High Transmittance Superhydrophobic Coatings with Durable Self-Cleaning Properties

Abstract

One of the most important factors determining a significant reduction in optical devices’ efficiency is the accumulation of soiling substances such as dust, which, especially in solar power plants, implies higher costs and materials ageing. The use of superhydrophobic (SH) coatings, water contact angle (CA) greater than 150°, represents a suitable solution to improve the self-cleaning action while at the same time providing high transmittance for energy conversion. A mixed organic–inorganic SH coating with surface roughness below 100 nm was prepared by an easily scalable spray method and employed, allowing us to modulate the covered area and transparency. The coating has been also investigated while simulating pollution agents like acid rain, harsh environments, and the impact of continuous water droplets and dust particles with different physicochemical properties. The spray coating method allows us to obtain a modulated SH and self-cleaning surface showing CA > 170°, high transmittance in UV-Vis range and the ability to completely restore its initial properties in terms of wettability and transmittance after durability and soiling tests.

Spheroid Formation and Recovery Using Superhydrophobic Coating for Regenerative Purposes

“…A glass substrate was spray-coated employing 2.0 g/L of the above dispersion [ 27 ]. The resulting SHS were cleaned with deionized water to remove any physical adsorbed impurities potentially affecting cell viability and to assess in situ their high hydrophobicity.…”

Mammalian Cell Spheroids on Mixed Organic–Inorganic Superhydrophobic Coating

“…The mixed organic-inorganic-coated glass was prepared on glass by the spray coating technique, using the dispersion of fumed silica nanoparticles at a concentration of 2 g/L in a fluoropolymer blend [30]. Table 1 summarizes the physicochemical characteristics of the proposed substrates, ranging from hydrophilic to superhydrophobic, based on the CA values.…”

Wetting Properties of Simulated and Commercial Contaminants on High Transmittance Superhydrophobic Coating

“…For this reason, in this work, the authors studied the effects of simulated and anthropogenic pollutants on the surface and optical properties of highly hydro and oleophobic coating. In previous works, the durability of such coating has been investigated in on-field tests in real conditions of urban polluted areas [ 37 ]. The results show the effectiveness of the combination of roughness and composition in the protection of a surface in solar panels from water-based formulations and providing information for the preparation of agricultural sprays with a lower impact on solar plant maintenance procedures.…”