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Mixtures of surfactant or amphiphilic molecules and solvents are known to display a large number of lyotropic mesophases. Although the physics of thermotropic liquid crystals has been vastly discussed in the literature, lyotropic mesophases have been much less explored. This book gives a unifying presentation of the structural and physical properties of lyotropic liquid crystalline systems, including a set of experimental results and a discussion of the characterization of different structures and the corresponding phase transitions. The initial chapters contain a description of the main experimental results and techniques associated with the characterization of lyotropic mixtures, and an overview of some theoretical approaches to account for the phase transitions and phase diagrams of these mesophases. This book includes discussions on periodically organized lyotropic systems, micellar and bicontinuous structures, modulated and cholesteric structures, and a number of related developments (magnetic colloids, microemulsions, films, and lyo-banana mesophases).

Intermolecular interactions stem from the electric properties of atoms. Being the cause of molecular aggregation, intermolecular forces are at the roots of chemistry and are the fabric of the world. They are responsible for the structure and properties of all condensed bodies — the human body, the food we eat, the clothes we wear, the drugs we take, the paper on which this book is printed. In the last forty years or so, theoretical and experimental research in this area has struggled to establish correlations between the structure of the constituent molecules, the structure of the resulting condensed phase, and the observable properties of any material. As in all scientific enterprise, the steps to follow are analysis, classification, and prediction, while the final goal is control; which in this case means the deliberate design of materials with specified properties. This last step requires a synthesis and substantial command of the three preceding steps. This book provides a brief but accurate summary of all the basic ideas, theories, methods, and conspicuous results of structure analysis and molecular modelling of the condensed phases of organic compounds: quantum chemistry, the intermolecular potential, force field and molecular dynamics methods, structural correlation, and thermodynamics. The book also exposes the present status of studies in the analysis, categorisation, prediction, and control, at a molecular level, of intermolecular interactions in liquids, solutions, mesophases, and crystals. The main focus here is on the links between energies, structures, and chemical or physical properties.