@misc{shen_salmon_2023, title={Biocatalytic Membranes for Carbon Capture and Utilization}, volume={13}, ISSN={["2077-0375"]}, url={https://doi.org/10.3390/membranes13040367}, DOI={10.3390/membranes13040367}, abstractNote={Innovative carbon capture technologies that capture CO2 from large point sources and directly from air are urgently needed to combat the climate crisis. Likewise, corresponding technologies are needed to convert this captured CO2 into valuable chemical feedstocks and products that replace current fossil-based materials to close the loop in creating viable pathways for a renewable economy. Biocatalytic membranes that combine high reaction rates and enzyme selectivity with modularity, scalability, and membrane compactness show promise for both CO2 capture and utilization. This review presents a systematic examination of technologies under development for CO2 capture and utilization that employ both enzymes and membranes. CO2 capture membranes are categorized by their mode of action as CO2 separation membranes, including mixed matrix membranes (MMM) and liquid membranes (LM), or as CO2 gas–liquid membrane contactors (GLMC). Because they selectively catalyze molecular reactions involving CO2, the two main classes of enzymes used for enhancing membrane function are carbonic anhydrase (CA) and formate dehydrogenase (FDH). Small organic molecules designed to mimic CA enzyme active sites are also being developed. CO2 conversion membranes are described according to membrane functionality, the location of enzymes relative to the membrane, which includes different immobilization strategies, and regeneration methods for cofactors. Parameters crucial for the performance of these hybrid systems are discussed with tabulated examples. Progress and challenges are discussed, and perspectives on future research directions are provided.}, number={4}, journal={MEMBRANES}, author={Shen, Jialong and Salmon, Sonja}, year={2023}, month={Apr} }
 @article{shen_zhang_fang_salmon_2023, title={Carbonic Anhydrase Enhanced UV-Crosslinked PEG-DA/PEO Extruded Hydrogel Flexible Filaments and Durable Grids for CO2 Capture}, volume={9}, ISSN={["2310-2861"]}, url={https://www.mdpi.com/2310-2861/9/4/341}, DOI={10.3390/gels9040341}, abstractNote={In this study, poly (ethylene glycol) diacrylate/poly (ethylene oxide) (PEG-DA/PEO) interpenetrating polymer network hydrogels (IPNH) were extruded into 1D filaments and 2D grids. The suitability of this system for enzyme immobilization and CO2 capture application was validated. IPNH chemical composition was verified spectroscopically using FTIR. The extruded filament had an average tensile strength of 6.5 MPa and elongation at break of 80%. IPNH filament can be twisted and bent and therefore is suitable for further processing using conventional textile fabrication methods. Initial activity recovery of the entrapped carbonic anhydrase (CA) calculated from esterase activity, showed a decrease with an increase in enzyme dose, while activity retention of high enzyme dose samples was over 87% after 150 days of repeated washing and testing. IPNH 2D grids that were assembled into spiral roll structured packings exhibited increased CO2 capture efficiency with increasing enzyme dose. Long-term CO2 capture performance of the CA immobilized IPNH structured packing was tested in a continuous solvent recirculation experiment for 1032 h, where 52% of the initial CO2 capture performance and 34% of the enzyme contribution were retained. These results demonstrate the feasibility of using rapid UV-crosslinking to form enzyme-immobilized hydrogels by a geometrically-controllable extrusion process that uses analogous linear polymers for both viscosity enhancement and chain entanglement purposes, and achieves high activity retention and performance stability of the immobilized CA. Potential uses for this system extend to 3D printing inks and enzyme immobilization matrices for such diverse applications as biocatalytic reactors and biosensor fabrication.}, number={4}, journal={GELS}, author={Shen, Jialong and Zhang, Sen and Fang, Xiaomeng and Salmon, Sonja}, year={2023}, month={Apr} }
 @article{xiao_thompson_shen_salmon_liu_2023, title={Carbonic anhydrase textile structured packing for efficient CO2 absorption in methyldiethanolamine solvent}, volume={8}, ISSN={["1547-5905"]}, url={https://doi.org/10.1002/aic.18191}, DOI={10.1002/aic.18191}, abstractNote={Abstract}, journal={AICHE JOURNAL}, author={Xiao, Min and Thompson, Jesse and Shen, Jialong and Salmon, Sonja and Liu, Kunlei}, year={2023}, month={Aug} }
 @article{tonelli_shen_2023, title={Conformational Source of Comonomer Sequence-Dependent Copolymer Glass-Transition Temperatures}, url={https://doi.org/10.26434/chemrxiv-2023-8m6b9}, DOI={10.26434/chemrxiv-2023-8m6b9}, abstractNote={This brief review addresses the source of the dependence of copolymer glass transition temperatures (Tgps) on their comonomer sequences. Here we show that a comparison of the conformational entropies obtained from the Rotational Isomeric State (RIS) conformational models of the poly-A and poly-B homopolymers and their resultant poly-A/B co-polymers, i.e., ΔSconf = (XASA + XBSB) - SA/B (X = comonomer fraction), can be used to predict/understand the Tgps of copolymers. For copolymers with ΔSconf ~ 0, we expect their Tgps to follow Fox behavior and to depend only on copolymer composition, because of the similar conformational flexibilities of the A and B homo- and A/B-copolymers. When the conformational entropy ΔSconf is negative the A/B copolymer is assumed more flexible than the weighted sum of polymer-A and polymer-B conformational entropies, resulting in Tgps that are lower than expected from the Fox equation. Conversely, a positive ΔSconf suggests the copolymer’s lower flexibility, resulting in higher Tgps than expected from the Fox relation. We use the successful comparison of the observed dependence of numerous copolymer Tgps to demonstrate the validity of using their calculated RIS conformational entropies to predict their comonomer sequence dependencies.}, author={Tonelli, Alan and Shen, Jialong}, year={2023}, month={Oct} }
 @misc{yuan_shen_salmon_2023, title={Developing Enzyme Immobilization with Fibrous Membranes: Longevity and Characterization Considerations}, volume={13}, ISSN={["2077-0375"]}, url={https://doi.org/10.3390/membranes13050532}, DOI={10.3390/membranes13050532}, abstractNote={Fibrous membranes offer broad opportunities to deploy immobilized enzymes in new reactor and application designs, including multiphase continuous flow-through reactions. Enzyme immobilization is a technology strategy that simplifies the separation of otherwise soluble catalytic proteins from liquid reaction media and imparts stabilization and performance enhancement. Flexible immobilization matrices made from fibers have versatile physical attributes, such as high surface area, light weight, and controllable porosity, which give them membrane-like characteristics, while simultaneously providing good mechanical properties for creating functional filters, sensors, scaffolds, and other interface-active biocatalytic materials. This review examines immobilization strategies for enzymes on fibrous membrane-like polymeric supports involving all three fundamental mechanisms of post-immobilization, incorporation, and coating. Post-immobilization offers an infinite selection of matrix materials, but may encounter loading and durability issues, while incorporation offers longevity but has more limited material options and may present mass transfer obstacles. Coating techniques on fibrous materials at different geometric scales are a growing trend in making membranes that integrate biocatalytic functionality with versatile physical supports. Biocatalytic performance parameters and characterization techniques for immobilized enzymes are described, including several emerging techniques of special relevance for fibrous immobilized enzymes. Diverse application examples from the literature, focusing on fibrous matrices, are summarized, and biocatalyst longevity is emphasized as a critical performance parameter that needs increased attention to advance concepts from lab scale to broader utilization. This consolidation of fabrication, performance measurement, and characterization techniques, with guiding examples highlighted, is intended to inspire future innovations in enzyme immobilization with fibrous membranes and expand their uses in novel reactors and processes.}, number={5}, journal={MEMBRANES}, author={Yuan, Yue and Shen, Jialong and Salmon, Sonja}, year={2023}, month={May} }
 @article{egan_wang_shen_baars_moxley_salmon_2023, title={Enzymatic textile fiber separation for sustainable waste processing}, volume={13}, ISSN={["2666-9161"]}, url={https://doi.org/10.1016/j.resenv.2023.100118}, DOI={10.1016/j.resenv.2023.100118}, journal={RESOURCES ENVIRONMENT AND SUSTAINABILITY}, author={Egan, Jeannie and Wang, Siyan and Shen, Jialong and Baars, Oliver and Moxley, Geoffrey and Salmon, Sonja}, year={2023}, month={Sep} }
 @article{diaz_white_sarnelli_shen_shen_folger_pham_sharafim_li_tonelli_2023, title={Potential Replacement of Toxic PVC Plasticizers with Urea, Its Derivatives, and Related Compounds}, url={https://doi.org/10.26434/chemrxiv-2023-tx97v}, DOI={10.26434/chemrxiv-2023-tx97v}, abstractNote={The primary plasticizers for the world’s most plasticized polymer, poly(vinyl chloride) (PVC), are organic phthalates, this despite being categorized as probable human carcinogens by the EPA. Di-2-ethylhexyl phthalate (DEHP or DOP) is such a typical PVC plasticizer. We sought to find an alternative plasticizer that lowered the glass transition temperature (Tg) and softened PVC, but was not as harmful to the environment and for our health as the currently employed phthalate plasticizers. We recently discovered that urea (U) could complex with amorphous polymers, such as atactic poly(methyl methacrylate) (PMMA) and poly(vinyl acetate) (PVAc). Compared to neat samples, the Tgs of the PMMA-U and PVAc-U complexes were increased and decreased, respectively. However, when complexed with dimethylurea (DMU), the Tg of the PMMA-DMU complex was lowered. Since Tgs of PMMA and PVAc were lowered by either U or one of its derivatives, this prompted us to investigate whether they could interact and complex with another largely amorphous polymer PVC, that is often plasticized, to soften and lower its Tg. Shifts in the vibrational frequencies observed by Fourier-Transform Infrared spectroscopy and Differential Scanning Calorimetry thermograms indicated that U, its derivative tetramethylurea (TMU)], and the related compound Acetamide (AC) were complexing with PVC. All three complexes (PVC-U, -TMU, and –AC) showed significantly lowered Tgs. Preliminary mechanical property measurements of PVC-U and PVC-AC films showed they were softer and more pliable than PVC films. Consequently, we believe our preliminary results warrant further examination of U, AC, and TMU as potential effective and less harmful PVC plasticizers.}, author={Diaz, Cristina Guillen and White, Jehlan and Sarnelli, Giovanni and Shen, Jiao and Shen, Jialong and Folger, Allison and Pham, Jessica and Sharafim, Sharaf and Li, Shanshan and Tonelli, Alan}, year={2023}, month={Jun} }
 @misc{shen_zhang_fang_salmon_2022, title={Advances in 3D Gel Printing for Enzyme Immobilization}, volume={8}, ISSN={["2310-2861"]}, url={https://doi.org/10.3390/gels8080460}, DOI={10.3390/gels8080460}, abstractNote={Incorporating enzymes with three-dimensional (3D) printing is an exciting new field of convergence research that holds infinite potential for creating highly customizable components with diverse and efficient biocatalytic properties. Enzymes, nature’s nanoscale protein-based catalysts, perform crucial functions in biological systems and play increasingly important roles in modern chemical processing methods, cascade reactions, and sensor technologies. Immobilizing enzymes on solid carriers facilitates their recovery and reuse, improves stability and longevity, broadens applicability, and reduces overall processing and chemical conversion costs. Three-dimensional printing offers extraordinary flexibility for creating high-resolution complex structures that enable completely new reactor designs with versatile sub-micron functional features in macroscale objects. Immobilizing enzymes on or in 3D printed structures makes it possible to precisely control their spatial location for the optimal catalytic reaction. Combining the rapid advances in these two technologies is leading to completely new levels of control and precision in fabricating immobilized enzyme catalysts. The goal of this review is to promote further research by providing a critical discussion of 3D printed enzyme immobilization methods encompassing both post-printing immobilization and immobilization by physical entrapment during 3D printing. Especially, 3D printed gel matrix techniques offer mild single-step entrapment mechanisms that produce ideal environments for enzymes with high retention of catalytic function and unparalleled fabrication control. Examples from the literature, comparisons of the benefits and challenges of different combinations of the two technologies, novel approaches employed to enhance printed hydrogel physical properties, and an outlook on future directions are included to provide inspiration and insights for pursuing work in this promising field.}, number={8}, journal={GELS}, author={Shen, Jialong and Zhang, Sen and Fang, Xiaomeng and Salmon, Sonja}, year={2022}, month={Aug} }
 @article{shen_yuan_salmon_2022, title={Carbonic Anhydrase Immobilized on Textile Structured Packing Using Chitosan Entrapment for CO2 Capture}, volume={6}, url={https://doi.org/10.1021/acssuschemeng.2c02545}, DOI={10.1021/acssuschemeng.2c02545}, abstractNote={Innovative carbon dioxide (CO2) capture approaches are urgently needed to lower and reverse CO2 emissions that lead to climate change. Here, we report the design, fabrication and testing of high efficiency biocatalytic textile-based gas–liquid contactors made using versatile, sustainable, and readily available polymers, cellulose, and chitosan, together with an immobilized carbonic anhydrase (CA) enzyme to accelerate CO2 absorption into benign, low-energy, aqueous potassium carbonate (K2CO3)-based solvents. This novel structured packing is able to withstand the CO2 scrubbing environment, will be simple to scale up, and will be useful as a “drop-in” for conventional chemical absorption systems as well as offer new possibilities for direct air capture. Immobilizing CA in a thin coating on textile packing surfaces minimizes the enzyme requirement, retains enzyme in the absorber for high catalytic benefit and longevity with repeated use, and allows downstream process flexibility by preventing CA from traveling to other unit operations, for example, high temperature desorption where enzyme could become inactivated. CA immobilization on cotton fiber textile packing materials by entrapment with chitosan exhibited an activity recovery of at least 49% and activity retentions of higher than 68% after 10 repeated wash and retest cycles over 5 days and up to 41% after a 31 day incubation in 10 wt % K2CO3 at 40 °C. The lightweight biocatalytic textile packing modules are sturdy and easily handled with no sharp edges or dusting issues as can accompany conventional metal packing- or particulate-immobilized enzymes. In laboratory-scale countercurrent CO2 absorption tests at 4 L per minute total gas flow rates, CA-immobilized textile packings delivered average CO2 absorption efficiencies of 52.3% and 81.7% for single and double-stacked packings, respectively, versus 26.6% and 46.4% for single and double-stacked no-enzyme control textile packings, and versus 3.6% for conventional glass Raschig rings filled to the equivalent single-stacked packing height. Textile packings exhibited excellent solvent distribution throughout the packing even at low liquid flow rates, maintaining uniform gas contact with the wetted solid contacting surfaces across a range of different liquid flow rates, leading to robust CO2 capture efficiency. Biocatalytic textile packing retained 66% of the initial CO2 capture performance after five cycles of washing, drying, ambient storage, and retesting over a period of 66 days. In a separate test with freshly made packing, 76.5% performance retention was observed after a continuous 120 h recirculation longevity test.}, journal={ACS Sustainable Chemistry & Engineering}, publisher={American Chemical Society (ACS)}, author={Shen, Jialong and Yuan, Yue and Salmon, Sonja}, year={2022}, month={Jun} }
 @misc{narayanan_shen_matai_sachdev_boy_tonelli_2022, title={Cyclodextrin-based nanostructures}, volume={124}, ISSN={["1873-2208"]}, url={https://doi.org/10.1016/j.pmatsci.2021.100869}, DOI={10.1016/j.pmatsci.2021.100869}, abstractNote={Cyclodextrins (CDs) are a unique class of molecules that are naturally available via degradation of starchy molecules. Their toroidal structure and abundant presence of hydroxyl groups have given scientists exceptional leverage resulting in synthesizing novel molecules for applications ranging from food packaging, controlled release of small molecules, antibacterial coating, agriculture, and air and water filtration. With the advent of nanotechnology, CDs have positioned itself in a variety of forms such as their ability to act as capping/reducing agents for metallic nanoparticles, or form stable nanofibers or nanoparticles or nano micelles, which can be subsequently utilized for sophisticated applications. In this review, we summarize researches on the presence of CDs in various aspects of nanotechnology ranging from nanoparticles, nanorods, nanomicelles, to nanofibers. In addition, through this review, we provide state-of-the-art applications that are being carried out using these nanostructures.}, journal={PROGRESS IN MATERIALS SCIENCE}, author={Narayanan, Ganesh and Shen, Jialong and Matai, Ishita and Sachdev, Abhay and Boy, Ramiz and Tonelli, Alan E.}, year={2022}, month={Feb} }
 @article{shen_yuan_salmon_2022, title={Durable and Versatile Immobilized Carbonic Anhydrase on Textile Structured Packing for CO2 Capture}, volume={12}, ISSN={["2073-4344"]}, url={https://www.mdpi.com/2073-4344/12/10/1108}, DOI={10.3390/catal12101108}, abstractNote={High-performance carbon dioxide (CO2)-capture technologies with low environmental impact are necessary to combat the current climate change crisis. Durable and versatile “drop-in-ready” textile structured packings with covalently immobilized carbonic anhydrase (CA) were created as efficient, easy to handle catalysts for CO2 absorption in benign solvents. The hydrophilic textile structure itself contributed high surface area and superior liquid transport properties to promote gas-liquid reactions that were further enhanced by the presence of CA, leading to excellent CO2 absorption efficiencies in lab-scale tests. Mechanistic investigations revealed that CO2 capture efficiency depended primarily on immobilized enzymes at or near the surface, whereas polymer entrapped enzymes were more protected from external stressors than those exposed at the surface, providing strategies to optimize performance and durability. Textile packing with covalently attached enzyme aggregates retained 100% of the initial 66.7% CO2 capture efficiency over 71-day longevity testing and retained 85% of the initial capture efficiency after 1-year of ambient dry storage. Subsequent stable performance in a 500 h continuous liquid flow scrubber test emphasized the material robustness. Biocatalytic textile packings performed well with different desirable solvents and across wide CO2 concentration ranges that are critical for CO2 capture from coal and natural gas-fired power plants, from natural gas and biogas for fuel upgrading, and directly from air.}, number={10}, journal={CATALYSTS}, author={Shen, Jialong and Yuan, Yue and Salmon, Sonja}, year={2022}, month={Oct} }
 @article{li_lv_ai_shen_tonelli_2020, title={A New Two-Step Strategy for Encapsulating Amorphous Polymer Chains in Thiourea Crystals}, volume={221}, ISSN={["1521-3935"]}, DOI={10.1002/macp.202000269}, abstractNote={Abstract}, number={20}, journal={MACROMOLECULAR CHEMISTRY AND PHYSICS}, author={Li, Shanshan and Lv, Dongxu and Ai, Ning and Shen, Jialong and Tonelli, Alan E.}, year={2020}, month={Oct} }
 @book{tonelli_shen_2020, title={Conformations}, ISBN={9780203703601}, url={http://dx.doi.org/10.1201/b22496}, DOI={10.1201/b22496}, publisher={CRC Press}, author={Tonelli, Alan and Shen, Jialong}, year={2020}, month={Apr} }
 @article{tonelli_shen_2020, title={Delivery of pharmaceuticals and other active ingredients with their crystalline cyclodextrin inclusion compounds}, volume={589}, ISSN={["1873-3476"]}, DOI={10.1016/j.ijpharm.2020.119856}, abstractNote={In honor of Prof. Thorsteinn Loftsson’s 70th birthday, we offer this personal review of our work using cyclodextrins (CDs) complexed with a variety of active ingredients, including pharmaceuticals, for the purpose of improving their delivery to polymer materials, e.g., fibers, films, hydrogels, etc. Using the affinity of CDs to host and form non-covalent inclusion complexes (ICs) with guest molecules, including a variety of high molecular weight polymers, it is possible to readily deliver these guest molecules into polymer materials via either melt or solution processing of their crystalline or soluble guest molecule-CD-ICs or -rotaxanes. This provides the following advantages: i. CDs are non-toxic, implantable, and biodegradable and have earned the GRAS rating from the FDA. ii. Guest molecules, even those that are neat liquids, can form solid crystalline CD-ICs that are thermally stable to ~ 200 °C and above. This approach permits facile melt-processing into polymer materials for delivery without migration, loss, or degradation of the active guest ingredient. iii. For guests harmful and toxic to their users and the environment, delivery in the form of crystalline CD-ICs can limit any contact with and release of the included toxic guests before they function and are used. iv. It has been demonstrated that, by simple precipitation methods, neat as-received CDs that adopt cage crystal structures can be readily transformed to their columnar crystal structures containing only water in their channels, which can be easily displaced by small molecule, as well as polymer guests. v. Guest-CD-rotaxanes are water soluble, they protect the threaded guest from sources of degradation, and the CD hydroxyl groups may be modified to direct the guest-CD-rotaxane to specific substrates. For these reasons, here we summarize our contributions to the study of CD inclusion and delivery of a variety of guest molecules, including antibacterials, spermicides, insecticides, flame retardants, and dyes, that can more usefully functionalize polymer materials.}, journal={INTERNATIONAL JOURNAL OF PHARMACEUTICS}, author={Tonelli, Alan E. and Shen, Jialong}, year={2020}, month={Nov} }
 @article{nada_ali_soliman_shen_abou-zeid_hudson_2020, title={Multi-layer dressing made of laminated electrospun nanowebs and cellulose-based adhesive for comprehensive wound care}, volume={162}, ISSN={["1879-0003"]}, DOI={10.1016/j.ijbiomac.2020.06.184}, abstractNote={In this work, multi-layer wound dressing was made of laminated layers of electrospun fibers supported by adhesive sheet. Graft copolymerization of methyl methacrylate (MMA) and 2-Ethyl-1-hexyl acrylate (EHA) onto carboxymethyl cellulose (CMC) was conducted to obtain an adhesive sheet with 1.52 (N/cm2) loop tack, 1.7 (N/cm) peel strength and 25 s shear strength. Diclofenac sodium, anti-inflammatory drug, was loaded to the adhesive sheet with encapsulation efficiency 73%. The contact layer to wound was made of synthesized anti-bleeding agents, chitosan iodoacetamide (CI) loaded into electrospun polyvinyl alcohol (PVA) fibers. It was fabricated from fiber diameter 300 nm by electrospinning of 5% wt/v of CI (D.S. 18.7%) mixed with 10% wt/v PVA, at 20 kV and 17 cm airgap. The second, pain-relief layer was fabricated by encapsulating up to 50% wt/wt of capsaicin into gelatin nanofibers (197 nm) crosslinked by glyoxal. The third, antimicrobial layer was fabricated from PVA electrospun fibers loaded with 2% wt/wt gentamicin. Biocompatibility test showed insignificant adverse effects of the fabricated layers on fibroblast cells. Animal test on rat showed accelerated wound healing from 21 to 7 days for the multi-layer dressing. Histopathological findings corroborated the intactness of the epidermis layer of the treated samples.}, journal={INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES}, author={Nada, Ahmed A. and Ali, Eman A. and Soliman, Ahmed A. F. and Shen, Jialong and Abou-Zeid, Nabil Y. and Hudson, Samuel M.}, year={2020}, month={Nov}, pages={629–644} }
 @article{shen_nada_abou-zeid_hudson_2020, title={Synthesis of chitosan iodoacetamides via carbodiimide coupling reaction: Effect of degree of substitution on the hemostatic properties}, volume={229}, ISSN={["1879-1344"]}, DOI={10.1016/j.carbpol.2019.115522}, abstractNote={Uncontrolled hemorrhage continues to be the leading cause of death from traumatic injuries both in the battlefield and in the civilian life. Chitosan is among the very few materials that have made the short list of military recommended field-deployable hemostatic dressings. However, the detailed mechanism of its action is still not fully understood. Moreover, in the cases when patients developed coagulopathy, the efficacy of the dressings rely solely on those mechanisms that work outside of the regular blood coagulation cascade. In addition to the well-known erythrocyte agglutination, we proposed to use the reactive N-iodoacetyl group on a new chitosan derivative to accelerate hemostasis. In this paper, we describe the synthesis of chitosan iodoacetamide (CI) with considerations of the stoichiometry among the reagents, the choice of solvent, the pH of the reaction medium, and the reaction time. The reaction was confirmed by FT-IR, 1H and 13C NMR, elemental analysis, iodine content analysis, and SEM-EDS. Water contact angle measurements and Erythrocyte Sedimentation Rate (ESR) method were used to evaluate the hemostatic potential of the newly synthesized CI as a function of their degree of substitution (DS). The range of DS was 5.9% to 27.8% for CI. The mid-range of DS gave the best results for the ESR. CIs exhibit favorable cytocompatibilities up to DS 18.7 compared to the generic unmodified chitosan. In general, the biocompatibility of chitosan iodoacetamide slightly declined with increasing the iodide content up to DS 21.5 owing to its affinity to SH groups of cells.}, journal={CARBOHYDRATE POLYMERS}, author={Shen, Jialong and Nada, Ahmed Ali and Abou-Zeid, Nabil Yousrie and Hudson, Samuel M.}, year={2020}, month={Feb} }
 @article{nada_abdellatif_soliman_shen_hudson_abou-zeid_2019, title={Fabrication and bioevaluation of a medicated electrospun mat based on azido-cellulose acetate via click chemistry}, volume={26}, ISSN={["1572-882X"]}, DOI={10.1007/s10570-019-02739-9}, number={18}, journal={CELLULOSE}, author={Nada, Ahmed A. and Abdellatif, Faten Hassan Hassan and Soliman, Ahmed A. F. and Shen, Jialong and Hudson, Samuel M. and Abou-Zeid, Nabil Y.}, year={2019}, month={Dec}, pages={9721–9736} }
 @article{shen_yildirim_li_caydamli_pasquinelli_tonelli_2019, title={Role of Local Polymer Conformations on the Diverging Glass Transition Temperatures and Dynamic Fragilities of Isotactic-, Syndiotactic-, and Atactic-Poly(methyl methacrylate)s}, volume={52}, url={https://doi.org/10.1021/acs.macromol.9b00434}, DOI={10.1021/acs.macromol.9b00434}, abstractNote={The profound stereosequence dependence of the glass transition temperature (Tg) of poly(methyl methacrylate)s (PMMAs) offers the possibility to evaluate any conformational contributions to their gl...}, number={10}, journal={Macromolecules}, publisher={American Chemical Society (ACS)}, author={Shen, Jialong and Yildirim, Erol and Li, Shanshan and Caydamli, Yavuz and Pasquinelli, Melissa A. and Tonelli, Alan E.}, year={2019}, month={May}, pages={3897–3908} }
 @misc{narayanan_shen_boy_gupta_tonelli_2018, title={Aliphatic Polyester Nanofibers Functionalized with Cyclodextrins and Cyclodextrin-Guest Inclusion Complexes}, volume={10}, ISSN={["2073-4360"]}, url={http://www.mdpi.com/2073-4360/10/4/428}, DOI={10.3390/polym10040428}, abstractNote={The fabrication of nanofibers by electrospinning has gained popularity in the past two decades; however, only in this decade, have polymeric nanofibers been functionalized using cyclodextrins (CDs) or their inclusion complexes (ICs). By combining electrospinning of polymers with free CDs, nanofibers can be fabricated that are capable of capturing small molecules, such as wound odors or environmental toxins in water and air. Likewise, combining polymers with cyclodextrin-inclusion complexes (CD-ICs), has shown promise in enhancing or controlling the delivery of small molecule guests, by minor tweaking in the technique utilized in fabricating these nanofibers, for example, by forming core–shell or multilayered structures and conventional electrospinning, for controlled and rapid delivery, respectively. In addition to small molecule delivery, the thermomechanical properties of the polymers can be significantly improved, as our group has shown recently, by adding non-stoichiometric inclusion complexes to the polymeric nanofibers. We recently reported and thoroughly characterized the fabrication of polypseudorotaxane (PpR) nanofibers without a polymeric carrier. These PpR nanofibers show unusual rheological and thermomechanical properties, even when the coverage of those polymer chains is relatively sparse (~3%). A key advantage of these PpR nanofibers is the presence of relatively stable hydroxyl groups on the outer surface of the nanofibers, which can subsequently be taken advantage of for bioconjugation, making them suitable for biomedical applications. Although the number of studies in this area is limited, initial results suggest significant potential for bone tissue engineering, and with additional bioconjugation in other areas of tissue engineering. In addition, the behaviors and uses of aliphatic polyester nanofibers functionalized with CDs and CD-ICs are briefly described and summarized. Based on these observations, we attempt to draw conclusions for each of these combinations, and the relationships that exist between their presence and the functional behaviors of their nanofibers.}, number={4}, journal={POLYMERS}, author={Narayanan, Ganesh and Shen, Jialong and Boy, Ramiz and Gupta, Bhupender S. and Tonelli, Alan E.}, year={2018}, month={Apr} }
 @article{li_shen_tonelli_2018, title={Self-assembled complexation of urea with poly (methyl methacrylate): A potential method for small molecule encapsulation in PMMA}, volume={156}, ISSN={["1873-2291"]}, DOI={10.1016/j.polymer.2018.09.055}, abstractNote={In this research we report a complex material formed between poly (methyl methacrylate) (PMMA) and urea. The disassociation temperatures of the PMMA/U complexes are higher than the glass transition temperature of neat PMMA and lower than the melting temperature of neat urea. As we reported previously, the as received-PMMA (asr-PMMA) contained a small amount of residual alkane-like surfactant. When forming the PMMA/U complexes with saturated urea-methanol solution, the originally contained contaminant can be encapsulated by urea in the form of a crystalline inclusion compound (IC) and dispersed within the PMMA/U complex. Since urea has been reported to form ICs with various small molecules, this phenomenon provides a potential way for small molecule encapsulation by using PMMA as the substrate and urea as the encapsulant.}, journal={POLYMER}, author={Li, Shanshan and Shen, Jialong and Tonelli, Alan E.}, year={2018}, month={Nov}, pages={95–101} }
 @article{shen_li_caydamli_narayanan_zhang_harrison_tse_tonelli_2018, title={The Role of Polymer Crystallizability on the Formation of Polymer-Urea-Inclusion Compounds}, volume={18}, ISSN={1528-7483 1528-7505}, url={http://dx.doi.org/10.1021/ACS.CGD.8B00240}, DOI={10.1021/acs.cgd.8b00240}, abstractNote={Polymer-urea inclusion compounds (P-U-ICs) were formed using a series of linear aliphatic polyesters with varying crystallizabilities: from highly crystalline to wholly amorphous. The traditional hexagonal P-U-ICs were obtained irrespective of the crystallinities of the neat guest polyesters. Two distinct co-crystallization mechanisms were evident based on the observation of the change in thermal stabilities of the ICs using DSC and the crystal morphologies by SEM; one involves polymer chain folding back and forth in a lamella-like crystal structure and the other grows much like short chain molecule U-ICs absent of chain reentering different channels. For polymers with sufficient chain length, their inherent flexibility is the key factor determining the co-crystallization mechanism while their crystallizability affects the kinetics, the consequences of which are more pronounced during recrystallization from melt. The amorphicity induced by random ester group placement is an interchain property, which does...}, number={5}, journal={Crystal Growth & Design}, publisher={American Chemical Society (ACS)}, author={Shen, Jialong and Li, Shanshan and Caydamli, Yavuz and Narayanan, Ganesh and Zhang, Nanshan and Harrison, Owen and Tse, Shiaoching and Tonelli, Alan E.}, year={2018}, month={Mar}, pages={3099–3106} }
 @article{li_shen_tonelli_2018, title={The influence of a contaminant in commercial PMMA: A purification method for its removal and its consequences}, volume={135}, ISSN={["1873-2291"]}, DOI={10.1016/j.polymer.2017.12.033}, abstractNote={An alkane-like contaminant was isolated from as-received commercial PMMA by forming a conventional urea inclusion compound during the preparation of a PMMA-urea complex. The contaminant, likely a surfactant used in the emulsion polymerization of PMMA, acts as a plasticizer in the commercial PMMA sample. After removing the contaminant, the resultant coalesced-PMMA showed an approximately 30 °C higher glass transition temperature than the as-received PMMA. Forming the PMMA-urea complex and then removing urea and the contaminant together with methanol can purify commercial PMMA and “unmask” its true Tg. Considering the large amount of research performed on PMMA blends, thin films, and nanocomposites, often with inconsistent or conflicting results, we believe the purity of some PMMAs used in past and future studies needs to be examined. Because commercial polystyrene is also obtained by emulsion polymerization and its blends, thin films, and nanocomposites have also been extensively studied, a similar contaminant may be affecting its behavior.}, journal={POLYMER}, author={Li, Shanshan and Shen, Jialong and Tonelli, Alan E.}, year={2018}, month={Jan}, pages={355–361} }
 @article{narayanan_caydamli_tekinalp_matai_boy_chung_shen_gupta_tonelli_2018, title={Thermal, mechanical, and topographical evaluation of nonstoichiometric alpha-cyclodextrin/poly(epsilon-caprolactone) pseudorotaxane nucleated poly(epsilon-caprolactone) composite films}, volume={56}, ISSN={["1099-0488"]}, DOI={10.1002/polb.24741}, abstractNote={ABSTRACT}, number={22}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, publisher={Wiley}, author={Narayanan, Ganesh and Caydamli, Yavuz and Tekinalp, Halil and Matai, Ishita and Boy, Ramiz and Chung, Ching-Chang and Shen, Jialong and Gupta, Bhupender S. and Tonelli, Alan E.}, year={2018}, month={Nov}, pages={1529–1537} }
 @article{shen_tonelli_2017, title={Demonstrating Unique Behaviors of Polymers}, volume={94}, ISSN={["1938-1328"]}, DOI={10.1021/acs.jchemed.7b00008}, abstractNote={Behaviors characteristic of and unique to polymers are demonstrated through four simple experiments: (i) comparison of the dilute solution viscosities of a small molecule and a high-molecular-weight polymer, (ii) observation of the properties of a “slime”, (iii) the stretching of a rubber band, and (iv) a simple paper-and-pencil simulation experiment for the step-growth polymerization of X–Y (or A–B) types of monomers. The described demos have been performed for audiences ranging from middle school to university graduate students to successfully introduce and explain why polymers and materials made from them behave uniquely.}, number={11}, journal={JOURNAL OF CHEMICAL EDUCATION}, author={Shen, Jialong and Tonelli, Alan E.}, year={2017}, month={Nov}, pages={1738–1745} }
 @article{caydamli_yildirim_shen_fang_pasquinelli_spontak_tonelli_2017, title={Nanoscale considerations responsible for diverse macroscopic phase behavior in monosubstituted isobutyl-POSS/poly(ethylene oxide) blends}, volume={13}, ISSN={["1744-6848"]}, url={https://doi.org/10.1039/C7SM01788J}, DOI={10.1039/c7sm01788j}, abstractNote={Nanocomposites prepared by incorporating polyhedral oligomeric silsesquioxane (POSS) into polymer matrices afford versatile hybrid materials but are exquisitely sensitive to even POSS monofunctionalization.}, number={46}, journal={SOFT MATTER}, publisher={Royal Society of Chemistry (RSC)}, author={Caydamli, Yavuz and Yildirim, Erol and Shen, Jialong and Fang, Xiaomeng and Pasquinelli, Melissa A. and Spontak, Richard J. and Tonelli, Alan E.}, year={2017}, month={Dec}, pages={8672–8677} }
 @article{gurarslan_joijode_shen_narayanan_antony_li_caydamli_tonelli_2017, title={Reorganizing Polymer Chains with Cyclodextrins}, volume={9}, url={https://doi.org/10.3390/polym9120673}, DOI={10.3390/polym9120673}, abstractNote={During the past several years, we have been utilizing cyclodextrins (CDs) to nanostructure polymers into bulk samples whose chain organizations, properties, and behaviors are quite distinct from neat bulk samples obtained from their solutions and melts. We first form non-covalently bonded inclusion complexes (ICs) between CD hosts and guest polymers, where the guest chains are highly extended and separately occupy the narrow channels (~0.5–1.0 nm in diameter) formed by the columnar arrangement of CDs in the IC crystals. Careful removal of the host crystalline CD lattice from the polymer-CD-IC crystals leads to coalescence of the guest polymer chains into bulk samples, which we have repeatedly observed to behave distinctly from those produced from their solutions or melts. While amorphous polymers coalesced from their CD-ICs evidence significantly higher glass-transition temperatures, Tgs, polymers that crystallize generally show higher melting and crystallization temperatures (Tms, Tcs), and some-times different crystalline polymorphs, when they are coalesced from their CD-ICs. Formation of CD-ICs containing two or more guest homopolymers or with block copolymers can result in coalesced samples which exhibit intimate mixing between their common homopolymer chains or between the blocks of the copolymer. On a more practically relevant level, the distinct organizations and behaviors observed for polymer samples coalesced from their CD-ICs are found to be stable to extended annealing at temperatures above their Tgs and Tms. We believe this is a consequence of the structural organization of the crystalline polymer-CD-ICs, where the guest polymer chains included in host-IC crystals are separated and confined to occupy the narrow channels formed by the host CDs during IC crystallization. Substantial degrees of the extended and un-entangled natures of the IC-included chains are apparently retained upon coalescence, and are resistant to high temperature annealing. Following the careful removal of the host CD lattice from each randomly oriented IC crystal, the guest polymer chains now occupying a much-reduced volume may be somewhat “nematically” oriented, resulting in a collection of randomly oriented “nematic” regions of largely extended and un-entangled coalesced guest chains. The suggested randomly oriented nematic domain organization of guest polymers might explain why even at high temperatures their transformation to randomly-coiling, interpenetrated, and entangled melts might be difficult. In addition, the behaviors and uses of polymers coalesced from their CD-ICs are briefly described and summarized here, and we attempted to draw conclusions from and relationships between their behaviors and the unique chain organizations and conformations achieved upon coalescence.}, number={12}, journal={Polymers}, publisher={MDPI AG}, author={Gurarslan, Alper and Joijode, Abhay and Shen, Jialong and Narayanan, Ganesh and Antony, Gerry J. and Li, Shanshan and Caydamli, Yavuz and Tonelli, Alan E.}, year={2017}, month={Dec}, pages={673} }
 @misc{gurarslan_joijode_shen_narayanan_antony_li_caydamli_tonelli_2017, title={Reorganizing polymer chains with cyclodextrins}, volume={9}, number={12}, journal={Polymers}, author={Gurarslan, A. and Joijode, A. and Shen, J. L. and Narayanan, G. and Antony, G. J. and Li, S. S. and Caydamli, Y. and Tonelli, A. E.}, year={2017} }
 @article{shen_caydamli_gurarslan_li_tonelli_2017, title={The glass transition temperatures of amorphous linear aliphatic polyesters}, volume={124}, ISSN={["1873-2291"]}, DOI={10.1016/j.polymer.2017.07.054}, abstractNote={A series of wholly amorphous linear aliphatic co- and tetra-polyesters were synthesized via bulk melt step-growth polymerization. Their glass transition temperatures were determined using DSC and were essentially unaffected by crystallinity. The glass transition temperatures of the polyesters increase linearly with the ratio of ester groups per methylene group. Extrapolations of the ratio to zero ester group content gave a reliable value for the Tg of amorphous polyethylene (PE). The experimental Tgs manifest a steeper slope on the Tg vs. ester group content plot compared to those calculated using Van Krevelen's group contribution method. The intramolecular equilibrium flexibilities were evaluated through the calculation of conformational entropies of individual polymer chains approximated by considering solely the short-range interactions between neighboring groups, as embodied in their RIS conformational models. Their calculated conformational entropies, Sconf, decrease linearly with increasing ester group content, leading to the observation that Sconf ∝1/Tg.}, journal={POLYMER}, author={Shen, Jialong and Caydamli, Yavuz and Gurarslan, Alper and Li, Shanshan and Tonelli, Alan E.}, year={2017}, month={Aug}, pages={235–245} }
 @article{zhu_yildirim_aly_shen_chen_lu_jiang_kim_tonelli_pasquinelli_et al._2016, title={Hierarchical multi-component nanofiber separators for lithium polysulfide capture in lithium-sulfur batteries: an experimental and molecular modeling study}, volume={4}, ISSN={["2050-7496"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84984804707&partnerID=MN8TOARS}, DOI={10.1039/c6ta04577d}, abstractNote={A multi-functional nanofiber membrane significantly improves the overall performance of Li–S batteries.}, number={35}, journal={JOURNAL OF MATERIALS CHEMISTRY A}, publisher={Royal Society of Chemistry (RSC)}, author={Zhu, Jiadeng and Yildirim, Erol and Aly, Karim and Shen, Jialong and Chen, Chen and Lu, Yao and Jiang, Mengjin and Kim, David and Tonelli, Alan E. and Pasquinelli, Melissa A. and et al.}, year={2016}, pages={13572–13581} }
 @article{gurarslan_caydamli_shen_tse_yetukuri_tonelli_2015, title={Coalesced Poly(epsilon-caprolactone) Fibers Are Stronger}, volume={16}, ISSN={["1526-4602"]}, DOI={10.1021/bm501799y}, abstractNote={Melt-spun fibers were made from poly(ε-caprolactone) (PCL) coalesced from stoichiometric inclusion complex crystals formed with host urea. Melting and crystallization behaviors, mechanical properties, and the birefringence of undrawn and cold-drawn fibers were investigated. Undrawn coalesced PCL fibers were observed to have 500-600% higher moduli than undrawn as-received (asr) PCL fibers and a modulus comparable to drawn asr PCL fibers. Drawn coalesced PCL fibers have the highest crystallinity, orientation, and 65% higher moduli than drawn asr PCL fibers. Drawn coalesced PCL fibers have only a 5% higher crystallinity than drawn asr PCL fibers, yet they have 65% higher moduli and lower elongation at break values. Clearly, the intrinsic alignment of the coalesced polymers is the reason for their higher moduli and lower elongation, as confirmed by the birefringence observed in drawn coalesced and asr-PCL fibers. The improved mechanical properties of coalesced PCL fibers make them a better candidate for use in tissue engineering as scaffolds.}, number={3}, journal={BIOMACROMOLECULES}, author={Gurarslan, Alper and Caydamli, Yavuz and Shen, Jialong and Tse, Shiaomeng and Yetukuri, Mahijeeth and Tonelli, Alan E.}, year={2015}, month={Mar}, pages={890–893} }
 @article{caydamli_ding_joijode_li_shen_zhu_tonelli_2015, title={Estimating Monomer Sequence Distributions in Tetrapolyacrylates}, volume={48}, ISSN={["1520-5835"]}, DOI={10.1021/ma5019268}, abstractNote={Recently Ting et al. [ACS Macro Lett. 2013, 2, 770−774] described the syntheses of acrylic tetrapolymers with controlled molecular weights and tetramonomer compositions. Relative reactivity ratios of all monomer pairs were determined and used in the Walling–Briggs terminal copolymerization model along with Skeist’s equations to address the expected compositional drift in the monomer feed ratios. The anticipated control of monomer incorporation based on this approach was verified experimentally on several tetrapolyacrylates synthesized by RAFT polymerization, which additionally controlled their molecular weights. Their “new and simple paradigm combining both predictive models provides complementary synthetic and predictive tools for designing macromolecular chemical architectures with hierarchical control over spatially dependent structure–property relationships for complex applications” is extended here to the derivation of expected monad compositions, and diad, triad, and tetrad monomer sequence distribu...}, number={1}, journal={MACROMOLECULES}, author={Caydamli, Yavuz and Ding, Yi and Joijode, Abhay and Li, Shanshan and Shen, Jialong and Zhu, Jiadeng and Tonelli, Alan E.}, year={2015}, month={Jan}, pages={58–63} }
 @article{zhang_shen_pasquinelli_hinks_tonelli_2015, title={Formation and characterization of an inclusion complex of triphenyl phosphate and beta-cyclodextrin and its use as a flame retardant for polyethylene terephthalate}, volume={120}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84937944788&partnerID=MN8TOARS}, DOI={10.1016/j.polymdegradstab.2015.07.014}, abstractNote={Triphenyl phosphate (TPP) is widely used as a flame retardant (FR). However, recent studies have indicated that FRs like TPP can be detected in household dust and wildlife and could contribute to obesity and osteoporosis in humans. We hypothesize that the formation of an inclusion complex (IC) between TPP and β-cyclodextrin (β-CD) will reduce its toxicological effects, while retaining the flame retarding properties of TPP, since the formation of FR-CD-ICs is expected to eliminate unnecessary loss of FRs, especially volatile FR compounds like TPP, and release them only during a fire when they are actually needed. After creating the TPP-β-CD-IC, we applied it to polyethylene terephthalate (PET) films by a hot press technique. Untreated PET films, as well as PET films embedded with uncomplexed β-CD and TPP, were prepared in the same way and had comparable thicknesses. Flame tests were conducted for all film samples by following a modified ASTM D 6413 standard. TPP-β-CD-IC exhibited flame resistant performance matching that of neat TPP, even though much less TPP was contained in its β-CD-IC. Incorporation of FRs and other chemical additives into textile substrates in the form of their crystalline CD-ICs is a promising way to reduce the exposure of hazardous chemicals to humans and to our environment while not impacting their efficacy.}, journal={Polymer Degradation and Stability}, publisher={Elsevier BV}, author={Zhang, Nanshan and Shen, Jialong and Pasquinelli, Melissa and Hinks, D. and Tonelli, A. E.}, year={2015}, pages={244–250} }
 @article{gurarslan_shen_caydamli_tonelli_2015, title={Pyriproxyfen cyclodextrin inclusion compounds}, volume={82}, ISSN={["1573-1111"]}, DOI={10.1007/s10847-015-0526-7}, number={3-4}, journal={JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY}, author={Gurarslan, Alper and Shen, Jialong and Caydamli, Yavuz and Tonelli, Alan E.}, year={2015}, month={Aug}, pages={489–496} }
 @article{gurarslan_shen_tonelli_2013, title={Single-component poly(epsilon-caprolactone) composites}, volume={54}, ISSN={["1873-2291"]}, DOI={10.1016/j.polymer.2013.08.017}, abstractNote={Abstract Non-covalently bonded crystalline inclusion compounds (ICs) have been formed by threading host cyclic starches, α-cyclodextrins (α-CDs), onto guest poly(e-caprolactone) (PCL) chains and by co-crystallization of guest PCL and host urea (U). PCLs were coalesced from both ICs by appropriate removal of the α-CD and U hosts. When added at low concentrations, PCL coalesced from its α-CD–IC served as an effective self-nucleating agent for the bulk crystallization of as-received PCL from the melt. Film sandwiches consisting of two layers of as-received (asr) (control), and one layer each of asr and self-nucleated (nuc) (composite) PCLs were produced by melt pressing. A composite sandwich consisting of a film of neat PCL coalesced from its U–IC (c-PCL) and a film of asr-PCL was also melt pressed. DSC showed that both composite films maintain their characteristic structures and properties even after melt-pressing them together. Both single component film sandwiches exhibited strong interfaces and better mechanical properties than the asr-PCL/asr-PCL control composite sandwiches. These results are similar to those previously obtained on similarly prepared nylon-6 (N-6) sandwich composites made with asr- and nuc-N-6 films with the same levels of crystallinity. However, while the elongation at break was greatly reduced in the asr-N-6/nuc-N-6 composite, asr-/asr-, asr-/c-, and asr-/nuc-, PCL/PCL-composites all showed similarly large elongations at break. The above room temperature and well below room temperature glass-transition temperatures of N-6 and PCL are likely the cause of their widely different elongations at break.}, number={21}, journal={POLYMER}, author={Gurarslan, Alper and Shen, Jialong and Tonelli, Alan E.}, year={2013}, month={Oct}, pages={5747–5753} }