Croatica Chemica Acta, Vol. 56 No. 4, 1983.
Conference paper
Electric Birefringence and Electrophoretic Light Scattering for Colloid Stability Characterisation
Barry R. Jennings
; Electro-Optics Group, Physics Department, Brunel University, Uxbridge, Middlesex, UK
Roger C. Fairwood
; Electro-Optics Group, Physics Department, Brunel University, Uxbridge, Middlesex, UK
Abstract
The effect of an electric field on a dilute suspension of asymmetric
colloidal particles is to impose rotational order which can
be detected as an induced birefringence in the sol. Furthermore,·
if the particles are charged, such rotation is followed by electrophoretic
translation. In a single apparatus, pulsed electric fields
have been applied to sols of the rod-like clay mineral attapulgite,
and both the transient induced birefringence and the variation in
the fluctuations of the scattered light have been measured. Experiments
involving the addition of CTAB surfactant, resulted in
the measurement of the electrical polarisability anisotropy, electrophoretic
mobility, translatory and rotary diffusion coefficients as
the inherent negative surface charge of the mineral particles was
swept through the zero point of charge and into a positive condition.
The accompanying changes in sol stability and flocculation
were monitored in terms of these parameters.
Keywords
Hrčak ID:
194189
URI
Publication date:
9.11.1983.
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