Phase Behavior, Fluid Structure, and Slow Dynamics in Polymer -Colloid Mixtures: Novel Liquid State Theory and Its Applications

Abstract

Collective colloid structure predictions agree quantitatively with scattering experiments over length scales of D-10D in the fluid phase. The theory captures the non-monotonic changes in the local cage order parameter S(k* &ap; 7 D) with increasing polymer concentrations. Accurate, no adjustable parameter predictions of the fluid structure are combined with a single particle version of idealized mode coupling theory to predict the gelation boundaries and elastic shear moduli for Rg/R < 0.1 suspensions. The calculated "transient gel lines" are in semi-quantitative agreement with measurements in deep quenched systems and buoyancy-matched systems. Calculations of the dependence of the elastic shear moduli on depletion attraction, solvent quality and scaled polymer concentration are in excellent agreement with experiment, and deep in the gel phase follow a power law dependence on polymer concentration and particle volume fraction.