A method for preparing transparent superhydrophobic surfaces was proposed

and its anti-frosting performance at cold surface temperatures -3–5℃ and relative humidity 20%–60% was investigated. The experimental results show that the maximum contact angle of the transparent superhydrophobic glass surface prepared using silicon dioxide and polydimethylsiloxane is as large as 154.1° and has very good transparency. Frosting tests under vertical natural convection conditions indicated that the modified glass surface had a good anti-frosting effect. The frost layer formed consisted of a wheat-like spike structure in the early stage and transformed into an irregular bifurcation structure in the later stage

which is different from that of the unmodified glass surface whose frost layer structure consisted of flower clusters in the early stage and hexagonal frost crystals in the later stage. The contact angle of the modified glass surface first increased and then decreased with the nano-SiO2 coating amount

that is

there exists an optimum nano-SiO2 coating amount

found to be 0.067 g/cm2 under the experimental conditions covered. This optimum surface can remain unfrosted for 700 s

which is 66.7% longer than that of an unmodified glass surface. The results also revealed that the higher the relative humidity

the more obvious the dendritic growth of the frost crystal. The directional characteristics of frost crystal growth on the transparent superhydrophobic surface became more obvious as the humidity increased.