP, which were in excellent agreement with the experimental results. Surprisingly, the insertion of the strong electron acceptor benzodithiazole in the ancillary ligand of IA-5 showed that the frontier LUMO shifted by 100% from 2,2′-bipyridyl-4,4′-dicarboxlic acid to the ancillary ligand containing benzodithiazole with electron injection accomplished from the anchoring group tethered to benzodithiazole. This new finding of relocating the LUMO from bipy-dicarboxylic acid to the other ancillary ligand would open the door for the molecular engineering of better light harvesting and more efficient Ru (II) complexes for DSSCs.}, journal={Solar Energy}, publisher={Elsevier BV}, author={Abdellah, Islam M. and Koraiem, Ahmed I. and El-Shafei, Ahmed}, year={2019}, month={Jan}, pages={642–651} }
 @article{su_ashraf_el-shafei_2019, title={Structure-property relationships: "Double-tail versus double-flap" ruthenium complex structures for high efficiency dye-sensitized solar cells}, volume={177}, ISSN={["0038-092X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85057598963&partnerID=MN8TOARS}, DOI={10.1016/j.solener.2018.11.038}, abstractNote={Six novel heteroleptic amphiphilic polypyridyl Ruthenium (II) complexes, coded FS01-FS06, with hetero-aromatic electron-donor ancillary ligands containing julolidine-derived moieties were synthesized to investigate the relationship between structure modulations of electron donors of Ru(II) dyes and their photophysical, electrochemical and photovoltaic properties for dye-sensitized solar cells (DSSCs). These modulations include: Ru(II) complexes with double “tails” (i.e. tetramethyl groups attached to the end of julolidine-based antennas, FS04) compared to the ones without double “tails” (FS01); complexes with double small “flaps” (i.e. small acyclic electron donor auxochromes ortho to the CH = CH bridge of stilbazole, FS02, FS05) compared to the ones with double large “flaps” (FS03, FS06). Their low energy metal-to-ligand charge transfers (MLCT) band and molar absorptivities were all better than those of the benchmark, N719. It was also shown that the incorporation of double “flaps” into the ancillary ligands caused a slight red shift of light absorption. The photovoltaic properties were evaluated under 1.5 AM standard illumination condition and compared to N719. The highest photocurrent density (JSC) was observed for the complex with double “tails” and double small “flaps” (FS05). The overall conversion efficiency for devices employing julolidine-derived Ru (II) complexes was in the following order FS05 > FS02 > FS04 > FS01 > FS06 > FS03. FS05 (8.16%) outperformed the benchmark N719 (7.75%) in the photovoltaic performance, which is due to its best light-harvesting ability, highest molar extinction coefficient and smallest energy band gap among all the six dyes. To probe the interrelationship among julolidine-based electron donors of ancillary ligands, photocurrent and photovoltage of these dyes, the equilibrium molecular geometries of the ancillary ligands were calculated using DFT. The equilibrium molecular geometries of these dyes the photocurrent and photovoltage are dependent on the donating effect of alkyloxy auxochromes, the steric effect generated from the auxochromes and julolidine moieties, and the orientation of longer alkyloxy group. The introduction of double “tails” resulted in less dye aggregation and higher charge recombination resistance, leading to higher photocurrents and photovoltages in the solar cell performances. Despite of the donating effect of alkyloxy groups, the bulky double “flaps” mainly jammed the hole transportation between the redox couple of the electrolyte and the HOMO of thiocyanate groups (−NCS), translating into the decrease of photocurrent.}, journal={SOLAR ENERGY}, author={Su, Rui and Ashraf, Saba and El-Shafei, Ahmed}, year={2019}, month={Jan}, pages={724–736} }
 @article{koraiem_abdellah_el-shafei_abdel-latif_abd el-aal_2019, title={Synthesis, optical characterization, and TD-DFT studies of novel mero/bis-mero cyanine dyes based on N-Bridgehead heterocycles}, volume={97}, ISSN={0008-4042 1480-3291}, url={http://dx.doi.org/10.1139/cjc-2018-0325}, DOI={10.1139/cjc-2018-0325}, abstractNote={ Novel mero/bis-mero cyanine dyes based on N-Bridgehead imidazo[1,2-g]quinolino[2,1-a][2,6]naphthyridine have been synthesized and characterized to evaluate intramolecular charge transfer (ICT) effect on the energy gap (E0-0). The UV–vis and emission spectral studies revealed that dyes are absorbed in the region of λmax 485–577 nm and emitted at 567–673 nm. Their solvatochromic behavior in solvents of various polarities, CCl4, C6H6, H2O, CHCl3, acetone, and DMF, was studied to emphasize the effect of solvent polarity on the absorption maxima, molar extinction coefficients of the dyes, and excitation energy of the dyes. Their electron cloud delocalization in HOMO/LUMO levels were studied by DFT using Gaussian 09 software. Time-dependent density functional theory (TD-DFT) was applied to theoretically explore the first excitation energy (E0-0) of these dyes, which was in good agreement with experimental results. }, number={3}, journal={Canadian Journal of Chemistry}, publisher={Canadian Science Publishing}, author={Koraiem, Ahmed I. and Abdellah, Islam M. and El-Shafei, Ahmed and Abdel-Latif, Fathy F. and Abd El-Aal, Reda M.}, year={2019}, month={Mar}, pages={219–226} }
 @article{lyu_su_al-qaradawi_al-saad_el-shafei_2019, title={Three-component one-pot reaction for molecular engineering of novel cost-effective highly rigid quinoxaline-based photosensitizers for highly efficient DSSCs application: Remarkable photovoltage}, volume={171}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85068505054&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2019.107683}, abstractNote={A simple three-component one-pot approach was developed to generate three novel highly rigid quinoxaline-based dyes, which were further investigated as sensitizers of dye-sensitized solar cells (DSSCs). The effect of different push-pull molecular motifs containing various donors and attachment of long alkyl chains on photophysical, electrochemical and photovoltaic performances, along with theoretical calculations were studied comprehensively. In particular, LY03-based DSSCs showed the highest efficiency of 7.04% with a short-circuit photocurrent density (JSC) of 14.32 mA cm−2, an open-circuit photovoltage (VOC) of 910 mV and a fill factor (FF) of 0.54% under AM 1.5 irradiation (100 mW cm−2). The results confirm that improving the molecular rigidity of sensitizer and incorporation of long alkyl chains into an auxiliary acceptor and donor is one of the most effective pathways to prevent “trade-off” effect, which translated into remarkable improvement in open-circuit photovoltage of 0.91 V, hence, enhancing the photovoltaic performance.}, journal={DYES AND PIGMENTS}, author={Lyu, Luping and Su, Rui and Al-Qaradawi, Siham Y. and Al-Saad, Khalid A. and El-Shafei, Ahmed}, year={2019}, month={Dec} }
 @article{naik_abdellah_abdel‐shakour_acharaya_pilicode_el‐shafei_adhikari_2018, title={An Efficient Aniline‐Based Co‐Sensitizer for High Performance N3‐Sensitized Solar Cells}, volume={3}, ISSN={2365-6549 2365-6549}, url={http://dx.doi.org/10.1002/slct.201802232}, DOI={10.1002/slct.201802232}, abstractNote={Abstract}, number={43}, journal={ChemistrySelect}, publisher={Wiley}, author={Naik, Praveen and Abdellah, Islam M. and Abdel‐Shakour, M. and Acharaya, Madhukara and Pilicode, Naveenchandra and El‐Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2018}, month={Nov}, pages={12297–12302} }
 @article{elmorsy_su_fadda_etman_tawfik_el-shafei_2018, title={Co-sensitization of Ru(II) complex with terthiophene-based D-pi-pi-A metal-free organic dyes for highly efficient dye-sensitized solar cells: influence of anchoring group on molecular geometry and photovoltaic performance}, volume={42}, ISSN={["1369-9261"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85049743627&partnerID=MN8TOARS}, DOI={10.1039/c8nj01482e}, abstractNote={In this work, we studied the photovoltaic performance of two novel metal-free organic dyes carrying the same donor but with different anchoring moieties.}, number={14}, journal={NEW JOURNAL OF CHEMISTRY}, author={Elmorsy, Mohamed R. and Su, Rui and Fadda, Ahmed A. and Etman, H. A. and Tawfik, Eman H. and El-Shafei, Ahmed}, year={2018}, month={Jul}, pages={11430–11437} }
 @article{naik_su_elmorsy_el-shafei_vasudeva adhikari_2018, title={Correction: New di-anchoring A–π-D–π-A configured organic chromophores for DSSC application: sensitization and co-sensitization studies}, volume={17}, ISSN={1474-905X 1474-9092}, url={http://dx.doi.org/10.1039/C8PP90007H}, DOI={10.1039/C8PP90007H}, abstractNote={Correction for 'New di-anchoring A-π-D-π-A configured organic chromophores for DSSC application: sensitization and co-sensitization studies' by Praveen Naik et al., Photochem. Photobiol. Sci., 2018, DOI: 10.1039/c7pp00351j.}, number={3}, journal={Photochemical & Photobiological Sciences}, publisher={Royal Society of Chemistry (RSC)}, author={Naik, Praveen and Su, Rui and Elmorsy, Mohamed R. and El-Shafei, Ahmed and Vasudeva Adhikari, Airody}, year={2018}, pages={363–363} }
 @article{lim_szymczyk_mehraban_ding_parrillo-chapman_el-shafei_freeman_2018, title={Data from X-ray crystallographic analysis and DFT calculations on isomeric azo disperse dyes}, volume={21}, ISSN={["2352-3409"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85055317185&partnerID=MN8TOARS}, DOI={10.1016/j.dib.2018.10.010}, abstractNote={X-ray crystallography and DFT calculations were used to characterize the molecular nature and excited state properties of isomeric photostable azo dyes for textile fibers undergoing extensive sunlight exposure. Structural data in CIF files arising from X-ray analysis are reported and the complete files are deposited with the Cambridge Crystallographic Data Centre as CCDC 1548989 (https://www.ccdc.cam.ac.uk/structures/Search?Ccdcid=1548989) and CCDC 1548990 (https://www.ccdc.cam.ac.uk/structures/Search?Ccdcid=1548990). Data from calculating the vertical electronic excitation of 20 excited states for each dye and from calculating excited state oxidation potential (ESOP) and Frontier HOMO/LUMO isosurfaces are also presented. This data is related to the article “Molecular and excited state properties of isomeric scarlet disperse dyes” (Lim et al., 2018) [1].}, journal={DATA IN BRIEF}, author={Lim, Jihye and Szymczyk, Malgorzata and Mehraban, Nahid and Ding, Yi and Parrillo-Chapman, Lisa and El-Shafei, Ahmed and Freeman, Harold S.}, year={2018}, month={Dec}, pages={675–683} }
 @article{elmorsy_su_fadda_etman_tawfik_el-shafei_2018, title={Effect of terthiophene spacer position in Ru(II) bipyridyl complexes on the photocurrent and photovoltage for high efficiency dye-sensitized solar cells}, volume={156}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85045755836&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2018.04.005}, abstractNote={Two novel ruthenium complexes, MR-1 and MR-2 were synthesized for use in dye-sensitized solar cells (DSSCs). Under similar fabrication conditions, the photovoltaic performances of these dyes were evaluated and compared to the standard ruthenium complex N719. MR-1 and MR-2 showed the efficiencies of 8.19% and 5.32%, respectively, while N719 achieved 7.66%. MR-1 also displayed higher VOC than MR-2, which is due to the larger molecular size and higher molar extinction coefficient of the former, which translates into less dye aggregation on a thinner film of TiO2. Incorporation of terthiophene as a linker reduces the band gap of MR-1 when compared to that of MR-2. The influence of π-conjugated bridge on optical and electrochemical properties was investigated. Results demonstrated that the absorption band of MR-1 displayed higher extinction coefficient with a broader absorption compared to MR-2 and the benchmark Ru(II) dye, N719, due to the enhancement of electron donating ability of π-conjugated bridge.}, journal={DYES AND PIGMENTS}, author={Elmorsy, Mohamed R. and Su, Rui and Fadda, Ahmed A. and Etman, H. A. and Tawfik, Eman H. and El-Shafei, Ahmed}, year={2018}, month={Sep}, pages={348–356} }
 @article{naik_elmorsy_su_el-shafei_adhikari_2018, title={Enhancing photovoltaic performance of DSSCs sensitized with Ru-II complexes by D-pi-A configured carbazole based co-sensitizers}, volume={42}, ISSN={["1369-9261"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85046823785&partnerID=MN8TOARS}, DOI={10.1039/c8nj00927a}, abstractNote={Simple D–π–A architectured carbazole based dyes, P1–4, were employed as co-sensitizers in DSSCs sensitized with Ru-II complexes, viz.NCSU-10 and N3. The results revealed that, the NCSU-10 sensitized devices displayed improved photovoltaic performance when co-sensitized with P1 and P3.}, number={12}, journal={NEW JOURNAL OF CHEMISTRY}, author={Naik, Praveen and Elmorsy, Mohamed R. and Su, Rui and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2018}, month={Jun}, pages={9443–9448} }
 @article{naik_keremane_elmorsy_su_el-shafei_adhikari_2018, title={Highly efficient carbazole based co-sensitizers carrying electron deficient barbituric acid for NCSU-10 sensitized DSSCs}, volume={169}, ISSN={["0038-092X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85046758816&partnerID=MN8TOARS}, DOI={10.1016/j.solener.2018.05.024}, abstractNote={Herein, we report a comparative study of four interesting metal-free carbazole based organic dyes with different structural configurations, carrying electron deficient barbituric acid (C1-4), as effective co-sensitizers in DSSCs sensitized with NCSU-10 dye. The new entities comprise different structural architectures, viz. D-A (C1), D-π-A (C2), D-D-π-A (C3) and D-A-π-A (C4) configurations with same accepting/anchoring moiety. They consist of carbazole as donor scaffold linked to barbituric acid as an acceptor/anchoring unit via different π-spacers. This paper describes the study of all the four co-sensitizers with regard to their structural, photophysical, electrochemical, theoretical and photovoltaic investigations. Also, it includes their structure-performance correlation study in detail. The devices co-sensitized with C1-4 displayed the superior photovoltaic performance when compared to NCSU-10 alone. The results ameliorate the role of efficient co-sensitizers to yield DSSC with improved performance.}, journal={SOLAR ENERGY}, author={Naik, Praveen and Keremane, Kavya S. and Elmorsy, Mohamed R. and Su, Rui and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2018}, month={Jul}, pages={386–391} }
 @article{naik_abdellah_abdel-shakour_su_keremane_el-shafei_adhikari_2018, title={Improvement in performance of N3 sensitized DSSCs with structurally simple aniline based organic co-sensitizers}, volume={174}, ISSN={["0038-092X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85054333887&partnerID=MN8TOARS}, DOI={10.1016/j.solener.2018.09.071}, abstractNote={In this work, we report comprehensive photovoltaic investigation of four structurally simple D-A configured organic dyes, A1-4 as active co-sensitizers in DSSCs sensitized with well-known Ru (II) based N3 dye. These effective co-sensitizers (A1-4) comprise N,N-dimethylaniline ring as donor scaffold linked with electron withdrawing functionalities, viz. barbituric acid (A1), N,N-dimethyl barbituric acid (A2), thiobarbituric acid (A3), and N,N-diethyl thiobarbituric acid (A4) as acceptor/anchoring units. In the present study, for the first time we have demonstrated the profound role of various simple organic molecules carrying different heterocyclic anchoring units on the photovoltaic parameters of the N3 sensitized devices. Also, the effect of concentration of sensitizer/co-sensitizers on the device performance characteristics has been investigated in depth. From the results, it is evident that, the device fabricated using co-sensitizer A2 carrying N,N-dimethyl barbituric acid along with sensitizer N3 in all concentrations outperformed when compared to N3 alone or other co-sensitizers. Interestingly, the best photovoltaic performance was obtained for the co-sensitized device fabricated using 0.3 mM co-sensitizer A2 along with 0.2 mM of N3 sensitizer. It displayed PCE of 7.02% with JSC of 15.27 mA·cm−2, VOC of 0.671 V and FF of 68.47%. Thus, the observed results have thrown new light upon the device optimization to yield DSSCs with improved performance by the selection of matchable co-sensitizers at appropriate concentrations.}, journal={SOLAR ENERGY}, author={Naik, Praveen and Abdellah, Islam M. and Abdel-Shakour, M. and Su, Rui and Keremane, Kavya S. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2018}, month={Nov}, pages={999–1007} }
 @article{ashraf_su_akhtar_siddiqi_el-shafei_2018, title={Influence of brominated-TPA-stilbazole based ancillary ligand on the photocurrent and photovoltage in dye-sensitized solar cells}, volume={150}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85038869855&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2017.12.035}, abstractNote={Two novel heteroleptic brominated-TPA-stilbazole based Ru (II)-sensitizers denoted as SD-11 and SD-11 mono were designed, synthesized and characterized for dye-sensitized solar cells (DSCs) in comparison to benchmarked dye N719. The molecular structures of SD-11 and SD-11 mono were confirmed using FTIR, 1H-NMR and mass spectrometry. The aim was to systematically study the effect of mono (SD-11 mono) versus bis-brominated-TPA moiety (SD-11) on molar absorptivity, ground and excited state oxidation potentials, light harvesting efficiency (LHE), incident-photon-to-current conversion efficiency (IPCE), short-circuit photocurrent density (Jsc), and total solar-to-electric conversion efficiency (η) for DSCs. Optical results revealed that SD-11 and SD-11 mono have higher molar extinction coefficients, narrower HOMO−LUMO gaps compared to N719. Hence, it was found that SD-11 exhibited remarkably greater Jsc than SD-11 mono and interestingly showed comparable extinction coefficients. However, in optimized conditions, SD-11 showed a higher Jsc of 22.1 mA cm−2, Voc of 0.68 V with (% η) of 8.7 compared to Jsc of 14.4 mA cm−2, Voc of 0.63 V and with (% η) of 5.8 for SD-11 mono whereas N719 attained a Jsc of 15.9 mA cm−2, Voc of 0.74 V with (% η) of 7.6 under the same experimental device conditions. It was concluded that SD-11 outperformed SD-11 mono in photovoltaic performance when anchored on TiO2, owing to better light-harvesting ability. These results clearly demonstrated that the enhancement of the photovoltaic performance in SD-11 can be attributed to the presence of more number of –Br group.}, journal={DYES AND PIGMENTS}, author={Ashraf, Saba and Su, Rui and Akhtar, Javeed and Siddiqi, Humaira M. and El-Shafei, Ahmed}, year={2018}, month={Mar}, pages={347–353} }
 @article{naik_su_elmorsy_el-shafei_adhikari_2018, title={Investigation of new carbazole based metal-free dyes as active photo-sensitizers/co-sensitizers for DSSCs}, volume={149}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85030704247&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2017.09.068}, abstractNote={Herein, we report the molecular design, synthesis and characterization of three new D-D-π-A configured metal-free chromophores D1-3 for their application in DSSCs as sensitizers as well as co-sensitizers. The new entities comprise carbazole as donor scaffold, 4-methoxyphenyl group as auxiliary donor and three different units, viz. cyanoacetic acid, 2, 4-thiazolidinedione and barbituric acid as acceptor/anchoring groups. Their photochemical, electrochemical and theoretical studies were carried out in order to assess their feasibility as active sensitizers. Further, D1-3 were exploited as co-sensitizers along with NCSU-10 dye. Their photoelectrochemical performances and charge transport properties in fabricated DSSCs were studied. The results revealed that D1 sensitizer displayed the highest PCE of 2.20% among the three dyes. D3 when co-sensitized with NCSU-10 displayed an improved PCE of 8.32% (JSC = 19.25 mA.cm−2, VOC = 0.680 V, FF = 63.7%) while NCSU-10 alone exhibited PCE of 8.25% (JSC = 20.41 mA.cm−2, VOC = 0.667 V, FF = 60.6%).}, journal={DYES AND PIGMENTS}, author={Naik, Praveen and Su, Rui and Elmorsy, Mohamed R. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2018}, month={Feb}, pages={177–187} }
 @article{lim_szymczyk_mehraban_ding_parrillo-chapman_el-shafei_freeman_2018, title={Molecular and excited state properties of isomeric scarlet disperse dyes}, volume={1161}, ISSN={["1872-8014"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85042332047&partnerID=MN8TOARS}, DOI={10.1016/j.molstruc.2018.02.028}, abstractNote={This work was part of an investigation aimed at characterizing the molecular and excited state properties of currently available disperse dyes developed to provide stability to extensive sunlight exposures when adsorbed on poly(ethylene terephthalate) (PET) fibers. Having completed the characterization of yellow, magenta, and cyan disperse dyes for PET-based fabrics used outdoors, our attention turned to the colors designed to enhance the color gamut of a standard 4-member (cyan/yellow/magenta/black) color set. The present study pertained specifically to the characterization of commercially available scarlet dyes. In this regard, HPLC analysis showed that a scarlet product used for PET coloration was mainly a 70/30 mixture of dyes, and the use of HRMS and single crystal X-ray diffraction analyses indicated that these two dyes were azo compounds derived from isomeric pyridine-based couplers which differed in the location of the primary amino (NH2) and anilino (NHPh) groups attached to the pyridine ring. One dye structure has the NHPh group para to the azo group (Sc2), while the other has that group in the ortho position (Sc3). The presence of either ortho substituent provides photostabilization through intramolecular H-bonding with the azo moiety. Further, results from molecular modeling studies showed that the lower excited state oxidation potential of Sc3 relative to that of Sc2 allows Sc3 to function as an energy quencher for the excited state of Sc2 – through thermodynamically favorable electron transfer.}, journal={JOURNAL OF MOLECULAR STRUCTURE}, author={Lim, Jihye and Szymczyk, Malgorzata and Mehraban, Nahid and Ding, Yi and Parrillo-Chapman, Lisa and El-Shafei, Ahmed and Freeman, Harold S.}, year={2018}, month={Jun}, pages={254–261} }
 @article{elmorsy_su_fadda_etman_tawfik_el-shafei_2018, title={Molecular engineering and synthesis of novel metal-free organic sensitizers with D-π-A-π-A architecture for DSSC applications: The effect of the anchoring group}, volume={158}, ISSN={0143-7208}, url={http://dx.doi.org/10.1016/J.DYEPIG.2018.05.011}, DOI={10.1016/J.DYEPIG.2018.05.011}, abstractNote={Herein, we report the design and synthesis of two metal-free organic sensitizers (MR-5 & MR-6) with a D-π-A-π-A architecture based on a trimethoxy benzene donor core carrying two different withdrawing/anchoring groups including cyanoacetic acid and rhodanine-3-acetic acid via thiophene as a π-spacer. Benzothiadiazole was incorporated as a strong auxiliary electron acceptor, which greatly improved the molar extinction coefficient and electronic coupling across the molecular diameter of the dyes. The optical and electrochemical properties of the two dyes were investigated. The photovoltaic studies revealed that MR-5 anchored with cyanoacetic acid showed significantly greater light harvesting (IPCE), which resulted in improved PCE with better photovoltaic parameters than MR-6. MR-5 achieved the higher total solar-to-electric conversion efficiency of 6.03% and showed an IPCE of 65% at 420 nm. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were used to study equilibrium molecular geometries, frontier molecular orbitals, vertical electronic excitations, and the theoretical data were consistent with experimental results.}, journal={Dyes and Pigments}, publisher={Elsevier BV}, author={Elmorsy, Mohamed R. and Su, Rui and Fadda, Ahmed A. and Etman, H.A. and Tawfik, Eman H. and El-Shafei, Ahmed}, year={2018}, month={Nov}, pages={121–130} }
 @article{naik_su_elmorsy_el-shafei_adhikari_2018, title={New carbazole based dyes as effective co-sensitizers for DSSCs sensitized with ruthenium (II) complex (NCSU-10)}, volume={27}, ISSN={["2095-4956"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85041655106&partnerID=MN8TOARS}, DOI={10.1016/j.jechem.2017.12.013}, abstractNote={Herein, we report the design and synthesis of three new D–A type metal-free carbazole based dyes (S1–3) as effective co-sensitizers for dye-sensitized solar cell (DSSC) sensitized with Ru(II) complex (NCSU-10). In this new design, the electron rich carbazole unit was attached to three different electron withdrawing/anchoring species, viz. 4-amino benzoic acid, sulfanilic acid and barbituric acid. The dyes were characterized by spectral, photophysical and electrochemical analysis. Their optical and electrochemical parameters along with molecular geometries, optimized from DFT have been employed to apprehend the effect of the structures of these co-sensitizers on the photovoltaic performances. Further, S1–3 dyes were co-sensitized along with a well-known NCSU-10 dye in order to broaden the spectral response of the co-sensitized devices and hence improve the efficiency. The photovoltaic performance studies indicated that, the device fabricated using S1 dye as co-sensitizer with 0.2 mM of NCSU-10 exhibited improved PCE of 9.55% with JSC of 22.85 mA cm−2, VOC of 0.672 V and FF of 62.2%, whereas the DSSC fabricated with dye NCSU-10 (0.2 mM) alone displayed PCE of 8.25% with JSC of 20.41 mA cm−2, VOC of 0.667 V and FF of 60.6%. Furthermore, electronic excitations simulated using time-dependent DFT, were in good agreement with the experimentally obtained results of the co-sensitizers, indicating that the exchange-correlation function and basis set utilized for predicting the spectra of the co-sensitizers are quite appropriate for the calculations. In conclusion, the results showed the potential of simple organic co-sensitizers in the development of efficient DSSCs.}, number={2}, journal={JOURNAL OF ENERGY CHEMISTRY}, author={Naik, Praveen and Su, Rui and Elmorsy, Mohamed R. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2018}, month={Mar}, pages={351–360} }
 @article{naik_su_elmorsy_el-shafei_adhikari_2018, title={New di-anchoring A-pi-D-pi-A configured organic chromophores for DSSC application: sensitization and co-sensitization studies}, volume={17}, ISSN={["1474-9092"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85044037092&partnerID=MN8TOARS}, DOI={10.1039/c7pp00351j}, abstractNote={Herein, we report the design and synthesis of three new un-symmetrical metal-free carbazole based organic dyes, E_1-3 with A-π-D-π-A architecture, as effective di-anchoring sensitizers in DSSCs. The new entities comprise carbazole as a donor scaffold connected to three different units, viz. cyano acetic acid, 2,4-thiazolidinedione and barbituric acid as acceptor/anchoring units via vinylene and phenylene as π-spacers at 3- and 6-positions of the carbazole ring, respectively. Photophysical, electrochemical and theoretical studies were carried out in order to assess their feasibility as active sensitizers. Furthermore, their photoelectrochemical performances and charge transport properties in fabricated DSSCs were evaluated. The results revealed that the device fabricated with the E_1 sensitizer displayed the highest PCE of 2.38% among the three dyes. Its J _SC, V _OC, and IPCE values were found to be 6.36 mA cm^−2, 0.599 V, and 57%, respectively. Its enhanced performance is attributed to the presence of a highly electron withdrawing cyano acetic acid unit on either side of the carbazole core through appropriate π-spacers. Interestingly, the DFT study indicated that the electron cloud of the LUMO level has been shifted significantly towards the 2-cyano phenyl acrylic acid connected at the 6^th position of the carbazole ring, when compared to the cyano acrylic acid linked at position 3, confirming efficient charge separation in E_1. The assigned lifetimes of E_1-3 obtained from EIS studies were found to be in accordance with experimentally obtained photovoltaic parameters. Furthermore, E_1-3, when co-sensitized with NCSU-10 sensitizer in DSSCs, displayed higher V_OC values, but lower PCE values than that of NCSU-10.}, number={3}, journal={PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES}, author={Naik, Praveen and Su, Rui and Elmorsy, Mohamed R. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2018}, month={Mar}, pages={302–314} }
 @article{al-mohsin_mineart_armstrong_el-shafei_spontak_2018, title={Quasi-Solid-State Dye-Sensitized Solar Cells Containing a Charged Thermoplastic Elastomeric Gel Electrolyte and Hydrophilic/phobic Photosensitizers}, volume={2}, ISSN={2367-198X}, url={http://dx.doi.org/10.1002/SOLR.201700145}, DOI={10.1002/SOLR.201700145}, abstractNote={As the threat of global climate change due to combustion emissions becomes increasingly alarming, the search for clean and sustainable alternative energy is of paramount importance. With this objective in mind, harnessing solar energy is particularly attractive due to ongoing improvements in silicon‐, perovskite‐, and organic‐based solar cells. Of these, dye‐sensitized solar cells (DSSCs) constitute a promising technology due to their relatively low cost, moderate conversion efficiency, and robust mechanical properties. An important breakthrough in the development of DSSCs is the use of polymer gel electrolytes. In this work, we employ amphi­philic thermoplastic elastomers (TPEs) in the form of sulfonated block ionomer (SBI) homologs for this purpose. Since the midblock of each charged copolymer is hydrophilic, the resultant microphase‐separated nanostructures consist of continuous ionic channels that facilitate electron diffusion. A unique characteristic of the SBI archetype studied here is that the morphology can be solvent‐templated. We exploit this feature by introducing either hydrophilic or hydrophobic photosensitizers into the DSSCs. When the SBI exhibits a primarily lamellar morphology, a hydrophilic dye yields the highest efficiency (7.0%), whereas the opposite is observed when the nanostructure consists of a solvent‐templated nonpolar matrix. Photosensi­tizer tunability is augmented by the intrinsic mechanical and adhesive properties of a TPE.}, number={3}, journal={Solar RRL}, publisher={Wiley}, author={Al-Mohsin, Heba A. and Mineart, Kenneth P. and Armstrong, Daniel P. and El-Shafei, Ahmed and Spontak, Richard J.}, year={2018}, month={Jan}, pages={1700145} }
 @article{al-mohsin_mineart_armstrong_el-shafei_spontak_2018, title={Quasi-solid-state dye-sensitized solar cells containing a charged thermoplastic elastomeric gel electrolyte and hydrophilic/phobic photosensitizers}, volume={2}, DOI={10.1002/solr.201770155}, abstractNote={To address the increasingly alarming threat of global climate change, Richard J. Spontak and co-workers demonstrate dye-sensitized solar cells, which are composed of amphiphilic, thermoplastic elastomeric block ionomers in article number 1700145. The midblock of each ionomer is hydrophilic and therefore the microphase- separated nanostructures are network-forming and solvent-templatable, consisting of continuous ionic channels that facilitate electron diffusion. The achieved effi ciency of these solar cells by using either hydrophilic or hydrophobic photosensitizers is as high as 7%.}, number={3}, journal={Solar RRL}, author={Al-Mohsin, H. A. and Mineart, K. P. and Armstrong, D. P. and El-Shafei, Ahmed and Spontak, Richard}, year={2018} }
 @inproceedings{salim_el-shafei_2018, title={Sustainable dyeing of cotton: Ultra deep black with excellent fastness properties via graft polymerization of DADMAC into cotton prior to dyeing}, volume={2018-March}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85048877263&partnerID=MN8TOARS}, booktitle={AATCC 2018 - 2018 AATCC International Conference Proceedings}, author={Salim, S. and El-Shafei, A.}, year={2018}, pages={43–52} }
 @article{naik_babu_su_el-shafei_adhikari_2018, title={Synthesis, Characterization and Performance Studies of a New Metal-Free Organic Sensitizer for DSSC application}, volume={5}, ISSN={["2214-7853"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85042432054&partnerID=MN8TOARS}, DOI={10.1016/j.matpr.2018.01.122}, abstractNote={In this present work we report, design, synthesis and performance studies of a new metal-free organic dye (N, N’-PABA) based on N,N-dimethyl-4-vinyl aniline carrying 4-amino benzoic acid as acceptor, as sensitizers for sensitizing photoanode (TiO2). In the sensitizers, N,N-dimethylaniline ring acts as anelectron donorwhile para amino benzoic acid function as electron acceptor/anchoring units. It was synthesized via condensation reaction starting from simple 4-(N,N-dimethyl amino)benzaldehyde and their structures were confirmed using spectral techniques like FTIR, 1HNMR, 13CNMR, MS and elemental analysis. Further, it was subjected to electrochemical and optical characterization in order to evaluate their band gap and absorption/emission behavior. Further, DFT studies were performed using turbo mole V6.6 software package to evaluate their optimized geometry and FMO levels. Finally, DSSC devices were fabricated using this dye under simulated solar radiation AM1.5G and result revealed that it shows a conversion efficiency of 1%.}, number={1}, journal={MATERIALS TODAY-PROCEEDINGS}, author={Naik, Praveen and Babu, Dickson D. and Su, Rui and El-Shafei, Ahmed and Adhikari, A. Vasudeva}, year={2018}, pages={3150–3157} }
 @article{koraiem_el-shafei_abdellah_abdel-latif_abd el-aal_2018, title={Theoretical and experimental spectroscopic investigation of new polymethine donor-π-acceptor cyanine dyes: Synthesis, photophysical, and TDDFT studies}, volume={1173}, ISSN={0022-2860}, url={http://dx.doi.org/10.1016/j.molstruc.2018.07.021}, DOI={10.1016/j.molstruc.2018.07.021}, abstractNote={New series of polymethine cyanine dyes with different length of π-chain have been synthesized and characterized. These new dyes are based on D-π-A architecture with long π-electron systems. The UV–vis/emission spectral studies showed that the dyes are absorbed in the region of λmax (485–570) nm and emitted at (540–600) nm. This makes these dyes favorable for the detection of biological and chemical analytes. Their electron cloud delocalization in HOMO/LUMO levels were studied by DFT using Gaussian 09 software. DFT results reveal that the dyes showed effective charge separation in its molecular orbitals levels, which reflected in its ICT behavior. Time-dependent density functional theory (TD-DFT) were applied to theoretically explored the first excitation energy (E0-0) of these dyes which in high compatibility with experimental results with an accuracy of 0.1–0.3 eV. This approach has been successfully applied to describe the great effect of π-conjugation length and substituents of chromophore on the variations of maximum absorption and excitation energy of the dyes.}, journal={Journal of Molecular Structure}, publisher={Elsevier BV}, author={Koraiem, Ahmed I. and El-Shafei, Ahmed and Abdellah, Islam M. and Abdel-Latif, Fathy F. and Abd El-Aal, Reda M.}, year={2018}, month={Dec}, pages={406–416} }
 @article{su_elmorsy_abed_islam_lord_fadda_el-shafei_2017, title={A Comparative Study on Two Ru-II Complexes with Thiophene-Based Ancillary Ligands for High-Efficiency Dye-Sensitized Solar Cells}, volume={2017}, ISSN={["1099-0682"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85028060292&partnerID=MN8TOARS}, DOI={10.1002/ejic.201700468}, abstractNote={Heteroleptic polypyridyl Ru complexes MMR‐1 and MMR‐2 containing 2‐(methylthio)thienyl and 2‐(4‐methoxyphenyl)thienyl units on the antennas of ancillary ligands, respectively, were designed, synthesized, and characterized as sensitizers for dye‐sensitized solar cells. The maximum absorption wavelength of MMR‐1 is more red‐shifted than that of MMR‐2, but MMR‐2 has a higher molar extinction coefficient, leading to better light harvesting. Under the same device‐fabrication conditions, the photovoltaic performances of these sensitizers were evaluated while anchored on mesoporous TiO2 and compared to that of the benchmark N719. Both MMR‐1 and MMR‐2 exhibited comparable or even higher solar‐to‐electric conversion efficiencies η with respect to N719 when employed as photosensitizers in DSSCs. Compared to MMR‐1, MMR‐2 exhibited better overall conversion efficiency, which was attributed to the electron‐donating effect of the 4‐methoxyphenyl group and the better absorptivity by harvesting higher‐energy photons. Complex MMR‐2 also showed higher open‐circuit voltage VOC than MMR‐1, which is likely due to the extension of the antenna of the ancillary ligand by inserting a phenyl group, which leads to less dye aggregation. The photovoltaic performance of MMR‐2 was better, with a short‐circuit photocurrent density of 16.76 mA cm–2, a VOC of 0.673 V, a fill factor of 73.5 %, and an η value of 8.29 % with the addition of 0.5 m 4‐tert‐butylpyridine (TBP) compared to 8.18 % for N719.}, number={31}, journal={EUROPEAN JOURNAL OF INORGANIC CHEMISTRY}, author={Su, Rui and Elmorsy, Mohamed R. and Abed, Mira and Islam, Ashraful and Lord, Meghan and Fadda, Ahmed A. and El-Shafei, Ahmed}, year={2017}, month={Aug}, pages={3690–3697} }
 @article{ashraf_yildirim_akhtar_siddiqi_el-shafei_2017, title={A comparative study of the influence of N, N '-dialkyl vs. N, N '-diaryl-based electron donor ancillary ligands on photocurrent and photovoltage in dye-sensitized solar cells (DSSCs)}, volume={19}, ISSN={["1463-9084"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85027680532&partnerID=MN8TOARS}, DOI={10.1039/c7cp02530k}, abstractNote={In this study, we report the synthesis of a novel heteroleptic Ru(ii)-sensitizer, denoted as SD-1; moreover, its photophysical, electrochemical, and photovoltaic performances were compared with those of N719 and K77-7.}, number={31}, journal={PHYSICAL CHEMISTRY CHEMICAL PHYSICS}, author={Ashraf, Saba and Yildirim, Erol and Akhtar, Javeed and Siddiqi, Humaira M. and El-Shafei, Ahmed}, year={2017}, month={Aug}, pages={20847–20860} }
 @article{zidan_el-shafei_noshy_salim_2017, title={A comparative study to evaluate conventional and nonconventional cleaning treatments of cellulosic paper supports}, volume={17}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85046288345&partnerID=MN8TOARS}, DOI={10.5281/zenodo.1005538}, number={3}, journal={Mediterranean Archaeology and Archaeometry}, author={Zidan, Y. and El-Shafei, A. and Noshy, W. and Salim, E.}, year={2017}, pages={337–353} }
 @article{naik_su_el-shafei_adhikari_2017, title={Improved photovoltaic performances of Ru (II) complex sensitized DSSCs by co-sensitization of carbazole based chromophores}, volume={86}, ISSN={["1879-0259"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85032805638&partnerID=MN8TOARS}, DOI={10.1016/j.inoche.2017.10.030}, abstractNote={Herein, we report photovoltaic performance studies of three carbazole based dyes (N1–3) derived from (Z)-3-(9-hexyl-9H-carbazol-3-yl)-2-(thiophen-2-yl)acrylonitrile scaffold as effective co-sensitizers in Ru (II) complex, i.e. NCSU-10 sensitized DSSCs. From the results it is evident that, the device fabricated using co-sensitizer N3 with 0.2 mM of NCSU-10 exhibited improved photon conversion efficiency (PCE) of 8.73% with JSC of 19.87 mA·cm− 2, VOC of 0.655 V and FF of 67.0%, while N1 displayed PCE of 8.29% with JSC of 19.75 mA·cm− 2, VOC of 0.671 V and FF of 62.6%, whereas NCSU-10 (0.2 mM) alone displayed PCE of 8.25% with JSC of 20.41 mA·cm− 2, VOC of 0.667 V and FF of 60.6%. However, their EIS studies confirm that, N1, showing higher VOC is efficient in suppressing the undesired charge recombination in DSSCs through enhanced surface coverage on TiO2 and thereby resulting in longer electron lifetime than that of NCSU-10 dye alone. Here, the higher PCE of N3 can be attributed to its improved light harvesting efficiency, which is due to the presence of highly electron withdrawing barbituric acid in its structure. Conclusively, the results showcase the potential of simple carbazole based dyes as co-sensitizers in improving efficiency of DSSCs.}, journal={INORGANIC CHEMISTRY COMMUNICATIONS}, author={Naik, Praveen and Su, Rui and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2017}, month={Dec}, pages={241–245} }
 @article{helmy_hauser_el-shafei_2017, title={Influence of atmospheric plasma-induced graft polymerization of DADMAC into cotton on dyeing with acid dyes}, volume={108}, ISSN={["1754-2340"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85014755559&partnerID=MN8TOARS}, DOI={10.1080/00405000.2017.1298206}, abstractNote={Abstract The primary objective of this work was to generate dyes sites in cotton fiber for acid dyes via free radical graft polymerization of diallyldimethylammonium chloride (DADMAC), to confer cationized cotton, and evaluate the dyeability of the cationized cotton toward acid dyes, which is unprecedented. Plasma-induced graft polymerization of DADMAC on cotton, using different plasma conditions, followed by dyeing with different acid dyes was studied. The color yield of dyed cotton was evaluated using K/S. Light fastness, color change, and staining following accelerated washing cycles were carried out to evaluate the effectiveness of cotton cationization. Cross-section dyed cotton was studied using scanning electron microscopy and showed deep dyeing of acid dyes into cotton fibers. This approach resulted in significant dye uptake into the fibers and considerably reduced the need for effluent treatment.}, number={11}, journal={JOURNAL OF THE TEXTILE INSTITUTE}, author={Helmy, Hany M. and Hauser, Peter and El-Shafei, Ahmed}, year={2017}, pages={1871–1878} }
 @article{naik_su_elmorsy_babu_el-shafei_adhikari_2017, title={Molecular design and theoretical investigation of new metal-free heteroaromatic dyes with D-pi-A architecture as photosensitizers for DSSC application}, volume={345}, ISSN={["1010-6030"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85019870789&partnerID=MN8TOARS}, DOI={10.1016/j.jphotochem.2017.05.033}, abstractNote={Herein, we report design, synthesis and photovoltaic performance of four new metal-free heteroaromatic dyes (P1-4) with D-π-A architecture carrying electron donating carbazole core connected to four different electron withdrawing/anchoring groups, viz. cyanoacetic acid, rhodanine-3-acetic acid, barbituric acid and thiobarbituric acid and phenylene ring as a π-spacer. The newly designed P1-4 were synthesized from carbazole derivative using Suzuki cross coupling approach followed by Knoevenagel condensation reaction. Their structures were confirmed by FTIR, NMR, Mass spectral and elemental analyses. The dyes were subjected to optical and electrochemical studies in order to investigate their absorption/emission behavior as well as HOMO/LUMO energies. The UV–vis spectral studies reveal that the P1-4 showed λmax at 412, 439, 458 and 489 nm, respectively. Their optical band-gap is in the range of 2.17 to 2.61 eV and fluorescence quantum yield is in the order of 44–70%. From energy level diagram, it is clear that all the dyes possess good thermodynamic feasibility for electron injection into CB edge of TiO2 as well as their regeneration from electrolyte system. The photovoltaic performance studies indicate that among the tested dyes, P1 anchored with cyanoacetic acid displayed the highest IPCE (32%), resulting in improved PCE (1.94%), JSC (4.68 mA cm−2), VOC (0.588 V) and FF (70.3%) values, when compared to other dyes. Finally, DFT studies were performed using Turbomole 7.1 V software to investigate their electron cloud delocalization in HOMO/LUMO levels and theoretical absorption spectral data. The results reveal that the dye P1 showed effective charge separation in its FMO levels, which has reflected in its ICT behavior and hence P1 displayed the improved photovoltaic performance.}, journal={JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY}, author={Naik, Praveen and Su, Rui and Elmorsy, Mohamed R. and Babu, Dickson D. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2017}, month={Aug}, pages={63–73} }
 @article{naik_elmorsy_su_babu_el-shafei_adhikari_2017, title={New carbazole based metal-free organic dyes with D-pi-A-pi-A architecture for DSSCs: Synthesis, theoretical and cell performance studies}, volume={153}, ISSN={["0038-092X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85020822743&partnerID=MN8TOARS}, DOI={10.1016/j.solener.2017.05.088}, abstractNote={Herein we report the design, synthesis and photovoltaic performance studies of three new D-π-A-π-A architectured organic chromophores (N1-3) derived from (Z)-3-(9-hexyl-9H-carbazol-3-yl)-2-(thiophen-2-yl) acrylonitrile scaffold. In the new design, the electron rich carbazole unit is connected to three different electron withdrawing/anchoring species, viz. cyano acetic acid, rhodanine-3-acetic acid and barbituric acid via cyano vinyl thiophene as π-spacer. Newly synthesized dyes were characterized by spectral, photophysical and electrochemical analyses. Their optical band-gap, GSOP and ESOP values, as calculated from the optical and CV studies were found to be in the range of 2.12–2.21, −5.52 to −5.43 and −5.40 to −3.25 eV respectively. The DFT and TD-DFT studies were performed using Turbomole 7.1V software and the results indicated the existence of proper charge separation between HOMO and LUMO levels of the dyes. Also, the results revealed good matching of theoretically generated optical spectral data with the experimental values. Finally, DSSC devices were fabricated using these three dyes and the dye N1 containing cyanoacetic acid as an acceptor unit showed better photo conversion efficiency (η) of 3.55% than the other two dyes. It’s JSC, VOC, and IPCE parameters were shown to be 9.06 mA cm−2, 0.577 V and 48%, respectively. The obtained EIS data and electron lifetimes of N1–3 sensitized devices are well in accordance with experimental photovoltaic parameters.}, journal={SOLAR ENERGY}, author={Naik, Praveen and Elmorsy, Mohamed R. and Su, Rui and Babu, Dickson D. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2017}, month={Sep}, pages={600–610} }
 @article{naik_su_babu_el-shafei_adhikari_2017, title={Structurally simple D-A-type organic sensitizers for dye-sensitized solar cells: effect of anchoring moieties on the cell performance}, volume={14}, ISSN={["1735-2428"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85032027118&partnerID=MN8TOARS}, DOI={10.1007/s13738-017-1180-3}, number={11}, journal={JOURNAL OF THE IRANIAN CHEMICAL SOCIETY}, author={Naik, Praveen and Su, Rui and Babu, Dickson D. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2017}, month={Nov}, pages={2457–2466} }
 @article{elsherbiny_yildirim_el-essawy_abdel-megied_el-shafei_2017, title={Structure-property relationships: Influence of number of anchoring groups in triphenylamine-carbazole motifs on light harvesting and photovoltaic performance for dye-sensitized solar cells}, volume={147}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85028554215&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2017.08.022}, abstractNote={Three novel organic sensitizers were molecularly designed and synthesized based on triphenylamine (TPA), as the core donor (DTPA), linked to one, two or three carbazole (DCarb) moieties with different number of anchoring groups (AG) to generate: DTPA-π-DCarb-A (DE1), DTPA(π-DCarb-A)2 (DE-2) and DTPA(π-DCarb-A)3 (DE-3). The primary goal of this study was to investigate the influence of bridging different number of DCarb and AG, through π-spacer, with TPA on the photovoltaic performance in DSSCs. The molar extinction coefficient increased with increasing the number of DCarb and A. DE-3 showed the greatest light harvesting in solution and when anchored onto TiO2. Hence, the increase in the number of DCarb and AG led to better light harvesting and stronger electronic coupling with TiO2, which reflected positively on the photovoltaic properties, and this is the first systematic study of its kind involving TPA-π-carbazole motif. DE-3 achieved the best efficiency of 5.44% and showed IPCE of 74% at 470 nm. The Voc increased with increasing the number of anchoring groups. Equilibrium molecular geometries and frontier molecular orbitals studied by DFT and TD-DFT calculations were in excellent agreement with experiments, which showed enhanced electronic coupling with TiO2 and photovoltaic performance as the number of anchoring groups increased.}, journal={DYES AND PIGMENTS}, author={Elsherbiny, Dalia and Yildirim, Erol and El-Essawy, Farag and Abdel-Megied, Ahmed and El-Shafei, Ahmed}, year={2017}, month={Dec}, pages={491–504} }
 @article{babu_su_naik_el-shafei_adhikari_2017, title={Synthesis and photovoltaic performance of a novel asymmetric dual channel co-sensitizer for dye-sensitized solar cell beyond 10% efficiency}, volume={141}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85012243986&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2017.02.010}, abstractNote={In this paper, we report the design and synthesis of a new bi-anchoring indole based co-sensitizer DBA-8 with A-π-D-A (acceptor-π bridge-donor-acceptor) architecture, carrying indole moiety as a donor and barbituric acid as acceptor/anchoring groups. Its photo-physical and electrochemical properties along with molecular geometries, calculated from Density Functional Theory (DFT) are employed to comprehend the effect of co-sensitizer structure on photovoltaic characteristics of DSSCs. The abovementioned organic dye (DBA-8) was employed as a co-sensitizer along with well-known ruthenium based sensitizer NCSU-10 in order to broaden the spectral responses of the co-sensitized DSSC. In the present work, for the first time we are demonstrating the profound role of a dual-anchoring co-sensitizer that can play in ameliorating the overall performance of a solar cell. The photovoltaic studies indicated that, the co-sensitizer DBA-8 succeeded in increasing the light harvesting ability in the device significantly. Notably, the device co-sensitized using 0.2 mM DBA-8 along with ruthenium based chromophore NCSU-10, showed a maximum efficiency of 10.68% (Jsc = 25.14 mAcm−2, Voc = 0.695 V, ff = 61.2%). Further, the good agreement between the theoretically and experimentally obtained λmax data vindicate that, the energy functional and basis set employed in this study can be successfully utilized for predicting the absorption spectra of new photosensitizers, with great precision before synthesis. Furthermore, all these findings showcase the vast potential of bi-anchoring molecules in improving the overall performance of the dye-sensitized solar cells.}, journal={DYES AND PIGMENTS}, author={Babu, Dickson D. and Su, Rui and Naik, Praveen and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2017}, month={Jun}, pages={112–120} }
 @article{ashraf_akhtar_siddiqi_el-shafei_2017, title={Thiocyanate-free ruthenium(II) sensitizers with a bi-imidazole ligand in dye-sensitized solar cells (DSSCs)}, volume={41}, ISSN={["1369-9261"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85022344639&partnerID=MN8TOARS}, DOI={10.1039/c7nj01363a}, abstractNote={In this study, tris-heteroleptic Ru(ii) sensitizers denoted as SD-15 and SD-16 with a 4,4′,5,5′-tetramethyl-1H,1′H-2,2′-bis-imidazole moiety as the ancillary ligand were designed, synthesized and characterized.}, number={14}, journal={NEW JOURNAL OF CHEMISTRY}, author={Ashraf, Saba and Akhtar, Javeed and Siddiqi, Humaira M. and El-Shafei, Ahmed}, year={2017}, month={Jul}, pages={6272–6277} }
 @article{cheema_younts_gautam_gundogdu_el-shafei_2016, title={Design and synthesis of BODIPY sensitizers with long alkyl chains tethered to N-carbazole and their application for dye sensitized solar cells}, volume={184}, ISSN={["1879-3312"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84994504448&partnerID=MN8TOARS}, DOI={10.1016/j.matchemphys.2016.09.024}, abstractNote={In this study, three boron dipyrromethenes (BODIPY) dyes with extended conjugation and electron donating carbazole groups with different alkyl chain lengths tethered to N-carbazole were synthesized and characterized for dye-sensitized solar cells. The goal was to study the effect of different alkyl chain lengths on dye aggregation at TiO2 surface. The proposed molecular strategy resulted in BODIPY dyes which showed interesting electronic absorption and fluorescence properties. It was observed that intramolecular energy transfer decreases with the increase in alkyl chain length possibly due to induced changes in molecular geometry caused by long alkyl chains. Additionally, interface analysis by impedance spectroscopy in comparison to N719 sensitized TiO2 solar cell showed significant charge transport related losses (Nyquist plot) most likely due to impedance resulted from aggregated BODIPY dye on TiO2 surface. Femtosecond transient absorption studies showed the loss of excited electrons by recombination with oxidized ground state of the sensitizers.}, journal={MATERIALS CHEMISTRY AND PHYSICS}, author={Cheema, Hammad and Younts, Robert and Gautam, Bhoj and Gundogdu, Kenan and El-Shafei, Ahmed}, year={2016}, month={Dec}, pages={57–63} }
 @article{babu_su_el-shafei_adhikari_2016, title={From Molecular Design to Co-sensitization; High performance indole based photosensitizers for dye-sensitized solar cells}, volume={198}, ISSN={["1873-3859"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84961817206&partnerID=MN8TOARS}, DOI={10.1016/j.electacta.2016.03.061}, abstractNote={Herein, we report the molecular design and synthesis of two novel organic co-adsorbers DBA-1((Z)-2-cyano-3-(5-(4-(cyclohexa-1,5-dien-3-ynyl(phenyl)amino)phenyl)-1-hexyl-1H-indol-3-yl)acrylic acid) and (DBA-2) 5-((5-(4-(diphenylamino)phenyl)-1-hexyl-1H-indol-3-yl)methylene)pyrimidine-2,4,6(1H,3H,5H)-trione with D-D-A (donor-donor-acceptor) architecture. We have combined the strong electron donating triphenylamine group with indole moiety attached to different acceptors/anchoring groups, as co-adsorbers for dye-sensitized solar cells and we present for the first time, the role of anchoring/acceptor unit on their co-adsorption properties. In this study, cyanoacetic acid and barbituric acid are employed as anchoring groups in the co-sensitizers DBA-1 and DBA-2, respectively. Their electrochemical and photo-physical properties along with molecular geometries, obtained from Density Functional Theory (DFT) are employed to vindicate the effect of co-sensitizer structures on photovoltaic properties of DSSCs. We have demonstrated that the co-sensitization effect is profoundly dependent upon the anchoring/acceptor unit in the co-adsorber molecule. Devices co-sensitized using DBA-1 and DBA-2 along with HD-2 (Ru-complex of 4, 4'-bis-(1,4-benzodioxan-5-yl-vinyl)-[2,2']bipyridine), displayed higher power conversion efficiencies (PCEs) than the device sensitized using only HD-2. In the present work, ruthenium based sensitizer, HD-2, has been chosen due to its better solar-to-power conversion efficiency and impressively higher photocurrent densities than that of standard N719. Among them, co-adsorber DBA-2, containing barbituric acid as the acceptor/anchoring group displays promising photovoltaic results and exhibited an enhanced efficiency of 8.06%. Further, good agreement between the calculated and experimental results showcase the precision of the energy functional and basis set utilized in this study. All these findings provide a deeper insight and better understanding into the intricacies involved in the design of superior co-sensitizers for development of highly efficient DSSCs.}, journal={ELECTROCHIMICA ACTA}, author={Babu, Dickson D. and Su, Rui and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2016}, month={Apr}, pages={10–21} }
 @article{babu_elsherbiny_cheema_el-shafei_adhikari_2016, title={Highly efficient panchromatic dye-sensitized solar cells: Synergistic interaction of ruthenium sensitizer with novel co-sensitizers carrying different acceptor units}, volume={132}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84969544853&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2016.05.016}, abstractNote={Herein, we report the molecular design, synthesis and photovoltaic performance studies of three new organic co-sensitizers, N1-3 carrying indole and thiophene units linked to different acceptors/anchoring groups, as co-adsorbents for dye sensitized solar cells. We present the role of anchoring/acceptor units on co-sensitization properties N1-3. Their photo-physical and electrochemical results along with molecular geometry, obtained from Density Functional Theory are utilized to rationalize the influence of co-sensitizer structures on photovoltaic properties for DSSCs. We have shown that, the co-sensitization effect is profoundly dependent upon the anchoring/acceptor unit in the co-adsorbents. Among them, N3 containing 4-aminobenzoic acid shows promising co-sensitization results and exhibits an enhanced efficiency of 9.26%, when co-sensitized with a ruthenium dye, HD-14. Further, the study highlights the importance of molecular matching between the sensitizer and co-sensitizer in enhancing the efficiency. Furthermore, vertical electronic excitations are calculated using time dependent density functional theory studies.}, journal={DYES AND PIGMENTS}, author={Babu, Dickson D. and Elsherbiny, Dalia and Cheema, Hammad and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2016}, month={Sep}, pages={316–328} }
 @article{babu_su_el-shafei_adhikari_2016, title={New indole based co-sensitizers for dye sensitized solar cells exceeding 10% efficiency}, volume={6}, ISSN={["2046-2069"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84969494215&partnerID=MN8TOARS}, DOI={10.1039/c6ra03866b}, abstractNote={In this work, we report the molecular engineering and synthesis of three novel indole co-sensitizers DBA-3, DBA-4 and DBA-5 with D–D–A (donor–donor–acceptor) architecture.}, number={36}, journal={RSC ADVANCES}, author={Babu, Dickson D. and Su, Rui and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2016}, pages={30205–30216} }
 @article{ramamoorthy_helmy_rajbhandari_hauser_e-shafei_2016, title={Plasma Induced Graft Polymerization of Cationic and Fluorocarbon Monomers into Cotton: Enhanced Dyeability and Photostability}, volume={55}, ISSN={["0888-5885"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84981346577&partnerID=MN8TOARS}, DOI={10.1021/acs.iecr.6b01069}, abstractNote={The objective of this work was to increase color yield of direct dyes on cotton with the aid of grafted quaternary ammonium monomers. Plasma-induced graft polymerization of diallyldimethylammonium chloride (DADMAC) and [2-(acryloyloxy)ethyl]trimethylammonium chloride (AOETMAC) on cotton followed by dyeing with direct dyes was studied using different concentrations of the monomers and plasma conditions, and the color yield was evaluated using K/S measurements. Colorfastness and staining after laundering were evaluated using the standard grayscale. A significant increase of 149% in color yield was achieved when 30 g/L of DADMAC was used. 100–300% increase in K/S was achieved when ∼20 g/L of AOETMAC was used. To enhance the wash and lightfastness of the direct dyes on cotton, plasma-induced graft polymerization of 1,1,2,2-tetrahydroperfluorododecyl acrylate was achieved on the dyed cotton and showed considerable enhancement in both the wash and lightfastness.}, number={31}, journal={INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH}, author={Ramamoorthy, Amsarani and Helmy, Hany M. and Rajbhandari, Rajeev and Hauser, Peter and E-Shafei, Ahmed}, year={2016}, month={Aug}, pages={8501–8508} }
 @article{bondock_gieman_el-shafei_2016, title={Selective synthesis, structural studies and antitumor evaluation of some novel unsymmetrical 1-hetary1-4-(2-chloroquinolin-3-yl)azines}, volume={20}, ISSN={["2212-4640"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84961311822&partnerID=MN8TOARS}, DOI={10.1016/j.jscs.2015.01.005}, abstractNote={A series of novel unsymmetrical 1-hetaryl-4-(2-chloroquinolin-3-yl) azines 4–9 was selectively synthesized in a three-step procedure starting from acetanilide (1). The molecular structures of 4–9 were established by elemental analyses, spectral data, hybrid density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations. Molecular conformation analysis for compounds 4–9, performed using DFT calculations utilizing the energy functional 3-Parameter (Exchange), Lee, Yang and Parr (B3LYP) and the full-electron basis set Density Gauss double-zeta with polarization functions (DGDZVP), on the synthesized azines considering the torsion angles (θ1, θ2, θ3) revealed 8 plausible conformers for each compound. Electronic and thermodynamic properties including the dipole moment and the thermodynamic energy values of the Frontier occupied and virtual molecular orbitals, HOMO and LUMO, respectively, were calculated for the most stable conformer for each compound. Furthermore, TD-DFT calculations coupled with the polarizable conductor calculation model (PCM), performed on the most stable conformers in DMF to account for the solvent effect, revealed that the optical properties including λmax and oscillator strength performed on the most stable conformers were in excellent agreement with the experimental λmax and molar extinction coefficient, which clearly validate the most stable molecular conformers identified for compounds 4–9. Comparison of the biological results to the calculated electronic and thermodynamic properties showed that the cytotoxicity is dependent on the low-lying ELUMO because compound 8 has the lowest ELUMO value and exhibited the greatest antitumor activity.}, number={6}, journal={JOURNAL OF SAUDI CHEMICAL SOCIETY}, author={Bondock, Samir and Gieman, Hanaa and El-Shafei, Ahmed}, year={2016}, month={Nov}, pages={695–702} }
 @article{cheema_younts_ogbose_gautam_gundogdu_el-shafei_2015, title={A femtosecond study of the anomaly in electron injection for dye-sensitized solar cells: the influence of isomerization employing Ru(II) sensitizers with anthracene and phenanthrene ancillary ligands}, volume={17}, ISSN={["1463-9084"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84949117754&partnerID=MN8TOARS}, DOI={10.1039/c4cp04741a}, abstractNote={HD-7 is prone to ISC and shows a continuous increase in the triplet TA signal, whereas HD-8 shows enhanced singlet injection, followed by decay in the TA signal.}, number={4}, journal={PHYSICAL CHEMISTRY CHEMICAL PHYSICS}, author={Cheema, Hammad and Younts, Robert and Ogbose, Louis and Gautam, Bhoj and Gundogdu, Kenan and El-Shafei, Ahmed}, year={2015}, month={Jan}, pages={2750–2756} }
 @article{dong_wu_el-shafei_xia_xi_ning_jiao_hou_2015, title={Ag-encapsulated Au plasmonic nanorods for enhanced dye-sensitized solar cell performance}, volume={3}, ISSN={["2050-7496"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84923091881&partnerID=MN8TOARS}, DOI={10.1039/c4ta05154h}, abstractNote={In this article, Ag-encapsulated Au nanorods (Au@Ag NRs) are prepared and introduced into dye-sensitized solar cells (DSSCs).}, number={8}, journal={JOURNAL OF MATERIALS CHEMISTRY A}, author={Dong, Hua and Wu, Zhaoxin and El-Shafei, Ahmed and Xia, Bin and Xi, Jun and Ning, Shuya and Jiao, Bo and Hou, Xun}, year={2015}, pages={4659–4668} }
 @article{el-shafei_hinks_boyle_freeman_2015, title={Characterization of non-genotoxic diarylides using experimental and molecular orbital methods}, volume={121}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84930664076&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2015.04.036}, abstractNote={The synthesis of colorants from non-genotoxic benzidine analogs such as 3,3′-dipropoxybenzidine and 2,2′-dimethyl-5,5ʹ-dipropoxybenzidine led to diarylides having atypical physical and chemical properties. For instance, the products obtained from coupling these diamines with acetoacetanilide and acetoacet-p-chloroanilide produced diarylides behaving more like dyes than pigments and thus had significantly lower photostability. In addition, unlike the well-known and widely used commercial diarylide pigments (e.g. CI Pigment Yellow 12) the present compounds had solubility, albeit low, in CHCl3 and CH2Cl2. To account for these observations, the diarylides in our study were characterized using single crystal X-ray crystallography whereupon it was found that they possess varying levels of twist about the biphenyl moiety, impacting the way they pack in the crystal state. The visible spectra for the diarylides were measured in the solid state and in solution, and a 12 nm higher λmax was observed in the solid state for the diarylide derived from 3,3′-dipropoxybenzidine and acetoacetanilde. To account for this λmax change, molecular conformations were probed by 2D dynamic VT-NMR (25–60 °C) in solution using homonuclear 2D-NMR (COSY, COSY-LR, and ROESY), which revealed a single conformation with a torsion angle (θ) across the biphenyl linkage of 56° in solution. The correlation of these results with λmax values for this system is presented.}, journal={DYES AND PIGMENTS}, author={El-Shafei, Ahmed and Hinks, David and Boyle, Paul D. and Freeman, Harold S.}, year={2015}, month={Oct}, pages={128–137} }
 @article{el-shafei_elshemy_abou-okeil_2015, title={Eco-friendly finishing agent for cotton fabrics to improve flame retardant and antibacterial properties}, volume={118}, ISSN={0144-8617}, url={http://dx.doi.org/10.1016/J.CARBPOL.2014.11.007}, DOI={10.1016/J.CARBPOL.2014.11.007}, abstractNote={This research work deals with flame retardant and antibacterial finishing agent for cellulosic fabrics using TiO2 nanoparticles and chitosan phosphate. TiO2 nanoparticles were prepared by sol–gel method using titanium tetraisopropoxide. The size of TiO2 nanoparticles was characterized using transmission electron microscope (TEM). The application of nano TiO2 onto cellulosic fabrics (cotton 100%) was achieved in presence of polycarboxylic acid [1,2,3,4-butane tetracarboxylic acid (BTCA)] with sodium hypophosphite (SHP) as catalyst and chitosan phosphate through conventional pad-dry-cure method. The effect of the finishing on the physical properties, flammability and antibacterial properties of cross-linked fabrics are investigated. Thermal gravimetric analysis (TGA) was employed to investigate the thermal decomposition behaviour of the treated samples. Limited oxygen indexes (LOI) of the treated cotton fabrics were investigated. The treated cotton fabric also reveals excellent antibacterial properties.}, journal={Carbohydrate Polymers}, publisher={Elsevier BV}, author={El-Shafei, A. and ElShemy, M. and Abou-Okeil, A.}, year={2015}, month={Mar}, pages={83–90} }
 @article{babu_cheema_elsherbiny_el-shafei_adhikari_2015, title={Molecular Engineering and Theoretical Investigation of Novel Metal-Free Organic Chromophores for Dye-Sensitized Solar Cells}, volume={176}, ISSN={["1873-3859"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84938295841&partnerID=MN8TOARS}, DOI={10.1016/j.electacta.2015.07.079}, abstractNote={In this work we report design and synthesis of three new metal free D-D–A–π–A type dyes (E1-3) with different acceptor/anchoring groups, as effective sensitizers for nanocrystalline titanium dioxide based dye sensitized solar cells. All the three dyes carry electron donating methoxy group as an auxiliary and indole as a principal donor, cyanovinylene as an auxiliary acceptor and thiophene as a π-spacer. Whereas, cyanoacetic acid, rhodanine-3-acetic acid and 4-aminobenzoic acid perform as acceptor/anchoring moieties, respectively in the dyes E1-3. Though the dye containing 4-aminobenzoic acid unit (E3) exhibits comparatively lower λmax, it shows the highest power conversion efficiency arising from the higher electron life time and good light-harvesting capability. The DFT studies reveal a better charge separation between the HOMO and LUMO levels of E3, further substantiating the experimental results. Among the three dyes, E3 shows the best photovoltaic performance with short-circuit current density (Jsc) of 9.35 mA cm−2, open-circuit voltage (Voc) of 620 mV and fill factor (FF) of 0.71, corresponding to an overall conversion efficiency of 4.12% under standard global AM 1.5G.}, journal={ELECTROCHIMICA ACTA}, author={Babu, Dickson D. and Cheema, Hammad and Elsherbiny, Dalia and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2015}, month={Sep}, pages={868–879} }
 @article{cheema_islam_han_el-shafei_2015, title={Monodentate pyrazole as a replacement of labile NCS for Ru (II) photosensitizers: Minimum electron injection free energy for dye-sensitized solar cells}, volume={120}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84928481607&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2015.04.005}, abstractNote={A mono-dentate ligand of 3-(trifluoromethyl) pyrazole, instead of the labile isothiocyanate ligand for Ru (II) photosensitizers, was developed. This molecular modulation resulted in a new structure motif (HD-11) with 50 nm red shift in the low energy metal-to-ligand charge transfer (MLCT) absorption peak. However, electrochemical measurements revealed that both ground and excited state oxidation potentials were stabilized, we attributed this to the presence of strong electron withdrawing group CF3 tethered to pyrazole, which resulted in more free energy for dye regeneration (−ΔGregenration), but less driving force for electron injection (less −ΔGinjection) into the conduction band of TiO2. Hence HD-11, resulted in lower Jsc of 12.89 mA cm−2 compared to 17.07 mA cm−2 of N719 under similar conditions. Additionally, Voc of HD-11 was lower than N719, owing to decreased eTiO2 life time of 0.674 ms compared to 8.8 ms of N719 for injected electrons as found by impedance measurements.}, journal={DYES AND PIGMENTS}, author={Cheema, Hammad and Islam, Ashraful and Han, Liyuan and El-Shafei, Ahmed}, year={2015}, month={Sep}, pages={93–98} }
 @article{el-shafei_helmy_ramamoorthy_hauser_2015, title={Nanolayer atmospheric pressure plasma graft polymerization of durable repellent finishes on cotton}, volume={12}, ISSN={["1935-3804"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84933672111&partnerID=MN8TOARS}, DOI={10.1007/s11998-015-9665-4}, number={4}, journal={JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH}, author={El-Shafei, Ahmed and Helmy, Hany and Ramamoorthy, Amsarani and Hauser, Peter}, year={2015}, month={Jul}, pages={681–691} }
 @article{edwards_hauser_el-shafei_2015, title={Nonflammable cellulosic substrates by application of novel radiation-curable flame retardant monomers derived from cyclotriphosphazene}, volume={22}, ISSN={["1572-882X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84925506336&partnerID=MN8TOARS}, DOI={10.1007/s10570-014-0497-7}, number={1}, journal={CELLULOSE}, author={Edwards, Brian and Hauser, Peter and El-Shafei, Ahmed}, year={2015}, month={Feb}, pages={275–287} }
 @article{tambe_di_zhang_bernacki_el-shafei_king_2015, title={Novel genipin-collagen immobilization of polylactic acid (PLA) fibers for use as tissue engineering scaffolds}, volume={103}, ISSN={["1552-4981"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84937440015&partnerID=MN8TOARS}, DOI={10.1002/jbm.b.33285}, abstractNote={Abstract}, number={6}, journal={JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS}, author={Tambe, Nisarg and Di, Jin and Zhang, Ze and Bernacki, Susan and El-Shafei, Ahmed and King, Martin W.}, year={2015}, month={Aug}, pages={1188–1197} }
 @inproceedings{cheema_yildrim_arangdad_burk_cleven_detwiler_shamey_pasquinelli_freeman_el-shafei_2015, title={Photo-aging of modified PET-based model compounds}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84970005964&partnerID=MN8TOARS}, booktitle={Fiber Society 2015 Fall Meeting and Technical Conference - Fibers: Where Tradition Meets Innovation}, author={Cheema, H. and Yildrim, E. and Arangdad, K. and Burk, C. and Cleven, C. and Detwiler, A. and Shamey, R. and Pasquinelli, M. and Freeman, H. and El-Shafei, A.}, year={2015} }
 @article{edwards_rudolf_hauser_el-shafei_2015, title={Preparation, Polymerization, and Performance Evaluation of Halogen-Free Radiation Curable Flame Retardant Monomers for Cotton Substrates}, volume={54}, ISSN={["0888-5885"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84921675306&partnerID=MN8TOARS}, DOI={10.1021/ie502915t}, abstractNote={Three halogen-free, phosphorus-based flame retardant monomers were synthesized with good yields and characterized using FT-IR, 1H NMR, and 31P NMR. Two of the monomers were novel phosphoramides and the third was derived from cyclotriphosphazene. Each monomer was coated onto cotton substrates with the aid of a UV flood curing system. The impacts of monomer concentration, photoinitiator concentration, UV exposure time and proximity of the specimen to the UV lamp on coating yield were evaluated by experiments designed with JMP Pro 10. Of the three monomers, the cyclotriphosphazene derivative was polymerized into a coating that was durable to Soxhlet extraction with acetone. Vertical burn testing showed that all three monomers are valuable flame retardants. These results agreed with thermogravimetric analysis findings that demonstrated quantitatively the effectiveness of each monomer at promoting char formation. For the cyclotriphosphazene derivative, the coating was easily visualized covering significant por...}, number={2}, journal={INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH}, author={Edwards, Brian and Rudolf, Stacy and Hauser, Peter and El-Shafei, Ahmed}, year={2015}, month={Jan}, pages={577–584} }
 @article{cheema_ogbose_el-shafei_2015, title={Structure-property relationships: Steric effect in ancillary ligand and how it influences photocurrent and photovoltage in dye-sensitized solar cells}, volume={113}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84906735583&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2014.08.005}, abstractNote={Here we report structure–property relationships of naphthalene-based ancillary ligands for DSCs employing Ru (II) bipyridyl complexes containing methoxy at 4,7-positions (HL-41) and ethoxy at 2-position (HL-42) on the naphthalene moiety respectively. 2-ethoxy naphthalene stilbazole-based ligand was strategically chosen as an ancillary ligand to ascertain the influence of steric effect of alkoxy group ortho to the spacer group (CHCH) of stilbazole on the photovoltaic properties. It was found that under similar conditions photocurrent response was in the following order HL-41 > HL-42 > N719. Both HL-41 and HL-42 showed similar redox potential. The overall conversion efficiency for devices employing HL-41, HL-42 and N719 were 7.8%, 7.6% and 7.6%, respectively. DFT calculations showed that the torsion angles between the naphthyl moiety and CHCH spacer was 34.81° and 39° for HL-41 and HL-42, respectively. Thus, for HL-42 ethoxy ortho to CHCH produces more twisted naphthyl which precludes efficient charge transfer from the ancillary ligand to the metal.}, journal={DYES AND PIGMENTS}, author={Cheema, Hammad and Ogbose, Louis and El-Shafei, Ahmed}, year={2015}, month={Feb}, pages={151–159} }
 @article{el-sherbiny_cheema_el-essawy_abdel-megied_el-shafei_2015, title={Synthesis and characterization of novel carbazole-based terpyridyl photosensitizers for dye-sensitized solar cells (DSSCs)}, volume={115}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84922373450&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2014.12.009}, abstractNote={Two novel terpyridyl-based Ru(II) complexes, DH-1 and DH-2, were synthesized and characterized as photosensitizers for dye-sensitized solar cells. To enhance the thermal and photostability, a strong electron donor bidentate carbazole-based ancillary ligand was molecularly engineered and used to replace two monodentate labile isothiocyanates. Photovoltaic characterizations, I–V curve and IPCE, of DH-1 and DH-2 were carried out in presence of deoxycholic acid as an additive to determine the best device working conditions. DH-1 showed IPCE of 45% at 540 nm, short circuit photocurrent density (Jsc) of 11.69 mA cm−2, open circuit photovoltage (Voc) of 0.64 V, fill factor of 0.63, producing an overall conversion efficiency (η) of 4.68%, where DH-2 showed IPCE of 45% at 540 nm, Jsc of 10.90 mA cm−2, Voc of 0.59 V and FF of 0.59, which translated into η of 3.82%. DFT calculations rationalized the light harvesting efficiency and charge separation of why DH-1 > DH-2.}, journal={DYES AND PIGMENTS}, author={El-Sherbiny, Dalia and Cheema, Hammad and El-Essawy, Farag and Abdel-Megied, Ahmed and El-Shafei, Ahmed}, year={2015}, month={Apr}, pages={81–87} }
 @article{fadda_el-mekawy_el-shafei_2015, title={Synthesis, antiviral, cytotoxicity and antitumor evaluations of A(4) type of porphyrin derivatives}, volume={19}, ISSN={["1099-1409"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84944514276&partnerID=MN8TOARS}, DOI={10.1142/s1088424615500480}, abstractNote={ This manuscript describes the synthesis of a new series of porphyrin structures 4a–4m, 7, 9, 12 and 14. These structures were investigated against two types of viruses such as HIV-1 and HSV-1. Also they were screened for their antitumor activity. Among all tested compounds, it was found that compound 4b showed a high activity against HIV-1 and HSV-1 and against four different tumor cell lines. Most of the tested compounds showed a moderate degree of a potent antimicrobial activity. The structure of these compounds was confirmed on the basis of their analytical and spectral data such as UV-vis, IR, 13 C NMR, 1 H NMR spectroscopy and mass spectral data. }, number={6}, journal={JOURNAL OF PORPHYRINS AND PHTHALOCYANINES}, author={Fadda, Ahmed A. and El-Mekawy, Rasha E. and El-Shafei, Ahmed I.}, year={2015}, month={Jun}, pages={753–768} }
 @article{hussain_islam_bedja_gupta_han_el-shafei_2014, title={A comparative study of Ru(II) cyclometallated complexes versus thiocyanated heteroleptic complexes: thermodynamic force for efficient dye regeneration in dye-sensitized solar cells and how low could it be?}, volume={16}, ISSN={["1463-9084"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84903529744&partnerID=MN8TOARS}, DOI={10.1039/c4cp00907j}, abstractNote={Although cyclometallation may produce significantly better light harvesting, a driving force <0.25 eV is not sufficient for effective dye regeneration in DSSCs.}, number={28}, journal={PHYSICAL CHEMISTRY CHEMICAL PHYSICS}, author={Hussain, Maqbool and Islam, Ashraful and Bedja, Idriss and Gupta, Ravindra Kumar and Han, Liyuan and El-Shafei, Ahmed}, year={2014}, pages={14874–14881} }
 @misc{dong_wu_gao_el-shafei_jiao_dai_hou_2014, title={A nanostructure-based counter electrode for dye-sensitized solar cells by assembly of silver nanoparticles}, volume={15}, ISSN={["1878-5530"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84901931261&partnerID=MN8TOARS}, DOI={10.1016/j.orgel.2014.03.004}, abstractNote={A nanostructure-based Pt counter electrode for dye-sensitized solar cells (DSSCs) is fabricated by assembly of silver nanoparticles on glass substrate and deposition of a thin Pt layer. This typical counter electrode has several unique behaviors such as good conductivity, quasi-uniform undulating morphology and high surface area. Studies indicate that the application of the FTO-free nanostructure-based Pt counter electrode in DSSCs can decrease the charge-transfer resistance of the Pt/electrolyte interface, enlarge the light pathway and enhance the light reabsorption superior to the devices with planar Pt counter electrode. In addition, theoretical analysis and experimental study demonstrate that the hot electrons injection effect caused by Localized Surface Plasmon Resonance effect of silver nanoparticles enhances the charge transport characteristic at the Pt/electrolyte interface, and this SPR effect makes the certain contributions on the enhancement of the photovoltaic performance of DSSCs. Compared to the DSSC with traditional planar counter electrode, the incident photon-to-current conversion efficiency, short-circuit current, and power conversion efficiency of DSSCs with nanoparticulate structure are increased by 1.117 times, 1.156 times, and 1.145 times, respectively; and the final power conversion efficiency (PCE) increases from 6.95% to 7.96%.}, number={7}, journal={ORGANIC ELECTRONICS}, author={Dong, Hua and Wu, Zhaoxin and Gao, Yucui and El-Shafei, Ahmed and Jiao, Bo and Dai, Yang and Hou, Xun}, year={2014}, month={Jul}, pages={1641–1649} }
 @article{cheema_islam_han_el-shafei_2014, title={Influence of Number of Benzodioxan-Stilbazole-based Ancillary Ligands on Dye Packing, Photovoltage and Photocurrent in Dye-Sensitized Solar Cells}, volume={6}, ISSN={["1944-8252"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84905002608&partnerID=MN8TOARS}, DOI={10.1021/am502400b}, abstractNote={Two novel heteroleptic Ru(II) bipyridyl complexes, HD-2 and HD-2-mono, were molecularly engineered, synthesized and characterized for dye-sensitized solar cells (DSCs). The influences of mono versus bis electron-donor benzodioxan ancillary ligands on optical, dye packing, electrochemical and photovoltaic properties were examined and compared to the benchmark N719. HD-2 and HD-2-mono achieved solar-to-power conversion efficiencies (%η) of 9.64 and 9.50, respectively, compared to 9.32 for N719 under the same experimental device conditions. Optical results showed that HD-2 and HD-2-mono have much higher molar extinction coefficients, longer excited state lifetimes and narrower HOMO-LUMO gaps compared to N719. Although the molar extinction coefficient of HD-2-mono was 27% less than that of HD-2, it outperformed HD-2 in photovoltaic performance when anchored on TiO2, owing to better dye packing and loading of the former. Charge recombination at the dye/TiO2 interface by impedance spectroscopy analysis showed that the recombination resistance and the lifetime of injected electron in TiO2 conduction band is directly proportional to the open-circuit voltage (Voc) observed. Furthermore, compared to HD-2 and HD-2-mono, the greater Voc of N719 can be attributed to the greater negative free energy for dye regeneration. Both HD-2 and HD-mono have almost the same negative free energy, which explains why they achieved almost the same Voc. Decay dynamic analysis for solar devices fabricated from the named dyes, by time correlated single photon counting (TCSPC), elucidated that the lowest excited state decay lifetime for HD-2-mono, HD-2 and N719 are 3, 10 and 20 ps, respectively. The shorter the decay lifetime, the less kinetic redundancy, which leads to better photocurrent, and that explanation is consistent with the measured photocurrent and total solar-to-power conversion efficiency of the named dyes in the order of HD-2-mono > HD-2 > N719.}, number={14}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Cheema, Hammad and Islam, Ashraful and Han, Liyuan and El-Shafei, Ahmed}, year={2014}, month={Jul}, pages={11617–11624} }
 @article{cheema_islam_han_gautam_younts_gundogdu_el-shafei_2014, title={Influence of mono versus bis-electron-donor ancillary ligands in heteroleptic Ru(II) bipyridyl complexes on electron injection from the first excited singlet and triplet states in dye-sensitized solar cells}, volume={2}, ISSN={["2050-7496"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84905571530&partnerID=MN8TOARS}, DOI={10.1039/c4ta01942c}, abstractNote={A novel Ru(ii) bipyridyl complex was designed for DSCs.}, number={34}, journal={JOURNAL OF MATERIALS CHEMISTRY A}, author={Cheema, Hammad and Islam, Ashraful and Han, Liyuan and Gautam, Bhoj and Younts, Robert and Gundogdu, Kenan and El-Shafei, Ahmed}, year={2014}, pages={14228–14235} }
 @article{qin_mirloup_leclerc_islam_el-shafei_han_ziessel_2014, title={Molecular Engineering of New Thienyl-Bodipy Dyes for Highly Efficient Panchromatic Sensitized Solar Cells}, volume={4}, ISSN={["1614-6840"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84905741050&partnerID=MN8TOARS}, DOI={10.1002/aenm.201400085}, abstractNote={Dr. C. Qin, Dr. A. Islam, Dr. L. Han Photovoltaic Materials Unit National Institute for Materials Science Sengen 1–2–1 , Tsukuba, Ibaraki 305–0047 , Japan E-mail: Islam.Ashraful@nims.go.jp A. Mirloup, Dr. R. Ziessel Laboratoire de Chimie Moléculaire et Spectroscopies Avancées (ICPEES-LCOSA) UMR 7515 au CNRS, Ecole Européenne de Chimie Polymères et Matériaux 25 rue Becquerel , 67087 , Strasbourg Cedex 02 , France E-mail: ziessel@unistra.fr Dr. N. Leclerc Institut de Chimie et Procédés pour l’Energie l’Environnement et la Santé (ICPEES) Université de Strasbourg, Ecole Européenne de Chimie Polymères et Matériaux 25 rue Becquerel , 67087 Strasbourg , France Dr. A. El-Shafei Polymer and Color Chemistry Program North Carolina State University Raleigh , NC 27695 , USA}, number={11}, journal={ADVANCED ENERGY MATERIALS}, author={Qin, Chuanjiang and Mirloup, Antoine and Leclerc, Nicolas and Islam, Ashraful and El-Shafei, Ahmed and Han, Liyuan and Ziessel, Raymond}, year={2014}, month={Aug} }
 @article{cheema_islam_younts_gautam_bedja_gupta_han_gundogdu_el-shafei_2014, title={More stable and more efficient alternatives of Z-907: carbazole-based amphiphilic Ru(II) sensitizers for dye-sensitized solar cells}, volume={16}, ISSN={["1463-9084"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84911879802&partnerID=MN8TOARS}, DOI={10.1039/c4cp04120h}, abstractNote={Here we report two novel amphiphilic Ru(ii) heteroleptic bipyridyl complexes, HD-14 and HD-15, compared to previously reported NCSU-10.}, number={48}, journal={PHYSICAL CHEMISTRY CHEMICAL PHYSICS}, author={Cheema, Hammad and Islam, Ashraful and Younts, Robert and Gautam, Bhoj and Bedja, Idriss and Gupta, Ravindra Kumar and Han, Liyuan and Gundogdu, Kenan and El-Shafei, Ahmed}, year={2014}, pages={27078–27087} }
 @article{dong_calzolari_felice_el-shafei_hussain_nardelli_2014, title={Optical Enhancement in Heteroleptic Ru(II) Polypyridyl Complexes Using Electron-Donor Ancillary Ligands}, volume={118}, ISSN={["1932-7455"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84899829963&partnerID=MN8TOARS}, DOI={10.1021/jp409733a}, abstractNote={Organic dyes are a viable alternative to silicon for energy conversion. Using simulations from first-principles, we show that chemical manipulation is a powerful tool for tuning the optical absorption spectra of a special class of dyes in a way that is convenient for exploitation in dye-sensitized solar cells. Specifically, we have carried out density functional theory calculations on three Ru(II) polypyridyl complexes with electron-donor ancillary ligands. These complexes were recently developed to study how different electron-donor ancillary ligands affect the photophysical and electrochemical properties of these dyes for light harvesting and photon-to-electron conversion efficiency. We found that the electron-donor ancillary ligands significantly enhance the light harvesting in the visible and the near-infrared regions relative to the reference dye N3. Furthermore, we detected a decrease in the ionization potential, which improves the energy alignment with the redox potentials of the electrolyte. These...}, number={17}, journal={JOURNAL OF PHYSICAL CHEMISTRY C}, author={Dong, Rui and Calzolari, Arrigo and Felice, Rosa and El-Shafei, Ahmed and Hussain, Maqbool and Nardelli, Marco Buongiorno}, year={2014}, month={May}, pages={8747–8755} }
 @article{dong_wu_lu_gao_el-shafei_jiao_ning_hou_2014, title={Optics-electrics highways: Plasmonic silver nanowires@TiO2 core-shell nanocomposites for enhanced dye-sensitized solar cells performance}, volume={10}, ISSN={["2211-3282"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84907992670&partnerID=MN8TOARS}, DOI={10.1016/j.nanoen.2014.09.011}, abstractNote={In this article, the unique bristled silver [email protected]2 core–shell nanostructure ([email protected]2) is introduced into the TiO2 photoanode and applied to assemble dye-sensitized solar cells (DSSCs). The effects of the “optics–electrics highways” composites on the photovoltaic and photocatalytic behaviors of DSSCs are investigated in detail. Experiment research and FDTD simulation indicate that both the localized surface plasmon resonance (LSPR) and plasmonic waveguide effect could enhance light harvesting efficiency. By electrical properties and electrochemical analysis, it is demonstrated that the [email protected]2 significantly accelerates electron transport as well as reduces recombination, then the charge collection efficiency of DSSCs is improved. The composite-modified DSSC exhibits the best performance with the power conversion efficiency of 8.84% which is superior to that of the free–modified DSSC with the PCE of 6.16%.}, journal={NANO ENERGY}, author={Dong, Hua and Wu, Zhaoxin and Lu, Fan and Gao, Yucui and El-Shafei, Ahmed and Jiao, Bo and Ning, Shuya and Hou, Xun}, year={2014}, month={Nov}, pages={181–191} }
 @article{dong_wu_gao_el-shafei_ning_xi_jiao_hou_2014, title={Silver-loaded anatase nanotubes dispersed plasmonic composite photoanode for dye-sensitized solar cells}, volume={15}, ISSN={["1878-5530"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84907224937&partnerID=MN8TOARS}, DOI={10.1016/j.orgel.2014.08.020}, abstractNote={In this article, a typical silver-loaded anatase TiO2 nanotube (Ag-TNTs) was developed and assembled in DSSCs. By blending the Ag-TNTs and TiO2 nanoparticles as the composite photoanode, this hybrid nanostructure exhibits a promising architecture for accelerating electron transport as well as enhancing dye adsorption. These nanotubes could provide direct charge transfer pathways and increase electrolyte penetration in comparison with the TiO2 nanoparticles alone network. Moreover, the presence of the Ag nanoparticles could enhance the light harvesting efficiency and promote the charge separation, which further improves the performance of the DSSCs. The DSSC with metal-modified hybrid nanostructures has achieved an efficiency of 8.19% which is about 56% higher than DSSCs based on TiO2 nanoparticles photoanode with 5.26%.}, number={11}, journal={ORGANIC ELECTRONICS}, author={Dong, Hua and Wu, Zhaoxin and Gao, Yucui and El-Shafei, Ahmed and Ning, ShuYa and Xi, Jun and Jiao, Bo and Hou, Xun}, year={2014}, month={Nov}, pages={2847–2854} }
 @article{el-shafei_hussain_islam_han_2014, title={Structure-property relationship of hetero-aromatic-electron-donor antennas of polypyridyl Ru (II) complexes for high efficiency dye-sensitized solar cells}, volume={22}, ISSN={["1099-159X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84906283126&partnerID=MN8TOARS}, DOI={10.1002/pip.2349}, abstractNote={ABSTRACT}, number={9}, journal={PROGRESS IN PHOTOVOLTAICS}, author={El-Shafei, Ahmed and Hussain, Maqbool and Islam, Ashraful and Han, Liyuan}, year={2014}, month={Sep}, pages={958–969} }
 @article{mazloumpour_malshe_el-shafei_hauser_2013, title={Conferring durable antimicrobial properties on nonwoven polypropylene via plasma-assisted graft polymerization of DADMAC}, volume={224}, ISSN={["0257-8972"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84876729566&partnerID=MN8TOARS}, DOI={10.1016/j.surfcoat.2013.02.022}, abstractNote={Spunbond nonwoven polypropylene (SB-PP), commonly used for hygienic products, was treated with diallyldimethylammonium chloride (DADMAC) to confer antimicrobial properties. Atmospheric pressure glow discharge plasma was used to induce free radical chain growth polymerization of DADMAC monomer onto the SB-PP in the presence of a crosslinker, which produced a graft polymerized network on the fabric with durable antimicrobial properties. The effects of different DADMAC concentrations and plasma operating condition parameters including the RF power (400–800 W) and the time of plasma exposure (0–120 s) were studied and the optimum treatment conditions were identified by determining the surface charge density on the treated fabrics. The presence of grafted poly-DADMAC on the polypropylene surface was confirmed using SEM, FT-IR and TOF-SIMS techniques. Antibacterial performance was investigated using the AATCC Test Method 100 for both gram positive and gram negative bacteria, and the antimicrobial test results showed 6 log reductions in the number of bacterial activities of Klebsiella pneumoniae and Staphylococcus aureus on the SB-PP samples, which is unprecedented.}, journal={SURFACE & COATINGS TECHNOLOGY}, author={Mazloumpour, Maryam and Malshe, Priya and El-Shafei, Ahmed and Hauser, Peter}, year={2013}, month={Jun}, pages={1–7} }
 @article{cheema_el-shafei_hauser_2013, title={Conferring flame retardancy on cotton using novel halogen-free flame retardant bifunctional monomers: synthesis, characterizations and applications}, volume={92}, ISSN={0144-8617}, url={http://dx.doi.org/10.1016/j.carbpol.2012.09.081}, DOI={10.1016/j.carbpol.2012.09.081}, abstractNote={Two novel halogen-free phosphorous-nitrogen flame retardant bifunctional monomers were synthesized and characterized using attenuated total reflectance/Fourier transform-infrared (ATR/FT-IR) and electrospray ionization mass spectrometry ((+)ESI-MS). The monomers were applied separately and graft polymerized on cotton in the presence of the thermal initiator K(2)S(2)O(8). The performance of each monomer was evaluated using thermal gravimetric analysis (TGA), grafting efficiency, and vertical flame test. It was shown that the performance of N,N-dimethyl di(acryloyloxyethyl)phosphoramide (DMDAEP) (monomer 2) as flame retardant outperformed that of ethyl di(acryloyloxyethyl)phosphorodiamidate (EDAEP) (monomer 1). The superior performance of DMDAEP was attributed to the presence of more nitrogen atoms compared to EDAEP. The increased nitrogen content in DMDAEP increased the synergistic effect of the P-N system. Cotton treated using padding methods showed more promising results than cotton treated by exhaust methods.}, number={1}, journal={Carbohydrate Polymers}, publisher={Elsevier BV}, author={Cheema, Hammad A. and El-Shafei, Ahmed and Hauser, Peter J.}, year={2013}, month={Jan}, pages={885–893} }
 @article{fadda_el-mekawy_el-shafei_freeman_hinks_el-fedawy_2013, title={Design, Synthesis, and Pharmacological Screening of Novel Porphyrin Derivatives}, volume={2013}, ISSN={["2090-9071"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84874820709&partnerID=MN8TOARS}, DOI={10.1155/2013/340230}, abstractNote={A series of porphyrin derivatives 2a–f was synthesized, namely, 5,10,15,20-mesotetrakis[p-methoxyphenyl]-21H,23H-porphyrin (2a), 5,10,15,20-mesotetrakis[2,6-dichloro-phenyl]-21H,23H-porphyrin (2b), 5,10,15,20-mesotetrakis[4-hydroxy-3,5-dimethoxyphenyl]-21H,23H-porphyrin (2c), 5,10,15,20-mesotetrakis[3,4-dimethoxyphenyl]-21H,23H-porphyrin (2d), 5,10,15,20-mesotetrakis[2,4-dichlorophenyl]-21H,23H-porphyrin (2e), and 5,10,15,20-mesotetrakis[3,4,5-trimethoxyphenyl]-21H,23H-porphyrin (2f), in high yields using a new method via a capping mechanism. These dyes were used as a model to study the free radical-induced damage of biological membranes and the protective effects of these porphyrins. It was demonstrated that these dyes were effective in the inhibition of the free radical-induced oxidative haemolysis of rat blood cells. Dyes 2d and 2f which bear methoxy functionality exhibited markedly higher antihaemolysis activity than the other analogs. Molecular modeling methods using ZINDO/INDO-1, with a configuration interaction of 26, and TD-DFT using the energy functional B3LYP and the basis set DGTZVP were used to study the vertical electronic excitations of porphyrins 2a–f and it was shown that the calculated using TD-DFT method was in excellent agreement with the experimental results, while the ZINDO method was inferior. Moreover, excellent correlation between the LUMO energy and cytotoxicity of dyes 2a–f was found.}, journal={JOURNAL OF CHEMISTRY}, author={Fadda, Ahmed A. and El-Mekawy, Rasha E. and El-Shafei, Ahmed and Freeman, Harold S. and Hinks, David and El-Fedawy, Andmanal}, year={2013} }
 @article{el-shafei_islam_akhtaruzzaman_2013, title={Functional Dyes}, volume={2013}, ISSN={["2090-9071"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84897785813&partnerID=MN8TOARS}, DOI={10.1155/2013/828910}, journal={JOURNAL OF CHEMISTRY}, author={El-Shafei, Ahmed and Islam, Ashraful and Akhtaruzzaman, Md.}, year={2013} }
 @article{el-shafei_hussain_islam_han_2013, title={Influence of cyclic versus acyclic oxygen-containing electron donor ancillary ligands on the photocurrent, photovoltage and photostability for high efficiency dye-sensitized solar cells}, volume={1}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84886923554&partnerID=MN8TOARS}, DOI={10.1039/c3ta12748f}, abstractNote={Three novel heteroleptic amphiphilic polypyridyl Ru-complexes, MH01, MH03, and MH05, with oxygen-containing-electron-donor stilbazole-based ancillary ligands were synthesized to study the influence of the cyclic-electron-donor (MH01), the presence of the cyclic electron donor coupled to acyclic electron-donor auxochromes (MH03) ortho to the CHCH bridge of stilbazole, and the presence of only acyclic electron-donor methoxy group (MH05) on molar extinction coefficient, light harvesting efficiency (LHE), ground and excited state oxidation potentials, and photovoltaic performance for DSSCs. Although MH05 has three electron donor methoxy groups, it achieved the lowest molar extinction coefficient of 18 250 M−1 cm−1 and exhibited the lowest photocurrent. The highest photocurrent density (JSC) was observed for the longest interatomic distance between the CHCH bridge of the stilbazole moiety and cyclic-electron-donor auxochromes (MH01). It was also shown that while incorporation of acyclic electron-donor auxochromes ortho to the CHCH bridge (MH03) has little effect on the ground and excited state oxidation potentials, λmax of the low energy MLCT, and molar absorptivity, the lowest photovoltage and %η were observed. When compared under the same experimental device conditions using 0.3 M tert-butylpyridine (TBP), only MH01-TBA achieved 18% more in JSC and 8.6% greater in η than the benchmark dye N719. To probe the interrelationship among the cyclic-vs.-acyclic oxygen-containing electron donors of the ancillary ligands, photocurrent and photovoltage of these dyes, the equilibrium molecular geometries of the ancillary ligands were calculated using DFT. The HOMO distribution on cyclic-vs.-acyclic electron donors and the position of OMe in the ancillary ligands rationalized the fundamental science behind the photovoltaic performance and photostability of these dyes.}, number={43}, journal={Journal of Materials Chemistry A}, author={El-Shafei, A. and Hussain, M. and Islam, A. and Han, L.}, year={2013}, pages={13679–13686} }
 @article{malshe_mazloumpour_el-shafei_hauser_2013, title={Multi-functional military textile: Plasma-induced graft polymerization of a C6 fluorocarbon for repellent treatment on nylon-cotton blend fabric}, volume={217}, ISSN={["0257-8972"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84873254605&partnerID=MN8TOARS}, DOI={10.1016/j.surfcoat.2012.11.081}, abstractNote={This paper reports preparation of a dual functional 50/50 nylon/cotton blend fabric (NyCo) with an anti-bacterial bulk and repellent front surface using atmospheric pressure glow discharge plasma. In this report, a C6 fluorocarbon monomer, 2-(perfluorohexyl)ethyl acrylate was graft polymerized using plasma on the front surface of a nylon–cotton fabric which was already grafted with polyDADMAC for anti-bacterial properties. The surface was characterized by Fourier-transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The presence of fluorine on the surface was mapped and confirmed by time-of-flight secondary ion mass spectroscopy (TOF-SIMS). Scanning electron microscopy (SEM) images showed a uniform layer of fluorocarbon polymer on the fiber surface. High water contact angle of 144° was obtained on the surface. The surface also achieved a high American Association of Textile Chemists and Colorists (AATCC) Test Method 193 rating of 8 and AATCC Test Method 118 rating of 5 indicating that the surface could repel a fluid with surface tension as low as 25 dyn/cm.}, journal={SURFACE & COATINGS TECHNOLOGY}, author={Malshe, Priya and Mazloumpour, Maryam and El-Shafei, Ahmed and Hauser, Peter}, year={2013}, month={Feb}, pages={112–118} }
 @article{ramamoorthy_el-shafei_hauser_2013, title={Plasma Induced Graft Polymerization of C6 Fluorocarbons on Cotton Fabrics for Sustainable Finishing Applications}, volume={10}, ISSN={["1612-8869"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84877275449&partnerID=MN8TOARS}, DOI={10.1002/ppap.201200111}, abstractNote={Abstract}, number={5}, journal={PLASMA PROCESSES AND POLYMERS}, author={Ramamoorthy, Amsarani and El-Shafei, Ahmed and Hauser, Peter}, year={2013}, month={May}, pages={430–443} }
 @article{wu_ma_liu_zhou_ning_el-shafei_zhao_hou_2013, title={Structure-Property Relationship of Amplified Spontaneous Emission in Organic Semiconductor Materials: TPD, DPABP, and NPB}, volume={117}, ISSN={["1089-5639"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84886635488&partnerID=MN8TOARS}, DOI={10.1021/jp405692c}, abstractNote={N,N'-Diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD) was demonstrated to be suitable for stimulated emission in doping and nondoping planar waveguide structure, but the mechanism for its lasing is of ambiguity. With the aim of providing a microsscopic picture for its lasing, we performed a combined experimental and theortical investigation of the absorption, photoluminescence (PL), and stimulated emission of TPD and other two similar molecules: 1,4-bis (diphenylamino)biphenyl (DPABP) and N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4″-diamine (NPB). It was found that DPABP shows the same amplified spontaneous emission (ASE) characteristics as TPD, but NPB did not. In theory, density functional theory (DFT) and Franck-Condon Principle were used to analyze the molecular geometry in the electronic ground state as well as the optically excited state and the vibrational levels in electronic ground state, respectively. The calculation results show that for TPD and DPABP, several strongly elongated high-frequency modes (1199-1664 cm(-1)) in the carbon rings contribute to the distinct first vibronic sideband in the PL spectra, which form an effective four-level system for lasing. For NPB, when the peripheral toluene or benzene is replaced with naphthyl, a number of strongly elongated low-frequency modes (11-689 cm(-1)) deriving from naphthyl leads to a series of energy sublevels, which destroys the four-level system. Our results provided a new insight and better understanding into the lasing of organic molecules.}, number={42}, journal={JOURNAL OF PHYSICAL CHEMISTRY A}, author={Wu, Zhaoxin and Ma, Lin and Liu, Peng and Zhou, Caihua and Ning, Shuya and El-Shafei, Ahmed and Zhao, Xiang and Hou, Xun}, year={2013}, month={Oct}, pages={10903–10911} }
 @article{akhtaruzzaman_menggenbateer_islam_el-shafei_asao_jin_han_alamry_kosa_asiri_et al._2013, title={Structure-property relationship of different electron donors: novel organic sensitizers based on fused dithienothiophene pi-conjugated linker for high efficiency dye-sensitized solar cells}, volume={69}, ISSN={["0040-4020"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84875232103&partnerID=MN8TOARS}, DOI={10.1016/j.tet.2013.02.058}, abstractNote={Three novel organic dyes, coded Ba-01–03, based on D–π–A building blocks were synthesized and characterized for dye-sensitized solar cells (DSCs) to study the influence of different electron donors on photocurrent and photovoltage. The electron donor of Ba-01 was based on N-methoxyphenylcarbazole and the electron donors for Ba-02 and Ba-03 were based on different indoline analogs. The photovoltaic performance of these sensitizers was characterized using incident-photon-to-current conversion efficiency (IPCE), photovoltage measurements, and total solar-to-electric conversion efficiency (η). It was shown that photovoltage of indoline donor based dye Ba-03 showed the highest efficiency of 6.38% compared to carbazole donor based dye of Ba-01. DFT calculations were proven to be an effective tool in the prediction of the vertical electronic excitation, charge separation, and photovoltage as it effectively predicted the delocalization and coefficient size of the HOMO and LUMO for Ba-01–03.}, number={16}, journal={TETRAHEDRON}, author={Akhtaruzzaman, Md. and Menggenbateer and Islam, Ashraful and El-Shafei, Ahmed and Asao, Naoki and Jin, Tienan and Han, Liyuan and Alamry, Khalid A. and Kosa, Samia A. and Asiri, Abdullah Mohamed and et al.}, year={2013}, month={Apr}, pages={3444–3450} }
 @article{hussain_el-shafei_islam_han_2013, title={Structure-property relationship of extended pi-conjugation of ancillary ligands with and without an electron donor of heteroleptic Ru(II) bipyridyl complexes for high efficiency dye-sensitized solar cells}, volume={15}, ISSN={["1463-9084"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84877693518&partnerID=MN8TOARS}, DOI={10.1039/c3cp51260f}, abstractNote={Two new heteroleptic Ru(II) bipyridyl complexes MH06 and MH11 were designed, synthesized and characterized for DSSCs. While the ancillary ligand of MH06 was molecularly engineered with a strong electron donating group coupled with an extended π-conjugated system, the ancillary ligand of MH11 contained a longer π-conjugated system only. Molecular modeling, photophysical, and photovoltaic properties were compared under the same experimental conditions against the benchmark N719. In an effort to understand the structure-property relationship, their photovoltaic and photoelectrochemical properties including Jsc, Voc, ground and excited state oxidation potentials, UV-Vis absorption, and molar extinction coefficients were studied. The UV-Vis results showed intense MLCT absorption peaks of MH06 and MH11 in the visible region with a red shift of 12 and 18 nm, respectively, with significantly higher molar extinction coefficients compared to N719. Tetrabutylammonium (TBA) substituted MH11-TBA demonstrated the most efficient IPCE of over 90% in the plateau region covering the entire visible spectrum and extending into the near IR region (ca. 890 nm), which showed a solar-to-power conversion efficiency (η) of 10.06%, significantly higher than that of the benchmark N719 dye (9.32%). The superior performance in terms of the IPCE and Jsc of MH11 can be attributed to the bulky and highly hydrophobic nature of the pyrene-based ancillary ligand, which behaves as a shielding barrier for hole-transport recombination between TiO2 and the electrolyte. In addition, the IMPS results showed that the contribution of dyes to the conduction band shift of the TiO2 level is almost similar, regardless of different substitutions on the bipy-moiety. This implies that the open-circuit photovoltage (Voc) increases with reduced charge recombination in the presence of a thick layer of tetrabutyl ammonium ions (TBA) of the dye anchored on the surface of TiO2.}, number={21}, journal={PHYSICAL CHEMISTRY CHEMICAL PHYSICS}, author={Hussain, Maqbool and El-Shafei, Ahmed and Islam, Ashraful and Han, Liyuan}, year={2013}, pages={8401–8408} }
 @article{fadda_el-mekawy_el-shafei_freeman_2013, title={Synthesis and Pharmacological Screening of Novel meso-Substituted Porphyrin Analogs}, volume={346}, ISSN={["0365-6233"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84872271916&partnerID=MN8TOARS}, DOI={10.1002/ardp.201200313}, abstractNote={Abstract}, number={1}, journal={ARCHIV DER PHARMAZIE}, author={Fadda, Ahmed A. and El-Mekawy, Rasha E. and El-Shafei, Ahmed I. and Freeman, Harold}, year={2013}, month={Jan}, pages={53–61} }
 @article{el-shafei_hussain_atiq_islam_han_2012, title={A novel carbazole-based dye outperformed the benchmark dye N719 for high efficiency dye-sensitized solar cells (DSSCs)}, volume={22}, ISSN={0959-9428 1364-5501}, url={http://dx.doi.org/10.1039/c2jm35267b}, DOI={10.1039/c2jm35267b}, abstractNote={Two novel high molar extinction coefficient heteroleptic Ru(II) isomers, NCSU-10 and NCSU-10′, based on carbazole antenna were synthesized with the aid of Knoevenagel reaction, to study the influence of the carbazole antenna and anchoring group (COOH) isomerization on the light harvesting efficiency (LHE), ground and excited state oxidation potentials, incident-photon-to-current conversion efficiency (IPCE), short-circuit photocurrent density (JSC), and total solar-to-electric conversion efficiency (η) for DSSCs, and their device performances were compared to the benchmark dye N719. The photophysical and photoelectrochemical properties discussed herein addressed the significant impact of the carbazole antenna and the position of the anchoring group on JSC and η in DSSCs. Tetrabutylammonium (TBA) substituted NCSU-10 achieved efficient sensitization of nanocrystalline TiO2 over the whole visible range, extending into the near IR region (ca. 870 nm) with an excellent power conversion efficiency (η) of 9.37% under an irradiation of full sunlight (100 mW cm−2) with mask compared to 8.17% of N719 under optimized conditions. NCSU-10 outperformed N719 by 45% in molar absorptivity, 18.8% in JSC, and 14.6% in the total conversion efficiency. Molecular modeling studies (DFT/TD-DFT) of NCSU-10 and NCSU-10′ showed that the HOMO is delocalized not only on Ru and NCS but also on the carbazole with a large coefficient, indicating that the second charge generation transfer in the visible region at ∼400 nm is a mixture of metal-to-ligand charge transfer (MLCT) and strong ligand–ligand charge transfer (LLCT) with a significant HOMO coefficient originating from the carbazole antenna (π) to the bipyridyl electron acceptor (π*). Moreover, DFT calculations showed that the 4,4′-isomer (NCSU-10) is a significantly stronger electron acceptor than the 5,5′-isomer (NCSU-10′), which explained the inferior electron injection and significantly lower JSC of the 5,5′-isomer.}, number={45}, journal={Journal of Materials Chemistry}, publisher={Royal Society of Chemistry (RSC)}, author={El-Shafei, Ahmed and Hussain, Maqbool and Atiq, Aasim and Islam, Ashraful and Han, Liyuan}, year={2012}, pages={24048} }
 @article{xu_shamey_hinks_el-shafei_2012, title={Cotton bleaching optimization using a butyrolactam-based cationic bleach activator}, volume={12}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84855978049&partnerID=MN8TOARS}, number={1}, journal={AATCC Review}, author={Xu, C. and Shamey, R. and Hinks, D. and El-Shafei, A.}, year={2012}, pages={66–70} }
 @article{akhtaruzzaman_seya_asao_islam_kwon_el-shafei_han_yamamoto_2012, title={Donor-acceptor dyes incorporating a stable dibenzosilole pi-conjugated spacer for dye-sensitized solar cells}, volume={22}, ISSN={["0959-9428"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84862671049&partnerID=MN8TOARS}, DOI={10.1039/c2jm30978e}, abstractNote={Four novel organic dyes including three based on dibenzosilole (YS01–03) and one based on fluorene (YS04) were synthesized, and their photophysical properties and dye-sensitized solar cell (DSC) performances were characterized. The silicon-containing dibenzosilole-based dyes (YS01–03) were superior to the carbon analogue fluorene-based dye YS04 in incident-photon-to-current conversion efficiency (IPCE), and total solar-to-electric conversion efficiency (η), with YS03, which has the bulkiest and most branched electron donor group, achieving the highest η of 5.07% compared to 2.88% of YS04. To better understand how silicon influences the excited state oxidation potentials (S+/*) and absorption maxima (λmax), the equilibrium molecular geometries of dyes YS01–04 were calculated using density functional theory (DFT) utilizing B3LYP energy functional and DGDZVP basis set. It was shown that the torsion angles (θ1 and θ2) across the biphenyl linkages of dyes containing silicon (YS01–03) were less twisted than that of the silicon-free dye (YS04), which enhanced the π–π* overlap, and that translated into photocurrent enhancements in the silicon-containing dyes YS01–03. Moreover, the vertical electronic excitations and S+/* of dyes YS01–04 were studied using different long-range corrected time-dependent DFT methods, including CAM-B3LYP, LC-BLYP, WB97XD, and LC-wPBE at the basis set level DGDZVP. Excellent agreement between the calculated, using CAM-B3LYP/DGDZVP, and experimental results was found.}, number={21}, journal={JOURNAL OF MATERIALS CHEMISTRY}, author={Akhtaruzzaman, Md. and Seya, Yohei and Asao, Naoki and Islam, Ashraful and Kwon, Eunsang and El-Shafei, Ahmed and Han, Liyuan and Yamamoto, Yoshinori}, year={2012}, pages={10771–10778} }
 @article{malshe_mazloumpour_el-shafei_hauser_2012, title={Functional Military Textile: Plasma-Induced Graft Polymerization of DADMAC for Antimicrobial Treatment on Nylon-Cotton Blend Fabric}, volume={32}, ISSN={0272-4324 1572-8986}, url={http://dx.doi.org/10.1007/S11090-012-9380-1}, DOI={10.1007/S11090-012-9380-1}, number={4}, journal={Plasma Chemistry and Plasma Processing}, publisher={Springer Science and Business Media LLC}, author={Malshe, Priya and Mazloumpour, Maryam and El-Shafei, Ahmed and Hauser, Peter}, year={2012}, month={May}, pages={833–843} }
 @article{yang_akhtaruzzaman_islam_jin_el-shafei_qin_han_alamry_kosa_hussein_et al._2012, title={Structure-property relationship of naphthalene based donor-pi-acceptor organic dyes for dye-sensitized solar cells: remarkable improvement of open-circuit photovoltage}, volume={22}, ISSN={["0959-9428"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84867347533&partnerID=MN8TOARS}, DOI={10.1039/c2jm34363k}, abstractNote={Four new donor–π–acceptor organic dyes (YF01–04), containing naphthalene-substituted amines as an electron donor and cyanoacrylic acid as an electron acceptor, were designed and synthesized, and their photophysical properties and dye-sensitized solar cells (DSCs) performances were characterized. Dyes YF02 and YF04, with 2,6-disubstituted naphthalene frameworks, were superior than their analog dyes YF03 and YF01, having 1,2-disubstituted naphthalene moiety, in incident-photo-to-current conversion efficiency (IPCE) and total solar-to-electric conversion efficiency (η). The DSCs based on YF02, comprised of diphenylamine moiety as the donor, produced the highest η of 5.29% compared to 4.03% of the analog dye YF04, which has pyrrolidine as the donor. Remarkably, a high open-circuit photovoltage (Voc) of 0.799–0.807 V was achieved in the cases of YF02–03, which have diphenylamine-donors. To better understand the structure–property relationship for DSCs application, molecular modelling was performed on YF01–04 and vertical electronic excitations were calculated using long-range corrected energy functional WB97XD and CAM-B3LYP at the basis set level DGDZVP, which were in excellent agreement with the experimental results. Moreover, the equilibrium molecular geometries of dyes YF01–04 were calculated at the density function theory (DFT) level using the hybrid energy functional B3LYP and basis set DGDZVP. The torsion angles (θ) between the naphthalene moiety and diphenylamine donor in YF02 and YF03 were more twisted than that of the pyrrolidine-donor dyes YF01 and YF04, precluding efficient intermolecular π–π charge transfer, which translated into high Voc. Compared to the reference dye TA-St-CA, which is based on diphenylamine as an electron donor linked to a phenyl ring, YF02 achieved higher Voc, which indicated that naphthalene substituted with diphenylamine is more efficient in retarding charge recombinations.}, number={42}, journal={JOURNAL OF MATERIALS CHEMISTRY}, author={Yang, Fan and Akhtaruzzaman, Md. and Islam, Ashraful and Jin, Tienan and El-Shafei, Ahined and Qin, Chuanjiang and Han, Liyuan and Alamry, Khalid A. and Kosa, Samia A. and Hussein, Mahmoud A. and et al.}, year={2012}, month={Nov}, pages={22550–22557} }
 @article{kale_palaskar_hauser_el-shafei_2012, title={Studies on atmospheric pressure glow discharge of helium-oxygen plasma treatment on polyester/cotton blended fabric}, volume={42}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84864772668&partnerID=MN8TOARS}, number={1}, journal={BTRA Scan}, author={Kale, K. and Palaskar, S. and Hauser, P.J. and El-Shafei, A.}, year={2012}, pages={1–11} }
 @article{widodo_el-shafei_hauser_2012, title={Surface nanostructuring of kevlar fibers by atmospheric pressure plasma-induced graft polymerization for multifunctional protective clothing}, volume={50}, ISSN={0887-6266}, url={http://dx.doi.org/10.1002/polb.23098}, DOI={10.1002/polb.23098}, abstractNote={Abstract}, number={16}, journal={Journal of Polymer Science Part B: Polymer Physics}, publisher={Wiley}, author={Widodo, Mohamad and El-Shafei, Ahmed and Hauser, Peter J.}, year={2012}, month={May}, pages={1165–1172} }
 @article{hussain_shamey_hinks_el-shafei_ali_2012, title={Synthesis of novel stilbene-alkoxysilane fluorescent brighteners, and their performance on cotton fiber as fluorescent brightening and ultraviolet absorbing agents}, volume={92}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-80053923377&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2011.06.034}, abstractNote={Two novel fluorescent brightening agents (compounds 3a–b shown in Figure 1) were synthesized, using a facile three-step synthetic route, from 4,4′-diamino-2,2′-disulfonic-stilbene, cyanuric chloride, and a readily cross-linkable 3-aminopropyltrimethoxy silane. The products contain hydrolytically active trimethoxysilyl, (–Si(OCH)3), functional groups that readily hydrolyze in the presence of water, and subsequently generate a water insoluble silicon cross-linked-network (Si–O–Si) via a condensation process. The cross-linked product hydrolyzes on treatment with hot aqueous sodium hydroxide to silanols (–Si(OH)3) to form compounds 4a–b which are readily water soluble and produce a clear fluorescent solution. The silanol forms of compounds 4a–b were used for further characterization and performance evaluation. The structures of compounds 4a–b were characterized by 1H-NMR, Fourier-Transform infrared (FT-IR) spectroscopy and negative electrospray ionization mass (−ESI-MS) spectroscopy. Compounds were applied to cotton fiber as fluorescent brightening agents and their performance was evaluated by measuring the degree of whiteness, ultraviolet protection factor (UPF), fluorescence and acid fastness. Results showed that application of 0.25% (o.w.f) of compounds 4a–b impart a high degree of whiteness (CIE WI = 144, 139) as well as good ultraviolet protection factor (UPF = 29, 27) on cotton fiber exhibiting a significant increase in whiteness and UV blocking properties compared to untreated substrate (CIE WI = 81, UPF = 5). Acid fastness tests of both compounds showed a slight change in fluorescence emission intensities as a function of pH. In acidic solutions, a shift in emission maximum occurs at pH 3 from 434 to 453 nm and from 435 to 457 nm, due to the protonation of amino and sulfonic groups of stilbene fluorophore which substantially reduces the quenching process.}, number={3}, journal={DYES AND PIGMENTS}, author={Hussain, Maqbool and Shamey, Renzo and Hinks, David and El-Shafei, Ahmed and Ali, Syed Ishrat}, year={2012}, month={Mar}, pages={1231–1240} }
 @article{edwards_el-shafei_hauser_malshe_2012, title={Towards flame retardant cotton fabrics by atmospheric pressure plasma-induced graft polymerization: Synthesis and application of novel phosphoramidate monomers}, volume={209}, ISSN={["0257-8972"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84866846185&partnerID=MN8TOARS}, DOI={10.1016/j.surfcoat.2012.08.031}, abstractNote={The synthesis of two novel phosphoramidate flame retardant monomers for application to cotton textiles using atmospheric pressure dielectric barrier discharge (DBD) plasma was achieved and the molecular structures were characterized using +ESI-MS and FT-IR. The effects of plasma exposure time, monomer concentration, crosslinker chemistry, crosslinker concentration and photoinitiator concentration on grafting yield were investigated and the process was optimized for highest grafting yield. SEM images of the treated fabrics showed a grafted polymer layer covalently bonded to the polymer structure of cotton that survived a lengthy extraction process to remove ungrafted homopolymer and/or unreacted monomer. Thermogravimetric analysis showed that fabrics treated with the monomers demonstrated an increased thermal stability relative to untreated cotton. Vertical burn testing demonstrated the effectiveness of the grafted phosphorus-containing polymer at promoting char formation even though the fabrics were not self-extinguishing. Measurement of the amount of phosphorus present on the treated samples confirmed that the add-on using this application strategy was too low for self-extinguishing properties, but the rest of the evidence suggested that these compounds have the potential for use in generating flame retardant cotton substrates provided that a more suitable application strategy is developed to further improve grafting yield.}, journal={SURFACE & COATINGS TECHNOLOGY}, author={Edwards, Brian and El-Shafei, Ahmed and Hauser, Peter and Malshe, Priya}, year={2012}, month={Sep}, pages={73–79} }
 @article{kale_palaskar_hauser_el-shafei_2011, title={Atmospheric pressure glow discharge of helium-oxygen plasma treatment on polyester/cotton blended fabric}, volume={36}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79958696253&partnerID=MN8TOARS}, number={2}, journal={Indian Journal of Fibre and Textile Research}, author={Kale, K. and Palaskar, S. and Hauser, P.J. and El-Shafei, A.}, year={2011}, pages={137–144} }
 @article{hauser_el-shafei_2011, title={Atmospheric pressure plasma treatments for repellent textiles}, volume={11}, number={1}, journal={AATCC Review}, author={Hauser, P. J. and El-Shafei, A.}, year={2011}, pages={70–74} }
 @article{hauser_el-shafei_2011, title={Atmospheric pressure plasma treatments for repellent textiles}, volume={11}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-78751494630&partnerID=MN8TOARS}, number={1}, journal={AATCC Review}, author={Hauser, P.J. and El-Shafei, A.}, year={2011}, pages={70–74} }
 @book{el-shafei_hinks_freeman_2011, title={Molecular modeling and predicting dye properties}, volume={1}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84942573132&partnerID=MN8TOARS}, DOI={10.1533/9780857093974.1.225}, abstractNote={Abstract: This chapter discusses the state-of-the-art molecular modeling methods in the prediction of electronic and thermodynamic properties of organic colorants. The utility of different molecular modeling methods such as Pariser, Parr and Pople (PPP), Zerner’s Intermediate Neglect of Differential Overlap (ZINDO) and Time Dependant-Density Functional Theory (TD-DFT) in the prediction of wavelength of maximum absorption (λmax), and the effect of crystal packing on λmax are discussed. Moreover, the prediction of crystal structures using ab initio methods and the use of quantitative-structure activity relationship (QSAR) in the prediction of dye–fiber affinity are presented.}, journal={Handbook of Textile and Industrial Dyeing: Principles, Processes and Types of Dyes}, author={El-Shafei, A. and Hinks, D. and Freeman, H.S.}, year={2011}, pages={225–244} }
 @article{davis_el-shafei_hauser_2011, title={Use of atmospheric pressure plasma to confer durable water repellent functionality and antimicrobial functionality on cotton/polyester blend}, volume={205}, ISSN={["0257-8972"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79957634922&partnerID=MN8TOARS}, DOI={10.1016/j.surfcoat.2011.04.035}, abstractNote={A non-thermal, high density atmospheric plasma glow discharge treatment was used to impart functionality to cotton/polyethylene terephthalate (PET) fabric to furnish a surface that is water repellent and then antimicrobial only. In this work, cotton/PET (50/50%) blend fabric was treated with a water repellent treatment through activating the surface with plasma, depositing a vaporized fluorocarbon based monomers, 1,1,2,2-tetrahydroperfluorodecyl acrylate (THPFDA) and 1,1,2,2-tetrahydroperfluorododecyl acrylate (THPFDDA), then graft polymerizing the monomer with a second plasma exposure. Samples were then further treated with an antimicrobial agent, diallyldimethylammonium chloride (DADMAC), a quaternary ammonium salt. Plasma treatment was used to induce free radical chain polymerization of the DADMAC, conferring a graft polymerized network on the fabric with potentially durable antimicrobial properties. It was shown that the water repellent treatment via plasma induced-graft polymerization was successful in yielding a highly hydrophobic fabric with a finish durable to laundering. The results of the antimicrobial tests showed that the treated fabric reduced the activity of both gram positive and gram negative bacteria by more than 99.994%, demonstrating that the antimicrobial agent can function effectively on the water repellent treated fabric. However, despite the evidence of the presence of fluorine containing compounds on the fabric following the antimicrobial treatment, which was confirmed by time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis, the water repellency was lost, which was attributed to changes in the orientation of the fluorocarbon polymer chains.}, number={20}, journal={SURFACE & COATINGS TECHNOLOGY}, author={Davis, Rachel and El-Shafei, Ahmed and Hauser, Peter}, year={2011}, month={Jul}, pages={4791–4797} }
 @article{el-shafei_fadda_bondock_khalil_tawfik_2010, title={FACILE SYNTHESIS, PURE DFT CALCULATIONS, AND PM3 SEMIEMPIRICAL MO METHOD VALIDATION OF REGIOSPECIFICITY OF NOVEL 1,4-DIHYDROPYRIDO[2,3-d] PYRIMIDINE DERIVATIVES}, volume={40}, ISSN={["0039-7911"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-77955441881&partnerID=MN8TOARS}, DOI={10.1080/00397910903534015}, abstractNote={Reaction of 6-aminothiouracil (or uracil) with equimolar amounts of different ketones or diketones and the appropriate aromatic aldehydes afforded di- and tricyclic linear pyrido[2,3-d]pyrimidine derivatives 4, 6–12, 14, 16–18, 20, and 21, and pyrimido[4,5-b]quinoline derivatives 15 and 19 in good yields. The regiospecificity, which led to the formation of compound 4 not 5, was validated using ab initio at the HF/6–31 G+(d,p) level and pure density functional theory (DFT) calculations using BLYP energy functional and the basis set DNP via studying the thermodynamics of their possible conformers and regioisomers. In addition, the total energy of the transition state was calculated for compounds 12 and 13 to determine whether the reaction products were thermodynamically or kinetically controlled. Hence, the linear structures and the regiospecificities of the reactions for the structures reported in this article were established by elemental analysis, spectral data, ab initio calculations, pure DFT, and PM3 parameters.}, number={18}, journal={SYNTHETIC COMMUNICATIONS}, author={El-Shafei, A. and Fadda, A. A. and Bondock, S. and Khalil, A. M. and Tawfik, Eman H.}, year={2010}, pages={2788–2805} }
 @article{yoon_king_michielsen_el-shafei_johnson_2010, title={Influence of surface modification on the adhesion between nitinol wire and fluoropolymer films}, volume={8}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-77952474444&partnerID=MN8TOARS}, number={1}, journal={Journal of Applied Biomaterials and Biomechanics}, author={Yoon, H. and King, M.W. and Michielsen, S. and El-Shafei, A. and Johnson, E.}, year={2010}, pages={7–13} }
 @inproceedings{el-shafei_mazloumpour_hauser_2010, title={Plasma induced graft polymerization of hydrophobic monomers on nonwoven substrates for fuel filtration applications}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84865956867&partnerID=MN8TOARS}, booktitle={American Association of Textile Chemists and Colorists International Conference 2010}, author={El-Shafei, A. and Mazloumpour, M. and Hauser, P.}, year={2010}, pages={307–315} }
 @article{he_el-shafei_freeman_boyle_2009, title={Erratum to “X-ray and Molecular Modelling Studies on 4-[N-Alkylamino]azobenzene Dyes” [Dyes Pigments 82 (2009), 299–306]}, volume={83}, ISSN={0143-7208}, url={http://dx.doi.org/10.1016/j.dyepig.2009.05.002}, DOI={10.1016/j.dyepig.2009.05.002}, number={2}, journal={Dyes and Pigments}, publisher={Elsevier BV}, author={He, Liang and El-Shafei, Ahmed and Freeman, Harold S. and Boyle, Paul}, year={2009}, month={Nov}, pages={267} }
 @article{el-shafei_2009, title={Molecular modelling of inclusion compounds from hydrophobic dyes and gamma-cyclodextrin}, volume={125}, ISSN={["1472-3581"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-69649104026&partnerID=MN8TOARS}, DOI={10.1111/j.1478-4408.2009.00198.x}, abstractNote={This paper arises from studies aimed at developing new approaches to combining the fabric formation and coloration steps of fabric processing. A key aspect of these studies involved the evaluation of cyclodextrin (CD)‐based compounds as hosts for dye molecules that could be released onto a fabric surface following fabric formation. In this study, experimental data from wide‐angle X‐ray diffraction and differential scanning calorimetry experiments were used in tandem with molecular modelling studies to confirm the formation of γ‐CD–dye complex inclusion compounds and to demonstrate the utility of parameterised model number 3 (PM3) semi‐empirical molecular modelling methods for predicting the nature of the preferred γ‐CD–dye inclusion compounds. Calculations revealed that the inclusion compounds containing two dye molecules was preferred over the inclusion compound containing one dye molecule. Further, molecular modelling of the inclusion compound obtained using γ‐CD linked to an epichlorohydrin‐based oligomer and commercial disperse dyes showed inclusion compound formation to be an energetically favourable process.}, number={4}, journal={COLORATION TECHNOLOGY}, author={El-Shafei, Ahmed}, year={2009}, pages={208–215} }
 @article{el-shafei_fadda_abdel-gawad_youssif_2009, title={Stereospecificity of Diels-Alder Reactions Validated Using Ab Initio Calculations: Synthesis of Novel Coumarin and Phenanthridine Derivatives}, volume={39}, ISSN={["1532-2432"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-67651087296&partnerID=MN8TOARS}, DOI={10.1080/00397910802711326}, abstractNote={Abstract A new series of coumarin derivatives (2–5) was synthesized by reaction of phenylsulfonylacetonitrile (1) with 2-hydroxy-1-naphthaldehyde and/or salicyaldehyde. Compounds 3 and 5 were converted to the corresponding phenanthridine analogs 6 and 7, respectively. Compound 9a was treated with different dienophiles to furnish the endo adducts of compounds (11a–d) rather than the exo adducts. Ab initio calculations at the Hartree-Fock (HF) level using the basis set 6-31 G (d,p) was used to study and validate the stereospecificity of compounds 11a–d and showed clearly that the endo adducts were thermodynamically favorable. PM3 parameters also showed that the endo adducts are thermodynamically and kinetically favorable. Tetrahydrobenzochromenone (11) was synthesized and allowed to react with different aromatic diazonium salts to give the corresponding 4-arylazo derivatives (13), which were converted to the corresponding diazaindenophenanthrene derivatives (14) by reaction with o-diamines.}, number={16}, journal={SYNTHETIC COMMUNICATIONS}, author={El-Shafei, A. and Fadda, A. A. and Abdel-Gawad, I. I. and Youssif, E. H. E.}, year={2009}, pages={2954–2972} }
 @article{el-shafei_fadda_khalil_ameen_badria_2009, title={Synthesis, antitumor evaluation, molecular modeling and quantitative structure-activity relationship (QSAR) of some novel arylazopyrazolodiazine and triazine analogs}, volume={17}, ISSN={["0968-0896"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-67650083498&partnerID=MN8TOARS}, DOI={10.1016/j.bmc.2009.05.053}, abstractNote={The synthesis, in vivo and in vitro antitumor evaluation, and QSAR studies of some novel pyrazole analogs against Ehrlich Ascites Carcinoma (EAC) cells were described. In vitro results revealed that compounds 10, 6 and 4 were the most potent analogs against EAC, respectively. Moreover, in vivo evaluation of compounds 6 and 10 proved their capability to normalize the blood picture in comparison to 5-FU, a well known anticancer drug. These novel pyrazole analogs were molecularly designed with the goal of having significant potent cytotoxic effect against EAC cells. To develop a QSAR model capable of identifying the key molecular descriptors associated with the biological activity of the novel pyrazole analogs and predicting the cytotoxic effect for other novel pyrazole analogs against EAC cells, different QSAR models, using different physicochemical and topological molecular descriptors, were developed. Different molecular descriptors were predicted solely from the chemical structures of 16 pyrazolo-diazine and triazine analogs following the prediction of the equilibrium molecular geometry of each analog at the DFT level using B88-LYP functional energy and double zeta valence polarized (DZVP) basis set. It was found that dipole moment, excitation energy, the energy value of LUMO, solvent accessible surface area, and heat of formation were the key molecular descriptors in descriping the cytotoxic effect of those compounds against EAC.}, number={14}, journal={BIOORGANIC & MEDICINAL CHEMISTRY}, author={El-Shafei, Ahmed and Fadda, A. A. and Khalil, A. M. and Ameen, T. A. E. and Badria, Farid A.}, year={2009}, month={Jul}, pages={5096–5105} }
 @article{he_el-shafei_freeman_boyle_2009, title={X-ray and molecular modelling studies of 4-[N-alkylamino]azobenzene dyes}, volume={82}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-64849101647&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2009.01.013}, abstractNote={Abstract 4-[N,N-Bisalkyl]amino-2′-chloro-4′-nitroazobenzenes were recrystallized from acetone in either triclinic or monoclinic cells with the space group P-1 or P21/c. The asymmetric unit cell of dyes having at least one N-cyanoethyl group contained two molecules that were symmetrically unequivalent. The aromatic rings in the azobenzene skeleton were essentially planar with respect to the plane of the azo group, although the C6–C1–N1–N2 torsion angle was 13.2° when the N,N-dicyanoethyl group was employed. X-ray studies were used as a basis for assessing the utility of nonlocal DFT calculations in predicting the equilibrium molecular geometry and solvatochromic properties of the compounds using MM3/ZINDO-S and the COSMO Solvation Model. Although B3LYP and PBE energy functionals were comparable in predicting bond lengths, PBE was slightly better than B3LYP in predicting torsion angles. Furthermore, the dipolarity/polarizability index (π∗) was the preferred solvent parameter for predicting the effects of solvents on λmax.}, number={3}, journal={DYES AND PIGMENTS}, author={He, Liang and El-Shafei, Ahmed and Freeman, Harold S. and Boyle, Paul}, year={2009}, month={Sep}, pages={299–306} }
 @article{szymczyk_el-shafei_freeman_2007, title={Design, synthesis, and characterization of new iron-complexed azo dyes}, volume={72}, ISSN={0143-7208}, url={http://dx.doi.org/10.1016/j.dyepig.2005.07.009}, DOI={10.1016/j.dyepig.2005.07.009}, abstractNote={As part of a continuing study pertaining to the use of Fe as a substitute for metals such as Cr and Co in the design and synthesis of metal-complexed azo and formazan dyes, the synthesis of dye ligands containing ortho-trifluoroacetamido or mesylamido groups in the diazo components was undertaken. It was anticipated that these groups would mimic the acidity and metallizing properties of an ortho-OH group, thus producing new Fe-complexed dyes. The target ligands were synthesized in 4–5 steps and 80–91% yields from commercially available intermediates. 1H NMR was used to confirm the structures of the target dye ligands. The resultant azo and formazan systems readily formed 1:2 Fe-complexes when an ortho-NHSO2Me group was employed, while preparation of Fe-complexes from dye ligands having an ortho-NHCOCF3 group proved difficult, with mixtures of unmetallized dye, Fe-complex, and Fe hydroxide obtained despite variations in reaction conditions. Results of DFT calculations suggest that electron density at the N-22 atom was significantly diminished by the electron-withdrawing power of the CF3 moiety, inhibiting complex formation.}, number={1}, journal={Dyes and Pigments}, publisher={Elsevier BV}, author={Szymczyk, Malgorzata and El-Shafei, Ahmed and Freeman, Harold S.}, year={2007}, month={Jan}, pages={8–15} }
 @article{yang_el-shafei_schilling_tonelli_2007, title={Why is stereoregular polyacrylonitrile obtained by polymerization in urea canals isotactic?}, volume={16}, ISSN={["1521-3919"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-36849034629&partnerID=MN8TOARS}, DOI={10.1002/mats.200700043}, abstractNote={Abstract}, number={9}, journal={MACROMOLECULAR THEORY AND SIMULATIONS}, author={Yang, Hyungchol and El-Shafei, Ahmed and Schilling, Frederic C. and Tonelli, Alan E.}, year={2007}, month={Nov}, pages={797–809} }
 @article{uyar_gracz_rusa_shin_el-shafei_tonelli_2006, title={Polymerization of styrene in gamma-cyclodextrin channels: Lightly rotaxanated polystyrenes with altered stereosequences}, volume={47}, ISSN={["0032-3861"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33748531256&partnerID=MN8TOARS}, DOI={10.1016/j.polymer.2006.07.054}, abstractNote={Modeling of polystyrene (PS) with various stereosequences in γ-cyclodextrin (γ-CD) channels has been conducted and it was found that only isotactic PS stereoisomers can fit into the γ-CD cavity. Thus, based on the modeling of stereoisomeric polystyrenes in narrow γ-CD channels, it was suggested that PSs with unusual microstructures might be produced via constrained polymerization of styrene monomer in its γ-CD-IC crystals. The in situ polymerization of styrene inside the narrow channels of its γ-CD-IC crystals suspended in aqueous media was performed. Alternatively, the solid-state polymerization of styrene/γ-CD-IC has also been conducted by exposure to γ-radiation. It was found that most host γ-CD molecules slip off during polymerization and the channel structure was not preserved. Consequently, much of the guest styrene monomer polymerizes outside of the host γ-CD channels, where the constrained environment is absent. Yet, a lightly rotaxanated structure has been obtained, where some threaded γ-CD molecules ∼15 wt% (∼1 γ-CD per 70 PS repeat units) are permanently entrapped along the PS chains after polymerization. 13C NMR spectra of PSs synthesized from styrene/γ-CD-IC and homogeneously in toluene show some differences, which are presumably due to variations in the stereosequences of PSs obtained from the partially constrained polymerization of styrene/γ-CD-IC.}, number={20}, journal={POLYMER}, author={Uyar, Tamer and Gracz, Hanna S. and Rusa, Mariana and Shin, I. Daniel and El-Shafei, Ahmed and Tonelli, Alan E.}, year={2006}, month={Sep}, pages={6948–6955} }
 @article{tonelli_uyar_el-shafei_hacaloglu_2006, title={The solid channel structure inclusion complex formed between styrene guests and gamma-cyclodextrin hosts}, volume={55}, number={109}, journal={Journal of Inclusion Phenomena and Macrocyclic Chemistry}, author={Tonelli, A. E. and Uyar, T. and El-Shafei, A. and Hacaloglu, J.}, year={2006} }
 @article{jenkins_el-tahlawy_el-shafei_freeman_hudson_2006, title={Use of gamma-cyclodextrin/epichlorohydrin polymer in merging fabric formation and coloration processes}, volume={122}, ISSN={["1472-3581"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33751023859&partnerID=MN8TOARS}, DOI={10.1111/j.1478-4408.2006.00051.x}, abstractNote={A candidate polymeric size was synthesised by the polymerisation of γ‐cyclodextrin with epichlorohydrin under alkaline conditions. The motivation for the synthesis was to produce a polymer that could not only function as a warp size for fabric formation, but also serve as a host for dye molecules that could subsequently be released after the weaving process, ultimately promoting the merging of fabric formation and coloration processes. The γ‐cyclodextrin/epichlorohydrin polymer has been found to promote the dissolution of textile dyes, such as CI Disperse Blue 3, CI Disperse Yellow 82 and CI Disperse Red 91 to yield pad baths capable of evenly coating polyester fabric. Upon padding and subsequent drying, the dye–γ‐cyclodextrin/epichlorohydrin polymer pad baths have been used for dyeing the fabric upon thermofixation. Furthermore, cross‐sections of fibre dyed in the same manner indicate dye penetration into the fibre.}, number={6}, journal={COLORATION TECHNOLOGY}, author={Jenkins, David W. and El-Tahlawy, Khaled and El-Shafei, Ahmed and Freeman, Harold S. and Hudson, Samuel M.}, year={2006}, pages={345–349} }
 @misc{horton_hinks_el-shafei_2005, title={Sock for detection of pressure points on feet}, volume={6,918,883}, number={2005 Jul. 19}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Horton, J. M. and Hinks, D. and El-Shafei, A.}, year={2005} }
 @article{uyar_el-shafei_wang_hacaloglu_tonelli_2005, title={The Solid Channel Structure Inclusion Complex Formed Between Guest Styrene and Host γ-Cyclodextrin}, volume={55}, ISSN={0923-0750 1573-1111}, url={http://dx.doi.org/10.1007/s10847-005-9026-5}, DOI={10.1007/s10847-005-9026-5}, number={1-2}, journal={Journal of Inclusion Phenomena and Macrocyclic Chemistry}, publisher={Springer Science and Business Media LLC}, author={Uyar, Tamer and El-Shafei, Ahmed and Wang, Xingwu and Hacaloglu, Jale and Tonelli, Alan E.}, year={2005}, month={Dec}, pages={109–121} }
 @article{gursoy_el-shafei_hauser_hinks_2004, title={Cationic bleach activators for improving cotton bleaching}, volume={4}, number={8}, journal={AATCC Review}, author={Gursoy, N. C. and El-Shafei, A. and Hauser, P. and Hinks, D.}, year={2004}, pages={37–40} }
 @article{gürsoy_el-shafei_hauser_hinks_2004, title={Cationic bleach activators for improving cotton bleaching}, volume={4}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-4344712068&partnerID=MN8TOARS}, number={8}, journal={AATCC Review}, author={Gürsoy, N.C. and El-Shafei, A. and Hauser, P. and Hinks, D.}, year={2004}, pages={37–40} }
 @inproceedings{freeman_szymczyk_el-shafei_2004, title={Design, synthesis, and characterization of new iron-complexed azo dyes}, ISBN={9788085119015}, booktitle={Colorchem '04: proceedings : 23-27 May 2004, Hotel Harmony, S?pindleru?v Mly?n, Czech Republic}, publisher={Pardubice: Vy?zkumny? u?stav organicky?ch synte?z}, author={Freeman, H.S. and Szymczyk, M. and El-Shafei, A.}, year={2004} }
 @article{el-shafei_hinks_boyle_freeman_2004, title={Non-mutagenic organic pigment intermediates. II. Isomorphous 2,2 '-dichloro-5,5 '-dipropoxybenzidine and 2,2 '-dimethyl-5,5 '-dipropoxybenzidine}, volume={60}, ISSN={["2053-2296"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-4444237632&partnerID=MN8TOARS}, DOI={10.1107/S0108270104014763}, abstractNote={The title compounds, C 18 H 22 Cl 2 N 2 O 2 and C 20 H 28 N 2 O 2 , respectively, are isomorphous. The molecules lie at general positions in the unit cell. In each structure, chemically equivalent but crystallographically inequivalent amine N atoms exhibit different degrees of pyramidalization. The structures exhibit weak N-H...N hydrogen bonding, which is influenced by the differences in hybridization around the amine N atoms. The torsion angles across the biphenyl linkage for the two compounds are 67.2 (2) and 68.3 (3)°.}, number={8}, journal={ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY}, author={El-Shafei, A and Hinks, D and Boyle, PD and Freeman, HS}, year={2004}, month={Aug}, pages={O569–O571} }
 @article{bae_freeman_el-shafei_2003, title={Metallization of non-genotoxic direct dyes}, volume={57}, ISSN={["0143-7208"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0037967378&partnerID=MN8TOARS}, DOI={10.1016/S0143-7208(02)00120-1}, abstractNote={Copper (II) salts were used as metallizing agents in the synthesis of new direct dyes for cotton. In this regard, direct dyes possessing ortho-propoxy, ortho′-hydroxy-substituted systems formed the corresponding dye–metal complexes. The complexes were characterized by neutron activation and spectrometric analyses and evaluated on cotton for color fastness.}, number={2}, journal={DYES AND PIGMENTS}, author={Bae, JS and Freeman, HS and El-Shafei, A}, year={2003}, month={May}, pages={121–129} }
 @article{el-shafei_boyle_hinks_freeman_2003, title={Non-mutagenic organic pigment intermediates. I. 3,3 '-Dipropoxybenzidine}, volume={59}, ISSN={["0108-2701"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0037295760&partnerID=MN8TOARS}, DOI={10.1107/S0108270102021303}, abstractNote={Crystals of the title compound, C(18)H(24)N(2)O(2), were grown from ethanol by slow evaporation and the structure has been determined. The molecule resides on a crystallographic inversion center and the biphenyl moiety is essentially planar. The structure forms an infinite two-dimensional array of N-H.pi(arene) interactions parallel to the (101) direction.}, number={2}, journal={ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS}, author={El-Shafei, A and Boyle, PD and Hinks, D and Freeman, HS}, year={2003}, month={Feb}, pages={O71–O73} }
 @article{hinks_rashad_el-shafei_2003, title={Towards a universal dye class for printing on multiple substrates}, volume={119}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0038474061&partnerID=MN8TOARS}, DOI={10.1111/j.1478-4408.2003.tb00153.x}, abstractNote={Textile printing using dyes requires different dye classes to be used for different substrates, which increases complexity in the printing operation. The development of a single (universal) class of dyes that can be applied to all fibres to produce prints with excellent technical properties is desirable. Reported is one approach to a universal dye class for printing on multiple substrates. A temporarily water soluble fibre‐reactive dye, 2‐[(4‐{(E)‐[4‐(diethylamino)phenyl]diazenyl}phenyl)sulphonyl]ethyl sodium sulphate, was synthesised and printed on cotton, polyester, polyester/cotton blend, wool, nylon and acrylic fabrics. A print–dry–cure process was employed. Bright, level prints with high colour strength, good rub fastness and fair to good wash fastness were obtained for all substrates except acrylic, which did not produce good prints. However, significant amounts of unfixed dye were removed during soaping.}, number={2}, journal={Coloration Technology}, author={Hinks, D. and Rashad, M. and El-Shafei, A.}, year={2003}, pages={70–75} }
 @article{hinks_el-shafei_draper_che_nakpathom_connelly_2001, title={Radiometeric measurements of area lighting critical to color assessment in the textile industry}, volume={1}, number={11}, journal={AATCC Review}, author={Hinks, D. and El-Shafei, A. and Draper, S. and Che, Q. and Nakpathom, M. and Connelly, R.}, year={2001}, pages={35–39} }
 @article{hinks_draper_el-shafei_nakpathom_che_connelly_2001, title={Radiometric measurement of area lighting critical to color assessment in the textile industry}, volume={1}, number={11}, journal={AATCC Review}, author={Hinks, D. and Draper, S. and El-Shafei, A. and Nakpathom, M. and Che, Q. L. and Connelly, R.}, year={2001}, pages={35–39} }
 @article{hinks_draper_el-shafei_nakpathom_che_connelly_2001, title={Radiometrie measurement of area lighting critical to color assessment in the textile industry}, volume={1}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0035507735&partnerID=MN8TOARS}, number={11}, journal={AATCC Review}, author={Hinks, D. and Draper, S. and El-Shafei, A. and Nakpathom, M. and Che, Q. and Connelly, R.}, year={2001}, pages={35–39} }
 @article{el-shafei_hinks_freeman_lye_2001, title={Semi-empirical molecular orbital methods in the design of organic colorants}, volume={1}, number={12}, journal={AATCC Review}, author={El-Shafei, A. and Hinks, D. and Freeman, H. S. and Lye, J.}, year={2001}, pages={23–26} }
 @article{el-shafei_hinks_freeman_lye_2001, title={Semi-empirical molecular orbital methods in the design of organic colorants}, volume={1}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0035682626&partnerID=MN8TOARS}, number={12}, journal={AATCC Review}, author={El-Shafei, A. and Hinks, D. and Freeman, H.S. and Lye, J.}, year={2001}, pages={23–26} }
 @article{el-shafei_hinks_freeman_2001, title={Semi-empirical molecular orbital methods in the design of organic pigments}, volume={1}, number={12}, journal={AATCC Review}, author={El-Shafei, A. and Hinks, D. and Freeman, H. S.}, year={2001}, pages={23–26} }
 @article{hinks_draper_che_nakpathom_el-shafei_connelly_2000, title={Assessment of the effect of lighting variability on color difference}, volume={32}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0033916735&partnerID=MN8TOARS}, number={6}, journal={Textile Chemist and Colorist and American Dyestuff Reporter}, author={Hinks, D. and Draper, S. and Che, Q. and Nakpathom, M. and El-Shafei, A. and Connelly, R.}, year={2000}, pages={16–20} }
 @article{habib_moawad_girges_el-shafei_1995, title={Potentially active antimicrobial agents from 2-benzenesulfonyloxyphenyl-3,1-benzoxazine-4-one derivative}, volume={134}, number={9}, journal={Bollettino Chimico Farmaceutica}, author={Habib, O.M. and Moawad, E.B. and Girges, M.M. and El-Shafei, A.}, year={1995}, pages={503–508} }
 @article{habib_girges_moawad_el-shafei_1995, title={Synthetic approaches and biological evaluation of some new sulfonate ester-containing quinazolone derivatives as potentially active antimicrobial agents}, volume={134}, number={4}, journal={Bollettino Chimico Farmaceutica}, author={Habib, O.M. and Girges, M.M. and Moawad, E.B. and El-Shafei, A.}, year={1995}, pages={209–215} }