Professor Thomas P. Russell from the University of Massachusetts in Amherst, gave a lecture on December 18, 2018 titled “Structuring Liquids”.
The ability to manipulate and lock-in the shape of one liquid in a second, i.e structuring the liquids, allows the generation of unique materials that have the dynamics and mobility of liquids but the structural integrity of a solid. Bicontinuous fluids for separations, novel encapsulants for delivery systems, or all-liquid charge transport systems can be envisioned. Yet, these fluids have shapes that are far removed from their equilibrium shape and developing routes to kinetically lock-in these non-equilibrium shapes while retaining the local fluidity is key. Professor Russell described the in situ generation of nanoparticle surfactants that assemble at the liquid/liquid interface. When the liquids are brought into non-equilibrium shapes, the nanoparticle surfactants will jam at the interface, freezing in the shapes of the liquids. The assemblies of nanoparticles surfactants assume in-plane mechanical properties that range from liquid-like to solid-like behavior, depending on the areal density of the assemblies. By integrating superparamagnetic nanoparticles into the assemblies, the structured liquids are found to exhibit rather unusual magnetic characteristics in response to an external magnetic field. External stimuli, as for example pH, electric or magnetic fields or temperature, can then be used to re-shape the liquids, so that the structured liquids can be adaptive. Professor Russell described the printing of water constructs in water by the formation of polycationic-polyanionic coascervates at the interface and the unique diffusive characteristics imparted tot eh printed assemblies.