Xiao Song, Wang Zhengjia, Chen Hsuan-Yi, Sheng Yu-Jane, Tsao Heng-Kwong
Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650500, China.
Department of Chemical and Materials Engineering, National Central University, Jhongli 320, Taiwan.
J Chem Phys. 2014 Nov 14;141(18):184902. doi: 10.1063/1.4901117.
The diffusivity and surface excess of nanoswimmers which are confined in two plates with the separation H are explored by dissipative particle dynamics. Both mean squared displacement and velocity autocorrelation function methods are used to study the diffusive behavior of nanoswimmers with the Brownian diffusivity D0 and the results obtained from both methods are consistent. The active diffusivity of confined nanoswimmers (D - D0) depends on the wall separation, swimming speed v(a), and run time τ. Our simulation results show that (D-D0)/v(a)(2)τ is a function of v(a)τ/H. The reduction in the diffusivity of active colloids is more significant than that of passive particles. The distribution of nanoswimmers between two parallel walls is acquired and two regions can be identified. The accumulation of nanoswimmers near walls is quantitatively described by the surface excess Γ. It is found that Γ grows as the nanoswimmer concentration c(b), swimming speed v(a), and run time τ are increased. The coupling between the ballistic trajectory of nanoswimmers and the walls results in nanoswimmer accumulation. The simulation outcomes indicate that Γ/Hc(b) is a function of H/v(a)τ.
通过耗散粒子动力学研究了限制在间距为H的两块平板间的纳米游动体的扩散系数和表面超额。均方位移和速度自相关函数方法都被用于研究具有布朗扩散系数D0的纳米游动体的扩散行为，且两种方法得到的结果是一致的。受限纳米游动体的主动扩散系数（D - D0）取决于壁间距、游动速度v(a)和游动时间τ。我们的模拟结果表明，(D - D0)/v(a)²τ是v(a)τ/H的函数。活性胶体扩散系数的降低比被动粒子更显著。获得了纳米游动体在两个平行壁之间的分布，并可识别出两个区域。纳米游动体在壁附近的积累通过表面超额Γ进行定量描述。发现Γ随着纳米游动体浓度c(b)、游动速度v(a)和游动时间τ的增加而增大。纳米游动体的弹道轨迹与壁之间的耦合导致纳米游动体的积累。模拟结果表明，Γ/Hc(b)是H/v(a)τ的函数。
