液滴撞击微结构疏水表面的动态特性

发布时间：2018-03-16 18:01

本文选题：水滴　切入点：撞击　出处：《化工进展》2016年12期 　论文类型：期刊论文

【摘要】：对去离子水滴撞击不同几何尺寸显微结构方柱和方孔状疏水表面的动态特性进行了研究。结果表明:当液滴以不同速度撞击微方柱疏水表面时,液滴展现铺展和回缩过程,且随着韦伯数(We数)增大,最大铺展直径增大,并伴随卫星液滴出现,但到达最大铺展直径的时间一致;而当液滴以相同的速度(We数相同)撞击间距不同的微方柱疏水表面时,液滴的最大铺展直径随着间距的增大而减小,且铺展过程会液滴浸润状态变得不稳定,发生由Cassie向Wenzel状态的浸润转变。当微方柱间距较小时,液滴受到的黏附功越小,越易发生向Cassie状态的转变;液滴撞击微方孔疏水表面时,液滴以规则的圆环状向外铺展和回缩,最后呈现近似规则的椭球状,不会发生向Wenzel状态的浸润转变,利用建立的物理模型对前述现象进行了分析。
[Abstract]:The dynamic characteristics of deionized water droplets impacting on microstructural square columns and square porous hydrophobic surfaces with different geometric sizes are studied. The results show that when droplets impact the hydrophobic surfaces of microcolumns at different velocities, the droplets exhibit spreading and retraction processes. And with the increase of Weber number and We number, the maximum spreading diameter increases and the satellite droplets appear, but the time to reach the maximum spreading diameter is the same, and when the droplet hits the hydrophobic surface of the microcolumn with different spacing at the same speed, The maximum spreading diameter of the droplet decreases with the increase of the spacing, and the soaking state of the droplet becomes unstable during the spreading process, which changes from the Cassie to the Wenzel state. The smaller the spacing of the micro-square column, the smaller the adhesion work of the droplet. The more easily the transition to the Cassie state occurs, when the droplets impact on the hydrophobic surface of the micropores, the droplets will spread out and shrink in a regular circular shape, and at the end, the droplets will present an ellipsoid shape similar to the rule, and no infiltration and transformation to the Wenzel state will take place. The above phenomena are analyzed by using the established physical model.
【作者单位】：上海理工大学能源与动力工程学院;
【基金】：国家自然科学基金(51176123) 上海市自然科学基金(11ZR1424800)项目
【分类号】：O647.1

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