Modification of hydrophilic, optical and electrical properties of bisphenol-A based polycarbonate polymeric films using DC O 2 plasma

In this work, Makrofol DE 1–1 films were treated with O 2 plasma for different treatment times ranging from 60 to 120 min at applied power 3.5 W and working pressure 0.4 Torr. The induced changes in Makrofol surface properties after plasma treatment were examined with Atomic Force Microscope (AFM), Scanning Electron Microscope (SEM), Photoluminescence (PL) spectroscopy, ultraviolet–visible (UV–Vis) spectroscopy techniques. The changes in the wettability property and surface free energy (SFE) of the plasma treated Makrofol polymer samples have been investigated by measuring the water and glycerol contact angles. Moreover, the induced changes in the dielectric Parameters and AC conductivity of plasma treated Makrofol samples were studied at a wide range of frequencies at room temperature. AFM analysis revealed that the average surface roughness (R a ) of Makrofol samples was increased after plasma treatment. Also SEM images clearly indicated that more enhanced surface roughness can be obtained with increasing treatment time. A noticeable increase in the intensity of PL emission spectra with increasing plasma treatment time was observed. This increase could be attributed to the increase in surface roughness and surface area of Makrofol samples after plasma treatment. The measurements of contact angle showed an enhancement in the wettability property and surface free energy of Makrofol samples after plasma treatment time. The analysis of the results of UV–Vis spectra revealed that the absorbance, Urbach energy (E U ), the refractive index (n), the extinction coefficient (k) and number of carbon per length (N) were increased while the transmission and optical energy band gap of Makrofol samples were decreased with increasing plasma treatment time. AC conductivity, dielectric constant and dielectric loss of Makrofol samples have been increased by increasing plasma treatment time.