Abstract
Due to their nanometric porosity and high specific surface area, nanoporous materials are at the heart of fundamental research aimed at studying the role of nanoconfinement and surface forces on thermodynamics and fluid dynamics. Moreover, by leveraging these properties in technological processes, this class of solids is also central to key industrial sectors : adsorption (e.g. detection, chromatography), energy (hydrogen storage, fuel cells, batteries), environment (phase separation, water treatment, nuclear waste storage), etc. Among nanoporous materials [~1-100 nm], solids with sub-nanometer pore sizes (e.g. activated carbons, zeolites) are of particular interest, as the extreme confinement within their porosity leads to novel adsorption and transport phenomena.
In this talk, we will illustrate how approaches based on statistical physics - including molecular simulation tools - can be used to develop simple models of adsorption and transport in these ultra-confined materials. In particular, we'll see how a simple thermodynamic model can rationalize confinement by considering reminiscent capillarity at infinitesimally small length scales. Next, we'll show how transport in nanoporous media can be described without having to invoke macroscopic concepts whose validity at these scales remains debatable. In particular, using parameters and coefficients obtained from simple experiments, we'll see how transport, under such severe confinement conditions, can be described using models such as intermittent Brownian motion or the De Gennes shrinkage model.
