At the macroscopic, continuum level, liquid/liquid and liquid/gas interfaces are crucial to define ourselves and the world around us, and yet, when it is our turn to define them, especially at the microscopic, atomistic level, we
often run into trouble.
The study of liquid/vapour interfaces by means of computer experiments is as old as the field itself and, since the very beginning, fundamental questions such as the shape of the interfaces or the presence of molecular layers, have been lively debated. Developments in experimental techniques and in computational approaches have later shown that the molecular layers are indeed observable in liquid metals, and that the intrinsic structure of the interface of liquids resembles that of their radial distribution function. Still, a clear, parameter-free definition of what interfacial atoms are has yet to be proposed, but this did not prevent investigations on interfacial properties to be extended from simple and molecular liquids to complex ones, including polymers, bilayers, micelles, proteins and colloids.
The field is in continuous development: recent results on simple liquids, based on larger and more accurate simulations and new theoretical analysis, have shown the limitations of the capillary wave theory and the importance of lateral correlations; New studies on the properties of ions at the water/vapour interface are changing our view on their organization and on the once-believed universal Hofmeister series; The surface roughness has been found to play an important role in determining activation energies, and the need has been underlined, to revise our theoretical approaches to describe chemical reactions occurring at or in the immediate vicinity of liquid/liquid interfaces; Several simulation studies underline the importance of hydration layers being carried along together with charged solutes when crossing liquid interfaces; The study of the distribution of stresses across liquid interfaces, with all the problems connected to its non-locality, as well as the proper evaluation of the surface tension have also seen a rise in interest in recent years; Finally, non-equilibrium phenomena such as the evaporation of solutes with Super- and Sub-Maxwellian kinetic distributions, and the coexistence of liquid- and vapour-like phases in active matter, are testing the limits of validity and applicability or thermodynamics in our understanding of the physics and chemistry at fluid/fluid interfaces.
The workshop will focus on recent development and possible future directions regarding (a) intrinsic properties of fluid/fluid interfaces (b) partially miscible systems (c) issues of non-locality and approaches beyond the capillary-waves theory (d) interfacial properties of membranes (e) reactions at interfaces (f) calculation of local stresses (g) non-equilibrium systems: active matter and non-Maxwellian distributions.