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

Studies on the dynamics of phase inversion available offer limited information due to the difficulty of following the transient mean and drop-size distribution. A new technique developed provides such data. A stereo microscope with a very shallow depth of field attached to a video camera gives sharp images of droplets in intensely-agitated, immiscible liquid dispersions by using a Strobotach pulsing at the camera framing rate. Droplets from 40 mu m upward at concentrations up to 70% by volume dispersed phase can be measured accurately. Droplets of continuous organic phase in aqueous drops can be seen. The pictures can be analyzed semiautomatically using a computer and in-house software to give, using a variety of discretizations, cumulative and frequency distributions to any base and any mean size. Means and distributions are a function of time for phase inversions generated in three ways. The technique gives a powerful tool for understanding fast, complex dispersion processes.