Electro-optical characterization of aqueous laponite suspensions

Electric birefringence measurements have shown that 0.01 wt.% laponite suspensions are very polydisperse, including both higher size aggregates than the expected 30 nm diameter plate-like particles and smaller particles with diameter below 7 nm. Kerr constant and electric polarizabilty seems to be in reasonable agreement with the results for higher size plate-like clay particles. At higher concentrations (0.1 and 1 wt.%) anomalous signals are observed. The usefulness of this approach to elucidating the gelation properties of laponite is discussed.