| In this work, two kinds of plasma polymerization for surface modification are discussed. In part-I, DC plasma polymerization is investigated for film properties, film growth mechanism and film application. The monomers heaxamethyldisiloxane (HMDSO) and pyrrole were selected to study the deposition rates change with discharge parameters such as pressure, flow rate, power, discharge current density. Structures and properties of film deposited at extreme conditions (high power/low pressure or low power/high pressure) were studied with FT-IR, SEM, TOF-SIMS, AIM, surface energy measurement and tribology test. This work also investigated DC plasma polymerization kinetics by combining plasma parameters with film deposited rate at different conditions. Both single and double Langmuir probes were used to measure the plasma parameters in pulsed power and continuous discharges. Plasma density and electron temperature are reported. A DC plasma polymerization kinetic model is Proposed based on the experimental data and a best-fit mathematical method.;DC plasma polymerization application was the other object of this study. Cold-rolled steel and copper were coated with pyrrole and HMDSO, respectively. Corrosion rate were obtained from electrochemical polarization methods, and tests in humidity chamber directly. Various monomers were used to change the substrate surface energy. Hydrophilic and hydrophobic surface were achieved respectively by different monomers. A water-soluble film was obtained with acrylic acid in mild plasma conditions.;In part-II, a initial study of powder surface modification has been done. The aim of this work was to investigate the possibility of changing powder surface properties with plasma-polymerized coatings. RF inductive plasma was used as a source to excite plasma polymerization for powder treatment. Plasma-polymerized pyrrole films were deposited on silica surface. Several techniques such as SEM, EDX, TOF-SIMS, FT-IF, DSC&TGA, and surface energy measurement were used for treated powder characterization. It was found that the film with several hundred angstrom thickness was deposited on silica surface. The silica became very hydrophobic. The performance test also showed that the rubber property was changed with pyrrole plasma treated silica. |
