NMR methods for strongly inhomogeneous magnetic fields : application on elastomers using the NMR-MOUSE

The general objectives of this work are related to the methodology of NMR in grossly inhomogeneous fields, especially of the NMR-MOUSE, and its applications in the material science. The results of the investigations can be summarized as follows: 1. An attempt was made to detect high resolution spectra in elastomers by the NMR-MOUSE. 2. Multipolar spin states like, dipolar encoded longitudinal magnetization, double-quantum (DQ) coherences and dipolar order were excited and detected for the first time in strongly inhomogeneous magnetic fields. A new method for detection of 1H DQ filtered signals using the decay curves with improved signal-to-noise ratio was developed suitable for the NMR-MOUSE. The anisotropy of the local strain, which affects the chain orientation was measured by multipolar spin states in stretched elastomers. As an additional promising future application, the possibility to map the space distribution of the strain in elastomers was investigated for the first time using the NMR-MOUSE. 3. A further method for characterizing the segmental order in elastomers, based on residual van Vleck moments was implemented. The possibility to excite and detect a magic echo in grossly inhomogeneous magnetic fields was shown. 4. The structure/properties relation in elastomers can be elucidated by measuring the slow motions of the polymer chains. A procedure to measure spin-lattice relaxation times in the rotating frame was investigated using the NMR-MOUSE. Summarizing, the results of this work will extend the range of applications of the mobile NMR sensor by providing qualitative and quantitative information about elastomers under various conditions. We extended the panoply of NMR parameters that can be used with the NMR-MOUSE for establishing structure-property relations in materials.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2001

Author dc:creator

• Wiesmath, Anette

Contributors dc:contributor

• Blümich, Bernhard

• info:eu-repo/classification/ddc/530
• Physik
• Elastomer
• NMR-Spektroskopie
• Hochauflösendes Verfahren
• Magnetfeld
• Inhomogenes Feld

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

eng

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123743%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:62153