STERICALLY STABILIZED COLLOIDAL PARTICLES AS MODEL HARD-SPHERES

In this paper we show that the same freezing-melting miscibility gap c an be identified for suspensions of spherical polymer particles of rad ii 138-440 nn sterically stabilized in all cases by the same coating o f a different polymer. Diffusion coefficients and sedimentation veloci ties of the colloidal fluid at the freezing concentration scale with t hat power of the particle radius expected for hard spheres. These obse rvations demonstrate that these suspensions constitute a good experime ntal representation of the ideal hard-sphere system.