1101 ナノ流路内のイオン輸送における電気二重層と界面電荷の影響(1)(OS11-1 ナノ・マイクロフルイディクス(ナノ・マイクロチャンネル),OS11 ナノ・マイクロフルイディクス,オーガナイズドセッション)

Abstract

Effects of overlapped electric double layer and interfacial charge on the ionic transport in 30 nm rectangular nanochannel are numerically investigated in this study. The numerical code which can calculates the electric field and ionic distribution in nanochannel is developed based on the Poisson-Nernst-Planck equation using finite difference method. The validity of the numerical code is confirmed from the view point of electro kinetic potential and electric neutrality. At lower ionic concentrations, the numerical result deviates from the Graham equation due to the overlapped electric double layer. The ionic distribution, electric field and ionic current are analyzed at various KCl concentrations. The ionic distribution in nanochannel is strongly affected by the interfacial charge especially at lower ionic concentrations and K^+ ions increased in nanochannel due to the electric neutrality. As the result, the ionic current increases at the lower KCl concentrations from 0.10 to 0.40 mol/m^3.