剪切力在碳酸钙污垢形成机制中的分子动力学模拟研究

Molecular Dynamics Simulation of Shear Force in the Formation Mechanism of Calcium Carbonate Scaling

摘要: 本研究以CaCO₃为研究对象，运用分子动力学方法构建了碳酸钙水溶液与方解石晶面(104和1~10)的体系，模拟在不同温度(273~353 K)下剪切速率(0、10~32 s⁻¹)对该体系的影响，重点考察了剪切速率对体系的结合能(E_bind)和扩散系数(MSD)的影响。研究结果表明：温度和剪切速率对Ca²⁺和$C{O}_3^{2-}$ 在方解石两晶面上作用不同，表现为溶液中的Ca²⁺和$C{O}_3^{2-}$ 更倾向在方解石(104)晶面上有序生长，离子键在碳酸钙水溶液与方解石体系中起主要作用，而范德华力作用起辅助作用。

Abstract: This study focused on CaCO₃ as the research object. Using the molecular dynamics method, a system of calcium carbonate aqueous solution and the crystal faces (104 and 1~10) of calcite was constructed. The influence of shear rate (0, 10 to 32 s⁻¹) at different temperatures (273~353 K) on this system was simulated. The effects of shear rate on the binding energy (E_bind) and diffusion coefficient (MSD) of the system were particularly investigated. The research results indicate that temperature and shear rate have different effects on the interaction of Ca²⁺ and $C{O}_3^{2-}$ on the two crystal faces of calcite, Ca²⁺ and $C{O}_3^{2-}$ in the solution are more inclined to grow in an ordered manner on the (104) crystal face of calcite. Ionic bonds play a dominant role in the aqueous solution of calcium carbonate and the calcite system, while van der Waals forces play a supporting role.