Development of robust amphiphobic hierarchical structure on polymer substrate by thermal imprinting and sputter etching

Abstract

Amphiphobic surfaces are found in many natural organisms for protection from external contamination because they can repel both water and oil. The development of an amphiphobic surface is based on the construction of hierarchical structures and chemical modification. In this study, thermal imprinting and sputter etching were conducted to create a micropillar array and nano-protrusions to form a hierarchical structure. Different hierarchical structures were developed by using different nickel stamps and upon varying the etching time. These structures were modified using an environment-friendly drysurf (G993G3, Harves) solution through a spraying method. The surface presented high repellency toward various liquid droplets with surface tensions ranging from 72 to 22 mN m −1 , with contact angles of 158° for water and 120° for hexadecane. The surface showed good self-cleaning performance without any traces of water droplets or glass bead particles. In addition, various tests including sand abrasion , bending, and immersion tests were conducted to evaluate the mechanical and chemical robustness of the hierarchical structure, which exhibited good performance. Hierarchical structures with these excellent properties are expected to be widely applied in surface waterproofing, antifouling, and self-cleaning treatments. • Micropillars with appropriate size are required to create hierarchical structure. • Net-like nanoprotrusions are fabricated on micropillars by sputter etching. • Hierarchical micro/nanostructure shows better amphiphobicity than micropillars. • The amphiphobic surface presents good chemical stability and mechanical robustness. • The amphiphobic surface can be applied as antifouling and self-cleaning materials.