Superamphiphobic coatings with polymer-wrapped particles: enhancing water harvesting

Abstract

In recent years, water harvesting in arid or semi-arid areas has gained increasing attention. Inspired by the fog harvesting ability of hydrophobic–hydrophilic surfaces associated with Namib desert beetles, considerable effort has been expended in creating such bionic surfaces. However, designing a surface with excellent water harvesting, superamphiphobic, and water/oil self-cleaning properties remains challenging. Herein, an innovative hybrid consisting of a superamphiphobic surface combined with hydrophilic/hydrophobic particles is fabricated by a facile method. This hybrid surface exhibits a praiseworthy drop nucleation effect, high removal efficiency, excellent water collection efficiency, and commendable water/oil self-cleaning performance. The surface’s water/oil wettability, condensation properties, water collection rate and its dependence on the relative humidity and fog flow velocity were systematically investigated. The results obtained strongly indicated that the proposed hybrid superamphiphobic surface exhibits enhanced water drop condensation and water collection performance. In fact, the hybrid superamphiphobic surface doped with silicon carbide particles wrapped with an acrylic acid polymer emulsion (SiC@PAA) exhibited a better water harvesting effect, with a water collection rate more than double that of the nano-SiO₂ superamphiphobic surface. The findings of this work are considered instrumental to the further design and implementation of hybrid superamphiphobic surfaces for cost-efficient atmospheric water harvesting.