纳米管道中德拜层的电势分布

基于净电荷守恒理论，提出了一种新的计算细长纳米管道内德拜层重叠时电势分布和离子浓度分布的理论模型.为了验证双电层是否重叠，首先根据德拜层的准确定义，用经典的泊松-玻尔兹曼方程来确定有效德拜层的长度.当有效德拜层的长度超过管道高度的一半时，符合重叠条件.在综合考虑管道高度、泊松-玻尔兹曼方程及离子浓度的条件下，根据电荷守恒计算出电势分布和离子浓度分布.结果表明，随着管道高度减少，壁面和管道中心电势差也减小，与实验结果一致.

Potential Distribution Inside the Debye Layers of the Nanochannel

Based on the net charge conservation theory， a new theoretical framework was proposed to describe the ion concentration distribution and the potential distribution accurately in thin nanochannels of overlapped Debye layers. To verify whether the double electrical layers were overlapped， the classical Poisson Boltzmann equation was firstly employed to calculate the effective Debye layers thickness according to its definition. The double layers were overlapped when the effective Debye thickness exceeds the half height of the channel. Taking channel height， Poisson Boltzmann equation and reservior ion concentration into account， the assumption of net charge conservation can then be used to deduce the potential distribution and corresponding ion concentration. The calculated results showed that the electric potential difference between the surface and mid plane will decrease with the reducing height of channel， which agrees well with the experimental data.