Development of Gelatin Bionanocomposite Films Containing Chitin and ZnO Nanoparticles

Abstract

The gelatin-based nanocomposite films (GNCFs) containing 0, 1, 3, and 5% zinc oxide nanoparticles (N-ZnO) and/or 0, 3, 5, and 10% chitin nanofibers (N-chitin) were prepared, and their water vapor permeability (WVP), chemical structure and microstructure, and their mechanical, thermal, and antifungal properties were investigated. Results showed that incorporation of N-ZnO improved WVP, mechanical, thermal, and antifungal properties of the gelatin-based films. Moreover, physicochemical and antifungal properties of the nanocomposite films improved by increasing N-ZnO concentration. However, applying N-chitin in gelatin films could not enhance barrier properties of the films against water vapor, probably due to the hydrophilic nature of N-chitin. On the other hand, tensile strength of the GNCFs containing N-chitin increased by an increase in nanoparticle concentration, up to 5%, Incorporation of N-chitin in the gelatin film raised both thermal stability and antifungal activity. Simultaneous incorporation of chitin and ZnO nanoparticles in the GNCFs had the interactive effect on improving the physicochemical and antimicrobial properties of GNCFs. For instance, thermograms of differential scanning calorimetry (DSC) showed that the GNCF containing both nanoparticles increased melting point and ∆H m in comparison with net gelatin film. Furthermore, thermograms of thermogravimetric analysis (TGA) indicated that applying both of nanoparticles in gelatin films led to higher thermal stability of polymer against decomposition at higher temperatures, compared to the gelatin film containing each of them.