Enhanced water collection of bio-inspired functional surfaces in high-speed flow for high performance demister

Abstract

Performance enhancement of thermal desalination processes requires the excellent water separation capabilities in demisters. However, in high-speed gas flow, the re-entrainment of captured water from the surfaces to the gas flow can considerably decrease the water collection capabilities and the corresponding separation efficiency. Herein, we report fabrication of micro-structured polymer surfaces with excellent water capturing properties in low- and high-speed gas flow conditions by using a facile molding process. Inspired by the surfaces of biospecies, the fabricated surfaces possess vertically-aligned micro-scale cone arrays and sets of microchannels to significantly enhance the capillary pressure. As a result, those hybrid-structured surfaces exhibit up to 2.4 and 4.7 times higher excellent water collection capabilities than control planar at low- and high-speed flow conditions, respectively. In addition, the mist eliminator with the hybrid surfaces performs 1.8 times higher water collection behavior than the control mist eliminator with bare surfaces. The results show the promise of developing the surfaces with engineered structures for significantly enhancing water collection without changing the shapes of flow passages in target objects.