Intermolecular and intramolecular contributions to the proton spin-lattice relaxation of the liquid crystal 4-cyano-4′-n-pentyl-d11-biphenyl: nematic and supercooled nematic regions

1987 ◽  
Vol 65 (2) ◽  
pp. 115-121 ◽  
Author(s):  
John S. Lewis ◽  
E. Tomchuk ◽  
E. Bock
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Qualitative Agreement ◽  
Nonlinear Least Squares ◽  
Lattice Relaxation ◽  
Proton Spin ◽  
Experimental Results ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Fitting Parameters

The intermolecular and intramolecular contributions to proton spin-lattice relaxation in 4-cyano-4′-n-pentyl-d11-biphenyl (5CB-d11) have been measured as a function of temperature and frequency. The theories of relaxation in nematic liquid crystals are presented in a form suitable for nonlinear least squares fitting to the data, and the experimental results compared with appropriate theories. It is found experimentally that it is not possible to distinguish between the Freed and the Ukleja et al. theories on intramolecular spin-lattice relaxation or between the Zumer–Vilfan and the Ukleja et al. theories on intermolecular spin-lattice relaxation. All three theories are in more or less equal qualitative agreement with experimental results and yield fitting parameters of comparable physical plausibility.

Dispersion of proton spin-lattice relaxation in a cholesteric liquid crystal

1983 ◽  
Vol 44 (10) ◽  
pp. 1179-1184 ◽  
Author(s):  
M. Vilfan ◽  
R. Blinc ◽  
J. Dolinšek ◽  
M. Ipavec ◽  
G. Lahajnar ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Cholesteric Liquid Crystal ◽  
Lattice Relaxation ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Spin Lattice

A proton FFT study of the aromatic and alkyl motions in the liquid crystal CBOOA: Orientational order fluctuations in the isotropic phase

1976 ◽  
Vol 54 (22) ◽  
pp. 2282-2286 ◽  
Author(s):  
J. J. Visintainer ◽  
E. Bock ◽  
Ronald Y. Dong ◽  
E. Tomchuk
Keyword(s):  
Liquid Crystal ◽  
Critical Temperature ◽  
Orientational Order ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Isotropic Phase ◽  
Spin Lattice ◽  
Temperature Dependences

Proton line shapes and spin–lattice relaxation were studied in the isotropic phase of the liquid crystal n-p-cyanobenzylidene-p-n-octyloxyaniline (CBOOA) using Fast Fourier Transform (FFT) spectroscopy. The proton spin–lattice relaxation time T1 above the nematic–isotropic phase transition was measured, at several Larmor frequencies, for the resolved peaks in the FFT spectra. The critical temperature dependences of (T1)cf, the T1, due to collective order fluctuations, are thus studied for the aromatic and the alkyl proton groups. The critical temperature behavior of CBOOA is compared with the predictions of the model based on short-range nematic orientational order fluctuations.

Proton Spin-Lattice Relaxation in Liquid Crystals

1969 ◽  
Vol 23 (25) ◽  
pp. 1421-1423 ◽  
Author(s):  
J. W. Doane ◽  
J. J. Visintainer
Keyword(s):  
Liquid Crystals ◽  
Lattice Relaxation ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Spin Lattice

Molecular dynamics study of the ferroelectric liquid crystal CI IPNOC by proton spin-lattice relaxation

1993 ◽  
Vol 14 (2) ◽  
pp. 415-426 ◽  
Author(s):  
A. Ferraz ◽  
J. L. Figueirinhas ◽  
P. J. Sebastião ◽  
A. C. Ribeiro ◽  
H. T. Nguyen ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Liquid Crystal ◽  
Lattice Relaxation ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Ferroelectric Liquid Crystal ◽  
Spin Lattice
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