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 external electric field has been studied by means of dieIectric time domain spectroscopy. The experiments were designed with a 2(7-3) reduced factorial 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 field. A model based on three main variables and two interaction terms was found to completely predict the experimental 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 combination 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) Contains contributions from interactions between volume fraction of the disperse phase and salinity, and from temperature and surfactant, while the interaction term X(1)X(5) contains contributions from the volume fraction of the disperse phase and surfactant and from salinity and temperature. The influence of the variables on the emulsion stability is discussed. (C) 1995 Academic Press. Inc.