DEVELOPMENT AND CHARACTERIZATION OF CHITOSAN HYBRID COATINGS BY SOL-GEL METHOD

This paper describes the preparation and characterization of hybrid coatings constituted by SiO2, TiO2 and chitosan in varying compositions on aluminium, and glass substrates by sol–gel method. The optimized sol-gel solutions were deposited using by dip-coating and spray coating and the thermal treatment conditions (temperature) were optimized. In particular, condensation reactions necessary to allow the formation of the metal oxide networks were performed by storing the films in an open-air oven at 100°C and 80 °C for 30 minutes. Moreover, the functionalization of hybrid has been carried out with vinyltrimethoxysilane (VTMS). The films were investigated by scanning electron microscopy (SEM), Fourier transformed infrared (FTIR) spectroscopy, hydrolytic degradation, corrosion resistance and adhesion test. The process yields transparent chitosan hybrid coatings with good adhesion on glass and aluminium substrates. The obtained results suggest that the functionalization of the hybrid coatings was affected through in situ hydrolysis–condensation reaction of vinyltrimethoxysilane (VTMS) in the reaction medium