ABSTRACT
This chapter reviews studies on the preparation of self-assembled chitin nanofibers and nanocomposites using an ionic liquid. Because chitin is one of the most abundant polysaccharides on the earth, there is major interest in conversion of native chitin resources into various useful materials after proper dissolution or gelation in suitable solvents. For the production of nanoscaled chitin materials, authors have been focusing on ionic liquids and found that an ionic liquid, 1-allyl-3-methylimidazolium bromide (AMIMBr), dissolved chitin in concentrations up to 4.8 wt% and mixtures of the higher amounts of chitin with AMIMBr gave ion gels. The self-assembled chitin nanofibers were fabricated by regeneration technique from the chitin ion gel with AMIMBr using methanol. Moreover, filtration of the resulting chitin nanofiber dispersion with methanol gave a chitin nanofiber film. Conventional
approaches to the production of chitin nanofibers have mainly been performed upon top-down procedures that break down the starting bulk materials from natural resources. The present method is the completely different approach from the above to produce chitin nanofibers, which follows self-assembling generative (bottom-up) route. The chitin nanofiber/synthetic polymer nanocomposite films were also prepared by surface-initiated graft polymerization approach of the appropriate monomers. 14.1 IntroductionThe polysaccharides are widely distributed in nature and have been regarded as structural materials and as suppliers of energy [1]. Because of better recent understanding of their possessing unique structures and properties, much attention has been paid to them as material sources. Of the many kinds of polysaccharides, chitin, a structural polymer in crustaceans, shellfish, and insects, is one of the most abundant natural polysaccharides in nature [2-6]. Despite its huge annual production and easy accessibility, chitin still remains an unutilized biomass resource primary because of its intractable bulk structure and insolubility in water and common organic solvents, and thus, only limited application has been paid to chitin, principally from its biological properties [7].
