The influence of the vacancy defect of the CaO surface on the wettability of molten alkali metal salt was studied by molecular dynamics simulations. The results indicated that in the temperature range of 800–1100 K, the molten Na₂SO₄ on both VD_calcium and VD_oxygen defect surfaces presented a poor wettability compared to that on the complete surface. Measurement of the density profile and the contact angle of the molten Na₂SO₄ showed that the higher the temperature and defect concentration, the worse the wettability. The micromechanism was revealed by calculating the polarization intensity that the vacancy defect surface led to the formation of the induced dipole moment in the molten Na₂SO₄. Induced polarization caused by defect surfaces reduces the wettability of Na₂SO₄. More importantly, as the temperature and defect concentration increase, various defect surfaces form loose and local weak liquidity structures. These structures are beneficial for the diffusion of carbon dioxide into the solid, but the reduction in the spreading area caused by poor wettability causes the efficiency of the CaL to decline. The vibration difference between Na₂SO₄ and CaO increases with the increased temperature and defect concentration. This means that the thermal energy transportability at the interface is suppressed by poor wettability.

中文翻译：

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钙环化过程中氧化钙表面空位缺陷对熔融金属碱金属盐润湿性的影响

通过分子动力学模拟研究了CaO表面空位缺陷对熔融碱金属盐润湿性的影响。结果表明，在800–1100 K的温度范围内，与完整表面相比，VD_钙和VD_氧气缺陷表面上的熔融Na ₂ SO ₄均具有较差的润湿性。熔融Na ₂ SO ₄的密度分布和接触角的测量结果表明，温度和缺陷浓度越高，润湿性越差。通过计算极化强度来揭示微机制，该极化强度是空位缺陷表面导致在熔融的Na ₂ SO _4中形成感应偶极矩的原因。由缺陷表面引起的诱导极化降低了Na ₂ SO ₄的润湿性。更重要的是，随着温度和缺陷浓度的增加，各种缺陷表面会形成松散的局部弱流动性结构。这些结构有利于二氧化碳向固体中的扩散，但是由于差的润湿性引起的扩散面积的减小导致CaL的效率下降。Na ₂之间的振动差SO ₄和CaO随着温度和缺陷浓度的增加而增加。这意味着差的润湿性抑制了界面处的热能传输性。