Transient scattering studies on crocidolite suspensions

Abstract

: Electric fields were imposed on aqueous suspensions of the rigid asymmetric particles of crocidolite. Orientational order resulted in the field and the intensity of the light scattered by the medium changed. Such intensity changes were recorded for pulsed electric fields of up to 500 V cm-1 amplitude and 1-5 kHz frequency. When combined with data for the scattered intensity prior to the application of the field, the average particle mass (8• 10 -15 g), length of the rod-like particles (1"3 pm), rotary diffusion coefficient (2.4 s-1) and electrical polarizability (22 • 10-29 Fm 2) were all evaluated for this sample. The relationship of the polarizability to the electric double layer structure of the sols is briefly discussed. The transient scattering method offers a reliable and rapid means of characterizing mineral sols.