Influence of operational parameters on plasma polymerization process at atmospheric pressure

In this paper, a dielectric barrier discharge working at atmospheric pressure has been used in order to investigate the plasma polymerization reactions using styrene vapors. The macroscopic parameters were carefully chosen in order to obtain polymer thin films with high deposition rate and high concentration of activated species consequently. Thus, the plasma polymerization processes can be described considering the dependence of polymer deposition rate by monomer flow rate and discharge power. The domains of plasma polymerization reactions were identified and the optimum operating conditions were obtained at a maximum deposition rate of 3.8 nm/s (discharge power: 7.5 W). Different techniques of analysis were used to identify the chemical composition of plasma polystyrene films and the domains of polymerization reaction. The film thickness was measured by optical interferometry and the chemical composition was analyzed by Fourier-transform infrared spectroscopy, UV spectroscopy, and x-ray photoelectron spectroscopy.