title: Alternating current electroosmotic flow in polyelectrolyte-grafted nanochannel.
abstract: In this work, we investigate the time periodic electroosmotic flow (EOF) of an electrolyte solution through a slit polyelectrolyte-grafted (PE-grafted) nanochannel under applied alternating current (AC) electrical field. The PE-grafted nanochannel is represented by a rigid surface covered by a polyelectrolyte layer (PEL) in a brush-like configuration. Under Debye-Hückel approximation, we obtain analytical solutions of electrical potential in decoupled regime of PE-grafted nanochannel, where the thickness of PEL is independent of the electrostatic effects triggered by polyelectrolyte charges. Based upon the electrical potential obtained above, we calculate EOF velocities with uniform and non-uniform drag coefficients for PE-grafted nanochannel and compare their results. The effects of pertinent dimensionless parameters on EOF velocity amplitude are discussed in detail. Moreover, the amplitude of EOF velocity in a PE-grafted nanochannel is compared with that in a rigid one. It is shown that larger EOF velocity and volume flow rate are found for a PE-grafted nanochannel. In addition, AC EOF velocity is further investigated. The oscillation of velocity reduces and is restricted within the region near the PEL-electrolyte interface for higher oscillating Reynolds number Re.
authors: School of Mathematical Science, Inner Mongolia University, Hohhot, Inner Mongolia 010021, PR China.
authors: Fengqin
authors: F
authors: Li
authors: School of Mathematical Science, Inner Mongolia University, Hohhot, Inner Mongolia 010021, PR China. Electronic address: jianyj@imu.edu.cn.
authors: Yongjun
authors: Y
authors: Jian
authors: School of Mathematical Science, Inner Mongolia University, Hohhot, Inner Mongolia 010021, PR China; School of Mathematics and Statistics, Inner Mongolia University of Finance and Economics, Hohhot, Inner Mongolia 010051, PR China.
authors: Long
authors: L
authors: Chang
authors: School of Mathematical Science, Inner Mongolia University, Hohhot, Inner Mongolia 010021, PR China.
authors: Guangpu
authors: G
authors: Zhao
authors: School of Mathematical Science, Inner Mongolia University, Hohhot, Inner Mongolia 010021, PR China.
authors: Liangui
authors: L
authors: Yang
mesh_terms: D004560:Electricity; D004563:Electrochemistry; D053841:Electroosmosis / Q000295:instrumentation*; D036103:Nanotechnology; D000071228:Polyelectrolytes / Q000737:chemistry*; D055672:Static Electricity
chemical_list: D000071228:Polyelectrolytes
keywords: AC electrical field; Oscillating Reynolds number; Polyelectrolyte-grafted nanochannel; Time periodic EOF