Robust self-cleaning surfaces that function when exposed to either air or oil

TLDR

Superhydrophobic self‑cleaning surfaces rely on micro/nanostructures but are mechanically fragile and lose function when exposed to oil. The authors developed an ethanolic suspension of perfluorosilane‑coated TiO₂ nanoparticles that can be applied as a paint to hard or soft substrates, providing self‑cleaning even when immersed in oil. Commercial adhesives were used to bond the paint to various substrates, enhancing durability. The treated surfaces retained water repellency after finger‑wipe, knife‑scratch, and 40 sandpaper abrasion cycles, and the formulations are suitable for clothes, paper, glass, and steel in diverse self‑cleaning applications.

Abstract

Superhydrophobic self-cleaning surfaces are based on the surface micro/nanomorphologies; however, such surfaces are mechanically weak and stop functioning when exposed to oil. We have created an ethanolic suspension of perfluorosilane-coated titanium dioxide nanoparticles that forms a paint that can be sprayed, dipped, or extruded onto both hard and soft materials to create a self-cleaning surface that functions even upon emersion in oil. Commercial adhesives were used to bond the paint to various substrates and promote robustness. These surfaces maintained their water repellency after finger-wipe, knife-scratch, and even 40 abrasion cycles with sandpaper. The formulations developed can be used on clothes, paper, glass, and steel for a myriad of self-cleaning applications.