Stability of a chitosan layer deposited onto a polyethylene surface

摘要

A two-step procedure was applied to obtain antimicrobial films; this procedure involved a corona treatment of the polyethylene (PE) surface and its chemical activation with 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride and N-hydroxysuccinimide, and this led to the covalent bonding of chitosan on the PE surface. Electrochemical methods were used to investigate the stability of the deposited chitosan layer. The potentiometric and polyelectrolyte titrations showed that some amount of chitosan desorbed faster from the surface until equilibrium was reached and also that the grafted chitosan layer was more stable than the physically adsorbed one. The chitosan immobilized on the PE surface exhibited the expected antibacterial activity when tested against three bacteria, which included two Gram-negative bacteria, Salmonella enteritidis and Escherichia coli, and one Gram-positive bacterium, Listeria monocytogenes.