Superhydrophobic surfaces fabricated by spray-coating micelle solutions of comb copolymers

A series of comb copolymers (poly(arylene alkylene ether) (FPAE)-polystyrene (PS)) with a highly fluorinated FPAE main chain and narrow dispersed PS-grafted chains have been prepared. They are used to prepare micelle solutions in methanol/acetone (M/A) mixed solvents which are good for the FPAE main chains and poor for the PS-grafted chains. In these solutions, the PS-grafted chains form the cores and the FPAE main chains form the corona layers of micelle particles. Uniform micelle particles are achieved because of the narrow molecular weight dispersion of the PS chain length. The micelle solutions are spray-coated onto glass substrates to fabricate hydrophobic surfaces. It is found that the stability of the micelle particles increases with the length of the PS-grafted chains, which further influences the morphology and hydrophobicity of the spray-coated films. The effects of the M/A ratio and the copolymer concentration on the morphology and hydrophobicity of the coating surfaces are also studied. The results prove that a binary nano/microsurface structure is important to achieve a superhydrophobic surface with a low contact angle hysteresis. This binary structure is formed from conglomeration of micelle particles by spray coating the micelle solutions. The best sample reported in this paper has a static contact angle of 163° and a sliding angle of 5.9°. This fabrication procedure is facile, less time consuming, and easily applicable for large-scale surface treatment.