| Summary: | 碩士 === 國立交通大學 === 光電工程系所 === 96 === The fluctuation-dissipation theorem of classical statistical mechanics reveals that there always exist spontaneous fluctuation behaviors induced by low-level excitations in all condensed matter physical systems. The main theme of this thesis study lay in the discussion about the dynamical molecular fluctuations of specific condensed matter material – liquid crystal (LC).
The anchoring strength of a LC cell is relevant to the surface treatment methods. In this thesis, we began the derivations from the dynamic light scattering theory, together with the hydrodynamic equation of LC director and certain specific boundary conditions. We finally obtained the relationship between the correlation time of the scattering light scattered by LC and the anchoring energy coefficient of the cell. After measuring the scattering light coming from various nematic cells with different surface treatments, the results obtained from dynamic light scattering technique confirmed the theoretical predictions well, that is, the anchoring energy coefficient produced by mechanical rubbing method that is often used in liquid crystal display industry is larger than that produced by photoalignment method by around two order of magnitude; moreover, depositing liquid crystal polymer on the photoalignment layer of the cell does improve the LC alignment quality.
Surface-stabilized ferroelectric liquid crystal devices have merits of fast response speed and wide viewing angle. However, the tendency toward defect formation owing to imperfect molecular alignment restrains their development in industrial applications. Doping ZnO nanocrystals into ferroelectric liquid crystal host can improve the quality of liquid crystal molecular alignment by virtue of the molecular binding effect. In this thesis, we observed a novel phenomenon that a portion of the liquid crystal molecules got rid of the influence of surface anchoring because of the improvement of doping-induced orientational order.
|
|---|
