Abstract
Using spin labelled palmitic acid three amphiphilic systems were investigated. Two of the systems exhibit no bilayer-monolayer structural changes and a monotonous decrease of the order parameter with increasing temperature is found. In the third system, however, where such pre-structuration occurs, the order parameter has two extrema coinciding with the phase transitions coagel-gel and gel-liquid crystal. In the liquid crystalline phase of the potassium palmitate-water amphiphilic system an additional phase transition is observed