skip to main content

Title: On the theory of double quantum NMR in polymer systems: The second cumulant approximation for many spin I = 1/2 systems

General analytical expressions for Double Quantum Nuclear Magnetic Resonance (DQ 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 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.
Authors:
 [1] ; ;  [2]
  1. Institute of Physics, Kazan Federal University, Kazan, 420008 Tatarstan (Russian Federation)
  2. Dept. Technical Physics II, Technische Universit├Ąt Ilmenau, 98684 Ilmenau (Germany)
Publication Date:
OSTI Identifier:
22251392
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 139; Journal Issue: 19; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ACCURACY; APPROXIMATIONS; INTERACTIONS; MAGNETIC DIPOLES; NUCLEAR MAGNETIC RESONANCE; POLYMERS; RELAXATION TIME; SPIN; TIME DEPENDENCE