Colberg Peter H, Kapral Raymond
Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
J Chem Phys. 2015 Nov 14;143(18):184906. doi: 10.1063/1.4935173.
Self-propelled chemically powered synthetic micron and nano-scale motors are being intensively studied because of the wide range of potential applications that exploit their directed motion. This paper considers even smaller Ångström-size synthetic motors. Such very small motors in bulk solution display effects arising from their self-propulsion. Recent experiments have shown that small-molecule catalysts and single enzyme molecules exhibit properties that have been attributed to their chemical activity. Molecular dynamics is used to investigate the properties of very small Ångström-size synthetic chemically powered sphere-dimer motors in a simple atomic-like solvent confined between walls separated by distances of tens of nanometers. Evidence for strong structural ordering of the motors between the walls, which reflects the finite size of solvent molecules and depends on solvent depletion forces, is provided. Dynamical properties, such as average motor velocity, orientational relaxation, and mean square displacement, are anisotropic and depend on the distance from the walls. This research provides information needed for potential applications that use molecular-scale motors in the complex confined geometries encountered in biology and the laboratory.
由于自驱动化学动力合成微米和纳米级马达具有广泛的潜在应用，可利用其定向运动，因此对其研究十分深入。本文考虑的是尺寸更小的埃量级合成马达。这种在本体溶液中的非常小的马达会因其自推进而呈现出各种效应。最近的实验表明，小分子催化剂和单酶分子展现出了一些归因于其化学活性的特性。利用分子动力学来研究在由几十纳米间距的壁分隔开的简单类原子溶剂中，尺寸为埃量级的非常小的合成化学动力球形二聚体马达的特性。提供了马达在壁之间存在强结构有序性的证据，这种有序性反映了溶剂分子的有限尺寸，并取决于溶剂耗尽力。诸如平均马达速度、取向弛豫和均方位移等动力学性质是各向异性的，且取决于与壁的距离。这项研究为在生物学和实验室中遇到的复杂受限几何结构中使用分子尺度马达的潜在应用提供了所需信息。
