透明超疏水表面的制备与抑霜性能研究

Fabrication of Transparent Superhydrophobic Surface and Its Anti-Frosting Performance

本文介绍了一种透明超疏水表面的制备方法,并在冷表面温度(-3~5℃)、相对湿度(20%~60%)下研究了其抑霜性能。结果表明:用纳米二氧化硅和聚二甲基硅氧烷制备的透明超疏水玻璃表面的最大接触角可达到154.1°,透光性能良好;在自然对流条件下竖直放置的超疏水玻璃表面有良好的抑霜效果,形成的霜层先是呈麦穗状,后期呈无规则分叉状,这与普通玻璃表面上先是花簇状、后期是霜晶呈六边形的霜层形成鲜明对照;接触角随纳米二氧化硅质量呈倒U型曲线关系,最佳质量为0.067 g/cm^(2),修饰玻璃表面可维持700 s表面不结霜,与普通玻璃表面结霜出现时间相比延长了66.7%;发现随着湿度增大,霜晶枝晶生长越明显,超疏水表面上霜层霜晶生长的方向性越明显。

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-SiO 2 coating amount,that is,there exists an optimum nano-SiO 2 coating amount,found to be 0.067 g/cm^(2) 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.