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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 2: Focus: Amphiphilic Systems II
CPP 2.7: Vortrag
Montag, 23. März 2009, 16:30–16:45, ZEU 222
Pressure-jump time-resolved NMR experiments on Phospholipides up to 250 bar and 3 ms jump time — •Günter Hempel1, Marina Krumova2, Uwe Heuert3, Martin Schiewek4, and Alfred Blume4 — 1Martin-Luther-Universität Halle, Institut für Physik, D-06099 Halle, Germany — 2Universität Konstanz, Fachbereich Chemie, D-78457 Konstanz, Germany — 3Fachhochschule Merseburg, D-06217 Merseburg, Germany — 4Martin-Luther-Universität Halle, Institut für Chemie, D-06099 Halle, Germany
Pressure is an important thermodynamic and kinetic variable in the investigation of soft condensed matter and biomolecular systems. It is recognized that conformational properties, aggregation and crystallization processes etc. are widely affected by the pressure.
Design and performance of a pressure-jump instrument for time-resolved NMR experiments are described. A special feature is the need of using non-ferromagnetic materials for all parts placed in or near the magnet. Fast pressure release at a time resolution of 3 ms is achieved opening a fastly acting valve driven by piezo stack. The pressure-jump cell is placed in an especially constructed NMR probe, which can be used in standard spectrometers.
We investigated a pressure-driven order/disorder phase transition of a chain-deuterated dimyristoyl-phosphatidyl*choline (DMPC)-water dispersion. First changes from ordered towards disorder-phase spectra could be detected after some 100 ms; the transformation process finished after about 30 s.