Hysteresis behaviour in temperature-induced emulsion inversion
Résumé
Emulsion inversion produced by a change in temperature usually takes place reversibly, ie at the same temperature whatever the direction of change. The present study indicates previously unreported hysteresis in a transitional inversion driven by a temperature variation in a non-ionic system containing Tween surfactant mixtures. In both directions of the temperature variation, a delay is exhibited with respect to the standard phase inversion temperature of the equilibrated system. The width of the hysteresis region depends on the rate of temperature change. This behaviour, which does not happen in the presence of alcohol, is attributed to the presence of liquid crystals.