Designer Binary Nanostructures toward Water Slipping Superhydrophobic Surfaces

This report demonstrates a synthetic route for ordering a set of Au nanoparticles on the vertically aligned conducting polymer (polypyrrole) for the superhydrophobic surfaces with low water flow friction. It demonstrates how one can use polymer nanorod pillars and a variety of Au nanoparticles to generate controlled surface roughness. Synthetic strategies utilized to make such surfaces include the electrochemical polymerization of conducting polymers within the confines of anodized alumina templates and subsequent Au nanoparticle immobilization on the surface of polymer pillars. This method provides a surface that contains roughness on two independently controllable levels, say, the submicroscopic roughness from polymer pillar dimensions and the nanoscopic roughness from the appropriate size selection of Au nanoparticles. With the present results, it is clearly evident that a combination of two scale roughnesses composed of nanorods and nanoparticles could be utilized for the synthesis of superhydrophobic surfaces, which mimics the lotus leaves.