Simple processes for the preparation of superhydrophobic polymer surfaces

Two simple processes; spin-coating, and doctor blade coating of silica/polymer dispersions are described for the preparation of superhydrophobic polymer surfaces. To demonstrate the versatility and broad applicability of the processes, polymeric surfaces modified included a thermoplastic resin, polystyrene and a thermoset, crosslinked epoxy resin. Micro/nano hierarchical nature of the surface topographies obtained were demonstrated by scanning electron microscopy, atomic force microscopy and white light interferometry studies. Formation of superhydrophobic surfaces were clearly demonstrated with very high static, advancing and receding water contact angles well above 150 degrees and contact angle hysteresis values of less than 10 degrees, similar to that of lotus leaves [1,2]. Roughness factor (r) and average surface roughness (Ra) values, which are critical in obtaining superhydrophobic surfaces were also determined for each polymeric system.