Determination of the optical and chemical properties of aniline doped plasma polymerized cineole thin films synthesized at various RF powers

Aniline-doped plasma polymerized cineole (PPCin) thin films were produced on glass substrates by plasma polymerization technique under varying Radio Frequency (RF) power levels. PPCin thin films were produced at 30 min deposition time and at 50, 75 and 100 W RF energies. Surface morphologies of pure and aniline-doped PPCin thin films obtained on glass substrates were investigated by AFM. It was found that the average surface roughness of pure PPCin thin films increased from 0.19 to 30.6 nm due to the dopant effect and RF energies. The optical band gap for pure polymer thin film was 3.65 eV, but with the effect of doping, these value was found to be 3.54, 3.29 and 3.93, respectively, with increasing RF energy. The extinction coefficient and refractive indices of PPCin thin films were calculated as between 0.065 and 0.92 and between 1.24 and 1.57 respectively, at the wavelength of 400 nm. Wettability analyzes of PPCin thin films were also determined using the water contact angle (WCA) measurement and all thin films were found to have hydrophilic character.