Fog collection efficiency of superhydrophobic surfaces with different water adhesion prepared by laser grid texturing

Abstract

Superhydrophobic surfaces are widely used in fog collection areas due to their water adhesion properties. Unfortunately, the relationship between the water adhesion and the fog collection efficiency of superhydrophobic surfaces has seldom been reported in the literature. Therefore, it is still a challenge to conduct scientific design of superhydrophobic surfaces for fog collection. In this work, superhydrophobic titanium alloy surfaces with different water adhesions were fabricated by laser grid texturing combined with silicone oil heat treatment. As the texturing interval increased from 50 µm to 500 µm, the adhesion force of the superhydrophobic surfaces correspondingly increased from 2.4 µN to 104.9 µN. The results show that the superhydrophobic surfaces with the texturing interval of 100 µm have the highest fog collection efficiency of 415.5 mg·cm−2·h−1. The reason is that an appropriate adhesion force (7.6 µN) of the superhydrophobic surface can effectively suppress the coalescence-induced droplets jumping. Furthermore, it can also facilitate the removal of condensed droplets by decreasing the critical size of droplets sliding.