摘要
许多工业生产过程涉及到湿润动力学问题,从20世纪60年代开始得到了广泛的研究,迄今仍有很多问题急待解决.本文将对相关研究和进展作一简要的综述和评介.湿润动力学的实验研究表明:动态接触角与接触线移动速度、液体物性、固体衬底物性和表面性质等诸多因素相关.动态接触角随毛细数Ca的变化方式可分为3个区域,Ca<2×10-6,动态接触角为常数,10-6<Ca<2×10-3,动态接触角随毛细数迅速增加,高于某个临界毛细数(大概在5×10-4<Ca<5×10-3)动态接触角随毛细数平缓单增.受实验技术限制,极低毛细数下(2×10-7<Ca<2×10-6)动态接触角的数据很少,仅有的几个研究表明,该区域下动态接触角有反常现象.动态接触角的理论研究主要包括流体力学滑移模型、前驱膜模型、统计力学模型和分子动力学模拟,各种方法均有其优缺点.
The dynamic wetting behavior of liquids on solid surface has been extensively investigated for several decades because of its critical importance for a variety of practical applications. However, there are still many unsolved problems. In this paper, a brief review with discussion is conducted to comprehensively understand the associated phenomena. Very clearly, the dynamic contact angle θ_D, an important parameter describing wetting, is mainly dependent upon the moving velocity of contact line, properties of fluids and solid surface, and surface roughness. Dynamic contact angle behavior is divided into three regions according to capillary number Ca, i.e. Ca<2×10^(-6), θ_D is approximately constant; 5×10^(-4)<Ca<5×10^(-3), θ_D rapidly increases with Ca; Ca is higher than a specified value ranging from 5×10^(-4) to 5×10^(-3), θ_D slowly increases with Ca. As indicated from only a few experiments, the dynamic contact angle displays some abnormal behavior at very small Ca(2×10^(-7)<Ca<2×10^(-6)). The methods available for studying the dynamic contact angle include the hydrodynamic slipping model, the precursor film model, the molecular kinetic model and molecular dynamic simulation. The advantages and disadvantages of these methods are discussed.
出处
《应用基础与工程科学学报》
EI
CSCD
2003年第4期396-404,共9页
Journal of Basic Science and Engineering
基金
国家自然科学基金(No.59976016)
中国博士后科学基金(2003034018)
国家"973"重大基础研究项目(No.G2000026301)资助
