@article{jin_spontak_2023, title={Fundamentals of and advances in nanocellulose and nanochitin systems}, volume={6}, ISSN={["2542-5048"]}, DOI={10.1016/j.aiepr.2023.04.003}, abstractNote={Due to the deleterious environmental consequences resulting from a broad spectrum of synthetic polymers during use or post-application disposal, interest in biomaterials obtained from eco-friendly and sustainable sources is growing. This review first examines some of the fundamental concepts regarding biologically-derived nanoparticles (“bionanoparticles”) extracted from the two most prevalent polymers on the planet: natural cellulose and chitin. With this background established, we turn our attention to several advances in this expanding field. Recent rheological studies have established that a “kink” often reported in steady-shear tests of fibrous nanocellulose suspensions is related to anisotropic flocs. Thorough analysis of this observation demonstrates the existence of dual yield points that pinpoint the processing conditions over which these flocs form. Another advance is isothermal titration calorimetry, which relates the formation of structure to viscous heating and provides a uniquely quick and precise analysis tool for measuring the concentration of cellulose nanocrystals responsible for the onset of mesomorphism in aqueous suspensions. In addition, the incorporation of various electrolytes in aqueous nanocellulose or nanochitin suspensions is capable of promoting cellulose or chitin nanocrystal (de)swelling or suspension templating of solid films, and positron annihilation lifetime spectroscopy can be used to follow changes in nanoscale free volume upon swelling in the presence of moisture, which can be independently used in conjunction with CO2-philic ionic liquids to achieve highly selective carbon capture in hybrid gas-separation membranes.}, number={4}, journal={ADVANCED INDUSTRIAL AND ENGINEERING POLYMER RESEARCH}, author={Jin, Soo-Ah and Spontak, Richard J.}, year={2023}, month={Oct}, pages={356–381} }
 @article{park_banerjee_jin_li_beck_purser_ford_2023, title={Organophosphate-Cyclodextrin Inclusion Complex for Flame Retardancy in Doped Cellulose Acetate Butyrate Melt-Spun Fibers}, ISSN={["1520-5045"]}, DOI={10.1021/acs.iecr.3c00712}, abstractNote={Organophosphates are widely used flame retardants (FR) in everyday applications, and their leaching over time is a gaining concern. In this research, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) was chosen as a representative organophosphate FR to examine inclusion complex (IC) formation with γ-cyclodextrins (γ-CD) to enhance char formation as well as prevent the unnecessary release of toxic FR chemicals. The addition of ionic salts, sodium chloride (NaCl), and calcium chloride (CaCl2) during the formation increased the yield of IC crystals by up to 50%. However, perfect crystals were formed only when pure IC was formed, devoid of only metal crystals. Continuous melt spinning of cellulose acetate butyrate (CAB) is practically very difficult in the presence of incompatible DOPO in the system. The formed IC was compatible with biopolymer CAB due to hydroxyl groups from γ-cyclodextrin at the periphery. CAB/IC fibers were melt-spun alongside reference pure CAB and CAB/CD fibers. CAB was found to form complexation with CD in the absence of DOPO in the cavity, as corroborated by FTIR and tensile properties. Furthermore, the response to flame was noted as compared to reference pure CAB and CAB/CD fibers. CAB/IC was found to have self-extinguishing behavior via the formation of a char layer even at ∼0.8 wt % DOPO fraction in the fiber.}, journal={INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH}, author={Park, Yaewon and Banerjee, Debjyoti and Jin, Soo Ah and Li, Shanshan and Beck, Susan and Purser, Lauren and Ford, Ericka}, year={2023}, month={Jul} }
 @article{jin_kamarainen_rinke_rojas_todorovic_2022, title={Machine learning as a tool to engineer microstructures: Morphological prediction of tannin-based colloids using Bayesian surrogate models}, ISSN={["1938-1425"]}, DOI={10.1557/s43577-021-00183-4}, abstractNote={
                Abstract
                Oxidized tannic acid (OTA) is a useful biomolecule with a strong tendency to form complexes with metals and proteins. In this study we open the possibility to further the application of OTA when assembled as supramolecular systems, which typically exhibit functions that correlate with shape and associated morphological features. We used machine learning (ML) to selectively engineer OTA into particles encompassing one-dimensional to three-dimensional constructs. We employed Bayesian regression to correlate colloidal suspension conditions (pH and pKa) with the size and shape of the assembled colloidal particles. Fewer than 20 experiments were found to be sufficient to build surrogate model landscapes of OTA morphology in the experimental design space, which were chemically interpretable and endowed predictive power on data. We produced multiple property landscapes from the experimental data, helping us to infer solutions that would satisfy, simultaneously, multiple design objectives. The balance between data efficiency and the depth of information delivered by ML approaches testify to their potential to engineer particles, opening new prospects in the emerging field of particle morphogenesis, impacting bioactivity, adhesion, interfacial stabilization, and other functions inherent to OTA.
              }, journal={MRS BULLETIN}, author={Jin, Soo-Ah and Kamarainen, Tero and Rinke, Patrick and Rojas, Orlando J. and Todorovic, Milica}, year={2022}, month={Feb} }
 @article{jin_khan_spontak_rojas_2021, title={Anion-Specific Water Interactions with Nanochitin: Donnan and Osmotic Pressure Effects as Revealed by Quartz Microgravimetry}, volume={37}, ISSN={["0743-7463"]}, url={https://doi.org/10.1021/acs.langmuir.1c01585}, DOI={10.1021/acs.langmuir.1c01585}, abstractNote={The development of new materials emphasizes greater use of sustainable and eco-friendly resources, including those that take advantage of the unique properties of nanopolysaccharides. Advances in this area, however, necessarily require a thorough understanding of interactions with water. Our contribution to this important topic pertains to the swelling behavior of partially deacetylated nanochitin (NCh), which has been studied here by quartz crystal microgravimetry. Ultrathin films of NCh supported on gold-coated resonators have been equilibrated in aqueous electrolyte solutions (containing NaF, NaCl, NaBr, NaNO3, Na2SO4, Na2SO3, or Na3PO4) at different ionic strengths. As anticipated, NCh displays contrasting swelling/deswelling responses, depending on the ionic affinities and valences of the counterions. The extent of water uptake induced by halide anions, for instance, follows a modified Hofmeister series with F– producing the highest swelling. In marked contrast, Cl– induces film dehydration. We conclude that larger anions promote deswelling such that water losses increase with increasing anion valence. Results such as the ones reported here are critical to ongoing efforts designed to dry chitin nanomaterials and develop bio-based and sustainable materials, including particles, films, coatings, and other nanostructured assemblies, for various devices and applications.}, number={38}, journal={LANGMUIR}, publisher={American Chemical Society (ACS)}, author={Jin, Soo-Ah and Khan, Saad A. and Spontak, Richard J. and Rojas, Orlando J.}, year={2021}, month={Sep}, pages={11242–11250} }
 @article{jin_facchine_rojas_khan_spontak_2021, title={Cellulose nanofibers and the film-formation dilemma: Drying temperature and tunable optical, mechanical and wetting properties of nanocomposite films composed of waterborne sulfopolyesters}, volume={598}, ISSN={["1095-7103"]}, url={https://doi.org/10.1016/j.jcis.2021.04.032}, DOI={10.1016/j.jcis.2021.04.032}, abstractNote={Waterborne sulfopolyesters have gained considerable interest as coating materials due to their excellent film-forming and optical properties. Their commercial use has been limited, however, due to their fragile nature. Incorporating cellulose nanofiber (CNF), a sustainable biopolymer, into the polymer matrix is expected to enhance the mechanical integrity of the nanocomposite as these two components synergistically interact. In this study, we have investigated the suspension and film characteristics of three sulfopolyesters varying in charge density, glass transition temperature and molecular weight, as well as their mixtures with CNF. We have performed steady-shear rheology on mixtures with different CNF loading levels, and resulting films have been subjected to quasistatic uniaxial tensile and water contact-angle tests to elucidate the effects of CNF on mechanical and surface properties. Addition of CNF to waterborne polyester promotes shear-thinning behavior that remains unaffected by the CNF content. Solid films cast from these suspensions possess enhanced mechanical properties, as well as tailorable surface hydrophilicity, depending on composition and film-drying temperature. Tensile tests reveal that films containing 10 wt% CNF display the greatest mechanical improvements, suggesting the existence of a previously unidentified Goldilocks composition window.}, journal={JOURNAL OF COLLOID AND INTERFACE SCIENCE}, publisher={Elsevier BV}, author={Jin, Soo-Ah and Facchine, Emily G. and Rojas, Orlando J. and Khan, Saad A. and Spontak, Richard J.}, year={2021}, month={Sep}, pages={369–378} }
 @article{jin_facchine_khan_rojas_spontak_2021, title={Mesophase characteristics of cellulose nanocrystal films prepared from electrolyte suspensions}, volume={599}, ISSN={["1095-7103"]}, url={https://doi.org/10.1016/j.jcis.2021.04.071}, DOI={10.1016/j.jcis.2021.04.071}, abstractNote={Cellulose nanocrystals (CNCs) exhibit a cholesteric mesophase above a critical concentration in aqueous suspensions. Above this concentration, CNCs self-organize into left-handed helicoidal structures that can be preserved in dried, stratified films. In this systematic study, we have prepared optically-active CNC films cast from different electrolyte suspensions and investigated, via circular dichroism and other techniques, the effects of counterion type (six mono/divalent salts, including those responsible for promoting “salting-out” and “salting-in” in the Hofmeister series) and ionic strength on mesomorphic behavior and cholesteric arrangement. The presence of electrolytes influences CNC colloidal stability by compressing the electric double layer and altering interactions among neighboring CNCs and water, thereby affecting the extent to which the CNCs form a mesophase. Interestingly, mesomorphic behavior and CNC alignment appear to be sensitive to cationic radius and charge valence, in which case the optical properties of CNC films can be adjusted for targeted sustainable applications. Such heuristic rules can be valuable for predicting the stability and characteristics of CNC microstructure in designer coatings and thin films prepared by introducing suitable cations prior to film formation.}, journal={JOURNAL OF COLLOID AND INTERFACE SCIENCE}, publisher={Elsevier BV}, author={Jin, Soo-Ah and Facchine, Emily G. and Khan, Saad A. and Rojas, Orlando J. and Spontak, Richard J.}, year={2021}, month={Oct}, pages={207–218} }
 @article{janakiram_ansaloni_jin_yu_dai_spontak_deng_2020, title={Humidity-responsive molecular gate-opening mechanism for gas separation in ultraselective nanocellulose/IL hybrid membranes}, volume={22}, ISSN={["1463-9270"]}, DOI={10.1039/d0gc00544d}, abstractNote={A class of “green” hybrid membranes composed of nanocellulose and an ionic liquid exhibits exceptional separation properties arising from a humidity-responsive size-exclusive “gate” that allows selective CO2 permeation.}, number={11}, journal={GREEN CHEMISTRY}, author={Janakiram, Saravanan and Ansaloni, Luca and Jin, Soo-Ah and Yu, Xinyi and Dai, Zhongde and Spontak, Richard J. and Deng, Liyuan}, year={2020}, month={Jun}, pages={3546–3557} }
 @article{torstensen_liu_jin_deng_hawari_syverud_spontak_gregersen_2018, title={Swelling and Free-Volume Characteristics of TEMPO-Oxidized Cellulose Nanofibril Films}, volume={19}, ISSN={["1526-4602"]}, DOI={10.1021/acs.biomac.7b01814}, abstractNote={Cellulose nanofibrils (CNFs) are becoming increasingly ubiquitous in diverse technologies requiring sustainable nanoscale species to form or modify films. The objective of the present study is to investigate the swelling behavior and accompanying free volume of self-standing TEMPO-oxidized (TO) CNF films in the presence of water vapor. For this purpose, we have performed time-resolved swelling experiments on films, prepared according to different experimental protocols, at 90% relative humidity (RH) and ambient temperature. Corresponding free-volume characteristics are elucidated by positron annihilation lifetime spectroscopy (PALS) conducted at ambient temperature and several RH levels. Increasing the drying temperature of the films (from ambient to 50 °C) is observed to promote an increase in film density, which serves to reduce bulk swelling. These elevated drying temperatures likewise cause the free-volume pore size measured by PALS to decrease, while the corresponding total free-volume fraction remains nearly constant. Similarly, dispersion of TO-CNF into aqueous suspensions by ultrasonication prior to film formation increases both the total free-volume fraction and pore size but reduces the size of individual nanofibrils with little net change in bulk swelling. The swelling and concurrent free-volume measurements reported here generally reveal an increase in the free volume of TO-CNF films with increasing RH.}, number={3}, journal={BIOMACROMOLECULES}, author={Torstensen, Jonathan O. and Liu, Ming and Jin, Soo-Ah and Deng, Liyuan and Hawari, Ayman I. and Syverud, Kristin and Spontak, Richard J. and Gregersen, Oyvind W.}, year={2018}, month={Mar}, pages={1016–1025} }