VIDEO TECHNIQUE FOR MEASURING DYNAMICS OF LIQUID-LIQUID DISPERSION DURING PHASE INVERSION

Studies on the dynamics of phase inversion available offer limited inf ormation due to the difficulty of following the transient mean and dro p-size distribution. A new technique developed provides such data. A s tereo microscope with a very shallow depth of field attached to a vide o camera gives sharp images of droplets in intensely-agitated, immisci ble liquid dispersions by using a Strobotach pulsing at the camera fra ming rate. Droplets from 40 mu m upward at concentrations up to 70% by volume dispersed phase can be measured accurately. Droplets of contin uous organic phase in aqueous drops can be seen. The pictures can be a nalyzed semiautomatically using a computer and in-house software to gi ve, using a variety of discretizations, cumulative and frequency distr ibutions to any base and any mean size. Means and distributions are a function of time for phase inversions generated in three ways. The tec hnique gives a powerful tool for understanding fast, complex dispersio n processes.