Moore Fergus, Russo John, Liverpool Tanniemola B, Royall C Patrick
Bristol Centre for Functional Nanomaterials, University of Bristol, Bristol BS8 1FD, United Kingdom.
Department of Physics, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.
J Chem Phys. 2023 Mar 14;158(10):104907. doi: 10.1063/5.0131340.
The transport of active particles may occur in complex environments, in which it emerges from the interplay between the mobility of the active components and the quenched disorder of the environment. Here, we explore the structural and dynamical properties of active Brownian particles (ABPs) in random environments composed of fixed obstacles in three dimensions. We consider different arrangements of the obstacles. In particular, we consider two particular situations corresponding to experimentally realizable settings. First, we model pinning particles in (non-overlapping) random positions and, second, in a percolating gel structure and provide an extensive characterization of the structure and dynamics of ABPs in these complex environments. We find that the confinement increases the heterogeneity of the dynamics, with new populations of absorbed and localized particles appearing close to the obstacles. This heterogeneity has a profound impact on the motility induced phase separation exhibited by the particles at high activity, ranging from nucleation and growth in random disorder to a complex phase separation in porous environments.
活性粒子的输运可能发生在复杂环境中，这种输运源于活性成分的迁移率与环境的猝灭无序之间的相互作用。在此，我们探究三维空间中由固定障碍物构成的随机环境里活性布朗粒子（ABP）的结构和动力学性质。我们考虑障碍物的不同排列方式。特别地，我们考虑对应于实验可实现设置的两种特殊情况。其一，我们对处于（非重叠的）随机位置的钉扎粒子进行建模，其二，在渗流凝胶结构中进行建模，并对这些复杂环境中ABP的结构和动力学给出全面的表征。我们发现，限制作用增加了动力学的不均匀性，在障碍物附近出现了新的被吸收和局域化的粒子群体。这种不均匀性对高活性下粒子表现出的运动诱导相分离有深远影响，范围从随机无序中的成核和生长到多孔环境中的复杂相分离。
