화학공학소재연구정보센터
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, Vol.347, 411-422, 2000
A deuterium nuclear magnetic resonance investigation of field induced director dynamics in a nematic slab subject to magnetic and pulsed electric fields
Deuterium nuclear magnetic resonance (NMR) spectroscopy has been used to investigate the field-induced director dynamics in a nematic liquid crystal, 4-pentyl-d(2)-4'-cyanobiphenyl (5CB-d(2)) deuteriated in the alpha -position of the pentyl chain, confined between two glass plates. The NMR spectra have been measured as a function of time after turning an electric field on and off It is demonstrated that the field-induced director dynamics in the nematic liquid crystal cells can be successfully time-resolved. In addition, it is found that the doubler NMR spectra become powder-like during the turn-on and rum-off processes. It is shown that the rotational viscosity and the diamagnetic anisotropy of 5CB-d(2) can be determined from the time-resolved NMR spectra by assuming uniform alignment of the director.