Physical and Chemical Degradation of Bacterial Cellulose via Rearranging Fibers

Abstract

Abstract Bacterial cellulose (BC) has unique properties such as high tensile strength, high crystallinity, and high purity. Fiber length of BC causes different attributes. Therefore, degradation of BC has been studied deeply. In this study, fibers of BC were rearranged via DMAc-LiCl solvent and BC was degraded in wet state. Two different degradation methods, milling with liquid nitrogen and autoclave treatment, were applied. Degraded BCs were characterized by FTIR, TEM, AFM, TGA, and XRD. The solvent helps to align the fibers, making it more crystalline. Degraded BCs had lower crystalline ratio than BC, because of increasing hydrogen bonding during degradation in wet state. Degradation with autoclave made two different degraded BCs as nanofibrils and spherical nanocrystals with no pretreatment and solvent pretreatment, respectively. The nanofibril lengths were between 312 – 700 nm depending on applied method and spherical nanocrystal size was 56 nm. The rearrangement via solvent causes an important difference in degradation of BC. Nanofibrils and nanocrystals can be obtained, depending on the rearrangement of fibers before degradation process.