Dielectric properties of interphasal water in water-in-oil microemulsions

By means of Differential Scanning Calorimetry applied to w/o microemulsions, the experimental evidence has been obtained of the presence of two forms of water, namely, “free” and “interphasal” distinguished by the melting temperatures of, respectively, 273 K and 263 K. In the case of a w/hexadecane microemulsion, the above water con configurations give rise to two separate endotherms upon steady heating of previously frozen samples. The dielectric properties of the system's water fraction melting at 263 K were studied in the frequency range 5 Hz–50 MHz. The temperature dependence of both ε′ and ε″/ε′ upon the steady cooling of the liquid samples as well as the heating of the frozen ones, was investigated in the interval (303 K – 90 K).