@article{zhang_shen_zhang_schroeder_chen_carnevale_salmon_fang_2024, title={3D-Printed Hydrogel Filter for Biocatalytic CO<sub>2</sub> Capture}, volume={7}, ISSN={["2365-709X"]}, url={https://doi.org/10.1002/admt.202400025}, DOI={10.1002/admt.202400025}, abstractNote={Abstract Innovative scalable CO 2 capture technologies are urgently needed to combat the climate crisis. Reactive absorption in alkaline liquids, an essential process for capturing CO 2 at atmospheric pressure, requires high gas–liquid contact and fast reaction kinetics. To meet these needs, self‐supporting hydrogel CO 2 gas–liquid contactors (or simply “CO 2 filters”) containing the CO 2 selective catalyst carbonic anhydrase (CA) are developed using the direct ink writing additive manufacturing approach. The multifunctional filters are composed of semi‐interpenetrating polymer network hydrogels (IPNHs) of poly (ethylene glycol) diacrylate/poly (ethylene oxide) (PEG‐DA/PEO) upon photocuring during 3D printing. Formulations with PEG‐DA levels of 30–60 wt% are sufficiently homogeneous and reactive to produce coherent grids. Based on operational parameters, a 56 wt% PEG‐DA formulation is selected to continuously print self‐supporting 3D stacked cylindrical grids, with or without enzymes in ink. The resulting enzyme‐laden IPHN filters deliver ≈3 times higher CO 2 capture efficiency than the no‐enzyme control filters in a laboratory‐scale absorption column test. However, the enhancement effect decreases significantly within 2 d of operation, likely due to burst release of enzymes caused by the flowing solution. Covalent crosslinking of CA near the surface, which can improve durability and CO 2 capture performance, will be evaluated in future studies.}, journal={ADVANCED MATERIALS TECHNOLOGIES}, author={Zhang, Sen and Shen, Jialong and Zhang, Peiqi and Schroeder, Thomas B. H. and Chen, Jiahui and Carnevale, Casey and Salmon, Sonja and Fang, Xiaomeng}, year={2024}, month={Jul} }
 @article{wyman_salmon_2024, title={Critical Factors in Lab-Scale Compostability Testing}, volume={9}, ISSN={["1572-8919"]}, url={https://doi.org/10.1007/s10924-024-03311-8}, DOI={10.1007/s10924-024-03311-8}, journal={JOURNAL OF POLYMERS AND THE ENVIRONMENT}, author={Wyman, Diana A. and Salmon, Sonja}, year={2024}, month={Sep} }
 @misc{albelo_raineri_salmon_2024, title={Materials and Methods for All-Cellulose 3D Printing in Sustainable Additive Manufacturing}, volume={5}, ISSN={["2673-4079"]}, url={https://doi.org/10.3390/suschem5020008}, DOI={10.3390/suschem5020008}, abstractNote={Additive manufacturing, commonly referred to as 3D printing, is an exciting and versatile manufacturing technology that has gained traction and interest in both academic and industrial settings. Polymeric materials are essential components in a majority of the feedstocks used across the various 3D printing technologies. As the environmental ramifications of sole or primary reliance on petrochemicals as a resource for industrial polymers continue to manifest themselves on a global scale, a transition to more sustainable bioderived alternatives could offer solutions. In particular, cellulose is promising due to its global abundance, biodegradability, excellent thermal and mechanical properties, and ability to be chemically modified to suit various applications. Traditionally, native cellulose was incorporated in additive manufacturing applications only as a substrate, filler, or reinforcement for other materials because it does not melt or easily dissolve. Now, the exploration of all-cellulose 3D printed materials is invigorated by new liquid processing strategies involving liquid-like slurries, nanocolloids, and advances in direct cellulose solvents that highlight the versatility and desirable properties of this abundant biorenewable photosynthetic feedstock. This review discusses the progress of all-cellulose 3D printing approaches and the associated challenges, with the purpose of promoting future research and development of this important technology for a more sustainable industrial future.}, number={2}, journal={SUSTAINABLE CHEMISTRY}, author={Albelo, Isabel and Raineri, Rachel and Salmon, Sonja}, year={2024}, month={Jun}, pages={98–115} }
 @article{albelo_raineri_salmon_2024, title={Materials and Methods for All-cellulose 3D Printing in Sustainable Additive Manufacturing}, url={https://doi.org/10.20944/preprints202404.0618.v1}, DOI={10.20944/preprints202404.0618.v1}, abstractNote={Additive manufacturing, commonly referred to as 3D printing, is an exciting and versatile manufacturing technology that is gaining traction and interest in both academic and industrial settings. Polymeric materials are essential components in a majority of the “inks” used across the various 3D printing technologies. As the environmental ramifications of sole or primary reliance on petrochemicals as a resource for industrial polymers continue to manifest themselves at a global scale, a transition to more sustainable bioderived alternatives could offer solutions. In particular, cellulose is promising due to its global abundance, biodegradability, excellent thermal and mechanical properties, and ability to be chemically modified to suit various applications. Thus far, cellulose has typically been incorporated in additive manufacturing applications as a substrate, filler, or reinforcement for other materials. However, due to its versatility and desirable properties, the exploration of all-cellulose 3D printing materials and associated methodologies is increasing. This review will discuss the progress and status of all-cellulose 3D printing approaches, associated challenges, and their potential as a key player in a more sustainable industrial future.}, author={Albelo, Isabel and Raineri, Rachel and Salmon, Sonja}, year={2024}, month={Apr} }
 @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={AbstractCarbonic anhydrase (CA) is an attractive biodegradable catalyst for CO2 absorption in solvent‐based CO2 capture. However, maintaining the stability of CA as a homogeneous component of the solvents is a challenge. Solvent regeneration temperature typically exceeds the enzyme thermal tolerance, which leads to CA deactivation. To reduce the need for frequent CA replenishment and to avoid inactive CA accumulation in the solvent, this work shows the benefits of an immobilization strategy where CA is fixed in a second‐generation design of textile structured packing (CATSP‐2) modules. The enzyme‐immobilized packing showed 1.5 times better performance in CO2 separation compared with traditional structured packing with a corresponding increased CO2 loading in the rich solvent. The modules exhibited good CA activity retention of ~80% during the tests without any CA replenishment. Applying CATSP‐2 could potentially decrease the packing height and absorber column size for a lower cost per amount of CO2 captured.}, journal={AICHE JOURNAL}, author={Xiao, Min and Thompson, Jesse and Shen, Jialong and Salmon, Sonja and Liu, Kunlei}, year={2023}, month={Aug} }
 @article{asaduzzaman_salmon_2023, title={Controllable Water-Triggered Degradation of PCL Solution-Blown Nanofibrous Webs Made Possible by Lipase Enzyme Entrapment}, volume={11}, ISSN={["2079-6439"]}, url={https://doi.org/10.3390/fib11060049}, DOI={10.3390/fib11060049}, abstractNote={Polymers in nanofibrous forms offer new opportunities for achieving triggered polymer degradation, which is important for functional and environmental reasons. The polycaprolactone (PCL) nanofibrous nonwoven polymer webs developed in this work by solution blow spinning with entrapped enzymes were completely, rapidly and controllably degraded when triggered by exposure to water. Lipase (CALB) from Candida antarctica was successfully entrapped in the PCL webs via an enzyme-compatible water-in-oil emulsion in the PCL–chloroform spinning solution with added surfactant. Protein (enzyme) in the nanofibrous webs was detected by Fourier Transform Infrared Spectroscopy (FTIR), while time of flight-secondary ion mass spectroscopy (ToF-SIMS) and laser confocal microscopy indicated that enzymes were immobilized within solid fibers as well as within microbead structures distributed throughout the webs. Degradation studies of CALB-enzyme functionalized solution-blown nonwoven (EFSBN)-PCL webs at 40 °C or ambient temperature showed that EFSBN-PCL webs degraded rapidly when exposed to aqueous pH 8 buffer. Scanning electron microscopy (SEM) images of partially degraded webs showed that thinner fibers disappeared first, thus, controlling fiber dimensions could control degradation rates. Rapid degradation was attributed to the combination of nanofibrous web structure and the distribution of enzymes throughout the webs. CALB immobilized in the solid dry webs exhibited long storage stability at room temperature or when refrigerated, with around 60% catalytic activity being retained after 120 days compared to the initial activity. Dry storage stability at ambient conditions and rapid degradation upon exposure to water demonstrated that EFSBN-PCL could be used as fibers or binders in degradable textile or paper products, as components in packaging, for tissue engineering and for controlled-release drug or controlled-release industrial and consumer product applications.}, number={6}, journal={FIBERS}, author={Asaduzzaman, Fnu and Salmon, Sonja}, year={2023}, month={Jun} }
 @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{wang_egan_salmon_2023, title={Preparation and characterization of cotton fiber fragments from model textile waste via mechanical milling and enzyme degradation}, volume={10}, ISSN={["1572-882X"]}, url={https://doi.org/10.1007/s10570-023-05527-8}, DOI={10.1007/s10570-023-05527-8}, journal={CELLULOSE}, author={Wang, Siyan and Egan, Jeannie and Salmon, Sonja}, year={2023}, month={Oct} }
 @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} }
 @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{asaduzzaman_salmon_2022, title={Enzyme immobilization: polymer-solvent-enzyme compatibility}, volume={9}, ISSN={["2058-9689"]}, url={https://doi.org/10.1039/D2ME00140C}, DOI={10.1039/d2me00140c}, abstractNote={Immobilization improves enzyme stability, allows easy enzyme separation from reaction mixtures, and enables repeatable use over prolonged periods, especially in systems requiring continuous chemical reactions.}, journal={MOLECULAR SYSTEMS DESIGN & ENGINEERING}, author={Asaduzzaman, Fnu and Salmon, Sonja}, year={2022}, month={Sep} }
 @article{wang_salmon_2022, title={Progress toward Circularity of Polyester and Cotton Textiles}, url={https://doi.org/10.3390/suschem3030024}, DOI={10.3390/suschem3030024}, abstractNote={Millions of tons of textile waste are landfilled or incinerated in the world every year due to insufficient recycle value streams and the complex composition of textile end products. The goal of this review is to highlight pathways for simplifying and separating textile wastes into valuable raw material streams that will promote their recovery and conversion to useful products. The discussion focuses on advances in sorting, separation, decolorization and conversion of polyester and cotton, the two most common textile fibers. Sorting processes are gaining automation using spectroscopic methods that detect chemical composition differences between materials to divide them into categories. Separation, through dissolving or degrading, makes it possible to deconstruct blended textiles and purify polymers, monomers and co-products. Waste cotton can produce high quality regenerated cellulose fibers, cellulose nanocrystals (CNCs) or biofuels. Waste polyester can produce colored yarns or can be chemically converted to its starting monomers for the recreation of virgin polymer as a complete closed loop. The current strategies for decolorization are presented. Life cycle assessment (LCA) studies found that recycling polyester/cotton blended fabrics for subsequent uses is more sustainable than incineration, and research on producing biomass-based poly-ester also offers feasible avenues for improving textile sustainability and promoting circular processing.}, journal={Sustainable Chemistry}, author={Wang, Siyan and Salmon, Sonja}, year={2022}, month={Sep} }
 @article{asaduzzaman_salmon_2023, title={Protease Immobilization in Solution-Blown Poly(ethylene oxide) Nanofibrous Nonwoven Webs}, url={https://doi.org/10.1021/acsaenm.2c00111}, DOI={10.1021/acsaenm.2c00111}, abstractNote={Enzyme-functionalized solution-blown nonwoven (EFSBN) fibers were produced by a single-step solution blow spinning method that utilizes high-velocity gas to simultaneously extrude the codissolved polymer–solvent–enzyme spinning solution and evaporate solvent at mild conditions to form a nanofibrous web with preserved enzyme activity. A broad concentration range of 0.6–7.4 wt % protein of subtilisin A protease from Bacillus licheniformis was successfully entrapped by poly(ethylene oxide) (PEO) during solution blow spinning nonwoven web production. The presence of enzyme protein in the solid nanofibers was detected by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Time of flight-secondary ion mass spectroscopy and laser confocal microscopy revealed the immobilized enzymes were mainly positioned inside the fibers and homogeneously distributed throughout the webs. Scanning electron microscopy showed that the fiber shape and diameter of PEO nanofibers containing enzymes were irregular compared to PEO-only nanofibers. Residual enzyme activity in the webs was measured by redissolving fibers in buffer and comparing the released enzyme activity to nonimmobilized free enzyme using a casein substrate-based assay. Immobilized protease (1.3% (w/w) protein in solid dry nanofiber webs) retained more than 90% of the free enzyme activity. Protease immobilized in solid nanofiber webs exhibited long storage stability at ambient (∼22 °C) and 4 °C temperature storage conditions, with more than 60% remaining catalytic activity after 300 days compared to the initial activity. Immobilized protease had equally good thermal stability as a stabilized liquid commercial protease, both retaining above 95% of their initial activity after treatment for 12 h at 65 °C. In contrast, the same liquid protease diluted in buffer lost activity within 2 h at that temperature. The nondusting, readily aqueous-soluble EFSBN solid materials are easy to handle and have good storage stability compared to liquid products.}, journal={ACS Applied Engineering Materials}, author={Asaduzzaman, Fnu and Salmon, Sonja}, year={2023}, month={Jan} }
 @article{salmon_2022, title={The Day Before a Breakthrough}, volume={1}, url={https://doi.org/10.52750/561349}, DOI={10.52750/561349}, abstractNote={Have you heard of the XPRIZE? It’s a global competition to crowdsource solutions to some of the world’s biggest challenges. Right now, their biggest competition ever is open — $100 Million for Carbon Removal — to take CO2 out of air. Here's one idea: What if a super-fast enzyme called carbonic anhydrase (the same type of enzyme that helps you breathe) could help pick CO2 molecules out of thin air? And what if a textile fabric (almost like the kind you wear) could be turned into a giant filter to help the enzyme do its job? NC State University researchers can already do this at lab scale; Sonja Salmon, Ph.D. explores how and what the implications may be.}, publisher={North Carolina State University}, author={Salmon, Sonja}, year={2022}, month={Jan} }
 @article{yuan_zhang_bilheux_salmon_2021, title={Biocatalytic Yarn for Peroxide Decomposition with Controlled Liquid Transport}, volume={8}, ISSN={["2196-7350"]}, url={https://publons.com/wos-op/publon/41826322/}, DOI={10.1002/admi.202002104}, abstractNote={AbstractA robust biocatalytic yarn with controllable liquid transport properties is created by coating thin layers of chitosan containing catalase onto a cellulosic yarn. The resulting material integrates enzyme catalytic functionality with protective coating properties of chitosan and structural functionality of the textile. Mild immobilization conditions and good affinity between the two polysaccharides minimize enzyme inactivation during the preparation steps and prevent enzyme from leaching during peroxide decomposition testing and washing, providing a novel and versatile enzyme immobilization strategy. The catalytic efficiency of enzymes in a reaction containing solid, liquid, and gas phases is facilitated when dissolved enzyme substrate is transported by liquid flowing through the coated textile structure. The flow‐through configuration decomposes at least two times more peroxide in a twenty‐times smaller reaction zone volume compared to a stirred tank configuration. Liquid transport through the yarn and liquid spatial distribution within the yarn are investigated by in situ neutron radiography and neutron computed tomography, revealing a constrained wicking mechanism that benefits biocatalytic yarn performance. This new class of sustainable and flexible biocatalytic textile matrices has beneficial multifunctional properties, not previously described, that are applicable for numerous small‐ and large‐scale applications including controlled flow reactors and reactive filtration.}, number={7}, journal={ADVANCED MATERIALS INTERFACES}, publisher={Wiley}, author={Yuan, Yue and Zhang, Yuxuan and Bilheux, Hassina and Salmon, Sonja}, year={2021}, month={Apr} }
 @article{yuan_li_leite_zhang_bonnesen_labbe_weiss_pingali_hong_urban_et al._2021, title={Biosynthesis and characterization of deuterated chitosan in filamentous fungus and yeast}, volume={257}, ISSN={["1879-1344"]}, url={https://publons.com/wos-op/publon/34591276/}, DOI={10.1016/j.carbpol.2021.117637}, abstractNote={Deuterated chitosan was produced from the filamentous fungus Rhizopus oryzae, cultivated with deuterated glucose in H2O medium, without the need for conventional chemical deacetylation. After extraction and purification, the chemical composition and structure were determined by Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and small-angle neutron scattering (SANS). 13C NMR experiments provided additional information about the position of the deuterons in the glucoseamine backbone. The NMR spectra indicated that the deuterium incorporation at the non-exchangeable hydrogen positions of the aminoglucopyranosyl ring in the C3 – C5 positions was at least 60–80 %. However, the C2 position was deuterated at a much lower level (6%). Also, SANS showed that the structure of deuterated chitosan was very similar compared to the non-deuterated counterpart. The most abundant radii of the protiated and deuterated chitosan fibers were 54 Å and 60 Å, respectively, but there is a broader distribution of fiber radii in the protiated chitosan sample. The highly deuterated, soluble fungal chitosan described here can be used as a model material for studying chitosan-enzyme complexes for future neutron scattering studies. Because the physical behavior of non-deuterated fungal chitosan mimicked that of shrimp shell chitosan, the methods presented here represent a new approach to producing a high quality deuterated non-animal-derived aminopolysaccharide for studying the structure-function association of biocomposite materials in drug delivery, tissue engineering and other bioactive chitosan-based composites.}, journal={CARBOHYDRATE POLYMERS}, author={Yuan, Yue and Li, Hui and Leite, Wellington and Zhang, Qiu and Bonnesen, Peter V and Labbe, Jessy L. and Weiss, Kevin L. and Pingali, Sai Venkatesh and Hong, Kunlun and Urban, Volker S. and et al.}, year={2021}, month={Apr} }
 @article{egan_salmon_2022, title={Strategies and progress in synthetic textile fiber biodegradability}, volume={4}, ISSN={["2523-3971"]}, url={https://doi.org/10.1007/s42452-021-04851-7}, DOI={10.1007/s42452-021-04851-7}, abstractNote={
                Abstract
                The serious issue of textile waste accumulation has raised attention on biodegradability as a possible route to support sustainable consumption of textile fibers. However, synthetic textile fibers that dominate the market, especially poly(ethylene terephthalate) (PET), resist biological degradation, creating environmental and waste management challenges. Because pure natural fibers, like cotton, both perform well for consumer textiles and generally meet certain standardized biodegradability criteria, inspiration from the mechanisms involved in natural biodegradability are leading to new discoveries and developments in biologically accelerated textile waste remediation for both natural and synthetic fibers. The objective of this review is to present a multidisciplinary perspective on the essential bio-chemo-physical requirements for textile materials to undergo biodegradation, taking into consideration the impact of environmental or waste management process conditions on biodegradability outcomes. Strategies and recent progress in enhancing synthetic textile fiber biodegradability are reviewed, with emphasis on performance and biodegradability behavior of poly(lactic acid) (PLA) as an alternative biobased, biodegradable apparel textile fiber, and on biological strategies for addressing PET waste, including industrial enzymatic hydrolysis to generate recyclable monomers. Notably, while pure PET fibers do not biodegrade within the timeline of any standardized conditions, recent developments with process intensification and engineered enzymes show that higher enzymatic recycling efficiency for PET polymer has been achieved compared to cellulosic materials. Furthermore, combined with alternative waste management practices, such as composting, anaerobic digestion and biocatalyzed industrial reprocessing, the development of synthetic/natural fiber blends and other strategies are creating opportunities for new biodegradable and recyclable textile fibers.
              
                
                           Article Highlights
                        
                
                  
                    Poly(lactic acid) (PLA) leads other synthetic textile fibers in meeting both performance and biodegradation criteria.
                  
                  
                    Recent research with poly(ethylene terephthalate) (PET) polymer shows potential for efficient enzyme catalyzed industrial recycling.
                  
                  
                    Synthetic/natural fiber blends and other strategies could open opportunities for new biodegradable and recyclable textile fibers.
                  
                
              }, number={1}, journal={SN APPLIED SCIENCES}, publisher={Springer Science and Business Media LLC}, author={Egan, Jeannie and Salmon, Sonja}, year={2022}, month={Jan} }
 @article{leimbrink_nikoleit_spitzer_salmon_bucholz_górak_skiborowski_2018, title={Enzymatic reactive absorption of CO2 in MDEA by means of an innovative biocatalyst delivery system}, volume={334}, ISSN={1385-8947}, url={http://dx.doi.org/10.1016/J.CEJ.2017.11.034}, DOI={10.1016/J.CEJ.2017.11.034}, abstractNote={Due to the increasing world population and industrialization the worldwide energy requirement is also increasing. About 82% of the world’s total primary energy supply stems from fossil sources and coal combustion in power plants accounted for 46% of the 32.4 Gt global carbon dioxide (CO2) emissions in 2014 (International Energy Agency, Key CO2 Emissions Trends: Excerpt from CO2 Emissions from Fuel Combustion (2016 edition)). The reduction of CO2 emissions from power plant flue gases is therefore essential to enable reliable and ecologically benign energy supply. An efficient technology to reduce CO2 emissions is reactive absorption in packed columns with aqueous amine-based absorption solvents, herein also called absorbents. The major drawback of conventional amine absorbents is their high absorption enthalpy, which causes high energy requirements during solvent regeneration. Alternative solvents that offer significantly lower absorption enthalpies suffer from lower absorption rates. To compensate for low absorption rates the enzyme carbonic anhydrase (CA) can be added to the absorbent to accelerate absorption kinetics by catalyzing the reaction between CO2 and water. For industrial applications, it can be desirable to immobilize CA which extends enzyme longevity by confining the enzyme to favorable process conditions, prevents unnecessary exposure to high process temperatures, and enables enzyme reuse. The CO2 absorption characteristics and handling properties of an innovative immobilized CA in the form of microparticles, called biocatalyst delivery system (BDS), were evaluated together with aqueous MDEA solvent. Operational feasibility parameters were validated in lab scale, followed by replicated CO2 absorption performance tests in a small demonstration scale counter-current packed column. A sixfold enhancement in total absorbed mole flow of CO2 in the presence of BDS was demonstrated versus blank MDEA solvent. Recyclability and longevity of BDS were validated.}, journal={Chemical Engineering Journal}, publisher={Elsevier BV}, author={Leimbrink, Mathias and Nikoleit, Klaudia Grazyna and Spitzer, Rüdiger and Salmon, Sonja and Bucholz, Tracy and Górak, Andrzej and Skiborowski, Mirko}, year={2018}, month={Feb}, pages={1195–1205} }
 @article{qi_liu_house_salmon_ambedkar_frimpong_remias_liu_2018, title={Laboratory to bench-scale evaluation of an integrated CO2 capture system using a thermostable carbonic anhydrase promoted K2CO3 solvent with low temperature vacuum stripping}, volume={209}, ISSN={0306-2619}, url={http://dx.doi.org/10.1016/J.APENERGY.2017.10.083}, DOI={10.1016/J.APENERGY.2017.10.083}, abstractNote={An advanced post-combustion CO2 capture process with combined attributes of a thermostable carbonic anhydrase (CA) enzyme catalyst, low-enthalpy K2CO3 solvent, and vacuum stripping utilizing low exergy steam was evaluated from laboratory concept to application performance testing in an integrated 30 standard liters per minute gas flow bench-scale system operated for 500 h. Laboratory concept studies were performed using a wetted wall column to characterize solvent CO2 absorption kinetics and using a recirculating temperature loop to evaluate CA thermo-stability. Wetted wall column tests showed a dramatic 5-fold increase in CO2 mass transfer coefficient when combining 2 g/L CA with aqueous 23.5 wt% K2CO3 solvent. Further increasing the CA concentration resulted in a gradual increase in mass transfer coefficient until a performance plateau was observed beyond a 4 g/L CA dose. Operating temperature had limited impact on CO2 capture over the range 30–50 °C. Surface tension measurements of 23.5 wt% K2CO3 solvent exhibited a gradual decrease with increasing CA concentration. Thermo-stability tests in a temperature cycling loop designed to mimic the temperature swings between absorption and desorption showed that CA longevity could be extended by decreasing the total cycle time spent at high temperature. Parametric tests in the bench-scale unit resulted in a CO2 capture efficiency increase of 4.6-fold when increasing the CA concentration from zero to 2.5 g/L. Capture efficiency increased with higher reboiler duty (i.e. reboiler temperature) and lower absorber temperature. Tests with a 30 °C absorber temperature delivered >90% capture. Variation in solvent flow rate had little impact on capture efficiency because the reaction closely reached equilibrium at the top of the absorber. The integrated bench-scale system operated successfully for an accumulated 500 h under conditions of 40 °C absorber temperature and stripper at 35 kPa pressure with an approximate 77 °C stripper bottom temperature, delivering an average 84% CO2 capture with 23.5 wt% K2CO3-based solvent containing 2.5 g/L CA. Dissolved CA replenishment and conventional process controls were demonstrated as straightforward approaches to maintain system performance of this benign, low-temperature, CA-promoted process for CO2 capture.}, journal={Applied Energy}, publisher={Elsevier BV}, author={Qi, Guojie and Liu, Kun and House, Alan and Salmon, Sonja and Ambedkar, Balraj and Frimpong, Reynolds A. and Remias, Joseph E. and Liu, Kunlei}, year={2018}, month={Jan}, pages={180–189} }
 @article{leimbrink_tlatlik_salmon_kunze_limberg_spitzer_gottschalk_górak_skiborowski_2017, title={Pilot scale testing and modeling of enzymatic reactive absorption in packed columns for CO2 capture}, volume={62}, ISSN={1750-5836}, url={http://dx.doi.org/10.1016/J.IJGGC.2017.04.010}, DOI={10.1016/J.IJGGC.2017.04.010}, abstractNote={Efficient processes for carbon dioxide (CO2) capture from post-combustion flue gases are required to combat global climate change. A key stage in post-combustion capture is selective CO2 separation from the flue gas stream. Separation of CO2 from mixed gases using countercurrent gas–liquid absorption in packed columns is a well-established technology for treatment of industrial gas streams. This approach can be adapted to remove CO2 from post-combustion flue gas, however, process improvements are needed to minimize the corresponding capital costs and energy requirements. Special challenges for CO2 recovery from flue gas arise from the very large volumes of gas to be processed, the need to operate the process with an inlet flue gas stream at atmospheric pressure, and the high amount of energy required to regenerate the absorption liquid. Aqueous solutions of the tertiary amine N-methyldiethanolamine (MDEA) are commercially used for high pressure CO2 separation due to high loading capacity for CO2, relatively good chemical and thermal stability and low volatility. Application of MDEA-based solutions to ambient pressure separations, such as CO2 capture from flue gases, is challenging since high reaction rates are required. High reaction rates for the MDEA system are achievable at high temperatures, which is conflicting with the preference of low temperatures to exploit high absorption capacity. This conflict can be overcome with the addition of a rate enhancing catalyst that enables high reaction rates at low temperatures. To put this innovative breakthrough technology closer to industrial application CO2 absorption in 30–50 wt.% aqueous solutions of MDEA in absence and presence of the CO2 absorption enhancing enzyme carbonic anhydrase (CA) was evaluated in pilot scale. The pilot scale investigation employed a packed column for parametric testing. Test variables included the liquid phase composition (30–50 wt.% MDEA), the column liquid load (8–24 m3 m−2 h−1), the absorber temperature (20–40 °C), and the application of CA in a dissolved or immobilized form. The CO2 absorption mass transfer enhancement provided by CA was measured. In the presence of dissolved CA, 30 wt.% aqueous MDEA showed superior performance in terms of absorption rates compared to operation using 50 wt.% MDEA(aq). No significant change in the CO2 absorption rate was observed for operation at given loads between 20 °C and 40 °C with dissolved CA present. At 20 °C with 30 wt.% MDEA the absorption rate with dissolved CA increased by more than 9 times compared to the absorption rate without enzyme. These results broaden the operation window for efficient CO2 absorption using MDEA solutions and allow for the exploitation of new process regimes, wherein high equilibrium loadings are achievable by applying lower absorption temperatures. Based on the experimental results obtained with dissolved CA, a simplified rate-based model of enzymatic reactive absorption (ERA), accounting for enzyme accelerated reaction kinetics, was developed which was capable of accurately predicting CO2 absorption rate when compared with experimental data. Implemented in a process simulator the model allows for the detailed investigation of the process behavior and the complex interactions of ab- and desorption operations in the presence of the CA. The validated model is intended to guide future experimental work as well as further performance optimization. In addition to the work exploiting the catalyst in its free form, the utilization of CA immobilized in a granular form and held in the pockets of Katapak-SP packing was successfully demonstrated.}, journal={International Journal of Greenhouse Gas Control}, publisher={Elsevier BV}, author={Leimbrink, Mathias and Tlatlik, Stephen and Salmon, Sonja and Kunze, Anna-Katharina and Limberg, Timo and Spitzer, Rüdiger and Gottschalk, Axel and Górak, Andrzej and Skiborowski, Mirko}, year={2017}, month={Jul}, pages={100–112} }
 @article{qi_liu_frimpong_house_salmon_liu_2016, title={Integrated Bench-Scale Parametric Study on CO2 Capture Using a Carbonic Anhydrase Promoted K2CO3 Solvent with Low Temperature Vacuum Stripping}, volume={55}, ISSN={0888-5885 1520-5045}, url={http://dx.doi.org/10.1021/ACS.IECR.6B03395}, DOI={10.1021/ACS.IECR.6B03395}, abstractNote={A bench-scale unit was fabricated and used to investigate use of carbonic anhydrase (CA) promoted K2CO3 solvent as an option for CO2 capture from coal-fired power plants. Bench-scale parametric tests were performed at various CA concentrations, solvent flow rates, and reboiler duties. The CO2 capture efficiency significantly increases, and regeneration energy requirement decreases, with increasing CA concentrations up to 2.5 g/L, with capture performance leveling off at higher enzyme doses (up to 4 g/L). Thus, at higher enzyme doses, the capture efficiency is equilibrium rather than kinetically controlled at the top of absorber, when using solvent regenerated via vacuum stripping at high (>35%) lean carbonate to bicarbonate (CTB) conversion levels, which limits the driving force for CO2 absorption. The CO2 capture efficiency also increases when reboiler duty was increased from 0.85 to 1.1 kW, although this also increases the regeneration energy penalty. In contrast, the effect of solvent flow rate on CO2 ...}, number={48}, journal={Industrial & Engineering Chemistry Research}, publisher={American Chemical Society (ACS)}, author={Qi, Guojie and Liu, Kun and Frimpong, Reynolds A. and House, Alan and Salmon, Sonja and Liu, Kunlei}, year={2016}, month={Nov}, pages={12452–12459} }
 @inbook{salmon_house_2015, title={Enzyme-catalyzed Solvents for CO2 Separation}, url={http://dx.doi.org/10.1016/b978-0-444-63259-3.00002-1}, DOI={10.1016/b978-0-444-63259-3.00002-1}, abstractNote={Carbonic anhydrase enzymes are biological catalysts, which accelerate the interconversion between dissolved carbon dioxide and bicarbonate ion, providing rapid approach to equilibrium between dissolved CO2 and HCO3− in aqueous solutions. This simple CO2 hydration reaction is fundamental to CO2 scrubbing processes that rely on chemical sorption in aqueous solvents for selective removal of CO2 from mixed gases, raising interest in carbonic anhydrase as a potential catalyst for industrial gas–liquid scrubbing applications. Although initially believed limited to ambient temperature regimes, a number of carbonic anhydrases are now known to be very stable at typical postcombustion CO2 absorber temperatures in the 30–50 °C range, and also show tolerance up to the moderate regenerator temperatures, around 70–80 °C, envisioned for use with low-enthalpy solvents. Furthermore, certain carbonic anhydrases exhibit good longevity in the alkaline and high molar or high ionic strength aqueous solvents required for efficient CO2 separation, especially important for processes operating near atmospheric pressure. These enzyme features open the possibility for new process approaches, which could lower the cost of CO2 scrubbing while mitigating implementation risks due to the close resemblance to conventional recirculating absorber–desorber scrubbing processes. This chapter describes the general mode of action of carbonic anhydrase in the context of CO2 gas–liquid scrubbing processes, including descriptions of corresponding analytical and methods. The current state of the art in carbonic anhydrase diversity and characteristics relevant to CO2 scrubbing applications are reviewed. Studies evaluating the utility and stability of carbonic anhydrase for CO2 scrubbing applications, including stability of different enzyme–solvent combinations and stability of the enzyme toward common gas processing contaminants are presented. Based on these characteristics, simplified schematic process configurations in the context of enzyme benefit and longevity are discussed, and perspective is provided on the potential for commercial deployment of enzyme-based CO2 scrubbing technology, as well as areas for further development.}, booktitle={Novel Materials for Carbon Dioxide Mitigation Technology}, publisher={Elsevier}, author={Salmon, Sonja and House, Alan}, year={2015}, pages={23–86} }
 @article{xu_salmon_2008, title={Potential Applications of Oxidoreductases for the Re‐oxidation of Leuco Vat or Sulfur Dyes in Textile Dyeing}, volume={8}, ISSN={1618-0240 1618-2863}, url={http://dx.doi.org/10.1002/elsc.200700070}, DOI={10.1002/elsc.200700070}, abstractNote={AbstractConventional textile dyeing by vat and sulfur dyes includes reduction and re‐oxidation steps (with chemical reductants and oxidants), so that the insoluble dyes can be solubilized in the dyeing solution, adsorbed by the fabric, and fixed onto the dyed fabric. The treatments often involve hazardous chemicals, expensive catalysts, or conditions that are suboptimally effective, energy‐intensive, caustic, or polluting. Improving these steps with enzyme technology could be of significant interest in terms of better dyeing, handling of hazardous chemicals, disposal of waste, or production economy. The idea of an enzymatic re‐oxidation step for vat and sulfur dyeings was tested under simplified laboratory conditions. Selected vat and sulfur dyes, including Vat Blue 43, Vat Orange 7, Vat Green 3, Vat Orange 2, Vat Red 13, Vat Yellow 2, and Sulfur Black 1, were first chemically reduced. The reduced (leuco) dyes were then re‐oxidized by aerated buffer solutions or H2O2, in the presence or absence of an oxidoreductase, selected from seven laccases from Myceliophthora thermophila, Scytalidium thermophilum, Coprinus cinereus, Trametes villosa, Rhizoctonia solani, Pycnoporus cinnabarinus, Botrytis cinerea, a bilirubin oxidase from Myrothecium verrucaria, and a heme peroxidase from Coprinus cineresu. It was shown that the enzymes were able to catalyze and accelerate the re‐oxidation of the reduced dyes, even when they were adsorbed on cotton fabric, by dissolved air (O2) or H2O2. Small redox‐active mediators could facilitate the enzymatic re‐oxidation. For Sulfur Black 1, a higher conversion of the leuco dye was achieved with laccase‐catalyzed re‐oxidation. The further development of this potential enzyme application is discussed.}, number={3}, journal={Engineering in Life Sciences}, publisher={Wiley}, author={Xu, F. and Salmon, S.}, year={2008}, month={Jun}, pages={331–337} }
 @inbook{schäfer_borchert_nielsen_skagerlind_gibson_wenger_hatzack_nilsson_salmon_pedersen_et al., title={Industrial Enzymes}, url={http://dx.doi.org/10.1007/10_2006_039}, DOI={10.1007/10_2006_039}, booktitle={Advances in Biochemical Engineering/Biotechnology}, publisher={Springer Berlin Heidelberg}, author={Schäfer, Thomas and Borchert, Torben Wedel and Nielsen, Vibeke Skovgard and Skagerlind, Peter and Gibson, Keith and Wenger, Kevin and Hatzack, Frank and Nilsson, Lone Dybdal and Salmon, Sonja and Pedersen, Sven and et al.}, pages={59–131} }
 @article{salmon_hudson_1997, title={Crystal Morphology, Biosynthesis, and Physical Assembly of Cellulose, Chitin, and Chitosan}, volume={37}, ISSN={1558-3724}, url={http://dx.doi.org/10.1080/15321799708018366}, DOI={10.1080/15321799708018366}, abstractNote={Abstract Cellulose and its chemical analogs chitin and chitosan are abundant and technologically important fibrous polysaccharides. Cellulose and chitin are, respectively, the first [1] and second [2] most abundant natural polysaccharides. Chitosan, though less prevalent in nature, is a useful and easily accessible derivative of chitin. All three polymers are biodegradable, renewable resources with versatile chemical and physical properties. As such, they are the subject of active scientific and commercial scrutiny.}, number={2}, journal={Polymer Reviews}, publisher={Informa UK Limited}, author={Salmon, Sonja and Hudson, Samuel}, year={1997}, month={May}, pages={199–276} }
 @article{salmon_hudson_1995, title={SHEAR-PRECIPITATED CHITOSAN POWDERS, FIBRIDS, AND FIBRID PAPERS - OBSERVATIONS ON THEIR FORMATION AND CHARACTERIZATION}, volume={33}, ISSN={["1099-0488"]}, url={http://dx.doi.org/10.1002/polb.1995.090330703}, DOI={10.1002/polb.1995.090330703}, abstractNote={AbstractChitosan powders and fibrids were prepared by shear precipitation of dissolved chitosan in a coagulating solution of sodium hydroxide. Following neutralization by washing and an alcohol dehydration step, the white to off‐white powders were fine and free flowing. The dried fibrids had a highly oriented, ribbon‐like shape that in bulk gave a lofty appearance and soft hand. Chitosan fibrids were readily converted to sheet structures by typical paper‐making procedures. The resulting chitosan papers were either smooth, flexible, and largely translucent when pressed dry from the moist mat, or were soft and opaque white when the moist mat was soaked in alcohol before drying. X‐ray diffraction, SEM, and optical microscopy were used to characterize the different chitosan powders, fibrids, and papers. Chitosan fibrid papers were found to have tensile properties comparable to that of cellulosic papers, though the wet strength and water sorption of chitosan fibrid papers was higher than that of the cellulose controls. ©1995 John Wiley & Sons, Inc.}, number={7}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, publisher={Wiley}, author={SALMON, S and HUDSON, SM}, year={1995}, month={May}, pages={1007–1014} }