Antibacterial and physical properties of poly(vinyl chloride)-based film coated with ZnO nanoparticles

Nanoparticles of ZnO and their application in coating systems have attracted a great deal of attention in recent years because of its multifunction property, especially antibacterial activity. In this study, antibacterial and physical properties of poly(vinyl chloride) (PVC) based film coated with ZnO nanoparticles were investigated. It was found that the antibacterial action should be attributed to the killing effect property of ZnO nanoparticles. The ZnO-coated films treated by shaking for 10 h exhibited a similar high antibacterial activity against Escherichia coli and Staphylococcus aureus as the untreated ZnO-coated films. This result indicated that the ZnO nanoparticles adhered very well to the plastic film. The antibacterial activity of the ZnO-coated film to inactivate E. coli or S. aureus was improved by UV irradiation. The analysis of physical properties of the ZnO-coated films revealed that the nano-ZnO particles showed less effects on the tensile strength and elongation at break of the film. The ultraviolet (UV) light fastness of the ZnO-coated PVC film was improved, which may be attributed to the absorption of ZnO nanoparticles against UV light. Water vapor transmission of the ZnO-coated film decreased from 128 to 85 g/m² • 24 h, whereas the thickness of film increased from 6.0 μm with increasing the amount of nano-ZnO particles coated from 0 to 187.5 μg/cm². This research revealed that the PVC film coated with nano-ZnO particles has a good potential to be used as an active coating system for food packaging.