Emulsions

Emulsions consist of two immiscible liquids, like oil and water, one dispersed in the other. Surfactants are used to stabilize these interfaces. This project focuses on coalescence and diffusion phenomena in emulsions to understand and improve emulsion stability. Coalescence of oil or water droplets as well as transport mechanisms are strongly dependent on the involved interfaces. Applying surface sensitive non-linear spectroscopy enables us to investigate the amount, ordering and charge of different surfactants at interfaces. For example, SHG (second harmonic generation) can be used in diluted emulsion systems to monitor adsorption behaviours. On the other hand, planar SFG (sum frequency generation) measurements reveal molecular fingerprints and therefore the composition of molecules (e.g. surfactants) at interfaces. Among further techniques to characterize emulsions, size distribution evolution of droplets over time can be one tool to describe emulsion stability. Additionally, diffusion will be examined in a leach cell setup.