EMULSIFICATION AND SIZE CONTROL OF INSULATING AND OR VISCOUS-LIQUIDS IN LIQUID LIQUID-SYSTEMS BY ELECTROSTATIC DISPERSION

Electrostatic emulsification of insulating and/or viscous liquids which have been impossible to disperse by ordinary methods was studied using a liquid/distilled-water system. A de potential was applied to a capillary nozzle to produce droplets. The size of the droplets decreased with increasing potential. The mean droplet diameter (corresponding to the applied potential) could be varied over a wide range (from several nm to μm). A very fine cloudy emulsion (mean diameter of c.a. 5 μm) having a narrow size distribution was obtained by applying approximately -3500 V to the nozzle. In the case of liquids with low viscosity, i.e., kerosene and carbon tetrachloride, droplets were produced regularly from the cusp of the meniscus formed at the nozzle tip. On the other hand, for castor oil, a highly viscous liquid, a liquid thread was drawn out from the meniscus and then disintegrated into small droplets. The mean diameter of the caster oil droplets was larger (one order of magnitude) than that of the low viscosity kerosene at the same applied potential. © 1993 Academic Press, Inc.