【摘要】 微纳复合管道是目前微流控应用中的热点之一。该文分别模拟了单根纳米通道和纳米通道阵列对微纳管道结合部的离子耗散作用的影响,计算了两种管道系统内的离子浓度场、电势场、速度场及压力分布。计算结果表明:阵列纳米通道比单纳米通道的离子耗散强度提高了5倍;由Nernst-Planck方程分析得出电场梯度引起的电迁移在耗散过程中其主导作用;采用Navier-Stokes方程引入电场体积力模拟得出,阵列纳米通道连接的微纳管道耗散区存在多对涡漩。这增强了耗散区扩展的速度,使耗散区浓度值更低且扩展空间更大,从而解释了阵列纳米管道连接的微纳复合管道相比单纳米通道具有更强的耗散效应的原因。更多还原

【Abstract】 Micro-nanochannel is one of hot topics in microfluidics application recently.In this paper,a single nanochannel and a nanochannel array were used to simulate the influence on depletion effect in the junction of micro-nanochannel,respectively.The ion concentration,the electric potential field,the velocity field and the pressure distribution in both systems were calculated.We found that the depletion efficiency in hybrid micro-nanochannel was 5 times stronger in nanochannels-array than that in the single nanochannel configuration.From Nerst-Planck equation,we analyzed that electric immigration is the dominant effect in the depletion process.Further simulation based on Navier-Stokes equation with electrical body force showed that the nanochannel array resulted in complex multi-vortices flow in the depletion region.This could enhance the velocity of depletion region expansion,and keep lower concentration and larger space in the depletion region,and thus could explain how the nanochannel array leaded to stronger depletion effect.更多还原