Transport properties of nanopores in electrolyte solutions: the diffusional model and surface currents
Transport properties of nanopores in electrolyte solutions: the diffusional model and surface currents
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DOI：
10.1088/1367-2630/7/1/132
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发表时间：
2005-05-24
影响因子：
3.3
通讯作者：
Siwy, Z
中科院分区：
文献类型：
--
作者：
Fulinski, A;Kosinska, I;Siwy, Z
通过单阳离子选择性纳米孔在薄的聚合物箔的离子传输实验研究和描述的扩散模型的基础上减少的三维Smoluchowski方程到一个一维的Fick-Jacobs型方程。该模型能够半定量预测的各种形状和表面电荷性质的纳米孔的传输特性，即使当使用各种参数的体电解质值。的实验电导率数据清楚地表明，表面电流分量的存在下，不描述的散装型扩散。所测量的表面电导率的值尤其取决于通道的内表面的性质。这些表面电流在整流过程中起着重要的作用，并部分负责高阳离子选择性的nanopores.Both理论和电解质电导率测量表明，不对称的nanopores部分整流电流的阳离子流的优先方向从高表面电荷密度的孔朝向低表面电荷密度的孔和/或从窄孔朝向宽孔的开口。
Ion transport through single-cation selective nanopores in thin polymer foils is examined experimentally and described by a diffusional model based on the reduction of the three-dimensional Smoluchowski equation into a one-dimensional equation of Fick-Jacobs type. The model enables semi-quantitative predictions of the transport properties of nanopores of various shapes and surface charge properties even when bulk electrolyte values of various parameters are used. The experimental conductivity data clearly indicate the presence of a surface current component not described by the bulk-type diffusion. The values of the measured surface conductivities depend, among others, on the properties of the channel's internal surface. These surface currents play a substantial role in the rectification processes and are partially responsible for the high-cation selectivity of nanopores.Both theory and electrolytic conductivity measurements show that asymmetric nanopores partially rectify the current with a preferential direction of cation flow from a pore of high surface charge density towards a pore of low surface charge density and/or from the narrow towards the wide opening of the pore.