Chapter 12: Confined Fluids: NMR Perspectives on Confinements and on Fluid Dynamics

Fluids confined to nanoporous matrices exhibit a rich variety of phenomena not present in their bulk state. Among them, transport properties may become notably affected by not only the geometric restrictions and pore wall interactions, but also by structural and phase changes occurring in confined materials. In this contribution we consider the classical structure-dynamics problem in the context of experimental diffusion NMR by bringing also this aspect into consideration. We start with a brief account of the basic properties of confined fluids, including transport mechanisms under different thermodynamic conditions. Thereafter, we discuss a broad spectrum of structural information delivered by diffusion studies. The final section focusses on the guest molecules accommodated by porous host materials and aims to address some of the fundamentals of fluid dynamics in confined spaces.