Small angle neutron scattering studies on an ion-exchanged polystyrene latex

Abstract

A small angle neutron scattering investigation has been carried out on aqueous polystyrene latices containing particles of mean diameter, 360 Å. At low volume fraction, 0.01, in 10 −3 mol dm −3 sodium chloride solution particle—particle interactions were minimized and the results were used to obtain the particle size. In a concentrated dispersion at a very low electrolyte concentration the arrangement of the particles was probed by determination of the structure factor. The radial distribution function was obtained from the latter by Fourier transformation of the data. Comparison with theoretical models showed that the particles in the concentrated system behaved essentially as hard spheres with an effective interaction radius much greater than the actual radius of the particles. The arrangement of the particles was found to be “liquid-like.”