Submitted to: ACS Symposium Series
Publication Type: Book / Chapter
Publication Acceptance Date: 7/9/2021
Publication Date: 10/27/2021
Citation: Easson, M.W., Jordan, J.H. 2021. Preparation of cellulose nanocrystals from cotton gin motes and cotton gin trash. In: Sarker, M.I., Liu, L.S., Yadav, M.P., Yosief, H.O., Hussain, S.A., editors. Conversion of Renewable Biomass into Bioproducts. ACS Symposium Series, Vol. 1392. Washington, DC:American Chemical Society. 1392:15-33. https://doi.org/10.1021/bk-2021-1392.ch003.
Interpretive Summary: Cotton gin motes and cotton gin trash are underutilized agricultural waste by-products from cotton gin operations. These biomasses are abundant, sustainable and excellent sources of cellulose for conversion into nanocellulose products. This book chapter details the process methods whereby these two feedstocks are converted into nanocellulose products. The process methods areas of mineral acid and ionic liquid hydrolyses, half-ester cleavage and TEMPO oxidation are highlighted. Process method selection is dependent on specific nanocrystalline property design.
Technical Abstract: Cotton gin by-products offer an enormous, but presently undeveloped biomass feedstock for production of nanocellulose. Nanocellulose in the form of cellulose nanocrystals (CNCs) is obtained by mechanically, chemically or enzymatically treating cellulose fibers. CNCs possess high crystallinity, modulus, aspect ratio, and large surface area, with typical nanoparticle dimensions of 5–10 nm in width and lengths of <100–300 nm. These favorable properties have garnered their use as a reinforcement material in polymers, films, gels, foams and composites. Only recently have CGT and CGM been investigated as biomass source materials to prepare CNCs. Previously, preparation of CNCs from cotton feedstock has primarily come from scoured and bleached cotton fibers or cotton linters, which are the small fiber stubble cut from cotton seeds. Processed cotton fibers are simply too expensive (currently at $0.91/lb) to be considered and, while there is literature precedent for using cotton stalks for CNC production, cotton gin by-products have largely been ignored up until this point. Given the millions of tons of CGT and the hundreds of thousands of tons of CGM available, these two agricultural by-products are promising biomass feedstocks for nanomaterial production and for further value-added applications.