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

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, T g , and the Hamaker constant, A H , of a generic suspension of nanoparticles. It follows that T g can be used as a convenient parameter (alternative to A H ) for controlling the stability of colloidal systems. Within the Derjaguin-Landau-Verwey-Overbeek theory, we show that the novel relationship, connecting T g to A H , implies the critical coagulation ionic strength to be a monotonically decreasing function of T g . We connect our predictions to recent experimental findings.