Melting point of ionic ternary systems (surfactant/salt/water) probed by electrical impedance spectroscopy

We have used electrical impedance spectroscopy to determine the influence of temperature on the electric characteristics of ionic surfactant/water and ternary systems composed by surfactant/salt/water and ionic surfactant/phospholipid/water, with the purpose of understanding the physical meaning of melting point of surfactants (called Krafft point) based on the fitting of Nyquist diagrams from the use of modified Randles circuit and to analyze the influence of salts actuating as lyotropic or hydrotropic electrolytes. The parameters obtained from the study of Gouy–Chapman double layer allow that important information about ionic and molecular distribution can be obtained in direction to describe the phase transition from hydrated solid surfactant to micelles in aqueous solutions.