碳酸钙水溶液结晶的MD模拟

Molecular Dynamics Simulation on an Aqueous Solution of Calcium Carbonate

研究了温度对碳酸钙水溶液中Ca2+和CO23-结晶的影响,应用分子动力学(MD)方法模拟了在不同温度下由方解石■晶面和300个水分子、2个Ca2+及2个CO23-组成的水溶液系统,计算了温度为283 K^373 K的水溶液中水分子、Ca2+和CO23-的扩散系数以及两种离子与表面的结合能。通过水分子和Ca2+及CO23-的扩散系数的计算证明在温度为353 K时水溶液中离子最容易反应形成离子对,进而长成微晶,而在343 K时离子最不易结晶。通过结合能的计算,可以看出在313 K时离子与表面的结合能最大,此时离子最容易被晶体表面吸附而在表面上形成新的结晶,而在373 K时结合能最小。

In order to study the influence of temperature on crystallization process of Ca2＋ and CO2-3,using MD simulates the system that is composed of calcite■ surface,300 hydrones,2 Ca2＋ and 2 CO2-3.The diffusion coefficient of hydrones,Ca^2＋ and CO23 in aqueous solution whose temperature is from 283 K to 373 K is calculated,also including the binding energy between ions and （^-110） surface.The diffusion coefficient indicates that Ca^2＋ and CO^2-3can easiliest crystallize when temperature is 353 K.On the contrary,it is hardest when temperature is 313 K. The binding energy between ions and （^-110） surface is the highest when the temperature is 313 K. At this temperature, the ions are so easily adsorbed that they can crystallize on the surface. The binding energy is lowest when the temperature is 373 K.