Self-diffusion studies by intra- and inter-molecular spin-lattice relaxometry using field-cycling: Liquids, plastic crystals, porous media, and polymer segments

2017 ◽  
Vol 101 ◽  
pp. 18-50 ◽  
Author(s):  
Rainer Kimmich ◽  
Nail Fatkullin
Keyword(s):  
Porous Media ◽  
Plastic Crystals ◽  
Self Diffusion ◽  
Spin Lattice ◽  
Diffusion Studies ◽  
Field Cycling ◽  
Molecular Spin

NMR Study of Molecular Dynamics in a D ho Columnar Mesophase

1998 ◽  
Vol 53 (10-11) ◽  
pp. 823-827 ◽  
Author(s):  
C. Cruz ◽  
P. J. Sebastião ◽  
J. Figueirinhas ◽  
A. C. Ribeiro ◽  
H. T. Nguyen ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Lattice Relaxation ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Self Diffusion ◽  
Spin Lattice ◽  
Nmr Study ◽  
Collective Movements ◽  
Field Cycling ◽  
Nmr Techniques

Abstract In this paper we report the first molecular dynamics study combining fast field-cycling and conven-tional NMR techniques in a thermotropic liquid crystal of discotic molecules exhibiting an ordered columnar hexagonal mesophase. Using the association of these techniques we obtained proton T1 data over a very large domain of Larmor frequencies (ω/2π from 500 Hz to 85 MHz). The proton spin-lattice relaxation results were analysed considering the structure of the mesophase and the types of movements which are expected to influence significantly the relaxation rate, namely local molecu-lar rotational reorientations, inter-columnar self-diffusion and collective movements corresponding to bending and compression of the columns. We verified that these mechanisms dominate the relaxation respectively for high, medium and low Larmor frequencies.

On the Structure and Dynamics of Microemulsions Self-Diffusion Studies

1982 ◽  
pp. 115-129 ◽  
Author(s):  
B. Lindman ◽  
N. Kamenka ◽  
B. Brun ◽  
P. G. Nilsson
Keyword(s):  
Self Diffusion ◽  
Structure And Dynamics ◽  
Diffusion Studies

scholarly journals NMR Spin-Lattice Relaxation and Tunnelling of Partially Deuterated Methyl Groups

1991 ◽  
Vol 46 (12) ◽  
pp. 1123-1130 ◽  
Author(s):  
H. Langen ◽  
W. Müller-Warmuth
Keyword(s):  
Lattice Relaxation ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Spin States ◽  
Relaxation Rates ◽  
Spin Lattice ◽  
Conversion Rates ◽  
Temperature Relaxation ◽  
Field Cycling ◽  
Additional Influence

Abstract Proton spin lattice relaxation rates have been measured at 15 and 30 MHz and down to 5 K for the partially deuterated molecular crystals 4-F-toluene, 4-Cl-toluene, and 2,6-Cl2-toluene. The behaviour of these materials is governed by methyl group tunnelling. As compared with the undeuterated compounds, the low temperature relaxation is enhanced and the details depend on the removal of the symmetry coupling between rotator and spin states. The hindering barriers remain unchanged, the A to E conversion rates are faster, and relaxation is dominated by spectral density contributions J(2ωo) and J(2ω0). In one case an additional influence of level-crossing energy transfer on relaxation is observed. Field-cycling spectroscopy reveals steps rather than peaks if the proton spin Zeeman and tunnelling splittings match

Time Domain Zero Field NMR and NQR

1986 ◽  
Vol 41 (1-2) ◽  
pp. 440-444 ◽  
Author(s):  
A. Bielecki ◽  
D. B. Zax ◽  
A. M. Thayer ◽  
J. M. Millar ◽  
A. Pines
Keyword(s):  
Time Domain ◽  
Relaxation Times ◽  
Low Frequency ◽  
High Sensitivity ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Zero Field ◽  
Spin Lattice ◽  
Field Cycling ◽  
The Time Domain

Field cycling methods are described for the time domain measurement of nuclear quadrupolar and dipolar spectra in zero applied field. Since these techniques do not involve irradiation in zero field, they offer significant advantages in terms of resolution, sensitivity at low frequency, and the accessible range of spin lattice relaxation times. Sample data are shown which illustrate the high sensitivity and resolution attainable. Comparison is made to other field cycling methods, and an outline of basic instrumental requirements is given.

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