Oriented LC-microdroplets in polymer matrices: prospects of application

To obtain oriented LC-polymer composites, in a first step randomly oriented (micro-) separated systems are produced by physical or chemical phase separation processes. The following step involves mechanical shearing or stretching. As a result, the composites become birefringent. Thin films of such material fabricated from nematic, cholesteric or smectic LC phases and doped with dichroic dyes are promosing for flexible displays, effective non-absorptive polarizers, polarization-sensitive light shutters, etc. In particular, we investigated the electro-optical properties of numerous PDLC (Polymer Dispersed Liquid Crystals) films constituted of micron-sized LC droplets and tested their morphological stability. Uniaxially oriented composite films were produced by a special mechanical unit. The effect of polymer matrix, LC concentration and stretching regime were studied. Finally, the suitability of this composite material for field controlled light modulation is discussed.