CaIFF Webinar: Alexandra Alicke
Complex Fluid-Fluid Interfaces: Linking Interfacial Assembly and Rheology to Soft Multiphase Material Stability
Abstract
The assembly of different colloidal building blocks at fluid–fluid interfaces governs the structure and properties of many soft multiphase materials, including emulsions and foams that are central to applications spanning food science to biomedical engineering. Particle-laden interfaces are widely used to impart stability in what is called Pickering–Ramsden mechanisms. Their colloidal nature makes them prone to irreversibly adsorb at fluid-fluid interfaces and the flexibility to tune interactions makes these systems ideal model platforms to explore interfacial assembly and mechanics. While particles are usually added in amounts that create densely packed or multilayer coverages on a bubble or droplet interface, even sub-monolayer coverages can provide significant stabilization.
In this talk, I will discuss different handles that are available to tune these interactions, and thereby the assembly and microstructure in these layers, which directly affect their mechanical (rheological) behavior. We show that by using custom-built interfacial rheometry set ups that enable clean kinematic conditions, not only in shear but also in compression, and combined with in-situ microscopy, it is possible to relate the rheological properties to underlying microstructural dynamics in two-dimensional particle layers. Lastly, I discuss the implications of these structure–property relationships for the stability of soft multiphase systems, focusing on coalescence and Ostwald ripening. Unraveling these links not only enables deliberate tuning of interfacial mechanics, but also provide insights into the fundamental mechanisms in bulk colloidal materials.
Speaker
Alexandra Alicke, Eindhoven University of Technology, Processing and Performance of Materials, Department of Mechanical Engineering
Registration link to Zoom Event
https://ucph-ku.zoom.us/webinar/register/WN_dKOX_lg8QX6qjSeRb4wnkw