Fabrication and analysis of hydrophobic mesh-metallic surface for moist air condensation

Abstract

ABSTRACT In the advancement of materials and their processing technologies, the alteration in the morphology of metallic surfaces to enhance the condensation rate of moist air is an emerging area of research for improving the performance of atmospheric water generators. In this work, hydrophobic mesh-metallic surfaces were fabricated via a thermal diffusion process in which a micro-order copper mesh with a diameter of 6 µm thermally diffuses on a steel surface of grade 100. The prepared surface was chemical etched before hexadecyltrimethoxysilane coating via the immersion method to grow silica nanostructure in a hierarchical order. A custom-built goniometer was used for measuring the surface wettability in terms of contact angle. The proposed surface has a 140 ± 5° static contact angle of the water droplet. The coated thermally diffused copper mesh to the steel surface fosters low wettability with respect to water. Eventually, a moist air condensation experiment was carried out in controlled atmospheric conditions on both coated and uncoated surfaces to demonstrate water harvesting from moist air. The hydrophobic mesh-metallic surface has high efficacy for moist air condensation as compared to the uncoated thermally diffused mesh-metallic surface. It makes the proposed hydrophobic coating substrate applicable for water harvesting from moisture.