Thermodynamic analysis and prediction on the wetting properties of pore array superhydrophobic laser-texturing surfaces

Superhydrophobic surfaces fabricated by laser irradiation on various materials have been reported recently to show excellent wetting properties. However, there are only limited works regarding the theoretical analysis and prediction of the wetting properties of different surface structures, especially the widely used pore array laser-texturing surfaces, whose fabrication process is simple and time-saving. Here we propose a two-dimensional thermodynamic structure model based on the actual pore array laser-texturing surfaces, and four wetting states are defined in our model. By minimizing the Gibbs free energy, equilibrium contact angle and contact angle hysteresis representing wetting properties are calculated, and the effects of defined parameters (intrinsic contact angle θ Y, pore space b, and pore depth H) on wetting properties are analyzed in detail to find out the critical transition conditions among different wetting states. Besides, actual pore array laser-texturing surfaces are fabricated for further validation, and the wetting properties in measurement are found to be in good agreement with those in prediction, indicating that our model is credible and can be used to guide the design of the pore array superhydrophobic laser-texturing surfaces.