Preparation and Optical Properties of Au-shell Submicron Polystyrene Particles

摘要

Micron and submicron Au-shell PS latex beads have been prepared by combining the self-assembly and seeding methods. The formation of Au-shell is based on the increase of the gold coverage by reaction with NH_2OH and HAuCl_4. This method of preparation allows an efficient control of the gold coverage and leads to relatively stable products. We have demonstrated, using TEM images, the formation of Au clusters and "streaky" gold nanoparticles on the surface of the PS beads. The results may indicate that the PEI polymer chains are most probably stretched out on the surface of the PS beads. In addition, one-layer SiO_2-coated Au/PS particles have also been prepared. UV-visible extinction spectra for different gold coverage show a significant influence on the plasmon resonance absorption in qualitative agreement with the Mie theory.