Review of chitosan nanomaterials for metal cation adsorption

Polysaccharides are polymers of long chains of monosaccharide units linked via glycosidic bonds. Starch, cellulose, chitin and their derivatives, such as chitosan, are examples of polysaccharides. Chitin is the second most common natural polysaccharide in the world (after cellulose). Chitin and chitosan are amino polysaccharides. Chitosan is often obtained by chemical, or sometimes enzymatic, deacetylation of chitin. These compounds are increasingly being modified to the nanometric scale. New engineering nanomaterials show better chemical, biological, mechanical, thermal, electrical and sorption properties than the primary materials. In this paper, the methods of chitosan nanomaterials synthesis and their adsorption properties of metal cations are discussed. As it is shown, the selected chitosan nanomaterials have promising adsorption properties of metal cations.