The application of dense ionic fluids requires a greater understanding of the complex nanostructure of ionic liquids that contain additional components such as neutral/polar solvents and oligomeric species. Such nanostructural complexity results in a range of useful dynamic properties that occur in response to external stimuli such as an electric field or mechanical stress. The study of dense ionic fluids in and out of equilibrium provides details on thermodynamics, phase behaviour, electron transfer and more, furthering our understanding of their structure and dynamics. How dense ionic fluids interface with biological and colloidal systems is also crucial to their application. The presence of a particle/interface on the nano and micro scale will determine the properties of an entire system. This volume details the cross-fertilisation of ideas and understanding between the distinct but adjacent communities working with different classes of dense ionic fluids and their different applications. In this volume the topics covered include: Structure and dynamics in dense ionic fluidsIonic fluids at equilibrium: thermodynamics, nanostructure, phase behaviour, activityIonic fluids out of equilibrium: electrodeposition, dissolution, electron transfer, driving forcesInterfaces and particles in dense ionic fluids: biological and colloidal systems spanning multiple length scales