Impact of Gamma Radiation on Physical Characteristics of Packaging Film Made from Chitosan, Bacterial Cellulose Nanofibers, and Zinc Oxide Nanoparticles

Introduction: Notwithstanding the numerous benefits associated with chitosan biopolymer in the fabrication of biodegradable films, its limited mechanical properties and susceptibility to moisture represent significant barriers to its broader application within the packaging sector. Therefore, in this study, chitosan film was combined with bacterial cellulose nanofibers (BCNF) and zinc oxide nanoparticles (ZnONPs) and then exposed to different doses of gamma rays to investigate its effect on physical properties of films. Materials and Methods: In this study, three types of films with three different formulations were prepared along with a control group, and then the effect of gamma rays on their physical characteristics in the first stage and structural properties were investigated in the second stage. Results: The outcome showed that ZnONPs significantly decreased the water vapor permeability (WVP) and increased the opacity of films (p < 0.05). Differential Scanning Calorimetry (DSC) test showed that the presence of ZnONPs and gamma ray irradiation improved the heat resistance of cellulose-chitosan films. The moisture content (MC) of cellulose-chitosan films significantly decreased after being combined with zinc oxide nanoparticles and the irradiation process. The solubility of films showed a significant decrease by adding ZnONPs and increasing irradiation doses. According to the results of FTIR, the samples of the tested films under the influence of irradiation treatments did not show significant difference in the spectrogram. Conclusion: The addition of BCNF and ZnONPs to chitosan-based films and the simultaneous application of gamma ray irradiation technology improved the physical properties of chitosan films.