(241b) Colloids at Fluid Interfaces: From Arrested Motion to Advanced Materials

Particle sequestration at fluid interfaces 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 sequestration
for spontaneous self-assembly of higher-order microstructures, such as bicontinuous
interfacially jammed emulsion gels (bijels), and bridged emulsion gels. From a fundamental
perspective, these multiphase materials enjoy intriguing geometrical attributes and
extremely rich and tunable rheology, driven primarily by the arrested dynamics of the
jammed particle monolayer at the sample-spanning interface. From an applications
standpoint, the distinct microstructural characteristics of bijels make them excellent
candidates for template-based synthesis of composite materials with unique and highly
tunable morphology at the nano- to micrometer scales. This talk will review the
fundamentals and recent developments in colloidal self-assembly at fluid interfaces, present
the bijel processing route that we have pioneered to synthesize a new class of materials
with highly unique microstructures, and demonstrate the applications of our technology in
electrochemical energy storage and conversion, tissue engineering, and cell delivery.
Finally, our ongoing efforts to better understand the link between the microstructure,
rheology, and processability of this new class of soft materials will be presented.