Search for ultra slow molecular motion in liquid crystals by spin thermometry
✍ Scribed by R.T. Thompson; D.W. Kydon; M.M. Pintar
- Publisher
- Elsevier Science
- Year
- 1976
- Tongue
- English
- Weight
- 199 KB
- Volume
- 42
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
The existence of a slow dynamic mode, \vhich relaxes the nuclear Zeeman energy at low fields, has been detected in liquid crystals by several nuclear magnetic resonance studies. To data, though, this slow mode has not been uniquely determined. The cross relaxation in the liquid crystal PAA and the dimercxchange in the alkoxy-benzoic acid homologous series, interfire with the analysis of the low frequency relaxation. In p-(pentyl) phenyl-p-pentyloxy benzoate, which is not a dimer and cross relaxation between protons and other nuclei is not possible, the spin relaxation was analysed at low and high fields. By measuring T, , Tl p, T,D and applying spin thermometry, the existence of a slow mode was uniquely determined in this Liquid crystal.