Influence of operating parameters on surface properties of RF glow discharge oxygen plasma treated TiO2/PET film for biomedical application

• Investigated the surface properties of TiO2/PET films modified by O2 plasma
• Studied the effect of operating parameters on surface properties of TiO2/PET films
• Mechanism of the plasma treatment on TiO2/PET was clearly investigated.
• Utilized various characterization techniques for analyzing the O2 plasma treated films
• Examined antibacterial activity and cytotoxicity of the TiO2/PET films

In this paper, a thin transparent titania (TiO2) film was coated on the surface of flexible poly(ethylene terephthalate) (PET) film using the sol–gel method. The surface properties of the obtained TiO2/PET film were further improved by RF glow discharge oxygen plasma as a function of exposure time and discharge power. The changes in hydrophilicity of TiO2/PET films were analyzed by contact angle measurements and surface energy. The influence of plasma on the surface of the TiO2/PET films was analyzed by atomic force microscopy (AFM) as well as the change in chemical state and composition that were investigated by X-ray photo electron spectroscopy (XPS). The cytotoxicity of the TiO2/PET films was analyzed using human osteoblast cells and the bacterial eradication behaviors of TiO2/PET films were also evaluated against Staphylococcus bacteria. It was found that the surface roughness and incorporation of oxygen containing polar functional groups of the plasma treated TiO2/PET films increased substantially as compared to the untreated one. Moreover the increased concentration of Ti3 + on the surface of plasma treated TiO2/PET films was due to the transformation of chemical states (Ti4 + → Ti3 +). These morphological and chemical changes are responsible for enhanced hydrophilicity of the TiO2/PET films. Furthermore, the plasma treated TiO2/PET film exhibited no citotoxicity against osteoblast cells and antibacterial activity against Staphylococcus bacteria which can find application in manufacturing of biomedical devices.

Mechanism of plasma treatment on the surface of TiO2/PET films.Figure optionsDownload as PowerPoint slide