Table 3.

Main chemical properties of chitosan, according the information reported in [28].

Linear aminopolysaccharide with a high nitrogen content

Rigid d-glucosamine structure: hydrophilicity, crystallinity

Weak base (pKa: 6.3). Deprotonated amino group can act as strong nucleophile

Enable to form intermolecular hydrogen bonds: high viscosity

Existence of reactive groups for chemical activation and cross-linking

Insoluble in water and organic solvents, but soluble in dilute aqueous acid solutions.

It forms salts with organic and inorganic acids

Complexing and chelating properties

Ionic conductivity

Polyelectrolytes (at acid pH)

Cationic biopolymer with high charge density (one positive charge per glucosamine residue)

Flocculating agent (interacts with negatively charged molecules)

Entrapment and adsorption properties (filtration and separation)

Film-forming ability (adhesive materials for isolation of biomolecules)

Biological properties (biocompatibility) bioadhesivity bioactivity non-toxic biodegradable adsorbable antimicrobial activity (fungi, bacterial, viruses) antiacid, antiulcer and antitumoral properties blood anticoagulants hypolipidermic activity