Experimental Demonstration of the Stabilization of Colloids by Addition of Salt

TL;DR

This paper presents a novel non-Derjaguin-Landau-Verwey-Overbeek method to stabilize colloids in liquids by adding antagonistic salts to mixtures, preventing sedimentation without direct surface interaction.

Contribution

It introduces a new stabilization technique for colloids using antagonistic salts in mixed liquids, expanding the understanding of colloid stability mechanisms.

Findings

Salt addition stabilizes colloids without surface adsorption.

Stability depends on salt content and mixture composition.

Method applicable to various colloidal systems.

Abstract

We demonstrate a general non--Derjaguin-Landau-Verwey-Overbeek method to stabilize colloids in liquids. By this method, colloidal particles that initially form unstable suspension and sediment from the liquid are stabilized by the addition of salt to the suspending liquid. Yet, the salt is not expected to adsorb or directly interact with the surface of the colloids. For the method to work, the liquid should be a mixture, and the salt needs to be antagonistic such that each ion is preferentially solvated by a different component of the mixture. The stabilization may depend on the salt content, mixture composition, or distance from the mixture's coexistence line.