Thermo-reversible liquid-crystal gels : towards a new processing route for twisted nematic displays

Thermo-reversible gels of the liq.-crystal system LC-TL 213 with 12-hydroxyoctadecanoic acid (HOA) were cast in a twisted nematic (TN) configuration that is switchable by a.c. elec. fields. Crit. in this process was to choose a processing temp. higher than the sol-gel temp. but lower than the nematic-isotropic transition of the system. The latter condition originates in the phase diagram of the system which displays a monotectic-type point at which a liq. is in equil. with a solid and a mesophase. The solid-like nature of the gels produced, combined with their electrooptical activity, opens the possibility to manuf. flexible TN cells via continuous processes as an alternative to the currently employed batch-type methods. [on SciFinder (R)