Molecular-Level Understanding of Efficient Thermal Transport across the Silica–Water Interface
Molecular-Level Understanding of Efficient Thermal Transport across the Silica–Water Interface
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DOI：
10.1021/acs.jpcc.1c06571
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发表时间：
2021-10
期刊：
影响因子：
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通讯作者：
Zhihao Xu;Dezhao Huang;T. Luo
中科院分区：
文献类型：
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作者：
Zhihao Xu;Dezhao Huang;T. Luo
在这项研究中，我们使用非平衡分子动力学模拟来研究二氧化硅-水界面的界面热输运。以金-水界面为对比，我们的结果表明，硅胶-水界面的界面热导(ITC)高出10倍以上。两个界面的振动功率谱(VPS)表明，硅水界面的振动耦合较强，这是高ITC的一个重要原因。此外，我们的分析表明，在二氧化硅-水界面上存在氢键，这为热传输提供了更多的通道。通过计算四种不同羟基密度的硅水界面的ITC，进一步研究了氢键效应。研究发现，不同类型的氢键之间存在竞争效应，水与固体表面之间的氢键可以显著提高ITC。为了评价振动耦合效应的效果，人为地改变水分子的质量来影响其振动性质，从而调节振动耦合效应。通过灵敏度分析，发现振动耦合效应是一个较大的影响因素。我们的结果可能为硬/软界面的强化换热提供新的见解。
In this study, we use nonequilibrium molecular dynamics simulations to study the interfacial thermal transport across the silica–water interface. Using a gold–water interface as a comparison, our results show that the silica–water interface has over 10 times higher interfacial thermal conductance (ITC). Vibrational power spectra (VPS) of the two interfaces indicate that the vibrational coupling at the silica–water interface is stronger, which is an important reason for the high ITC. In addition, our analysis indicates the existence of hydrogen bonds at the silica–water interface, which provides more channels for thermal transport. We further study the hydrogen-bond effect by calculating the ITC of four silica–water interfaces that have different hydroxyl densities. It is found that there are competing effects between different types of hydrogen bonds, and the hydrogen bonds between water and the solid surface can significantly enhance the ITC. In order to evaluate the effect of the vibrational coupling effect, the mass of the water molecules is artificially changed to influence its vibrational properties and thus tune the vibrational coupling effect. By applying sensitivity analysis, it is found that the vibrational coupling effect is a more influential factor. Our results may provide new insights for heat transfer enhancement at hard/soft interfaces.