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摘要
Two types of the superhydrophobic/hydrophilic micro-patterned surfaces were prepared through a ultraviolet photocatalytic etching technology. One is hydrophilic dot patterned surface another is hydrophilic square patterned surface. The hydrophilic dot patterned surface is mainly composed of hydrophobic surfaces, while the hydrophilic sites are arrayed in the hydrophobic region. The hydrophilic square patterned surface is mainly composed of hydrophilic surface. The latticed hydrophobic region cut the hydrophilic area into several independent small blocks. The surfaces with the superhydrophobic/hydrophilic pattern has a good control of the distribution of the liquid, which can influence the evaporation behavior of droplets and the evaporation rate of the dispersion droplets on the surface in a nonstructural manner. The effects of the two patterned surfaces on the evaporation rate of droplets by carrying out natural evaporation experiments and forced convection experiments with 4x4 droplets of two patterned surfaces at normal temperature and pressure respectively and the effect of the two surfaces on the droplet evaporation rate was compared with that of the homogeneous hydrophilic surface. The gas-liquid contact area of the droplets on the hydrophilic dot patterned surface is 76.9% higher than that of the homogeneous hydrophilic surface and the gas-liquid contact area of the droplets on the hydrophilic square patterned surface is increased 61.23% relative to the homogeneous hydrophilic surface. The increased gas-liquid contact area promotes the evaporation of droplets in the early stage. The droplet evaporation rate decreased in the late stage. It is mainly due to the anisotropy of humidity. In the horizontal direction between the drops along the wall, the gradient of humidity is lower than in the vertical direction over the top point of the droplet. As a result, the vapor flow on the droplet surface is significantly heterogeneous for many droplets.
- 出版日期2018-5-20
- 单位华南理工大学
