Three-Phase Coexistence in Colloidal Rod-Plate Mixtures.
Aqueous suspensions of clay particles, such as montmorillonite (MMT) platelets and sepiolite (Sep) rods, tend to form gels at concentrations around 1 vol %. For Sep rods, adsorbing sodium polyacrylate to the surface allows for an isotropic-nematic phase separation to be seen instead. Here, MMT is added to such Sep suspensions, resulting in a complex phase behavior. Across a range of clay concentrations, separation into three phases is observed: a lower, nematic phase dominated by Sep rods, a MMT-rich middle layer, which is weakly birefringent and probably a gel, and a dilute top phase. Analysis of phase volumes suggests that the middle layer may contain as much as 6 vol % MMT.
School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom.
Phillip
P
Woolston
School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom.
Jeroen S
JS
van Duijneveldt