Surface modification of Cu/PS nanocomposite films: A comparative study of DC N2 plasma and Gamma radiation and their effects on the films' antibacterial activity

Abstract

In this work, a comparative study on the efficiency of surface modifications of Copper/Polystyrene (Cu/PS) nanocomposite films, induced by N-2 DC plasma and gamma radiation to enhance their surfaces' antibacterial activity was conducted. Cu/PS nanocomposite films, with different concentrations of copper 0.4, 0.8 and 1 wt.%, were prepared by the solution casting method at room temperature. The samples were exposed to gamma rays at different radiation doses and N-2 DC plasma for different treatment time intervals. The structural and morphological properties of the samples were investigated before and after treatment by, water contact angle measurements, weight loss and scanning electron microscopy. The surfaces of the films were found to be more sensitive to N-2 DC plasma compared gamma radiation. The antibacterial properties of Cu/PS nanocomposite films against Staphylococcus aureus 15 have been evaluated by the optical density and colony forming unit's techniques. The results indicated that the N-2 DC plasma treatment enhanced more antibacterial properties than those induced by gamma radiation.