Summary

It is becoming increasingly evident that liquids and solutions are far from homogeneous and are structured on lengths scales from supramolecular to mesoscopic. Such structure ranges from hydrogen-bonded clusters in water, through pre-nucleation clusters in saturated solutions and mesoscopic structures in room-temperature ionic liquids, to macroscopic phase separation associated with liquid-liquid phase transitions. This gives rise to dynamics over a huge range of timescales ranging from femtoseconds to kiloseconds presenting a challenge to experiment and theory. Many aspects of liquid structuring such as the proposed presence of a second critical point in the supercooled phase of liquid water or the macroscopic phase separation of molecular liquids due to a liquid-liquid phase transition have proven to be controversial. Bringing together up to date contributions from experimentalists and theoretician, this Faraday Discussion will present these issues and their role in practical situations. This title will appeal to researchers interested in liquid structuring issues which play a defining role in determining chemical reactivity, transport properties, crystal nucleation, and other physicochemical properties important to engineering and biology.