Water-Repellent Properties of Superhydrophobic and Lubricant-Infused “Slippery” Surfaces: A Brief Study on the Functions and Applications

Abstract

Bioinspired water-repellent materials offer a wealth of opportunities to solve scientific and technological issues. Lotus-leaf and pitcher plants represent two types of antiwetting surfaces, i.e., superhydrophobic and lubricant-infused "slippery" surfaces. Here we investigate the functions and applications of those two types of interfacial materials. The superhydrophobic surface was fabricated on the basis of a hydrophobic fumed silica nanoparticle/poly(dimethylsiloxane) composite layer, and the lubricant-infused "slippery" surface was prepared on the basis of silicone oil infusion. The fabrication, characteristics, and functions of both substrates were studied, including the wettability, transparency, adhesive force, dynamic droplet impact, antifogging, self-cleaning ability, etc. The advantages and disadvantages of the surfaces were briefly discussed, indicating the most suitable applications of the antiwetting materials. This contribution is aimed at providing meaningful information on how to select water-repellent substrates to solve the scientific and practical issues, which can also stimulate new thinking for the development of antiwetting interfacial materials.

Recent Advances in the Fabrication of Superhydrophobic Surfaces

“…16,25,6567 In the solution, the substrate can be coated. Or it may contain two main steps, namely preparing the corresponding coatings for the certain substrate and using relevant coating technologies to coat the substrate with proper roughness such as spraying (like supersonic kinetic spraying), 34,47,6870 brushing coating, 71 spin coating, 72 dip-coating, 51,72 solvent casting, 52,73 and so on. In addition to these two main steps, the method includes some simple extra complementary processing, such as atmospheric pressure plasma treatment, substrate surface etching, chemical deposition, etc.…”

“…4.1.3 Other As-prepared Materials for Direct Coating: Most of coating method to prepare superhydrophobic materials is direct coating methods such as modified particle homogeneous dispersions (such as powders and colloidal nanoparticles), 38,47,51,52,6870,88,9496 solution, 31,34 and so on using appropriate coating technologies including dip-coating, spraying, spin coating, etc. In this section, we introduce the coating fabrication according to the different types of superhydrophobic materials.…”

“…Here, it is worth mentioning that the surface energy of one certain surface is an explicit value, which is decided by the substance forming the surface. The carbon black (candle soot) 17 and alkanes and their derivatives such as alkanethiols and alkanes containing silicon, 13,14,22,28,34 chlorine, 22,35 fluorine, etc. are all often used as modification materials.…”

Underwater superoleophobicity, anti-oil and ultra-broadband enhanced absorption of metallic surfaces produced by a femtosecond laser inspired by fish and chameleons

“…Interfacial materials with multiple properties offer many opportunities for the design of advanced technologies12345. Recently, underwater superoleophobic surfaces have emerged with potential applications in submerged antifouling6, oil-water separation789 and small oil-droplet transportation101112.…”

“…Recently, underwater superoleophobic surfaces have emerged with potential applications in submerged antifouling6, oil-water separation789 and small oil-droplet transportation101112. Taking inspiration from nature is an exciting approach for designing smart and functional materials5. For example, fish can retain moisture outside of water, swim freely underwater and maintain clean scales even in oil-polluted water1314.…”