Dresden 2009 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 15: POSTERS Dynamics and Diffusion

CPP 15.9: Poster

Dienstag, 24. März 2009, 14:00–16:30, P3

Low Field NMR for Analysis of Heterogeneous Mixtures and Polymers under Stress — •Ute Böhme and Ulrich Scheler — Leibniz-Institut für Polymerforschung Dresden, Hohe Str. 6, 01069 Dresden

Small and low-cost NMR systems based on permanent magnets provide an interesting alternative for NMR in materials characterization. They are used as fast, non-destructive tools for the routine analysis of foodstuffs, cosmetics and chemicals. They are of particular interest, when shift information is not required, i.e., when there is a priory knowledge about the system. NMR relaxation times provide a wealth of information on molecular mobility, they are influenced by the composition and treatment of the sample. Impacts like stress, heating or cooling change the molecular mobility. Extending the relaxation time measurements to two-dimensions significantly enhances the resolution of the components of the sample despite lack of chemical shift resolution. For our investigations we use an in-house built portable NMR system with Halbach magnets arrangement and a proton Larmor frequency of 32 MHz. Examples shown include the determination of the principal components of water- in- oil- emulsion and stretched polypropylene using T1-T2 correlation experiments at low field. Comparison to results obtained with high-field measurements confirm the results obtained.