Liquid Crystal Orientation on Various Surfaces

Abstract
The liquid crystal orientation on various surfaces were investigated by using the “Liquid Crystal Chromatography,” which is useful for observing the true orientation by eliminating impurities in the liquid crystal materials. As the result, it was found that all nematic liquid crystals of Schiff base-, biphenyl-, ester-, PCH-, and azoxy-compounds aligned parallel to the surfaces of In2O3, Al2O3, soda-lime glass, SiO, etc. On the other hand, some of the liquid crystals such as MBBA, 5CB have been known to have a tendency to align perpendicular to the surface like In2O3. Then, the reason of this discrepancy was also investigated and it was found that impurities produced by hydrolysis of these liquid crystals had amphiphilic characteristic which induced a perpendicular alignment of these liquid crystals.