@article{kaschuk_borghei_solin_tripathi_khakalo_leite_branco_sousa_frollini_rojas_2021, title={Cross-Linked and Surface-Modified Cellulose Acetate as a Cover Layer for Paper-Based Electrochromic Devices}, volume={3}, ISSN={["2637-6105"]}, DOI={10.1021/acsapm.0c01252}, abstractNote={We studied the surface and microstructure of cellulose acetate (CA) films to tailor their barrier and mechanical properties for application in electrochromic devices (ECDs). Cross-linking of CA was carried out with pyromellitic dianhydride to enhance the properties relative to unmodified CA: solvent resistance (by 43% in acetone and 37% in DMSO), strength (by 91% for tensile at break), and barrier (by 65% to oxygen and 92% to water vapor). Surface modification via tetraethyl orthosilicate and octyltrichlorosilane endowed the films with hydrophobicity, stiffness, and further enhanced solvent resistance. A detailed comparison of structural, chemical, surface, and thermal properties was performed by using X-ray diffraction, dynamic mechanical analyses, Fourier-transform infrared spectroscopy, and atomic force microscopy. Coplanar ECDs were synthesized by incorporating a hydrogel electrolyte comprising TEMPO-oxidized cellulose nanofibrils and an ionic liquid. When applied as the top layer in the ECDs, cross-linked and hydrophobized CA films extended the functionality of the assembled displays. The results indicate excellent prospects for CA films in achieving environmental-friendly ECDs that can replace poly(ethylene terephthalate)-based counterparts.}, number={5}, journal={ACS APPLIED POLYMER MATERIALS}, author={Kaschuk, Joice Jaqueline and Borghei, Maryam and Solin, Katariina and Tripathi, Anurodh and Khakalo, Alexey and Leite, Fabio A. S. and Branco, Aida and Sousa, Miriam C. Amores and Frollini, Elisabete and Rojas, Orlando J.}, year={2021}, month={May}, pages={2393–2401} }
 @article{pirzada_sohail_tripathi_farias_mathew_li_opperman_khan_2021, title={Toward Sustainable Crop Protection: Aqueous Dispersions of Biodegradable Particles with Tunable Release and Rainfastness}, volume={11}, ISSN={["1616-3028"]}, url={https://doi.org/10.1002/adfm.202108046}, DOI={10.1002/adfm.202108046}, abstractNote={Fabrication of aqueous particulate dispersions of biodegradable cellulose esters (CEs) as efficient carriers of agrochemical active‐ingredients (AIs) for foliar applications, is reported. The use of different ester substituent groups on CE permits modulation of particle morphology and size, from irregular shapes (<350 nm) to spheres (≈1.1 µm diameter), while maintaining stability as supported by minimal change in zeta potential and particle size over one year. Rainfastness is tested by simulating >50 mm h−1 rainfall on coated banana and tomato leaves and silicon. Surface coverage loss as low as 9%, based on the nature of leaf and formulation, confirms the rainfastness of the formulations. Variation in the release kinetics of a model AI fluopyram from different CEs can be attributed to the particle morphology and the nature of binding between fluopyram and various CEs. Thermodynamic analysis demonstrates spontaneous binding between fluopyram and multiple sites of CEs, justifying its two‐step release from CE particles. System functionalities are corroborated via in‐vitro fungal inhibition assays demonstrating a 100% inhibition of the fungal growth. This “lab‐to‐leaf” approach of materials development involving fundamental insights and functional performance reveals CE dispersions are promising green agricultural formulations with the potential to impact a myriad of crops around the globe.}, journal={ADVANCED FUNCTIONAL MATERIALS}, publisher={Wiley}, author={Pirzada, Tahira and Sohail, Mariam and Tripathi, Anurodh and Farias, Barbara V and Mathew, Reny and Li, Chunying and Opperman, Charles H. and Khan, Saad A.}, year={2021}, month={Nov} }
 @article{tripathi_tardy_khan_liebner_rojas_2019, title={Expanding the upper limits of robustness of cellulose nanocrystal aerogels: outstanding mechanical performance and associated pore compression response of chiral-nematic architectures}, volume={7}, ISSN={["2050-7496"]}, DOI={10.1039/c9ta03950c}, abstractNote={Anisotropy in liquid crystal dispersions of cellulose nanocrystals is demonstrated to drastically enhance the mechanical attributes of derived aerogels.}, number={25}, journal={JOURNAL OF MATERIALS CHEMISTRY A}, author={Tripathi, Anurodh and Tardy, BlaiseL. and Khan, Saad A. and Liebner, Falk and Rojas, Orlando J.}, year={2019}, month={Jul}, pages={15309–15319} }
 @article{klockars_tardy_borghei_tripathi_greca_rojas_2018, title={Effect of Anisotropy of Cellulose Nanocrystal Suspensions on Stratification, Domain Structure Formation, and Structural Colors}, volume={19}, ISSN={["1526-4602"]}, DOI={10.1021/acs.biomac.8b00497}, abstractNote={Outstanding optical and mechanical properties can be obtained from hierarchical assemblies of nanoparticles. Herein, the formation of helically ordered, chiral nematic films obtained from aqueous suspensions of cellulose nanocrystals (CNCs) were studied as a function of the initial suspension state. Specifically, nanoparticle organization and the structural colors displayed by the resultant dry films were investigated as a function of the anisotropic volume fraction (AVF), which depended on the initial CNC concentration and equilibration time. The development of structural color and the extent of macroscopic stratification were studied by optical and scanning electron microscopy as well as UV–vis spectroscopy. Overall, suspensions above the critical threshold required for formation of liquid crystals resulted in CNC films assembled with longer ranged order, more homogeneous pitches along the cross sections, and narrower specific absorption bands. This effect was more pronounced for the suspensions that were closer to equilibrium prior to drying. Thus, we show that high AVF and more extensive phase separation in CNC suspensions resulted in large, long-range ordered chiral nematic domains in dried films. Additionally, the average CNC aspect ratio and size distribution in the two separated phases were measured and correlated to the formation of structured domains in the dried assemblies.}, number={7}, journal={BIOMACROMOLECULES}, author={Klockars, Konrad W. and Tardy, Blaise L. and Borghei, Maryam and Tripathi, Anurodh and Greca, Luiz G. and Rojas, Orlando J.}, year={2018}, month={Jul}, pages={2931–2943} }
 @article{tripathi_ago_khan_rojas_2018, title={Heterogeneous Acetylation of Plant Fibers into Micro- and Nanocelluloses for the Synthesis of Highly Stretchable, Tough, and Water-Resistant Co-continuous Filaments via Wet-Spinning}, volume={10}, ISSN={["1944-8244"]}, DOI={10.1021/acsami.8b17790}, abstractNote={Heterogeneous acetylation of wood fibers is proposed for weakening their interfibrillar hydrogen bonding, which facilitates their processing into micro- and nanocelluloses that can be further used to synthesize filaments via wet-spinning. The structural (SEM, WAXD), molecular (SEC), and chemical (FTIR, titration) properties of the system are used to propose the associated reaction mechanism. Unlike the homogeneous acetylation, this method does not alter the main morphological features of cellulose fibrils. Thus, we show for the first time, the exploitation of synergies of compositions simultaneously comprising dissolved cellulose esters and suspended cellulose micro- and nanofibrils. Such colloidal suspension forms a co-continuous assembly with a matrix that interacts strongly with the micro- and nanofibrils in the dispersed phase. This facilitates uninterrupted and defect-free wet-spinning. Upon contact with an antisolvent (water), filaments are easily formed and display a set of properties that set them apart from those reported so far for nanocelluloses: a remarkable stretchability (30% strain) and ultrahigh toughness (33 MJ/m3), both surpassing the values of all reported nanocellulose-based filaments. All the while, they also exhibit competitive stiffness and strength (6 GPa and 143 MPa, respectively). Most remarkably, they retain 90% of these properties after long-term immersion in water, solving the main challenge of the lack of wet strength that is otherwise observed for filaments synthesized from nanocelluloses.}, number={51}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Tripathi, Anurodh and Ago, Mariko and Khan, Saad A. and Rojas, Orlando J.}, year={2018}, month={Dec}, pages={44776–44786} }
 @article{tripathi_parsons_khan_rojas_2018, title={Synthesis of organic aerogels with tailorable morphology and strength by controlled solvent swelling following Hansen solubility}, volume={8}, ISSN={["2045-2322"]}, url={https://doi.org/10.1038/s41598-018-19720-4}, DOI={10.1038/s41598-018-19720-4}, abstractNote={We introduce a generalized approach to synthesize aerogels that allows remarkable control over its mechanical properties. The Hansen solubility parameters are used to predict and regulate the swelling properties of the precursor gels and, consequently, to achieve aerogels with tailored density and mechanical properties. As a demonstration, crosslinked organogels were synthesized from cellulose esters to generate aerogels. By determination of Hansen's Relative Energy Difference, it was possible to overcome the limitations of current approaches that solely rely on the choice of precursor polymer concentration to achieve a set of aerogel properties. Hence, from a given concentration, aerogels were produced in a range of mass densities, from 25 to 113 mg/cm3. Consequently, it was possible to tailor the stiffness, toughness and compressive strength of the aerogels, in the ranges between 14-340, 4-103 and 22-373 kPa, respectively. Additionally, unidirectional freeze-drying introduced pore alignment in aerogels with honeycomb morphologies and anisotropy. Interestingly, when the swelling of the polymeric gel was arrested in a non-equilibrium state, it was possible to gain additional control of the property space. The proposed method is a novel and generic solution to achieving full control of aerogel development, which up to now has been an intractable challenge.}, journal={SCIENTIFIC REPORTS}, author={Tripathi, Anurodh and Parsons, Gregory N. and Khan, Saad A. and Rojas, Orlando J.}, year={2018}, month={Feb} }