Analysis of self-electrophoretic motion of a spherical particle in a nanotube: effect of nonuniform surface charge density.
Analysis of self-electrophoretic motion of a spherical particle in a nanotube: effect of nonuniform surface charge density.
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纳米管中球形颗粒的自电泳运动分析：表面电荷密度不均匀的影响。
DOI：
10.1021/la703924w
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
S. Joo
中科院分区：
文献类型：
--
作者：
Shizhi Qian;S. Joo
利用连续统理论研究了球形纳米粒子在充满电解质溶液的纳米管中的自主运动，该理论包括离子浓度的能斯特-普朗克方程、溶液中电势的泊松方程和流体动力场的斯托克斯方程。与通常的电泳相反，在电泳中，外加电场来指导带电粒子的运动，而自主运动源于围绕不对称带电粒子的液体介质的离子浓度极化所产生的自生电场。除了粒子运动外，极化溶液中产生的电场和自由电荷之间的相互作用也会引起电渗透流动。研究了流体和粒子的自主运动，重点研究了粒子表面电荷分布、纳米管尺寸和双电层厚度对粒子运动方向和速度的影响。
Autonomous motions of a spherical nanoparticle in a nanotube filled with an electrolyte solution were investigated using a continuum theory, which consisted of the Nernst-Planck equations for the ionic concentrations, the Poisson equation for the electric potential in the solution, and the Stokes equation for the hydrodynamic field. Contrary to the usual electrophoresis, in which an external electric field is imposed to direct the motion of charged particles, the autonomous motion originates from the self-generated electric field due to the ionic concentration polarization of the liquid medium surrounding an asymmetrically charged particle. In addition to the particle motion, the interaction between the electric field generated and the free charges of the polarized solution induces electroosmotic flows. These autonomous motions of the fluid as well as the particle were examined with focus on the effects of the surface-charge distribution of the particle, the size of the nanotube, and the thickness of the electric double layer, which affected the direction and the speed of the particle significantly.