Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, Vol.304, 59-59, 1997
Liquid-Crystal Formulations
Chiral-Nematic Dispersions and Encapsulations were investigated for different mixture concentrations of the nematic liquid crystal E7 and E48 and the cholesteric liquid crystals TM74A and TM75A in the Infrared and Visible regime. Liquid crystal (E7:TM74A) dispersions as stand alone systems and as polymer dispersed materials were found to be bistable in the near IR region.double dagger Chiral-nematic dispersion of E48:TM74A displayed different bright colors in the 400-760 visible range and exhibited thermochromic properties at room temperature. The PVA encapsulated E48:TM74A mixture (60:40) also showed thermochromicity between 30 degrees C to 43 degrees C. A ternary system was formulated from TM74A:TM75A:E48. Mixtures with high cholesteric concentration exhibited thermochromicity whereas systems with low cholesteric concentration showed electro-optic properties. Gel dispersion was done on mixtures with low cholesteric concentration using a liquid crystal polymer cinnamate. The polymer network effected stabilization on the liquid crystal molecules. Electro-optic tests showed that threshold voltage increases as the cholesteric amount increases in the different LC mixtures. Polymer and gel dispersions also increased the threshold voltages.