玻璃基底上平衡态液滴接触角特性  

Characteristics of Equilibrium Contact Angle of a Sessile Droplet on Silica Substrate

作　　者：吴春梅[1] 李友荣[1] C A Ward 

机构地区：[1]重庆大学动力工程学院低品位能源利用技术及系统教育部重点实验室,重庆400044 [2]加拿大多伦多大学机械工程学院

出　　处：《工程热物理学报》2014年第2期362-365,共4页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.50976129);高等学校博士学科点专项科研基金资助课题(No.20110191110015)

摘　　要：为了了解玻璃基底上平衡态液滴接触角特性,采用实验和理论相结合的方法分析了玻璃基底表面水滴平衡时应满足的热力学条件,得到了液滴汽-液界面形状以及平衡态接触角大小。分析发现,玻璃基底上平衡态液滴接触角是与三相接触线压力相关的热力学参数,当三相接触线曲率一定时,平衡态液滴接触角随三相接触线处压比的增加而增大.同时,考虑到固-液界面吸附特性,根据平衡态时系统亥姆霍兹自由能最小这一热力学判据可以预测出液滴平衡接触角大小,结果和实验值吻合。The characteristics of the equilibrium contact angle of water droplet on a silica substrate were experimentally investigated. Combining the theory of thermodynamics and experimental measurements, the equilibrium droplet shape was calculated, and agreed well with measurements over a range of contact angle. It was found that for an isothermal vapor-water-silica system, the equilibrium contact angle of a sessile droplet is a thermodynamic parameter, not a physical property. For a fixed three-phase contact line curvature, the equilibrium contact angle has dependence on pressure ratio at the three-phase contact line. As the pressure ratio increases, the equilibrium contact angle increases. On the other hand, from the Helmholtz function, the equilibrium contact angle also can be predicted, and the result was in good agreement with the experiments.

关 键 词：平衡态 接触角 液滴 界面 

分 类 号：TK123[动力工程及工程热物理—工程热物理]