Molecular-level relation between intra-particle glass transition temperature and 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 intra-particle glass transition. By dealing with the latter process from a solid-state perspective, we estabilish a proportionality relation between the intra-particle 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 DLVO theory, we show that the novel relationship, connecting Tg to AH, implies the critical coagulation ionic strength (CCIS) to be a monotonically decreasing function of Tg. We connect our predictions to recent experimental findings.