ABSTRACT
I. Introduction 24
II. Phase Behavior of Microemulsions 27 A. Microemulsions 27 B. Phase diagrams 27 C. Characteristic size of droplets 29 D. Specific heat 31 E. Free energy 34 F. Latent heat 39 G. Step in the specific heat 41
III. Phase Separation Kinetics 43 A. Energy barrier 43 B. Experimental observation of oscillations 45 C. Mechanism of phase separation 47 D. Temperature dependence of the droplet-droplet distance 48
IV. Conclusion 54
References 56
I. INTRODUCTION Mixtures containing surfactants and hydrophilic (for instance, water) and hydrophobic (for instance, alkanes) components show a fascinating thermodynamic and kinetic behavior. Gaining an understanding of this behavior poses a large variety of interesting physical and chemical challenges, which have been a focus of fundamental research in colloid science throughout recent decades. In addition to this interest from a statistical physics point of view, this research is also strongly stimulated by applications. Surfactants are ingredients of various products such as pharmaceuticals, lubricants, and cosmetics [1]. They are of importance for tertiary oil recovery and for emulsion polymerization. To improve production capacities, a better understanding of the varying forces of interaction between the surfactant molecules and the other ingredients in the course of production is desirable. In this review, we highlight recent insights into the driving forces of phase transitions and their kinetics in these mixtures that have been made possible by microcalorimetric studies.
