Aa. Garrouch et al., DIELECTRIC-DISPERSION OF DILUTE SUSPENSIONS OF COLLOID PARTICLES - PRACTICAL APPLICATIONS, Journal of physical chemistry, 100(42), 1996, pp. 16996-17003
The two characteristic relaxation frequencies at which either the Maxw
ell-Wagner or the double layer polarization mechanism prevails have be
en defined in terms of characteristic parameters for colloidal suspens
ions subjected to an oscillating electric field. Both frequencies are
found to increase with increasing ion diffusion coefficient, with decr
easing particle radius, and with increasing salinity. For both thin an
d thick double layers, these frequencies appear to be invariant at low
zeta potential (zeta) values. Correlations are developed between thes
e characteristic relaxation frequencies and the colloid suspension par
ameters. The correlations constants appear to be related to the Boltzm
an constant, temperature, and electrostatic charge. These correlations
can be useful for estimating particle size and counterion diffusion c
oefficient and can be used in developing dielectric dispersion models
for colloid particles suspensions and for porous media. A rigorous dis
persion model has been inverted to reciprocate simultaneously the aver
age zeta potential (zeta), particle size, and particle volume fraction
of the dispersed material from dielectric permittivity data at three
distinct frequencies, Relaxation of colloidal suspensions appears to b
e an adequate alternative for quantifying these parameters as opposed
to using intricate measurements of electrophoretic mobility.