Research Projects

The stability and mechanical properties of emulsions, foams, and gels depend significantly on how interfaces between immiscible liquids are structured. Dense monolayers of particles—either formed in situ (via crystallization or biological processes) or externally introduced—are known to form solid-like 2D networks that endow fluid interfaces with rigidity, viscoelasticity, and resistance to coalescence. Despite their utility in surfactant-free formulation strategies across various industrial sectors (food, pharma, energy), there is a lack of systematic understanding of the differences and similarities in mechanical behavior and structure of in situ versus introduced particle networks. This proposal seeks to address this gap using the concepts of soft matter physics and through a combination of experiments and simulations. In-house experimental setups will be designed and developed to enable simultaneous imaging of interfaces while probing their rheology. While the interfacial rheology of particle-stabilized emulsions and foams is well-established, most studies are fragmented—focusing either on introduced colloidal particles (e.g., silica, polystyrene) or in situ crystallizing species (e.g., monoglycerides, proteins). Further, real-time visualization of structural evolution under deformation remains technically challenging and underexplored. The current project proposes a unified, comparative framework that integrates: experimental emulsion systems formed using both in situ and externally introduced particles, quantitative interfacial rheology (shear and dilational), real-time imaging using Brewster angle and optical microscopy under dynamic shear. This project will significantly advance understanding of interfacial jamming, gelation, and glass-like transitions in particle-laden interfaces. It will also support sustainable formulation strategies by enabling design without synthetic surfactants.