Ordering in monodispersed polymer latices induced by a temperature gradient

Abstract

The ordering in a monodispersed latex suspension induced by a temperature gradient through the suspension has been investigated systematically using several latex samples with different particle sizes. The behaviour is influenced extensively by the temperature gradient (ΔT), and the critical value of ΔT needed to generate the ordering decreased when either the particle size of the sample or the salt concentration in the medium were decreased. Furthermore, to estimate the interparticle spacing in the ordered layers, the reflection spectra from these layers were measured and the enhanced number ratios with regard to the original value were calculated under different experimental conditions. Experimental results showd that the enhanced ratios ranged from 1.5 to 2.0 and increased when the value of ΔT and the salt concentration in the medium were increased.