Sustaining enhanced condensation on hierarchical mesh-covered surfaces

• Published in: National science review 2018-11, Vol.5 (6), p.878-887
• Main Authors: Wen, Rongfu, Xu, Shanshan, Zhao, Dongliang, Yang, Lixin, Ma, Xuehu, Liu, Wei, Lee, Yung-Cheng, Yang, Ronggui
• Format: Article
• Language: English
• ISSN: 2095-5138; 2053-714X
• DOI: 10.1093/nsr/nwy098

Controlling the solid–liquid–vapor tri-phase interface is of fundamental importance for a broad range of industrial applications including biomedical engineering, energy production and utilization, environmental control, water production, and thermal management. Although a lot of progress has been made over the past few decades on surface manipulation for promoting droplet removal, it is challenging to accelerate both droplet growth and surface refreshing for enhancing vapor-to-liquid condensation. Here we present a superhydrophobic hierarchical mesh-covered (hi-mesh) surface to enable continuous sucking flow of liquid condensate, which achieves fourfold-higher droplet growth and 36.8% faster surface refreshing compared to the state-of-the-art dropwise condensation. Unprecedented enhanced condensation heat transfer is observed to be sustained over a wide range of surface subcooling on the hi-mesh surfaces. This demonstration of sustained enhanced condensation enhancement is not only of fundamental scientific importance, but also provides a viable strategy for large-scale deployment of micro/nanostructured surfaces in a diverse range of technologies.