Enhancing the abrasion resistance of hydrophobic coatings by flower bush-like micro rough structure of alumina

Abstract

The anti-fouling design of ceramics is of great significance in improving their effectiveness and range of applications. Generally, constructing a micro rough structure coated with a low surface energy polymer substance is an effective strategy for creating a super-hydrophobic layer on ceramic surfaces. However, to be operated under certain wear conditions, the abrasion resistance of hydrophobic materials constructed by conventional methods is far from the requirements for application. Inspired by the multi-scale porous structure of the flower bush, a flower bush-like multi-scale micro rough structure (FMMS) has been constructed on ceramics using alumina pellets as petals. Compared with single-scale micro rough structures and non-connected pore micro rough structures, this structure enabled hydrophobic coatings which accelerated failure once worn, to attain an excellent contact angle (CA) of 143° and a sliding angle (SA) of 8.7° after a 100th abrasion test, demonstrating that the FMMS can significantly improve the mechanical stability of the coating. The hydrophobic model designed for the FMMS indicates that the excellent performance of the structure was achieved by a multi-scale protection mechanism for the hydrophobic material and a multi-scale pore-forming mechanism for the surface, and this provides a new idea for the design of highly abrasion-resistant super-hydrophobic surfaces on ceramics.