Microgels at Interfaces: From Model Interfaces to the Stabilization of Dispersed Systems

Many microgels readily adsorb at liquid interfaces and exhibit remarkable potential as stabilizers in foams and emulsions. Their intrinsic softness and deformability confer unique interfacial properties, driven by their ability to undergo conformational changes. This chapter explores the distinctive characteristics of microgel-laden interfaces across multiple scales, from flat model systems to fully formulated emulsions and foams. A comprehensive understanding of the kinetic stability of these systems requires considering both inter-microgel interactions at interfaces and interactions between microgel-laden interfaces. We examine how these interactions govern the structural and mechanical properties, as well as the overall stability of emulsions and foams. Using poly( N -isopropylacrylamide) as a model system, we discuss the influence of microgel architecture and charge on interfacial behavior. We also emphasize the critical role of the emulsification process and the effects of microgel responsiveness—particularly swelling behavior—on the final properties of emulsions and foams. When extended to bio-based chemistries, microgel-stabilized systems open up promising avenues for innovative applications.