Chemical Engineering Seminar Series: Ali Mohraz
Particle sequestration at the interface of immiscible fluids has been known for more than a century and exploited in the formulation of solid-stabilized (Pickering-Ramsden) emulsions for drug delivery, oil recovery, food, and personal care products, to name a few. More recently, new classes of multiphase mixtures have emerged that exploit interfacial colloid jamming, bridging, ordering, and aggregation for the self-assembly of complex higher-order structures from colloidal building blocks, such as bicontinuous interfacially jammed emulsion gels (bijels), and bridged emulsion gels. The multiphase nature of these mixtures combined with their unique microstructural characteristics make them excellent templates for the synthesis of composite materials with tunable morphology at the nano- to micrometer scales, and our group has recently demonstrated various examples of functional materials derived from these soft matter templates. However, to expand these capabilities into a robust materials synthesis platform, the factors that mediate the mechanical stability and processability of these multiphase mixtures must be better understood. In this talk, I will review the fundamentals and recent developments in colloidal self-assembly at fluid interfaces, present a novel materials synthesis route that we have pioneered based on these concepts, and discuss the applications of our technology in electrochemical energy conversion and storage, tissue engineering, and scaffolds for cell delivery. Finally, I will discuss our ongoing efforts to better understand the link between the microstructure, rheology, and processability of this new class of soft materials.