采用分子动力学方法模拟了电场驱动下纳米通道中NaCl水溶液的电渗输运特性,壁面为无电荷和带有负电荷两种情况,统计了速度、密度、黏度和热传导系数的分布规律。在壁面电荷作用下,Na~+被壁面吸附,Cl~-聚集在通道中央;Na~+与水分子朝电场负方向、Cl~-朝电场正方向运动;Na~+、Cl~-呈电渗流动,水分子则较为复杂,呈电渗流和被离子拖拽混杂流动;在壁面作用下,水分子和Na~+/Cl~-的有序度、系统的自扩散系数增大;热传导系数分布呈靠近壁面处大,主流区小的特点。
The flow characteristics of NaCl solution in different nanotubes were investigated.The tubes differ in charge.One has no charge and the other has negative charge.The distribution of velocity, density,viscosity and thermal conductivity were got.It is found the Na~+ is absorbed by charged wall,Cl~-is expelled to the center of the tube.Na~+ and water travel towards the cathode and Cl~- travels towards the anode.Ions travel as electro-osmotic flow and water travels as a mixture of electroosmotic flow and dragged flow.The order of particles in NaCl solution and diffusion are strengthened by charged wall.The thermal conductivity near the wall is larger than in the center area.