Long-time dynamics in poly(dimethylsiloxane) networks studied by deuterium nuclear magnetic resonance

Sotta, P.; Deloche, B.
March 1994
Journal of Chemical Physics;3/15/1994, Vol. 100 Issue 6, p4591
Academic Journal
A deuterium NMR (nuclear magnetic resonance) method is proposed to investigate long-time correlation of chain orientation in poly(dimethylsiloxane) networks. It is based on the observation of a quadrupolar echo after a Jeener pulse sequence, which is possible owing to the presence of nonzero residual interactions in the system related to local chain orientations. The time evolution of the quadrupolar echo amplitude is calculated in the framework of a slow chain reorientational motion. An experimental result is presented which shows that local orientation is frozen within the time scale investigated, up to 0.3 s.


Related Articles

  • Analysis of deuterium nuclear magnetic resonance line shapes in anisotropic media. Wittebort, R. J.; Olejniczak, E. T.; Griffin, R. G. // Journal of Chemical Physics;5/15/1987, Vol. 86 Issue 10, p5411 

    Methods for the analysis of motional effects on 2H NMR solid state line shapes are described. Several simple models of anisotropic motions in solids are presented from which line shapes and relaxation experiments are calculated. Using these methods order parameters of fast limit spectra can be...

  • Anisotropic reorientation and internal chain dynamics in liquid crystals: A deuterium nuclear magnetic resonance study. Dong, Ronald Y.; Richards, G. M. // Journal of Chemical Physics;12/1/1989, Vol. 91 Issue 11, p7276 

    The spectral densities of motion J1(ω) and J2(2ω) were measured at 15.3 MHz in the nematic phase of p-methoxy-d3-benzylidene-d1-p-n-butyl-d9-aniline for the methine and butyl chain deuterons. The present study concentrates on measurements near the clearing temperature as well as extends...

  • Heteronuclear dipolar dephasing of deuterium quadrupole echoes. Heaton, Nicholas J.; Vold, Regitze R.; Vold, Robert L. // Journal of Chemical Physics;7/1/1989, Vol. 91 Issue 1, p56 

    Analytical expressions are derived for the NMR signal from isolated dipolar coupled 2H–14N spin pairs following a quadrupole echo pulse sequence. The expressions are used to calculate the pulse spacing dependence of the deuterium quadrupole echo intensity and the powder line shape. The...

  • A deuterium NMR study of ammonium thiocyanate-d4. Gruwel, Marco L. H.; Facey, Glenn; Wasylishen, Roderick E. // Journal of Chemical Physics;11/15/1986, Vol. 85 Issue 10, p6240 

    The results of a deuterium NMR study of ND4SCN between 125 and 420 K are reported. The deuterium T1 data indicate phase transitions at 352 and 383 K, however no evidence was found for a recently reported reversible phase transition at 203 K in NH4SCN.

  • Asymmetry in molecular ordering in the nematic phase: DMR study. Wu, Bao-Gang; Ziemnicka, Barbara; Doane, J. William // Journal of Chemical Physics;1/15/1988, Vol. 88 Issue 2, p1373 

    Deuterium nuclear magnetic resonance (2H-NMR) was performed on the rigid perdeuterated fluorene segment of the compound 2-fluorenyl-4’-tetradecyloxy benzoate (FLOC 14-d9) to unambiguously measure the order parameter U which reflects the degree of asymmetric ordering of the molecule in the...

  • A slow-turning method for measuring large anisotropic interactions in inhomogeneously broadened... Hill, Edward A.; Yesinowksi, James P. // Journal of Chemical Physics;6/1/1997, Vol. 106 Issue 21, p8650 

    Proposes a nuclear magnetic resonance (NMR) method for measuring anisotropic spin-Hamiltonian parameters in anisotropic crystalline materials. Involvement of slow turning of a powdered sample about an axis perpendicular to the external magnetic field; Demonstration of theoretical analysis.

  • Three-dimensional measurements of the nuclear magnetic resonance chemical shift and a new analytic data transform for the shift anisotropy. de Swiet, Thomas M.; de Swiel, Thomas M. // Journal of Chemical Physics;5/15/2000, Vol. 112 Issue 19 

    Three-dimensional measurements of the [sup 13]C nuclear magnetic resonance (NMR) chemical shift in methyl-α-D-glucopyranoside are presented. One dimension measures the isotropic shift under ordinary magic angle spinning. In the remaining two dimensions, the chemical shift anisotropy (CSA) is...

  • Director reorientation processes in a monodomain thin nematic liquid crystal film: A deuterium NMR spectroscopy study. Luckhurst, G. R.; Miyamoto, T.; Sugimura, A.; Timimi, B. A. // Journal of Chemical Physics;9/22/2002, Vol. 117 Issue 12, p5899 

    Deuterium nuclear magnetic resonance (NMR) spectroscopy has been used to investigate the director dynamics in the nematic liquid crystal, 4-pentyl-4'-cyanobiphenyl (5CB), confined between two glass plates and subject to magnetic and electric fields. The nematic cell was held in the NMR probe...

  • Influence of cholesterol on dynamics of dimyristoylphosphatidylcholine bilayers as studied by... Trouard, Theodore P.; Nevzorov, Alexander A.; Alam, Todd M.; Job, Constantin; Zajicek, Jaroslav; Brown, Michael F. // Journal of Chemical Physics;5/1/1999, Vol. 110 Issue 17, p8802 

    Investigates the influence of cholesterol on dynamics of dimyristoylphosphatidylcholine bilayers as studied by deuterium nuclear magnetic resonance (NMR) relaxation. Role of deuterium NMR relaxation rates in membrane function and dynamics; Measurement of spin-lattice and quadropolar order...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics