S. Cutillas et al., PHASE-SEPARATION AND TURBIDITY OF ELECTRORHEOLOGICAL FLUIDS, International journal of modern physics b, 10(23-24), 1996, pp. 3093-3101
The turbidity of a suspension of silica particles in a silicone oil is
studied in the presence of an electric field. We present experimental
results which show a very strong attenuation of a laser beam when the
electric field is switched on. We give a theoretical interpretation o
f these results with the help of a Rayleigh Gans Debye theory applied
to cylinders. This model allows us to obtain the average length of the
aggregates as a function of the coupling parameter lambda which is th
e ratio of the electrostatic energy to kT. These results agree with a
theoretical prediction and also with the results of Monte-Carlo simula
tions. The kinetics of the beginning of field induced aggregation can
be obtained from the change of the turbidity with time after the appli
cation of a voltage step.