Rationally Designed Metallic Reentrant Superomniphobic Structures toward Anti-Icing for Low-Surface-Tension Liquids

Abstract

Icing poses a serious threat to the safe operation of key sectors such as aerospace and energy transmission. Although conventional superhydrophobic surfaces exhibit good anti-icing performances for pure water, their design generally does not incorporate superlyophobicity, rendering them ineffective against icing for mixed liquids or organic solvents which are commonly encountered in practical environments. Herein, a type of rationally designed reentrant superomniphobic structures are presented and controllably fabricated on metal surfaces toward anti-icing for both multiple aqueous solutions and low-surface-tension (down to below 30 mN∙m^(-1)) organic liquids. Through the synergistic anti-icing effects of microreentrant and nanowire structures, two major challenges (i.e., low temperature, a factor determined by external environment, and low surface tension, an intrinsic factor of liquids) in keeping super-repellent surfaces in the Cassie-Baxter state are well addressed. Specifically, the ice adhesion strengths for sulfuric acid and hexadecane on the metallic reentrant superomniphobic structures are as low as 3.9 kPa and 4.2 kPa, respectively, along with favorable long-term deicing durability. Under conditions of −20 °C and 50 % relative humidity, droplets of sulfuric acid and peanut oil rapidly roll off after impact, demonstrating ideal dynamic anti-icing performance. In‑situ observation further elucidates the underlying mechanism responsible for the outstanding multi‑liquid anti‑icing performances. To the best of our knowledge, this is the first report of a fully metallic, highly durable superomniphobic surface possessing exceptional anti‑icing performances across both aqueous solutions and organic liquids. We believe this study can expand the application boundaries of anti-icing technologies and provide a feasible technical pathway for constructing multi-liquid anti-icing surfaces to meet the requirement of practical scenarios.