Research progress of biomimetic superhydrophobic surface characteristics, fabrication, and application

Yunqing Gu,Wenqi Zhang,Lanfang Jiang,Evan Wang,Jiegang Mou,Zhuangzhi Sun,Shuihua Zheng

doi:10.1177/1687814017746859

Abstract

The biomimetic superhydrophobic surface derived from lotus effect is one of the hotspot issues in recent years and also a specific application case of biomimetic in modern industry. Based on the excellent characteristics of bionic superhydrophobic surface, such as self-cleaning, anti-icing, drag reduction, and anti-corrosion, it has great application value in the fields of industry, military, and biomedicine. Based on the effect of water contact angle and water sliding angle of superhydrophobic surface on the hydrophobicity, we discussed the wetting behavior of biomimetic superhydrophobic surface, the important properties of biomimetic superhydrophobic surface were reviewed in detail, and we provided the necessary theoretical basis for the application of superhydrophobic surface. The methods of fabrication of biomimetic superhydrophobic surface were summarized and elaborated three kinds of low-cost and simple methods of spraying, chemical etching, and flame treatment, and the development trend of biomimetic superhydrophobic surface was also prospected.

Highlights

Due to a high water contact angle (CA) and a very low water sliding angle, biomimetic superhydrophobic surfaces show excellent repellency
Superhydrophobic surfaces were initially observed on the surface of some animals and plants, and the most well-known example is the lotus leaf, and Barthlott and Neinhuis[1] studied on the microstructural of lotus leaf surface and found that it was the nanoscale hydrophobic epicuticular wax crystals of lotus leaf surface that made the lotus leaf have a self-cleaning property, and this phenomenon is called of lotus effect
There are a lot of fabrication of superhydrophobic surface technology, some of the methods have their limitation, such as lithography and femtosecond laser pulsing are expensive and difficult to be applied to large structures; the templating has great potential for large-scale production, it is often used only in soft polymers.[19]

Summary

Introduction

Due to a high water contact angle (CA) and a very low water sliding angle, biomimetic superhydrophobic surfaces show excellent repellency. If the CA is greater than 150°, and the sliding angle is less than 10°, the contact area of water droplets on superhydrophobic surface is relatively small, and water droplets will fall when the surface is slightly tilted. As shown in Cassie–Baxter model, superhydrophobic surfaces have much convex microstructure, which keeps a lot of air in the groove between solid surface, that is, the actual contact surface between the liquid and the superhydrophobic surface is composed of two interfaces: liquid–solid interface and liquid–gas interface. The fabrication of superhydrophobic surface on ship surface can reduce the fluid resistance of the ship, save energy, and reduce consumption

Fabrication methods of superhydrophobic surface

Summary and outlook