Electrophoresis of a Spherical Polyelectrolyte-Grafted Colloid in Monovalent Salt Solutions: Comparison of Molecular Dynamics Simulations with Theory and Numerical Calculations
Electrophoresis of a Spherical Polyelectrolyte-Grafted Colloid in Monovalent Salt Solutions: Comparison of Molecular Dynamics Simulations with Theory and Numerical Calculations
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DOI：
10.1021/ma502238z
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发表时间：
2015-01
期刊：
影响因子：
5.5
通讯作者：
Shervin Raafatnia;Owen A. Hickey;Christian Holm-
中科院分区：
文献类型：
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作者：
Shervin Raafatnia;Owen A. Hickey;Christian Holm-
我们研究了聚电解质接枝胶体浸泡在一价盐溶液中的电泳通过显式离子分子动力学模拟，包括远程流体动力学相互作用，通过格子玻尔兹曼流体。我们扩大了我们以前的工作，通过调查净中性和净带电复合材料的电荷和盐浓度的影响。我们表明，在较高的盐浓度的聚电解质的主导作用，防止净负软胶体，以扭转流动性，除了在极高的净电荷。我们解释我们所有的模拟结果，通过详细检查周围的胶体和德拜长度刷高度的比率的离子和单体密度分布。我们的模拟结果显示出良好的协议与近似的解析表达式和数值解的基础上扩展的标准电动力学模型的聚合物接枝的球形胶体。
We study the electrophoresis of a polyelectrolyte-grafted colloid immersed in monovalent salt solution by means of explicit-ion molecular dynamics simulations including long-ranged hydrodynamic interactions via a lattice-Boltzmann fluid. We expand on our previous work on the subject by investigating the effect of charges and the salt concentration on both net-neutral and net-charged composites. We show that the dominant role of the polyelectrolytes at higher salt concentrations prevents a net-negative soft colloid to reverse mobility with respect to net charge except at extremely high net charges. We explain all our simulation results by examining in detail the ion and monomer density profiles around the colloid and the ratio of the Debye length to the brush height. Our simulation results show good agreement with both approximate analytic expressions and numerical solutions based on an extended standard electrokinetic model for polymer-grafted spherical colloids.