Electrostatic property, chitosan polyelectrolyte

Electrostatic complex. Chitosan being a polyelectrolyte is able to form interesting electrostatic complexes with other oppositely charged macromolecules to give hydrogels. The properties of these complex materials depend on the polymer concentration, temperature, pH, ionic concentration, and so on. Few examples are given in the following. 

This chapter describes the main properties and methods for the characterization of polyelectrolytes derived from the biomass. The most important sources are plants, with cellulose and starch, which turn to polyelectrolytes after chemical modifications. CarboxymethylceUulose is the main cellulose derivative used in many industrial applications as good thickener and hydrophilic polymer for aqueous media. Cationic starches are mainly used in the paper industry for fiUa- retention or paper wet-strength. Natural polyelectrol5des are produced by algae with anionic alginates and carrageenans as the major representatives, which are used in food applications and for biomedical devices. In this respect, alginates are often associated in an electrostatic complex with a pseudo-natural polyelectrolyte (chitosan), a cationic polymer extracted from crustaceous shells. 

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