Strzelewicz Anna, Cieśla Michał, Dybiec Bartłomiej, Krasowska Monika
Faculty of Chemistry, Silesian University of Technology, 44-100 Gliwice, Poland.
Institute of Theoretical Physics, and Mark Kac Center for Complex Systems Research, Jagiellonian University, 30-348 Kraków, Poland.
Entropy (Basel). 2025 Mar 12;27(3):293. doi: 10.3390/e27030293.
Simulations of the Brownian dynamics of diffusing particles in complex environments provide important information about the characteristics of the medium and the properties of biological processes. Notable examples include the diffusion of ions and macromolecular solutes through channels of varying cross-section, such as pores in biological membranes, living tissues, zeolites, carbon nanotubes, and synthetic porous materials. In these systems, the observed diffusion can exhibit anomalous behavior characterized by a nonlinear increase in the mean squared displacement. In this article, we present a toy model of the diffusion of rod-shaped particles through a narrowing, conical pore with a trapezoidal longitudinal cross-section. Particles of different sizes undergo a random walk due to interactions with the environment (modeled as noise). We study how the diffusion properties change with particle size as a function of pore width. The numerical analysis of diffusion-driven transport through narrowing conical channels reveals its effective subdiffusive, i.e., anomalous, character.
对复杂环境中扩散粒子的布朗动力学进行模拟，可提供有关介质特性和生物过程属性的重要信息。显著的例子包括离子和大分子溶质通过不同横截面通道的扩散，如生物膜、活组织、沸石、碳纳米管和合成多孔材料中的孔隙。在这些系统中，观察到的扩散可能表现出异常行为，其特征是均方位移呈非线性增加。在本文中，我们提出了一个棒状粒子通过具有梯形纵向横截面的变窄锥形孔扩散的简化模型。由于与环境的相互作用（建模为噪声），不同大小的粒子进行随机游走。我们研究了扩散特性如何随粒子大小作为孔径的函数而变化。对通过变窄锥形通道的扩散驱动输运进行的数值分析揭示了其有效的亚扩散特性，即异常特性。
