Effect of the degree of acetylation on the physicochemical properties of α-chitin nanofibers.

The effective utilization of abundant α-chitin resources for materials engineering applications requires methods for controlling the physicochemical properties of α-chitin nanofiber (NF) dispersions. Herein, the relationship between the degree of acetylation (DA) of α-chitin and the physicochemical properties of α-chitin nanofibers (α-ChNFs) was investigated. α-Chitin with different DAs was prepared by varying the deacetylation treatment time. These α-chitin samples were disintegrated into NFs using wet pulverization. The average width of the α-ChNFs decreased with decreasing DA. Furthermore, the transmittance and viscosity of the α-ChNF dispersions increased with decreasing DA. We successfully developed a simple model for estimating the average width of α-ChNFs with different DAs. These results indicate that the DA is an effective parameter for defining and controlling the physicochemical properties of α-ChNFs.