Repellent surfaces. Turning a surface superrepellent even to completely wetting liquids

Tingyi Leo Liu; Chang-Jin C J Kim

doi:10.1126/science.1254787

Repellent surfaces. Turning a surface superrepellent even to completely wetting liquids

Science. 2014 Nov 28;346(6213):1096-100. doi: 10.1126/science.1254787.

Authors

Tingyi Leo Liu¹, Chang-Jin C J Kim²

Affiliations

¹ Department of Mechanical and Aerospace Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
² Department of Mechanical and Aerospace Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA. Department of Bioengineering, UCLA, Los Angeles, CA 90095, USA. cjkim@ucla.edu.

PMID: 25430765
DOI: 10.1126/science.1254787

Abstract

Superhydrophobic and superoleophobic surfaces have so far been made by roughening a hydrophobic material. However, no surfaces were able to repel extremely-low-energy liquids such as fluorinated solvents, which completely wet even the most hydrophobic material. We show how roughness alone, if made of a specific doubly reentrant structure that enables very low liquid-solid contact fraction, can render the surface of any material superrepellent. Starting from a completely wettable material (silica), we micro- and nanostructure its surface to make it superomniphobic and bounce off all available liquids, including perfluorohexane. The same superomniphobicity is further confirmed with identical surfaces of a metal and a polymer. Free of any hydrophobic coating, the superomniphobic silica surface also withstands temperatures over 1000°C and resists biofouling.