Direct measurement of the viscoelectric effect in water
File(s)
Published version
Author(s)
Jin, Di
Hwang, Yongyun
Kampf, Nir
Klein, Jacob
Type
Journal Article
Abstract
The viscoelectric effect concerns the increase in viscosity of a polar liquid in an electric field due to its interaction with the dipolar molecules, and was first determined for polar organic liquids more than 80 years ago. For the case of water, however, the most common polar liquid, direct measurement of the viscoelectric effect is challenging and has not to date been carried out, despite its importance in a wide range of electrokinetic and flow effects. In consequence, estimates of its magnitude for water vary by more than 3 orders of magnitude. Here we measure the viscoelectric effect in water directly using a surface force balance (SFB), by measuring the dynamic approach of two molecularly-smooth surfaces with a controlled, uniform electric field between them across highly-purified water. As the water is squeezed out of the gap between the approaching surfaces, viscous damping dominates the approach dynamics; this is modulated by the viscoelectric effect under the uniform transverse electric field across the water, enabling its magnitude to be directly determined as a function of the field. We find a value for this magnitude which differs respectively by 1 and by 2 orders of magnitude from its highest and lowest previously estimated values.
Date Issued
2021-12-30
Date Acceptance
2021-11-16
Citation
Proceedings of the National Academy of Sciences of USA, 2021, 119 (1), pp.1-7
ISSN
0027-8424
Publisher
National Academy of Sciences
Start Page
1
End Page
7
Journal / Book Title
Proceedings of the National Academy of Sciences of USA
Volume
119
Issue
1
Copyright Statement
© 2021 Th Author(s). This article is distributed underCreative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND).
Identifier
https://www.pnas.org/doi/abs/10.1073/pnas.2113690119
Publication Status
Published
Date Publish Online
2021-12-30