Dielectric Properties of Water-liquid Paraffin Emulsion Systems at the Microwave Frequency of 9.4 GHz

The state of water contained in emulsions, particularly in o/w emulsions, was studied as a model of water orientation at the peripheries of biomembranes. Dielectric measurements made at microwave frequency on emulsions containing water and liquid paraffin in various ratios with emulsifiers revealed that the o/w emulsions possessed considerably reduced dielectric loss as compared with theoretical values obtained in accordance with the Maxwell-Wagner model, while the dielectric properties of w/o emulsion were in good agreement with the theoretically expected values. The observations seem to be explained by assuming changes in the state of water in the oil-water interfacial layer in o/w emulsions. The preparation of stable emulsions for use in this study is also discussed.