High-barrier and antibacterial films based on PET/SiOx for food packaging applications

Abstract High-barrier and antibacterial materials have potential applications in the field of preservative packaging for fresh meat products. In this paper, UV irradiation and silane coupling agent (KH550) were used to modify the surface of SiOx coating on polyester (PET)/SiOx film to prepare the PET/SiOx/chitosan and PET/SiOx/chitosan-nano-ZnO composite film, respectively. The contact angle test revealed that KH550 improved the surface hydrophilicity of SiOx significantly compared to UV irradiation, and thus PET/SiOx/chitosan and PET/SiOx/chitosan-nano ZnO composite films were successfully prepared and their physical and chemical properties were characterized. SEM images showed that the surface of the composite film was a smooth and layered structure. The mechanical performance testing of the films has revealed that mechanical performance of the PET was improved by SiOx deposition while the coating (KH550, chitosan, and chitosan-nano ZnO) does not affect the mechanical performance of PET/SiOx. The oxygen resistance of PET/SiOx films treated with KH550 was enhanced with the addition of chitosan and chitosan-nano ZnO coating, but the moisture resistance was slightly decreased. Furthermore, PET/SiOx/chitosan and PET/SiOx/chitosan-nano ZnO composite films showed excellent growth inhibition against Staphylococcus aureus and Escherichia coli. The PET/SiOx/chitosan-nano-ZnO films had exhibited the strongest inhibition of bacteria.