微结构疏水表面的液滴浸润特性

以聚二甲基硅氧烷(PDMS)为基底采用光刻蚀法制备了具有不同粗糙度的微方柱结构疏水表面,研究了微结构疏水表面的液滴浸润特性.结果表明,微方柱高度对表观接触角影响很小,但会显著影响疏水表面液滴浸润状态的稳定性,当微方柱边长和间距一定时,存在一个临界高度,当微方柱高度大于该临界值时,液滴具有良好的稳定性.通过对不同温度下疏水表面液滴浸润状态的研究表明,在露点温度至环境温度区间内,随着温度的增加,表观接触角呈增大趋势;在环境温度至沸点温度区间内,随着温度的升高,表观接触角呈减小的趋势.研究认为,合理的微结构尺寸和应用环境温度对液滴浸润状态的稳定具有重要意义.

Wetting Characteristics of Droplets on Microstructured Hydrophobic Surfaces

The square-post hydrophobic surfaces with different roughness were prepared with the polydimethyl-siloxane (PDMS) substrate using photolithography techniques.The wetting characteristics were analyzed by measuring the superficial contact angles (CAs) of different surfaces.The experimental results show that the height of the micro pillars has a little effect on the CAs but affect the stability of wetting state on microstructured hydrophobic surfaces obviously.When the pitch and spacing are fixed,the stability of droplets becomes weaker with the decrease of the height.Moreover,the wetting characteristics were studied at different temperature.It is found that the CAs have a tendency to grow bigger with the temperature increasing from the dew point temperature to environment temperature,and from environment temperature to boiling point,the changing trend appears in opposite direction.The results suggest that the reasonable microstructure size and suitable environmental temperature have great significance on the stability of the wetting state.