Preparation and Properties of Optically Transparent Chitin Nanofibers Sheet by Different Simple Mechanical Methods

Abstract

Chitin nanofibers were prepared from commercially available dried chitin powders by different simple mechanical methods under acid conditions after removal of minerals and proteins. The fibrillated chitin samples were observed by FE-SEM and there was a fine network structure formed by chitin nanofibes with a width of approximately 10-50 nm and high aspect ratio. The mechanical treatment under acid conditions was crucial to facilitate the fibrillation of chitin fibers into nanofibers. The high pressure homogenization in combination with grinding was used to obtain the most transparent chitin nanofibers sheet with a transmittance of 88.5% and tensile strength of 82.34MPa, and the sheet even had a Young’s modulus of 6.17GPa. Thus, chitin nanofibers provide excellent potential as reinforcement of transparent flexible composites to improve the properties of nanocomposites.