介电泳微流控制分离不同尺寸碳纳米管研究

Separation of carbon nanotubes with different sizes by dielectrophoresis based on microfluidics

采用介电泳微流控制技术,利用不同尺寸碳纳米管在流动介电液中受到的大小不等的介电泳力,从而产生不同运动轨迹实现分离.通过建立介电泳数学模型和微流控制通道几何模型,对不同尺寸碳纳米管的分离过程进行仿真研究.结果表明:电场强度、流体流速和碳纳米管受到的介电泳力在主通道内最大,不同尺寸碳纳米管的运动轨迹在主通道开始出现分离,最终从不同的出口流出;当交变电压从±5V到±30V逐渐增大时,入口1与入口2的流速和流速比也逐渐增大;相较于异丙醇,用去离子水做介电液,流体流速近似高一个数量级.

Carbon nanotubes（CNTs）with different sizes could be separated using dielectrophoresis（DEP）based on microfluidics,under which CNTs with different sizes in a dielectric fluid flow were suffered with unequal DEP forces and therefore they were forced to move with flow in different trajectories.DEP model and microfluidic channel model were established for CNT separation,and simulation of separation process of CNTs with different sizes was carried out.Results show that the maximal values of electric field strength,flow velocity,and DEP force on CNTs appear at the main channel.Trajectories of CNTs separate from each other at the main channel and eventually CNTs with different sizes enter into different outlets.As the voltage amplitude increases gradually from ±5Vto±30V,flow velocities at inlets 1,2and their ratios are required to gradually increase as well.The flow velocities of deionized water as dielectric fluid are one order of magnitude higher than those of isopropyl alcohol.