METAL-PARTICLE ADSORPTION AND DIFFUSION IN A MODEL POLYMER/METAL COMPOSITE SYSTEM

We have developed a model polymer/metal composite system based on the adsorption of colloidal gold particles from a dilute aqueous suspension to the surface of poly(2-vinylpyridine) (PVP). Particle coverages and tracer diffusion coefficients for the particles within a PVP matrix phase were measured by Rutherford backscattering spectrometry. The adsorption process is quantitatively described by a diffusion-limited mechanism where gold particles irreversibly adsorb to the surface of the polymer film. Model dispersions produced in this way are excellent model systems for studying the fundamental properties of metal particle dispersions, since the particle size and the areal density of particles on the surface are well-controlled. Diffusion coefficients for the gold particles within PVP were also measured. The diffusion of the gold particles was found to be coupled to the bulk viscosity of the polymer, even though the size of the gold particles was only slightly larger than the mesh size of the entanglement network for PVP. (C) 1995 John Wiley and Sons, Inc.