PdCl2 anchorage onto the surface of polystyrene films via oxygen and ammonia plasma treatment

The surface properties of polystyrene as a possible catalytic support for a ctive coordinative species were investigated. To improve the surface proper ties, discharge treatments in the presence of oxygen and ammonia were carri ed out. The polymer surface was studied before and after the plasma treatme nts. Contact angles for the polymer surface were measured in order to deter mine the surface free energy. Polymer-bound complex catalysts were prepared by anchoring PdCl2 on the surface of the polystyrene samples. The chemical compositions were studied by X-ray Photoelectron Spectroscopy (XPS). Plasm a treatments in the presence of oxygen or ammonia caused an increase in the surface free energy of polystyrene, as a consequence of the higher concent ration of oxygenated or nitrogenated functional groups, respectively, on th e polymer surface. Contact angle measurements are in agreement with the cor responding values obtained by XPS. After treatment with PdCl2, the amount o f palladium anchored to the polymer surface treated with ammonia is greater than in the case of the oxygen plasma treatments; this may be explained on the basis of the higher nucleophilic character of the amine groups. No pal ladium was detected in the untreated polystyrene surface. (C) 2000 Society of Chemical Industry.