Related Experiment Video
Updated: Jul 16, 2026

Confocal Imaging of Confined Quiescent and Flowing Colloid-polymer Mixtures
Published on: May 20, 2014
Macroion virial contribution to the osmotic pressure in charge-stabilized colloidal suspensions
E Trizac1, Luc Belloni, J Dobnikar
1NSF Center for Theoretical Biological Physics, UCSD, La Jolla, California 92093-0374 USA.
Abstract:
Our interest goes to the different virial contributions to the equation of state of charged colloidal suspensions. Neglect of surface effects in the computation of the colloidal virial term leads to spurious and paradoxical results. This pitfall is one of the several facets of the danger of a naive implementation of the so called one component model, where the microionic degrees of freedom are integrated out to only keep in the description the mesoscopic (colloidal) degrees of freedom. On the other hand, due incorporation of wall induced forces dissolves the paradox brought forth in the naive approach, provides a consistent description, and confirms that for salt-free systems, the colloidal contribution to the pressure is dominated by the microionic one. Much emphasis is put on the no salt case but the situation with added electrolyte is also discussed.
Related Concept Videos
Osmotic Pressure
Colloids and Suspensions
Osmosis and Osmotic Pressure of Solutions
The Colloidal State
Intermolecular Forces in Solutions
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Such a solution is called an ideal solution. A mixture of ideal gases (or gases such as helium and argon,...
Electrolytes: van't Hoff Factor

