The dynamic contact angle of a gas–liquid–solid system depends on the contact line velocity and ignoring this effect could lead to inaccurate estimations of the capillary pressures in microporous media. While most existing coarse-grained molecular dynamics (CGMD) models use one particle to represent a few molecules, we present a novel CGMD framework to model microscale CO2/water flows in silica with each particle representing hundreds of thousands of molecules. The framework can reproduce the densities and viscosities of water and CO2, water–CO2 interfacial tension, and static contact angle over a wide range of pressures. The validated framework is applied to study the velocity-dependency of contact angle of the microscale CO2–water–silica system. The results indicate that the assumption in the molecular kinetic theory that liquid–solid interaction is similar to the reversible work of adhesion between liquid and solid may not hold for CO2–water–silica systems.

中文翻译：

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使用粗粒分子方法对 CO2-水-二氧化硅系统微尺度动态接触角的数值研究

气-液-固系统的动态接触角取决于接触线速度，忽略这种影响可能会导致对微孔介质中毛细管压力的估计不准确。虽然大多数现有的粗粒度分子动力学 (CGMD) 模型使用一个粒子来表示几个分子，但我们提出了一种新颖的 CGMD 框架来模拟二氧化硅中的微尺度 CO2/水流，每个粒子代表数十万个分子。该框架可以在很宽的压力范围内重现水和 CO2 的密度和粘度、水-CO2 界面张力和静态接触角。验证框架用于研究微尺度 CO2-水-二氧化硅系统接触角的速度依赖性。