The ultimate goal of this research is to be able to control both the size and spatial distribution of very small metallic particles that are distributed within a polymeric matrix. The size-scale of interest is illustrated in the following image, which shows 16 nm colloidal gold particles that have adsorbed to the surface of a polymer.

In general, metal particles are able to diffuse only when the average separation between the particles is larger than the typical dimensions of a polymer molecule. Diffusion of well-separated colloidal gold particles is discussed in reference 26. Diffusion of evaporated gold particles with much smaller interparticle separations is discussed in reference 33, and in more detail in reference 38. Incorporation of block copolymers gives much more control over the spatial distribution of gold particles, and is the focus of some of our current work in this area.