Bio‐Inspired Superoleophobic Fluorinated Wax Crystalline Surfaces

Abstract

AbstractA novel, single‐step and single‐component bio‐inspired fabrication method of hierarchical superoleophobic surfaces is presented. The method consists in thermal deposition of self‐assembling ultra‐low‐surface‐energy fluorinated wax on diverse surfaces. The thermal deposition results in crystalline, oriented, three‐dimensional hierarchical structures with high surface roughness and re‐entrant curvature, which in combination with the low surface energy of the fluorinated wax results in high contact angles of low‐surface‐tension liquids and low contact‐angle hysteresis (CAH) values (Δθ). The values achieved for Δθ are below 10° even for ethanol, which exhibits a surface tension as low as 22.4 mN·m−1. In addition to their superoleophobic properties our substrates exhibit extreme superhydrophobic qualities (CAH as low as 2° and contact angle >170°) with exceptional surface stability over many months. The proposed fabrication method may be utilized for a variety of applications where non‐wetting of low‐surface‐tension liquids is required, for example non‐staining surfaces and antifouling. The ease of fabrication and the variety of substrates that can be modified will undoubtedly widen its use.