Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
J Chem Phys. 2013 Nov 21;139(19):194710. doi: 10.1063/1.4832378.
We have investigated the structural and dynamic properties of the basal and prismatic facets of the ice Ih/water interface when the solid phase is drawn through the liquid (i.e., sheared relative to the fluid phase). To impose the shear, we utilized a velocity-shearing and scaling approach to reverse non-equilibrium molecular dynamics. This method can create simultaneous temperature and velocity gradients and allow the measurement of transport properties at interfaces. The interfacial width was found to be independent of the relative velocity of the ice and liquid layers over a wide range of shear rates. Decays of molecular orientational time correlation functions gave similar estimates for the width of the interfaces, although the short- and longer-time decay components behave differently closer to the interface. Although both facets of ice are in "stick" boundary conditions in liquid water, the solid-liquid friction coefficients were found to be significantly different for the basal and prismatic facets of ice.
我们研究了冰 Ih/水界面的基面和棱柱面在固相穿过液相(即相对于液相发生剪切)时的结构和动力学特性。为了施加剪切,我们利用速度剪切和标度方法来反转非平衡分子动力学。这种方法可以在界面处产生同时的温度和速度梯度,并允许测量界面处的输运性质。在很宽的剪切速率范围内,发现冰层和液相的相对速度对界面宽度没有影响。分子取向时间相关函数的衰减给出了界面宽度的相似估计值,尽管在更接近界面的位置,短时间和长时间衰减分量的行为不同。尽管冰的两个面都处于液相的“粘滞”边界条件,但发现冰的基面和棱柱面的固-液摩擦系数有显著差异。