Condensed solute droplets templated honeycomb pattern on polymer films

A method to generate honeycomb pattern on polymer films is demonstrated. Briefly, a polymer solution in a volatile solvent containing a nonvolatile liquid solute is cast into a thin layer, with the fast evaporation of the volatile solvent, the liquid solute is enriched at the top surface of the layer. The enriched liquid solute condenses into uniform droplets after reaching its saturation state, meanwhile, the polymer precipitates at the interface of the droplets. With this method, we prepared the honeycomb-patterned polysulfone, polystyrene, and polyvinylidene fluoride films. This method provides a new approach to manipulate the surface geometry of polymer films.