Long-Term Resistance to Phase Change-Induced Wetting Transition on Biphilic Armored Superhydrophobic Surfaces

Abstract

Material surfaces maintaining a liquid super-repellent is crucial in fields such as anti-fouling, drag reduction, and heat transfer. Superhydrophobic surfaces provide an effective approach but suffer from phase change-induced wetting transitions, hindering their practical applications. In this work, Biphilic armored superhydrophobic surfaces (BASS) are designed by integrating hydrophilic interconnected surface frames with superhydrophobic nanostructures. The hydrophilic top of the frame provides spatial selectivity for condensate droplet nucleation, and superhydrophobic nanostructures enable staying dry. Further growth, coalescence, jumping, and roll-off of the condensate droplets on BASS, show remarkable resistance to phase change-induced wetting transition. It still maintains stable superhydrophobicity when exposed to 100 °C of steam for 240 h, at least two orders of magnitude improvement over traditional superhydrophobic surfaces. Such a designing BASS provides an effective approach to address the phase change-induced wetting transition, thereby extending the practical application in the fields of condensation heat transfer, anti-fouling, and fluid transportation of superhydrophobic surfaces.