Dual superlyophobic surfaces with superhydrophobicity and underwater superoleophobicity

Abstract

Lotus leaf-inspired superhydrophobic, fish scale-inspired underwater superoleophobic, and the switchable superwetting surfaces have been broadly developed by entire modification with water-repellent, water-loving, and smart components, respectively. Inspired by beetles, here a strategy of fractional modification is proposed to construct dual superlyophobic surfaces that have both superhydrophobic and underwater superoleophobic properties. Specifically, copper-based coatings on various substrates are fractionally modified by adjusting the concentration of perfluorinated mercaptan. The obtained dual superlyophobic surfaces display mutual advantages like using either superhydrophobic or underwater superoleophobic materials without any continuous external stimulus, for example on-demand oil–water separation. In theory, the distinctive dual superlyophobic state exists in a narrow range of surface chemistry, and thus needs elaborate surface modification. This discovery will facilitate the extension of the surfaces with completely opposite superwettability to enjoy the superiority in interfacial issues and applications.