Diluters' effects on high Δn and low-viscosity negative Δε terphenyl liquid crystals

Abstract

Lateral difluoro terphenyls exhibit a high birefringence, fairly low viscosity and modest dielectric anisotropy, but their alignment in a vertical alignment (VA) cell often deteriorates at elevated temperatures if their concentration is high. We have studied the effects of six diluters for lowering the viscosity while stabilizing the VA of the terphenyl host mixture at elevated temperatures. The pros and cons of each diluter are analysed.

Keywords:

• high birefringence
• fluorinated terphenyl
• liquid crystals
• vertical alignment