Statistical mechanics of interfaces: dynamic phenomena
CECAM-DE-MMS at Freie Universität Berlin, Germany
- abstract submissions until 6 August 2018 (talks), posters anytime (30/9 latest)
(via this web page, after registration)
- notification of acceptance: 15 August 2018
- invited and contributed talks, flash talks featuring posters
- registration is free, lunch and coffee breaks will be provided
- venue: Freie Universität Berlin, Institute of Mathematics, Arnimallee 6, 14195 Berlin-Dahlem, Germany
- download flyer
- transport at and across interfaces
- capillary waves and surface tension
- wetting and confined liquids
- grain boundaries
- phase segregation and cavitation
- melting in two dimensions
- crystal growth and nucleation kinetics
- lipid bilayers and membranes
Interfaces are essential for the thermodynamics and kinetics of any first-order phase transition. Coexisting phases are separated from each other by interfaces and the free energy cost for the formation of interfaces causes, e.g., the free energy barriers associated with rare nucleation events. Also the interface itself can be subjected to phase transitions; examples are the roughening transition or the interface delocalisation transition in thin films. The statistical mechanics of interfaces is associated with a wealth of phenomena such as capillary waves, wetting, segregation, cavitation, or crystal growth that are particularly important for numerous applications in nanotechnology. The strong coupling of interfaces to their surroundings give rise to complex dynamics.
A common classification of interfaces distinguishes between the nature of the two adjacent bulk phases: Fundamental questions are addressed by studies of heat or mass transport across liquid-vapour or liquid-solid interfaces [1-3], respectively. The dynamics of many interfacial phenomena, such as surface waves [4,5], is governed by the surface tension and its interplay with the mass transport towards and along the interface, as described by transport coefficients such as the viscosity or the mutual or species diffusion for liquid mixtures [6-9]. A subject on its own is the study of the surface tension [10-12] and its link to interfacial structure [13-16].
Simulations of the phase segregation of confined liquid mixtures [17-19] and of cavitation in glasses  provided recent insight into the formation of liquid-liquid and liquid-glass interfaces, respectively. Liquid-solid interfaces emerge from crystallisation, the kinetics of which results from the combination of rare nucleation events with a non-equilibrium growth process [21-25]. This implies an inherent sampling problem, which called for various innovative solutions [26-28]. Solid-solid interfaces are realised by grain boundaries, which exhibit diffusion due to phase transformations . The converse process of melting in case of 2D crystals was clarified only recently by simulations, resolving a puzzle about the role of a hexatic phase [30,31] —a scenario that could be verified experimentally for colloidal hard spheres .
Adding particles to liquid interfaces opens up a wealth of applications , a few examples being particle-assisted wetting , the formation of Pickering emulsions , and solvent-coarsening in colloidal suspensions . A ubiquitous interface type in cell biology are lipid bilayers, which show non-trivial dynamics by themselves , but also diffusion anomalies of hydration water [38,39] and of embedded proteins [40,41].
Statistical mechanics provides the unifying mathematical framework to describe stochastic phenomena such as the dynamics of fluctuations, non-equilibrium response, and rare events. Most of the mentioned studies have in common that they rely on coarse-grained or atomistic molecular dynamics simulations, which are computationally demanding, thus require high-performance computing (HPC) facilities, and offer scope for innovative hardware and massively parallel algorithms.
This international workshop aims at being a stimulating platform for the exchange of ideas across community boundaries, sharing wisdom about mathematical tools and advanced algorithms. Open questions that shall be discussed include:
- the relation between interface mobility and transport processes,
- the dynamics of capillary waves,
- the frequency and wavenumber dependence of transport coefficients,
- the passage from simple model systems to realistic descriptions, and
- challenges and opportunities of the increasingly parallel, but heterogeneous computer hardware.
Juergen Horbach ( Universitaet Duesseldorf, Inst. f. Theoret. Physik II, 40225 Duesseldorf, Germany ) - Organiser
Felix Höfling ( Freie Universität Berlin, Institute of Mathematics ) - Organiser