Effects of Temperature and Polydispersity on the Dielectric Relaxation of Dilute Ethylcellulose Suspensions

摘要: The role of temperature on the low-frequency dielectric dispersion is analyzed for moderately polydisperse suspensions spherical ethylcellulose latex particles. study carried out in 10-50 degrees C range two different electrolyte concentrations, namely, 5 x 10(-5) and 10(-4) M NaCl. It found that relaxation frequency increases with temperature, whereas amplitude decreases when raised. This agrees qualitatively predictions based classical electrokinetic theory (DeLacey, E. H. B., White, L. R., J. Chem. Soc., Faraday Trans. 2 77, 2007 (1983)). However, quantitative agreement very far from being satisfactory. To try to overcome these differences, we have applied a more complete model which tangential motions ions inner part electric double layer allowed (DSL model, Mangelsdorf, C. S., 86, 2859 (1990)). Although most situations DSL models considerably improve between experiment, our case dynamic Stern correction does not seem be enough bring much closer experimental data predictions. this reason also consider fact are strictly monodisperse. Keeping polydispersity mind (this can done by simply taking volume average particle radius as representative size parameter) introducing it shown better description main features dispersion, is, increment, characteristic reached. Copyright 1999 Academic Press.