Research progress of transparent and super-hydrophobic surface

High optical transparency is one of the most crucial criteria for the overwhelming majority of optical devices, such as solar cell system, windscreen, and camera lens, etc. The properties of these devices may be seriously influenced by large amounts of dust and dirt, because they are exposed to the outdoor environment frequently. Transparent super-hydrophobic surface has a high prospect in the field of optical equipment by virtue of its excellent optical properties and anti-fouling properties. This paper firstly summarizes the theory of surface wettability, mainly including Young wetting equation, Wenzel wetting model and Cassie wetting model, and based on the theory of wettability, it puts forward the conditions of preparing super-hydrophobic surface: namely low surface energy substance and rough structure into the material surface, both of which are indispensable. Secondly, the competitive relationship between roughness and transparency is discussed, and through sorting out the Rayleigh scattering and Mie scattering theory, this paper finds that the surface roughness shall be less than 100 nm, which is the essential condition for the preparation of transparent super-hydrophobic surface. Thirdly, this paper summarizes the common preparation methods of transparent super-hydrophobic surface in recent ten years, such as sol-gel method, chemical vapor deposition method, template method, and phase separation method, etc. It also analyzes these preparation ideas and methods, and summarizes some problems existing in these methods accordingly. Finally, this paper briefly introduces the application of transparent super-hydrophobic surface in the field of solar cells, optical components, and photocatalytic materials, etc., and forecasts the future research direction and application prospect of transparent super-hydrophobic surface. © 2021, Chongqing Wujiu Periodicals Press. All rights reserved.