Structural and Rheological Properties of Soft Repulsive Glasses with Hard Sticky Inclusions

We aim to provide a microscopic understanding of soft attractive glasses formed by dispersing hard (H) and soft (S) colloids in a Newtonian solvent. Our system consists of deformable P(AA/Am) microgel particles and silica nanoparticles (NPs), where the tunable "stickiness" between H and S colloids is controlled via chemical modifications and solvent composition. While previous studies explored this system at low volume fractions, forming gels, we focus on its high-volume fraction counterpart, where NPs localize at microgel interfaces, creating colloidal glasses with arrested dynamics. Using rheo-(U)SAXS and XPCS, we will investigate NP structure and dynamics under shear. Inspired by findings that attractive nanofillers reinforce polymer hydrogels through network percolation, we propose testing this mechanism in dense microgel suspensions to understand their shear-induced fluidization, offering insights into hybrid glass behavior and composite yield stress fluids.