A MULTIVARIATE-ANALYSIS OF W O EMULSIONS IN HIGH EXTERNAL ELECTRIC-FIELDS AS STUDIED BY MEANS OF DIELECTRIC TIME-DOMAIN SPECTROSCOPY/

The destabilization of w/o emulsions in the presence of a high externa l electric held has been studied by means of dieIectric time domain sp ectroscopy. The experiments were designed with a 2(7-3) reduced factor ial design and analyzed in terms of multivariate regression models. A regression model based only on the main variables fails to predict the value of the electric held. A model based on three main variables and two interaction terms was found to completely predict the experimenta l findings. These main variables were the amount of the disperse phase (X(1)), the salinity in the disperse phase (X(2)), and the amount of surfactant (X(5)), while the interaction terms were identified as a co mbination of the first and the second (X(1)X(2)) and the first and the third variable (X(1)X(5)) above, The interaction term X(1)X(5) Contai ns contributions from interactions between volume fraction of the disp erse phase and salinity, and from temperature and surfactant, while th e interaction term X(1)X(5) contains contributions from the volume fra ction of the disperse phase and surfactant and from salinity and tempe rature. The influence of the variables on the emulsion stability is di scussed. (C) 1995 Academic Press. Inc.