Tailoring conducting polymer chemistry for the chemical deposition of metal particles and clusters

We report chemical deposition of metal particles and clusters with various sizes and morphologies on top of the polyaniline (PANI) thin films and porous asymmetry membranes. Immersing the PANI membrane into the PtCl42- gives rise to 3-5 nm Pt nanoparticles spread evenly on the membrane surface, while immersing undoped PANI membrane into AgNO3 aqueous solution leads to the formation of micrometer size Ag sheets with strong anisotropy. In contrast to the Ag deposited on the undoped PANI membrane, Ag metal deposited on the doped PANI membrane has a random morphology and shows no preferential growth along a specific crystallographic direction. The Au metal deposited on the undoped and doped PANI membranes exhibit morphological differences from a sheetlike structure to larger particles comprised of smaller Au particulates (rice-grain shape). Furthermore, by varying the nature of the dopant, we can achieve deposition of metal structures with fiber, sheet, cube, yarn-ball, and leaf-like morphologies. Our studies demonstrate that tunable metal size and morphology can be easily achieved through tailoring the surface chemistry of conducting polymer by varying the dopant, oxidation state (doped and undoped), and polymer chain orientation. Our future goal is to further enhance the control over metal structure and morphology using a simple chemical deposition method.