Hairy superhydrophobic surfaces with excellent mechanical robustness, underwater stability and drag-reduction property

Abstract

Since superhydrophobic surfaces show extremely low friction with water, they have been tried for drag-reduction purpose for ships or pipe systems for liquid transportation in recent years. However, the superhydrophobic surfaces combining comprehensive performance, feasible fabrication method as well as low manufacturing cost are still big issues, limiting their real applications. Inspired by the fine hairs and cilia of creature, we prepare hairy surfaces by electrostatic flocking and subsequent surface modification. The optimal hairy surfaces exhibit excellent superhydrophobicity, satisfactory abrasion resistance that is superior to the superhydrophobic surfaces ever reported, long-term underwater stability with/without additional air pressure and good drag-reduction efficiency at low shearing rates. The correlations between microstructure of samples and key properties are analyzed. This work may shed new light on design and preparation of mechanical robust, underwater stable and drag-reduction surfaces that can be easily manufactured in large scale.