Preparation and performance of nanoparticles-based anti-frosting transparent hydrophobic surfaces

Abstract

Hydrophobic surface has been used for restraining frost deposition on cold non-transparent surfaces. However, anti-frosting surfaces with good transparency, esp. transparent hydrophobic surfaces are receiving more and attention from both industries and researchers. A simple method for preparing transparent hydrophobic surface is thus proposed and used to fabricate anti-frosting hydrophobic surfaces. A series of frosting experiments on transparent hydrophobic surfaces and unmodified glass surfaces were carried out under natural convection conditions. The results show that the maximum contact angle of the modified hydrophobic surface is increased by 39.3°, which means an increase of 44.1% over that of the unmodified plain glass surface. The surface properties are the best when TEOS addition is 10 mL. In the range of visible light, the surface transmittance is greater than 87%. A very special condensate droplets freezing mechanism, i.e. , the ice bridge mechanism is observed. And the frost crystal appearance time on the hydrophobic surface is more than 660 s, which is 540 s longer than that on the unmodified glass surface. The frost coverage of the hydrophobic surface is significantly smaller than that of the unmodified plain glass surface, the speed of frost propagation is only 47.5 μm/s, which is 29.6% lower than that of unmodified surface. Therefore, compared with the unmodified surface, the hydrophobic glass surface can effectively inhibit the growth of frost layer without much loss of its transparency. • Transparent hydrophobic surface was fabricated successfully by gel-sol method. • Visible light transmittance of transparent hydrophobic surface is as large as 87%. • Good anti-frosting performance of the surface is confirmed under high cold surface temperature conditions.