论文标题
通过分子理论方法测量聚电解质移植的纳米孔中电流流的特征
Measuring the characteristics of electroosmotic flow in a polyelectrolyte grafted nanopore by molecular theory approach
论文作者
论文摘要
在本文中，我们介绍了离子的分子理论分析和电势分布，聚电解质（PE）刷子的电离程度，速度分布，体积流量，离子选择性，离子选择性，离子选择性，离子传导和电流流量通过聚酸（PA）/聚体（PB）移植的nanAnopores中的电流流。旋转异构体模型产生的构象用于执行系统的自由能功能的最小化，包括由介电常数的变化，电解质的pH，弱PE刷，离子分配和离子大小的植入密度引起的诞生能量的影响。然后，在考虑界面流体/壁滑动的过程中，在求解Navier-Stokes-Brinkman方程的过程中获得了速度场。同样，通过将离子电导率的当前结果与现有的实验数据进行比较，用于用4PVP刷子用作合成质子门控离子通道的纳米孔的现有实验数据来检查数值溶液的准确性。本方法的应用使我们能够用不同因素来描述PE移植纳米孔中电流动流的电流动力学特征，包括电解质的pH，块状盐浓度和PE刷的接枝密度。我们表明，感兴趣量的依赖性本质上取决于聚合物链的类型。例如，增加电解质的pH值会导致PA/PB刷中带电位点的程度的增加/降低，并且在PA/PB接枝纳米孔的离子选择性变化中存在最小/最大点，而电解质的pH值则存在。但是，对于两种类型的PA和PB接枝纳米孔，离子传导和对流大约是体内盐浓度的上升功能，而PE层的低范围移植密度。
In this paper, we present a molecular theory analysis of ions and potential distribution, degree of ionization of polyelectrolyte (PE) brushes, velocity profile, volumetric flow rate, ionic selectivity, ionic conduction and advection by electroosmotic flow in poly-acid (PA)/poly-base (PB) grafted nanopores. The generated conformations by the Rotational Isomeric State model are used in performing the minimization of the free energy functional of the system including the effects of the Born energy arising from the variation of permittivity, pH of the electrolyte, grafting density of weak PE brushes, ion partitioning and ionic size. Then, the velocity field is obtained in the process of solving the Navier-Stokes-Brinkman equation by considering the interfacial fluid/wall slippage. Also, the accuracy of the numerical solutions is examined by comparing the present results of ionic conductivity with the existing experimental data for a nanopore grafted with 4PVP brushes used as a synthetic proton-gated ion channel. The application of the present methodology enables us to describe the electrohydrodynamic characteristics of electroosmotic flow in PE grafted nanopores in terms of different factors including the pH of the electrolyte, bulk salt concentration and the grafting density of PE brushes. We show that the dependency of the quantities of interest are essentially rely on the type of the polymer chains. For instance, increasing the pH of the electrolyte results in an increase/decrease of the degree of charged sites in the PA/PB brushes, and there exists a minimum/maximum point in the variation of magnitude of the ion selectivity of PA/PB grafted nanopore with the pH of the electrolyte. However, for both types of PA and PB grafted nanopores, ionic conduction and advection are approximately the ascending function of the bulk salt concentration and low range grafting density of the PE layer.
