Improvement of chitosan solubility and bactericidity by synthesis of N-benzimidazole-O-acetyl-chitosan and its electrodeposition.

Chitosan solubility and its antibacterial activity have been improved first of all with a chemical synthesis of N-benzimidazole-O-acetyl-chitosan in acetic medium and foremost through a potentiodynamic electrodeposition of this derivative. An association of one benzimidazole and three acetyl moieties per two units of the biopolymer chain was evidenced by FTIR and 1H NMR, pH-metric titration and TG analysis. Cyclic voltammetry study of the modified polymer in acetonitrile solution reveals its anodic oxidation at a platinum disk and a progressive growing of a thin film, through the cycling of potential. An enhancement of the solubility of the biopolymer as well as its antibacterial activity against Salmonella typhimurium, Escherichia coli, Staphylococcus aureus and Pseudomoenas aeruginosa bacteria have been observed with these chemical and after electrochemical modifications.