Cruz-Chu Eduardo R, Aksimentiev Aleksei, Schulten Klaus
Beckman Institute for Advanced Science and Technology.
J Phys Chem C Nanomater Interfaces. 2009 Feb 1;113(5):1850. doi: 10.1021/jp804724p.
Nanopores immersed in electrolytic solution and under the influence of an electric field can produce ionic current rectification, where ionic currents are higher for one voltage polarity than for the opposite polarity, resulting in an asymmetric current-voltage (I-V) curve. This behavior has been observed in polymer and silicon-based nanopores as well as in theoretically studied continuum models. By means of atomic level molecular dynamics (MD) simulations, we have performed a systematic investigation of KCl conductance in silica nanopores with a total simulation time of 680 ns. We found that ion-binding spots at the silica surfaces, such as dangling atoms, have effects on the ion concentration and electrostatic potential inside the nanopore, producing asymmetric I-V curves. Conversely, silica surfaces without ion-binding spots produce symmetric I-V curves.
浸没在电解液中且受电场影响的纳米孔会产生离子电流整流现象，即离子电流在一种电压极性下比在相反极性下更高，从而导致电流-电压（I-V）曲线不对称。这种行为已在聚合物和硅基纳米孔中观察到，也在理论研究的连续介质模型中出现。通过原子级分子动力学（MD）模拟，我们对二氧化硅纳米孔中的氯化钾电导率进行了系统研究，总模拟时间为680纳秒。我们发现二氧化硅表面的离子结合位点，如悬空原子，会对纳米孔内的离子浓度和静电势产生影响，从而产生不对称的I-V曲线。相反，没有离子结合位点的二氧化硅表面会产生对称的I-V曲线。
