Comparison of barrier properties for a superhydrophobic epoxy coating under different simulated corrosion environments

Using soft lithography, a superhydrophobic epoxy coating was prepared with lotus leaf-like surface microstructures. Electrochemical measurements were performed to compare barrier properties of the superhydrophobic coating with a regular smooth coating during immersion, wet-dry cyclic immersion and salt spray tests. The results demonstrated that the superhydrophobic coating can act as a much stronger barrier than can the regular coating when immersed because of trapped air films in the surface microstructures. However, the ultrafine electrolyte particles in the salt spray can easily penetrate these microstructures and deposit on the coating surface, which leads to the faster deterioration of the superhydrophobic coating.