Improved dc dynamic scattering with redox dopants in ester liquid crystals

Abstract

Redox dopants are used to improve the dc dynamic scattering (DS) characteristics of phenyl benzoate liquid crystals as compared to the use of salt-type conductive dopants. The redox dopants are selected by their electrochemical properties so that they react preferentially and reversibly at the electrodes, thus providing the current carriers for the dc-DS effect. Low-threshold voltages (∼2 V), high scattering efficiency (99% at 20 V), and long dc-DS lifetimes (up to 18 000 h) are obtained with an ester liquid crystal containing a redox dopant pair consisting of di-n-butyl-ferrocene and (2,4,7-trinitro-9-fluorenylidene) malononitrile.