Nanoconfined fluids under strong electric fields

by Prof. Jacob Klein

Department of Materials and Interfaces, Weizmann Institute of Science

at Biological and soft-matter physics

Thu, 01 Jun 2023, 11:00
SPECIAL SEMINAR - Joint with the dept. of Mechanical Engineering, Building # 55, Seminar Room # 117

Abstract

I describe first direct measurements* of the increase in water viscosity under electric fields, the so-called viscoelectric effect, which arises from the interaction of the field with the dipolar water molecules. This basic effect, believed to occur for polar liquids due to coupling of the field with the molecular dipoles, was first experimentally determined for polar organic liquids more than 80 years ago, but for the case of water, 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. A related study* which I describe concerns the interaction between lipid-bilayer-coated surfaces across water, when a high transverse electric field causes a massive (up to 3 orders of magnitude), reversible change in the frictional dissipation between them as they slide past each other. All atom molecular dynamics simulations reveal the surprising origin of this, which has an intriguing connection to electroporation and hemifusion of membranes of living cells.

(*I thank Di Jin and Yu Zhang from my group for their contributions to these studies)

Created on 27-05-2023 by Granek, Rony (rgranek)
Updaded on 27-05-2023 by Granek, Rony (rgranek)