Wenzhou Institute, University of Chinese Academy of Science,Wenzhou, Zhejiang 325000, China.
Oujiang Laboratory, Longwan District, Wenzhou, Zhejiang 325001, China.
J Phys Chem B. 2022 Aug 25;126(33):6171-6179. doi: 10.1021/acs.jpcb.2c03976. Epub 2022 Aug 10.
The rate at which a Brownian particle confined in a closed space escapes from the space by passing through a narrow passage is called the escape rate. The escape rate is relevant to many diffusion limited processes in polymer and colloidal systems, such as colloidal aggregation, polymerization reaction, polymer translocation through a membrane, etc. Here, we propose a variational principle to calculate the escape rate of complex molecules doing Brownian motion in a multi-dimensional phase space. We propose a regional minimization method in which we divide the whole phase space into regions, conduct the minimization for each region, and combine the results to get the minimum in the entire space. As an example, we discuss (1) the escape rate of a point particle that escapes from a confinement passing through a long corridor and (2) the escape rate of a rod-like particle that escapes through a small hole made in the wall of the confinement.
在封闭空间中，布朗粒子通过狭窄通道逃离空间的速度称为逃逸率。逃逸率与聚合物和胶体系统中的许多扩散限制过程有关，例如胶体聚集、聚合反应、聚合物通过膜的易位等。在这里，我们提出了一种变分原理来计算在多维相空间中做布朗运动的复杂分子的逃逸率。我们提出了一种区域最小化方法，其中我们将整个相空间划分为区域，对每个区域进行最小化，并结合结果得到整个空间中的最小值。作为一个例子，我们讨论了（1）点粒子通过长通道从限制中逃逸的逃逸率，以及（2）棒状粒子通过限制壁上的小孔逃逸的逃逸率。
