Adsorption and diffusion of small metal particles in polymer matrices

We have studied the properties of colloidal gold dispersions in matrices of poly(2-vinylpyridine) as part of a detailed study of this model polymer/metal composite system. The results described above indicate that two dimensional metal particle dispersions with well controlled surface densities can easily be prepared by a simple adsorption process. This result can be understood in qualitative terms by requiring that the gold particles carry a layer of polymer chains with them when they diffuse, thereby increasing the effective particle radius. Such a polymer layer is in fact expected, based on earlier results which indicate that equilibration at the PVP/gold interface is exceptionally slow.