A simple approach to fabricate morphological gradient on polymer surfaces

This paper presents a novel and feasible approach for fabrication of morphological gradient surfaces based on the film-formation of nanocomposite polymer latex. In this method, when the polymer latex with relatively low glass transition temperature (T_g) was blended with colloidal silica and then dried at certain temperatures, a morphological evolution with deeper pores from the center to the edge could be directly obtained on polymer surface. Neither careful control of experimental conditions nor any complex processes are needed. The T_g of polymer, the silica content, the solvent and the drying temperature have significant influences on this surface morphology. The film-formation mechanisms at different drying temperatures are also discussed.