Singh Jalim, Mustakim Mahammad, Kumar A V Anil
Physical Sciences, National Institute of Science Education and Research, Jatni, Khurda, Bhubaneswar, Odisha, 752050, INDIA.
School of Physical Sciences, National Institute of Science Education and Research, Jatni, Khordha, Odisha, 752050, INDIA.
J Phys Condens Matter. 2020 Dec 16. doi: 10.1088/1361-648X/abd428.
We report results from the molecular dynamics simulations of a binary colloidal mixture subjected to an external potential barrier along one of the spatial directions at low volume fraction, $\phi=$ 0.2. The variations in the asymmetry of the external potential barrier do not change the dynamics of the smaller particles, showing Arrhenius diffusion. However, the dynamics of the larger particles shows a crossover from sub-Arrhenius to super-Arrhenius diffusion with the asymmetry in the external potential at the low temperatures and low volume fraction. Super-Arrhenius diffusion is generally observed in the high density systems where the transient cages are present due to dense packing, e.g., supercooled liquids, jammed systems, diffusion through porous membranes, dynamics within the cellular environment, etc. This model can be applied to study the molecular transport across cell membranes, nano-, and micro-channels which are characterised by spatially asymmetric potentials.
我们报告了在低体积分数$\phi = 0.2$下，二元胶体混合物在沿一个空间方向受到外部势垒作用时的分子动力学模拟结果。外部势垒不对称性的变化不会改变较小粒子的动力学，呈现出阿仑尼乌斯扩散。然而，在低温和低体积分数下，较大粒子的动力学表现出从亚阿仑尼乌斯扩散到超阿仑尼乌斯扩散的转变，这与外部势的不对称性有关。超阿仑尼乌斯扩散通常在高密度系统中观察到，在这些系统中，由于紧密堆积会形成瞬态笼，例如过冷液体、堵塞系统、通过多孔膜的扩散、细胞环境中的动力学等。该模型可用于研究跨细胞膜、纳米和微通道的分子传输，这些体系的特征是具有空间不对称势。
