Liquid Crystalline Composite Based on a Clay Mineral

Abstract

Novel liquid crystalline composites (LCC) based on a nematic liquid crystal and fine plate-like caly minerals have been prepared by mixing the two components. The observation of the LCCs by a polarized optical microscope revealed that the plate like particles of the clay mineral were dispersed homogeneously and their sizes were about several micrometers or less. In a nematic phase, the LCCs exhibit a very fine multidomain. structure which is the cause of a light scattering effect of the LCC cells. When an electric field was applied to the cell, it became transparent from milky white. Even after the electric field was switched off, the transparent state was maintained, thus exhibiting memory effect. After 3 months, no change in the transparency of the memory state was observed. Also, the thermo-optic effect of the LCC cells was discussed.

Key Words:

• Liquid crystalline composite
• montmorillonite clay
• electrooptic memory effect
• light scattering effect.