A facile strategy for the fabrication of a bioinspired hydrophilic–superhydrophobic patterned surface for highly efficient fog-harvesting

Abstract

Fog water collection represents a meaningful effort in the places where regular water sources, including surface water and ground water, are scarce. Inspired by the amazing fog water collection capability of Stenocara beetles in the Namib Desert and based on the recent work in biomimetic water collection, this work reported a facile, easy-to-operate, and low-cost method for the fabrication of hydrophilic-superhydrophobic patterned hybrid surface toward highly efficient fog water collection. The essence of the method is incorporating a (super)hydrophobically modified metal-based gauze onto the surface of a hydrophilic polystyrene (PS) flat sheet by a simple lab oven-based thermal pressing procedure. The produced hybrid patterned surfaces consisted of PS patches sitting within the holes of the metal gauzes. The method allows for an easy control over the pattern dimension (e.g., patch size) by varying gauze mesh size and thermal pressing temperature, which is then translated to an easy optimization of the ultimate fog water collection efficiency. Given the low-cost and wide availability of both PS and metal gauze, this method has a great potential for scaling-up. The results showed that the hydrophilic-superhydrophobic patterned hybrid surfaces with a similar pattern size to Stenocara beetles's back pattern produced significantly higher fog collection efficiency than the uniformly (super)hydrophilic or (super)hydrophobic surfaces. This work contributes to general effort in fabricating wettability patterned surfaces and to atmospheric water collection for direct portal use.

Bioinspired Special Wettability Surfaces: From Fundamental Research to Water Harvesting Applications

“…Finally, with a fixed pressure on the top of materials and a pre‐setting temperature heating in an oven, the two materials were merged. It was found that the samples with the gauze of 50 and treated at 130 °C exhibited the best fog‐collecting ability in a homemade fog‐collecting system due to its optimal hydrophilic‐super‐hydrophobic patterned surface …”

Are vacuum-filtrated reduced graphene oxide membranes symmetric?

“…24 The rGO membrane sample (2.5 cm × 2.5 cm) was fixed on a glass substrate with the same size. The sample was hung with its surface perpendicular to the horizontal plane.…”

Bioinspired materials for water supply and management: water collection, water purification and separation of water from oil

“…Copyright 2007 American Chemical Society); (b) hydrophilic steel needles pierced through superhydrophobic film (adapted with permission from [27]. Copyright 2015 American Chemical Society); (c) superhydrophobic copper mesh pressed into hydrophilic (relative to the copper mesh) polymer sheet [28]; and (d) dewetted hydrophilic polymer regions atop a hydrophobic (relative to the hydrophilic polymer regions) polymer (adapted with permission from [29]. Copyright 2015 American Chemical Society).…”