Spectroscopic Analysis of Liquid/Liquid Interfaces in Multiphase Microflows

Microscopic quasi-elastic laser scattering (μQELS) spectroscopy has been developed for analysis of interfacial phenomena at laminar multiphase microflow in a microchannel. Transport phenomena of a metal chelate through a water/toluene interface were measured, and transient adsorption of the chelate in the initial step of the transport was measured. A water/methanol miscible interface was also measured, and the interfacial free energy of a miscible interface was determined for the first time. The μQELS is expected to be very effective not only for physicochemical investigations of transport and mixing, but also for elemental process analysis of heterogeneous reactions.