9/2/25 (in-person) Prof. Emanuela Del Gado, Georgetown University
Title:Â Â Fluctuations, rheology, and memory in self-assembled gel networks
Abstract:Â Many materials we eat, spread, squeeze, or 3D print are gels, soft amorphous solids whose solid component comprises self-assembled networks of particles, fibers, or agglomerates of proteins, polymers, and colloids. The space between and within human cells is permeated by self-assembled gel networks, the extra-cellular matrix and the cytoskeleton, whose self- organization and heterogeneity is central to biological functions. Self-assembled gels have adaptive, tunable, and nonlinear rheology determined by a complex interplay between the molecular cohesion and surface interactions, the aggregation kinetics that drive for- mation of various types of structures, and the effect of external forces that can promote breaking or reforming of the load-bearing backbone. Solidification processes are typically sources of frozen-in stresses and help build a memory of the processing history in these amorphous solids. Disorder and self-organization determine stress localization under load and the feedback between stress heterogeneities, structural disorder, and nonequilibrium conditions is therefore key to the mechanical response of these fascinating and ubiquitous materials.