Project area 3
Transport through Porous Materials
Project area 3 uses high resolution NMR methods and theoretical approaches to analyze fundamental physico-chemical principles for ion transport in porous materials and the interaction of ions with material interfaces. The results from project area 3 will be used to design pores in the project areas 1 and 2.
Solid-state NMR of water and sodium in pores
Principal Investigator: Gerd Buntkowsky
Information for the construction of pores is obtained from experimental data on ion transport in porous systems at the atomic level. Gerd Buntkowsky’s group (Chemistry) studies the behavior of small fluid sample molecules in confinement of complex mesoporous systems using solid-state NMR spectroscopy. Their work shows that the characterization of fluid properties using solid-state NMR is possible and the technique is used to analyze the dynamic behavior of water and sodium ions in pores. A combination of solid-state NMR and DNP hyperpolarization technique is intended to detect the interior the ion channel pores of project area 2.
Particle transport in surface-modified solid-state pores
Principal Investigator: Michael Vogel
The particle transport in nanopores in nature as well as in technology is of enormous importance. In general, the mobility of a particle (molecule or ion) in confinement differs substantially from the mobility in bulk. The interactions of the particle with the pore walls are responsible for this difference, they cause a sharp slowdown in particle dynamics. Because of this, guest-host interaction exists in confinement usually a spatial dependence of the particle mobility, with reduced mobility near the pore walls and a bulk-like behavior in the pore center. The particle transport in nanopores thus depends both on the pore geometry (size /shape) and on the interactions at the inner pore surfaces, i.e. of the surface texture. Michael Vogel’s group (Physics) investigates the influence of the pore diameter, pore shape (cylindrical /conical) and the pore surface on the mobility of ions and water in confinement. These findings provide an important basis for the preparation of biomimetic solid-state pores. Various NMR methods are used for this project. In particular, NMR experiments allow to study both microscopic dynamics and mesoscopic diffusion. This allows to explore the effect of the spatial dependence of the particle mobility, in particular the slowdown at the pore walls, on the long-range particle transport. These studies are complementary in an ideal manner to the work in other project areas, in which peptide-functionalized solid-state pores are characterized in terms of structural properties.
Molecular simulation of ion transport in functionalized nanopores
Principal Investigator: Nico van der Vegt
Information and inspiration for the design of pores arise furthermore from theoretical approaches. Nico van der Vegt’s group (Chemistry) deals with the statistical thermodynamics and molecular simulation of solvatation-processes and ion-specific effects in soft matter in order to understand the interactions between ions, proteins and synthetic macromolecules in aqueous solution. Combined with methodological developments in the area of multiscale-modeling of soft matter the opportunity arises to theoretically predict ion-selective, switchable pores based on functionalized pore-surfaces.