Nanoporous Polypyrrole Film by Template-Directed Electrodeposition

There has been increasing research interest in conductive polymers since the first conducting plastics were discovered at the Plastics Research Laboratory in Germany. The Polypyrrole is one of the most commonly used conducting polymers in electronic industry. The preparation of polypyrrole film (PPy) has been extensively studied because of the good solubility of pyrrole monomer in a wide range of solvents and easily electro-polymerization in both aqueous and non-aqueous solvents. PPy is finding increasing applications in sensors, medical devices, and rechargeable batteries due to its high conductivity, environmental stability, and electroactive nature with low oxidation potential. In the present work, we combine the slef-assembled polystyrene tempalate with the electrochemical deposition technique to create a porous PPy film. Briefly, a monolayer of polystyrene spheres was first self assembled on the gold surface. And the pyrrole monomer was then electrochemically deposited on the gold surface that is covered by the sphere template under the constant current. Subsequently, the spheres were removed, leading to a porous structure. The dimension and the separation between the pores can be easily controlled by changing the diameters of the spheres. The morphology and the thickness of the film were controlled by adjusting the electrodeposition parameters such as the applied current, the deposition time, the total charge, and the composition of the electrolyte. Our experimental results show that during the electropolymerization process the total charge has a significant effect on the thickness of the polypyrrole film. The synthesized PPy film exhibits a uniform pore size and inter-distance of pores (Fig.1).