Molecular-Level Relation between the Intraparticle Glass Transition Temperature and the Stability of Colloidal Suspensions.

Abstract

In many colloidal suspensions, the dispersed colloidal particles are amorphous solids, resulting from vitrification. A crucial open problem is understanding how colloidal stability is affected by the intraparticle glass transition. By dealing with the latter process from a solid-state perspective, we estabilish a proportionality relation between the intraparticle glass transition temperature, Tg, and the Hamaker constant, AH, of a generic suspension of nanoparticles. It follows that Tg can be used as a convenient parameter (alternative to AH) for controlling the stability of colloidal systems. Within the Derjaguin-Landau-Verwey-Overbeek theory, we show that the novel relationship, connecting Tg to AH, implies the critical coagulation ionic strength to be a monotonically decreasing function of Tg. We connect our predictions to recent experimental findings.