Comparison of electro-optical switching between polymer-stabilised cubic and amorphous blue phases

Abstract

We prepared polymer-stabilised cubic and amorphous blue phase liquid crystals consisting of the same materials at different UV-curing temperatures using photopolymerisation. Then we investigated the effects of polymer stabilisation on their physical properties. The UV-curing temperature does not affect phase stabilisation of the polymer-stabilised amorphous BPIII (PS-BPIII). Temperatures of the PS-BPIII were found to be extended to more than 50 K. However, a critical temperature exists in the polymer stabilisation process for the PS-cubic BP. Although no substantial difference in response speed was found between the polymer-stabilised cubic and amorphous structures, larger hysteresis and higher residual birefringence were observed in the PS-cubic BP than in the PS-BPIII. Amorphous BPIII with an amorphous network of disclination lines has no critical temperature for the polymer stabilisation and realises a high-performance display.

Keywords:

• liquid crystal
• blue phase
• amorphous
• polymer stabilisation
• display

Additional information

Funding

This work was supported by a Grant-in-Aid for Scientific Research [grant number 25107702] on the Innovation Areas: ‘Fusion Materials’ [area number 22006] from MEXT.