# Solvo-osmotic flow in electrolytic mixtures

## TL;DR

This paper introduces solvo-osmotic flow, a novel electrokinetic phenomenon where an electric field induces flow in electrolytic mixtures near neutral surfaces, influenced by ion solvation asymmetry and temperature.

## Contribution

The study presents the concept of solvo-osmotic flow, derives a modified Helmholtz-Smoluchowski equation, and demonstrates control of flow via temperature, expanding electrokinetic theory.

## Key findings

- Flow magnitude comparable to electro-osmotic flow
- Flow depends on ionic strength differently than electro-osmotic flow
- Flow can be controlled by temperature

## Abstract

We show that an electric field parallel to an electrically neutral surface can generate flow of electrolytic mixtures in small channels. We term this solvo-osmotic flow, since the flow is induced by the asymmetric preferential solvation of ions at the liquid-solid interface. The generated flow is comparable in magnitude to the ubiquitous electro-osmotic flow at charged surfaces, but for a fixed surface charge density, it differs qualitatively in its dependence on ionic strength. Solvo-osmotic flow can also be sensitively controlled with temperature. We derive a modified Helmholtz-Smoluchowski equation that accounts for these effects.