Effect of Grinder Pretreatment for Easy Disintegration of Chitin into Nanofiber

Abstract

Chitin nanofibers were prepared by grinder pretreatments and subsequent mechanical treatment using a high-pressure water-jet (HPWJ) system. From SEM observations, grinder pretreatment improved disintegration efficiency in subsequent HPWJ treatment. That is, with pretreatment, excellent nanofiber networks were observed after a single HPWJ treatment, and sufficient nano-fibrillation was accomplished with 5 cycles of HPWJ treatments. The characteristic crystalline structure of α-chitin and degree of relative crystallinity were maintained after a series of mechanical treatments. From UV-Vis spectra, grinder pretreatment improved transparency of chitin nanofiber slurry, indicating the pretreatment facilitated subsequent HPWJ mechanical disintegration. Viscosities of chitin nanofiber slurry also showed that the grinder pretreatment and HPWJ treatment disintegrated the chitin into nanofiber very well. However, excessive HPWJ treatment decreased nano-fiber length, resulting in lower viscosity.