Interactions between Polyelectrolyte-Gel Surfaces

Scientific Achievement

We analyzed electrostatic forces between two surfaces composed of polyelectrolyte chains by using coarse-grained molecular dynamics simulations and theoretical models.

Significance and Impact

The work explains origins of repulsive forces between polymeric surfaces, and thus is of great importance for systems, where the gels are at contact, including colloids encapsulated by gels, as well as for crack formation in gel electrolytes.

Aykut Erbaş and Monica Olvera de la Cruz, Macromolecules, 2016, 49 (23), pp 9026–9034

Research Details

  • We find that interactions between two the surfaces are mainly dominated by the osmotic pressure of excess counterions occupying the volume between two surfaces.
  • At a critical pressure, this osmotic pressure inside the gels and within the separation layer becomes equal and the gels begin to form.

Work performed at Northwestern University