From double colloidal networks to core-shell and mixed composites through sequential gelation

Multicomponent gel systems have garnered much interest due to their compelling mechanical properties in the past decade. Yet, some mechanisms associated with multicomponent gels, such as sequential gelation, have been explored primarily in the context of chemical non-reversible polymeric and protein gels rather than in physical, reversible colloidal ones. In this study, we use mesoscale simulation techniques to model the sequential gelation of two-component colloidal systems whose inter- and intraspecies electrostatic interactions can be modified independently. We show that by simply leveraging temporal control and interspecies interactions, we can construct markedly different networks—from double networks to mixed and core-shell composite structures of varying coarseness and heterogeneity. These findings present a compelling case for further exploration of multicomponent colloidal systems.