The apparent contact angle of water droplet on the micro-structured hydrophobic surface

作     者：YANG ChangWei, HE Feng & HAO PengFei School of Aerospace, Tsinghua University, Beijing 100084, China 

作者机构：School of Aerospace Tsinghua University Beijing China 

出 版 物：《Science China Chemistry》 (中国科学（化学英文版）)

年 卷 期：2010年第53卷第4期

页      面：912-916页

核心收录：

学科分类：0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 070205[理学-凝聚态物理] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 10672089 and 10872106) 

主　　题：apparent contact angle three-phase contact line mixed model Cassie-Baxter model Wenzel model 

摘      要：The apparent contact angle of Cassie-Baxter state water droplets can be calculated by the existing theoretical formula, but due to the defects of the micro-structured hydrophobic surface and some inevitable tiny disturbances in the experiment, Cassie-Baxter state water droplets will appear partly in Wenzel state, that is, the mixed state water droplets. In this paper, apparent contact angles of Cassie-Baxter state and mixed state water droplets on micro-structured hydrophobic surfaces are compared. The research shows that if the projected area fraction of water-solid F in the Cassie-Baxter formula is replaced by the local projected area fraction of water-solid F′, the apparent contact angles of water droplets in both Cassie-Baxter state and the mixed state can be calculated. Further experimental results indicate that the contact state of water droplets nearby the outermost three-phase contact line plays a more important role in determining the apparent contact angle. This conclusion is significant to the understanding of the apparent contact angle and wetting property.