TY - JOUR A1 - Friedrich, Jörg Florian A1 - Retzko, Iris A1 - Kühn, Gerhard A1 - Unger, Wolfgang A1 - Lippitz, Andreas T1 - Plasma polymers with chemically defined structures in contact with metals N2 - The retention of chemical structure and functional groups during plasma polymerization was investigated. Usually plasma polymer layers, prepared by a continuous wave radio-frequency plasma, are often chemically irregular in their structure and composition. To minimize these irregularities low wattages and the pulsed plasma technique were applied to avoid fragmentations. The first goal was to produce plasma polymers comprising double or triple bonds as precursors for electrically conducting polymers. Acetylene, ethylene, butadiene and polystyrene were used as monomers and deposited as thin polymer films by pulsed plasmas of low wattages. Styrene polymerization was strongly enhanced in the dark phase (plasma off) of a pulsed r.f. plasma caused by the reactivity of the vinyl-type double bond. This could be confirmed by a verification of a rather high chemical regularity of the film sample. The oxygen content of this film measured by X-ray photoelectron spectrometry (XPS) was in situ 0% and after 24 h exposure to air lower than 1%. Additionally, post-plasma oxidations of trapped radicals with air could be suppressed using NO gas as radical quencher. Such quenched plasma polymer layers were completely stable against oxidation for a number of weeks. During the low-wattage pulse plasma polymerization metal atoms were simultaneously or layer by layer evaporated into the growing layer and in situ measured by XPS. These metal atoms are acting as dopants. Here, Li, K, Mg and Cr were used at different concentrations providing electrical conductivity and magnetic properties for the film. KW - Pulsed plasma KW - Plasma polymerization KW - Doping with metal atoms KW - Encapsulation of nanoparticles PY - 2001 U6 - https://doi.org/10.1016/S0257-8972(01)01051-9 SN - 0257-8972 VL - 142-144 SP - 460 EP - 467 PB - Elsevier Science CY - Lausanne AN - OPUS4-6972 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Mix, Renate A1 - Kühn, Gerhard T1 - Adhesion of metals to plasma-induced functional groups at polymer surfaces N2 - The peel strength of aluminium to polypropylene and poly(tetrafluoroethylene) was determined in dependence on the type and the concentration of functional groups on the polymer surface. For this purpose the polymer surface was equipped with monotype functional groups. The first method to produce monotype functionalized surfaces was an introduction of O functional groups using an oxygen plasma treatment and converting these groups to OH groups applying a wet chemical reduction. In result of this two-step treatment the hydroxyl group concentration at the polymer surface could be increased from 3–4 to 10–14 OH groups/100 C atoms. The second method consists in the deposition of a 150 nm adhesion-promoting layer of plasmapolymers or copolymers onto the polymer surface using the pulsed plasma technique. For that purpose functional groups carrying monomers as allyl alcohol, allylamine and acrylic acid were used. Applying the plasma-initiated copolymerization and using neutral “monomers” like ethylene or butadiene the concentration of the functional groups was varied. A correlation of peel strength with the ability of forming chemical interactions between Al atoms and functional groups was found: COOH > OH >> NH2 > H(CH2–CH2). KW - Peel strength KW - Aluminium KW - Polypropylene KW - Poly(tetrafluoroethylene) KW - Pulsed plasma KW - Allyl alcohol KW - Allylamine KW - Acrylic acid KW - Plasma surface treatment KW - Adhesion PY - 2005 SN - 0257-8972 VL - 200 IS - 1-4 SP - 565 EP - 568 PB - Elsevier Science CY - Lausanne AN - OPUS4-10897 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -