A Short History of Phase Transitions in Ionic Fluids

The paper reviews the development of theory and experiments concerning the nature of the critical point in ionic fluids. Because of the long-range nature of the Coulomb interactions the possibility of mean-field critical behaviour was discussed as a possibility. Although some experiments supported mean-field criticality, simulations on the model fluid of charged hard spheres and later experiments on ionic solutions have shown that phase transition of ionic systems belong to the Ising universality class like phase transitions in non-ionic fluids. Experiments concerning the crossover from Ising to mean field-behaviour are discussed as well as systematic differences between the phase behaviour predicted for the model fluid of charged hard spheres and that observed in ionic solutions ((c) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)