A joint research team from the Ruđer Bošković Institute in Zagreb has developed a novel preparation process for PET/ZnO composite materials. This technology, through atmospheric pressure plasma jet treatment combined with nanoparticle integration, significantly improves the antibacterial performance and functionality of food packaging materials. The study provides an innovative solution for the food packaging industry.

The research team prepared high-purity zinc oxide nanoparticles in water using pulsed laser ablation technology. Subsequently, the surface of commercial PET foil was treated with an atmospheric pressure plasma jet, increasing its roughness from 6nm to 13nm, creating favorable conditions for nanoparticle attachment. By repeating the plasma treatment process, zinc oxide nanoparticles were firmly embedded into the polymer surface, forming a unique two-dimensional nanostructure. This composite material preparation method effectively overcomes the limitations of traditional PET materials in terms of surface properties.

Atomic force microscopy analysis showed that the treatment process improved the uniformity of nanoparticle distribution. Leaching tests confirmed that zinc was firmly embedded in the PET substrate, which has positive implications for the environmental safety and sustainability of the material. The modified PET foil exhibited a 29% improvement in ultraviolet protection performance, helping to extend food shelf life. At the highest zinc oxide concentration (245.75mg Zn/kg PET), the material achieved antibacterial efficiency close to 100% against Escherichia coli and Staphylococcus aureus.

The first author of the paper, Rafaela Radičić, stated: "These results highlight the effectiveness of our synthesis method, as it demonstrated strong antibacterial performance against both bacterial strains. Importantly, the leaching tests confirmed that the nanoparticles were firmly embedded in the PET surface, proving the potential of these antibacterial surfaces for applications in the packaging industry." The research results have been published in the journal Progress in Applied Surface Science.

The novel PET/ZnO composite material technology brings innovative development directions to the food packaging industry. Its excellent antibacterial properties and enhanced physical performance demonstrate broad application prospects. This material modification method provides a new pathway for improving the performance of polymer packaging materials.