Physical Review E 2000; 62, 41

Itamar Borukhov * and Ludwik Leibler

Unité Mixte de Recherche CNRS Elf Atochem (UMR 167),
95 rue Danton, B.P. 108, 92303 Levallois-Perret Cedex, France

(November 18, 1999)

The interactions between spherical colloids covered with end-grafted polyrners (brushes) immersed in a polymer melt are studied theoretically. We show that attractive enthalpic interactions between the two polymer species, characterized by a negative Flory parameter (x < 0), can stabilize the colloid dispersion. The stabilizing mechanism is a result of a structural change from a dry brush, where the melt chains do not penetrate deeply into the brush, to a wet brush, where the free chains penetrate the brush and force the grafted chains to extend into the melt.

61.25.Hq (polymer melts etc.), 82.70.Dd (colloids), 83.70.Hq (block copolymers etc.)