A Review of Fabrication Methods, Properties and Applications of Superhydrophobic Metals

Abstract

Hydrophobicity and superhydrophobicity with self-cleaning properties are well-known characteristics of several natural surfaces, such as the leaves of the sacred lotus plant (Nelumbo nucifera). To achieve a superhydrophobic state, micro- and nanometer scale topography should be realized on a low surface energy material, or a low surface energy coating should be deposited on top of the micro-nano topography if the material is inherently hydrophilic. Tailoring the surface chemistry and topography to control the wetting properties between extreme wetting states enables a palette of functionalities, such as self-cleaning, antifogging, anti-biofouling etc. A variety of surface topographies have been realized in polymers, ceramics, and metals. Metallic surfaces are particularly important in several engineering applications (e.g., naval, aircrafts, buildings, automobile) and their transformation to superhydrophobic can provide additional functionalities, such as corrosion protection, drag reduction, and anti-icing properties. This review paper focuses on the recent advances on superhydrophobic metals and alloys which can be applicable in real life applications and aims to provide an overview of the most promising methods to achieve sustainable superhydrophobicity.

A Review of Recent Advances in Superhydrophobic Surfaces and Their Applications in Drag Reduction and Heat Transfer

“…Chemical etching is an inexpensive and simple approach method of immersing metal substrates into acid or base solution to create binary micro-nano structures; those solutions could be a strong acid, such as HCl and H 2 SO 4 , and a strong base, such as NaOH. Moreover, the technique is universal and can be applied to almost any metal or alloy [ 60 ]. After the surface roughness structures are created, low surface energy materials are then modified to the surface to fabricate a superhydrophobic surface.…”

Preparation of a bionic lotus leaf microstructured surface and its drag reduction performance

“…How to prepare a superior performance bionic lotus leaf surface has been a research topic for years. 8 By the chemical vapor deposition method, Wang et al prepared a lotus-leaf-like superhydrophobic carbon nanotube film with micro/nanoscale hierarchical structure, which could effectively prevent the small water droplets from penetrating the film. 9 By the nanosecond laser processing method, Hauschwitz et al prepared lotus leaf double-scale structures on an aluminium alloy.…”

Surface Characterization of Polytetrafluoroethylene (PTFE) Substrate after Oxygenated Plasma Treatment towards Potential Food Processing Application

“…Plasma modification can introduce oxygen rich functional groups which can modify the surface properties of PTFE including wettability and surface energy [18]. Plasma treatment is a surface modification method based on a dry process and therefore this does not involve the use of a corrosive solution [19].…”