Fluorescent dye guest-host effects in advanced ferroelectric liquid crystals

Abstract

Previous work has shown that guest-host ferroelectric systems incorporating dichroically absorbing dyes are suitable for use in colour display applications. These utilize either the dichroic absorption of a conventional dye, or the emission of a fluorescent dye. We present here the electrooptical properties of several advanced ferroelectric liquid crystals doped with a new fluorescent dye, coloured blue in emission. The data consists of measurements of tilt angle, response time, spontaneous polarization, and rotational viscosity, from which we conclude that certain hosts are not adversely affected by the fluorescent dopants. These results are then discussed in connection with the use of these mixtures in two novel colour display configurations, which are also presented, utilizing either the dichroic absorption or the polarized fluorescence of the fluorophore guests.

Coumarin-based emissive liquid crystals

“…[52][53][54][55] However, the guest dye typically has a limited solubility in the host mesogen and, at high concentrations, often disrupts mesophase formation. [56,57] On the other hand, it is well established that the in-situ photopolymerisation of oriented reactive liquid crystals provides an excellent, versatile and facile method to produce anisotropic films. [58] This method has already been applied to produce oriented luminescent films.…”

New 4-(2-(4-alkoxyphenyl)-6-methoxypyridin-4-yl)benzonitriles: synthesis, liquid crystalline behavior and photo physical properties

“…Luminescent liquid crystals (LLCs) have received significant attention because of their favorable molecular self-assembly with intrinsic light generation capabilities. Because of these unique properties they are quite useful in novel optical device applications such as emissive LC displays, [1][2][3][4] polarized dye lasers, [5][6][7] anisotropic organic light-emitting diodes (OLEDs), [8][9][10] and ordered electron transport systems. 8,11 In this context, several molecular architectures involving rod-, bent-, or discshaped arrangements have been designed and reported in the literature as active LLCs for device applications.…”