Net fluid flow and non-Newtonian effect in induced-charge electro-osmosis of polyelectrolyte solutions

Huicheng Feng; Teck Neng Wong

doi:10.1103/PhysRevE.100.013105

Net fluid flow and non-Newtonian effect in induced-charge electro-osmosis of polyelectrolyte solutions

Phys Rev E. 2019 Jul;100(1-1):013105. doi: 10.1103/PhysRevE.100.013105.

Authors

Huicheng Feng^{1

2}, Teck Neng Wong²

Affiliations

¹ Unmanned System Research Institute, Northwestern Polytechnical University, Xi'an 710072, China.
² School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.

PMID: 31499862
DOI: 10.1103/PhysRevE.100.013105

Abstract

This paper reports an interesting net fluid flow in the induced-charge electro-osmosis (ICEO) of poly(sodium 4-styrenesulfonate) (NaPSS) solutions measured through microparticle image velocimetry (μPIV). The net fluid flow is attributed to the significantly unequal cations and poly-anions of NaPSS. Owing to the phase delay effect of ions, different flow patterns appear with the alternating electric field. The inflow velocity and outflow velocity are found to be unequal and their relative magnitude shows a dependence on the electric field strength. The ICEO velocity is positively correlated with the NaPSS concentration. As NaPSS introduces the non-Newtonian effect, the well-known quadratic relationship between ICEO velocity and electric field strength in Newtonian fluids breaks. The ICEO velocity varies differently with the electric field strength as the NaPSS concentration changes. These new findings can contribute to the understanding of ICEO of complex fluids, e.g., biofluids.