Berlin 2018 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 2: Biomaterials and Biopolymers (joint session BP/CPP)
BP 2.2: Vortrag
Montag, 12. März 2018, 09:45–10:00, H 1058
Ion and Molecule Transport Bulk and in Nanopores - a NMR study — •Sarah Schneider and Michael Vogel — TU Darmstadt Institut fuer Festkoerperphysik, Darmstadt, Germany
We analyze ion and molecule transport in aqueous salt solutions confined to nanopores as part of a project that aims to develop a new generation of nanosensors by combining biological and synthetic nanopores. While being highly selective and sensitive, biological ion channels lack the robustness for technological applications. Contrarily silica pores are well-proven in industrial and clinical environments, but possess inferior capabilities, e.g. no selectivity. A hybrid system would combine the favorable properties of both fields.
To optimize such pores, it is of strong interest to understand the influence of the confinement on the T-dependent ion and molecule transport inside. We vary the pore parameters systematically and study their effects on the dynamics by NMR. Using 1H and 2H NMR we can selectively investigate water dynamics whereas 7Li and 23Na NMR analyze the local and long-range dynamics of ionic species. Analyzing the local ion and water dynamics reveals a slowdown with increasing salt concentration, which may differ in bulk and confinement due to altered prospensity for crystallization. At a given concentration there is a slowdown in confinement with more heterogenious dynamics. Both can be explained by a slower layer at the pore walls and bulk-like dynamics in the pore center. Field-gradient NMR is applied to measure self-diffusion. The extent of the effect and the relation between short- and long-range dynamics depend on the confinement properties.