Effects of surface charge and boundary slip on time-periodic pressure-driven flow and electrokinetic energy conversion in a nanotube.

Mandula Buren,Yingchun Zhao,Long Chang,Quansheng Liu,Yongjun Jian

doi:10.3762/bjnano.10.158

Abstract

Time-periodic pressure-driven slip flow and electrokinetic energy conversion efficiency in a nanotube are studied analytically. The slip length depends on the surface charge density. Electric potential, velocity and streaming electric field are obtained analytically under the Debye–Hückel approximation. The electrokinetic energy conversion efficiency is computed using these results. The effects of surface charge-dependent slip and electroviscous effect on velocity and electrokinetic energy conversion efficiency are discussed. The main results show that the velocity amplitude and the electrokinetic energy conversion efficiency of the surface charge-dependent slip flow are reduced compared with those of the surface charge-independent slip flow.

Highlights

Micro- and nanofluidic devices [1] have a wide range of applications in science and engineering, e.g., liquid pumping and energy conversion
This section discusses the effects of the surface charge-dependent boundary slip on the time-periodic pressure-driven flow and electrokinetic energy conversion efficiency in the nanotube using the analytical results obtained above
The reason is that the slip length is decreased by the surface charge effect and, the velocity of slip flow is further reduced

Summary

Introduction

Micro- and nanofluidic devices [1] have a wide range of applications in science and engineering, e.g., liquid pumping and energy conversion. The electrokinetic energy conversion efficiency and the electroviscous effects of micro-and nanoscale flows have been widely studied under the no-slip assumption [4,5,6,7,8,9,10]. The electrokinetic energy conversion efficiencies of time-periodic pressure-driven no-slip flows of a viscoelastic fluid between two parallel plates and in a circular tube were, respectively, by Bandopadhyay and Chakraborty [8] and Nguyen and co-workers [10].

Results

Conclusion