Solvent quality dependent continuum van der Waals attraction and phase behavior for colloids bearing nonuniform adsorbed polymer layers

Abstract

A liquid-gel transition measured for a polymerically stabilized dispersion as a function of solvent quality and particle volume fraction is compared with theoretical predictions of phase behavior. The experimental liquid-gel transition is interpreted from rheological measurements of 360 nm polystyrene (PS) particles with adsorbed F108 Pluronic (PEO-PPO-PEO) layers in aqueous 0.5 M NaCl as a function of temperature, which controls solvent quality for the adsorbed Pluronic. The measured liquid-gel transition occurs at temperatures when attractive interactions are not expected to occur from either core PS particle van der Waals forces or Pluronic mixing interactions. To consider an alternative ..