Photo-active chitosan-based hybrid films

Abstract Biodegradable films for food packaging have received increasing attention from the industry in recent years. Due to its extraordinary properties, chitosan has demonstrated to be an exceptional candidate for that kind of applications. In this study, chitosan-based films modified with an azopolymer and silver nanoparticles were prepared by solvent-casting. The quality and homogeneity of the samples was satisfactory and films with thicknesses of the order of 25 µm and of various sizes, with diameters ranging from 5 to 15 cm, were obtained. The developed hybrid films were characterized by several experimental techniques including: atomic force microscopy, attenuated total reflectance-Fourier transformed infrared spectroscopy, thermogravimetric analysis, ultraviolet–visible spectroscopy and water contact angle measurements. In addition, the mechanical properties of the samples were investigated. Specifically, the tensile strength and the elastic modulus were enhanced in the films modified with azopolymer and silver nanoparticles. Moreover, the developed films showed reversible induced birefringence properties, indicating that they could be used for optical storage applications.