Chitin and Chitosan Nanocomposites: From the Synthesis to the Application

Abstract

Chitin is a bio-based and biodegradable polymer since it is the second most abundant natural polysaccharide on earth after cellulose. It is composed of N-acetyl-d-glucosamine, and it is found in different organisms such as in the exoskeleton of crustacean, insects, annelids, mollusks, plants, and some microorganisms. On the other hand, Chitosan is generally obtained by the controlled deacetylation of chitin in the presence of alkali, composed of randomly distributed β-(1–4) linked d-glucosamine (deacetylated unit) and N-acetyl-d-glucosamine (acetylated unit). Chitin and chitosan are different based on the degree of deacetylation. These polysaccharides possess different physicochemical and biological properties which has been modified and/or improved thanks to the development of chitin and chitosan nanocomposites. There are various methods for the development of chitin and chitosan-based nanocomposites, including solvent casting, spray coating, layer-by-layer, and extrusion. Also, it has been combined with different nano compounds to obtain these nano composites. This chapter summarizes some of the most important technologies involved in synthesizing chitin and chitosan nanocomposites, as well as the study of its physicochemical and biological properties, its production costs and ending in the analysis and discussion of the applications that these materials have in various fields.