Surface Modification and Property Characterization of Antibacterial Preservative Composite PET/SiO_x Membrane

The chitosan and/or ZnO (nano-particle) -doped chitosan layers were synthesized by spray coating on the substrate of PET/SiO_x membrane surface-modified with KH550 transition layer or by ultraviolet (UV) irradiation. The impact of the KH550 layer or UV-irradiation on the interface adhesion and properties of PET/SiO_x membrane was investigated with scanning electron microscopy and conventional surface probes. The preliminary results show that the Zn O-doped chitosan and KH550 composite layers improved, to varying degrees, the interfacial adhesion, permeation of H₂O (O₂), hydrophilicity and anti-bacterial activity. To be specific, the Zn O-doped chitosan or chitosan coatings strongly increase the permeation of O₂ and weakly decrease the permeation of moisture; and it significantly inhibits growth of Staphylococcus aureus and Escherichia coli. In addition, KH550 itself is capable of inhibiting the growth of germs. We suggest that the chitosan-coated PET/SiO_x composite membrane may be a good antibacterial preservative packaging material.