Liu Kun, Wang Yue, Du Zhongjie, Zhang Chen, Mi Jianguo
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China.
Changzhou Institute of Advanced Materials, Beijing University of Chemical Technology, Beijing, 100029, China.
Chemphyschem. 2020 Mar 17;21(6):531-539. doi: 10.1002/cphc.201901163. Epub 2020 Feb 21.
The diffusion dynamics of colloidal particles in a good solvent confined between two parallel quartz walls have been studied within the framework of dynamical density functional theory. The highly ordered density layers induced by interfacial effects give rise to the oscillating dynamics, resulting in position-dependent structural relaxations and diffusivities. Further investigation reveals that particle size, particle-wall interaction, and slitpore width play different roles in affecting the oscillating behaviors along different directions. As a result, the theory yields the local mean square displacements in perpendicular and parallel directions, which agree remarkably well with prior experimental measurements. The results indicate that the mean square displacements can be quantitatively predicted based on the knowledge of inhomogeneous thermodynamics and dynamics. The local and averaged free energy evolution of the binary particles has been described and presented to understand their dynamic mechanism in confined geometry.
在动态密度泛函理论的框架内，研究了限制在两个平行石英壁之间的良溶剂中胶体粒子的扩散动力学。界面效应诱导的高度有序密度层产生了振荡动力学，导致了位置依赖的结构弛豫和扩散率。进一步的研究表明，粒径、粒子-壁相互作用和狭缝孔宽度在影响沿不同方向的振荡行为中起着不同的作用。因此，该理论得出了垂直和平行方向的局部均方位移，与先前的实验测量结果非常吻合。结果表明，基于非均匀热力学和动力学知识，可以定量预测均方位移。描述并给出了二元粒子的局部和平均自由能演化，以理解它们在受限几何结构中的动力学机制。
