Thermal analysis of the dielectric behavior of complex liquids

The system investigated is a multicomponent liquid, macroscopically monophasic, consisting of water spherical droplets stabilized by a surfactant shell, with diameter in the nano meter range, dispersed in a continuous hydrocarbon phase (oil). The system is thermodynamically stable. The dielectric properties of the above system were investigated at room temperature in the frequency range 1.6 KHz - 100 MHz, against the increase of the water concentration. The temperature dependence was studied by thermally stimulated depolarization (TSD) by applying to the samples in the liquid state, a very low intensity static electric field. Therefore the specific effect of the temperature change was evidenced by differential scanning micro calorimetry (DSC), by studying the basic thermodynamics of the system. Both the freezing exotherms and the melting endotherms were analyzed by DSC. Last but not least, the percolative behavior, typical of such systems when the water globule concentration reaches a given value, was considered both from the dielectric and the thermodynamic point of view.