Cluster, glass, and gel formation and viscoelastic phase separation in aqueous clay suspensions.
We have systematically investigated the phase diagram of clay particles in water to understand the relation between the local and macroscopic properties and the structures of clay suspensions. We focused, in particular, on sodium Cloisite (CNa) particles at concentrations typically used in nanocomposites (concentrations from 1 to 4 wt %) and at an extended range of ionic strengths (10(-5) to 10(-2) M NaCl). The suspensions have been characterized using rheology and a combination of scattering techniques (neutrons, X-rays, and light). We demonstrate the existence of a liquid cluster phase at low clay and intermediate salt concentrations and provide new insight into the nature of the solid-like dispersions at low and high ionic strengths.
Shalkevich
Andrey
A
Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, Chemin du Musée 3, CH-1700 Fribourg, Switzerland.
Stradner
Anna
A
Bhat
Suresh Kumar
SK
Muller
François
F
Schurtenberger
Peter
P