Effect of dc glow discharge plasma treatment on PET/TiO2 thin film surfaces for enhancement of bioactivity

In this paper, the surfaces of PET/TiO2 thin film were modified by DC glow discharge plasma as a function of discharge potentials for improving the bioactivity. The hydrophilicity of the plasma-treated PET/TiO2 film was measured by contact angle measurement and the surface energy was estimated by using Fowkes method. The structural and chemical composition of the plasma-treated PET/TiO2 was analysed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Immersion in a simulated body solution (SBF) solution was used to evaluate the bioactivity of the plasma-treated PET/TiO2 samples in vitro. It was found that the plasma treatment modified the surfaces both in chemical composition and crystallinity which makes surface of the PET/TiO2 to become more hydrophilic compared with untreated one. Analytical and microstructural investigations of SBF results, showed considerable higher rates of apatite formation on the plasma-treated PET/TiO2 compared to the untreated films.