Transparent superhydrophobic and thermal insulating dual‐functional coatings fabricated by a rapid thermal process

Abstract Superhydrophobic coatings with a thermal insulation property were fabricated via a rapid thermal process. In brief, coating solutions containing low‐melting‐point glass powder, antimony‐doped tin oxide nanopowder, and other additives were first applied to glass substrates. Subsequently, the coated samples underwent a rapid thermal process in a tube furnace at 690°C for 2 min. The relationship between the antimony‐doped tin oxide nanopowder content and the coatings’ performance was examined systematically. The coatings’ hydrophobic and thermal insulation properties were measured and their morphology, phase, and surface roughness were characterized. The optimized coating has a water contact angle of 154°, demonstrating its superhydrophobicity. The infrared transmittance of the optimal sample between 780 and 2500 nm is reduced by 13.3%, and after being exposed to an infrared lamp for 5 min, the temperature below the sample is 4.7°C lower, compared to the bare glass substrate, showing the dual functionalities of the prepared samples. Moreover, since the rapid thermal process can be achieved by a conventional glass tempering process, the fabrication for this coating is simple and readily realized.