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arXiv · 1309.5188

On the theory of Double Quantum NMR in polymer systems: the second cumulant approximation for many spin I=1/2 systems

N. Fatkullin·C. Mattea·S. Stapf
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Abstract

General analytical expressions for Double Quantum Nuclear Magnetic Resonance (NMR) kinetic curves of many-spin I=1/2 systems are derived with an accuracy of the second cumulant approximation. The expressions obtained exactly describe the initial part of the kinetic curves and provide a reasonable approximation up to times of about twice the effective spin-relaxation time. For the case when the system contains two isolated spins, this result exactly reproduces known expressions. In the case of polymer melts, the intermolecular magnetic dipole-dipole interactions significantly influence the time dependence of the DQ NMR kinetic curves.

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N. Fatkullin, C. Mattea, S. Stapf. 2013-09-20. On the theory of Double Quantum NMR in polymer systems: the second cumulant approximation for many spin I=1/2 systems. https://doi.org/10.1063/1.4830410

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