We investigated the dynamics of photoinduced nematic-isotropic transition especially the back relaxation time and its influence on three different parameters. The parameters are (a) Order parameter: the temperature dependence of the response time was calculated in a material exhibiting a photostimulated isothermal Nematic-Isotropic transition. Using a simple description we show that the temperature dependence of this response time can be understood in terms of the order parameter excess between the equilibrium and photostimulated states. (b) Electric field: application of an electric field accelerates the recovery of trans isomers from the photoinduced cis isomers. An important consequence of this effect is the rapid return of the equilibrium nematic phase from the photo-driven isotropic phase of liquid crystals. (c) Confinement: by confining liquid crystals in an in situ created network of aerosil particles. The DSC scans taken at slower rates for a particular composite in the soft gel regime have a two-peak profile across the N-I transition. In contrast, the bulk has a single peak at all rates investigated. The double peak profile is associated with a crossover from random-dilution to random-field regime. The dielectric measurements, which are the first such measurements on the photoisomerization-driven isothermal phase transitions in LC-aerosil composite bring out several interesting features including the dependence of the photo-driven shift in the transition temperature and the response time on the concentration of aerosil.
Achieving adhesion on plastic materials needs not only good photoaligning materials but also it needs lot of optimization in the production process. Here we are going to attempt to solve this problem by utilizing biocomposite mixture. Proposed method is cost effective and also easy to use.
We present two LCD modes enabling short rise and fall switching time, being in the microsecond range in most of the
modes. Polymeric network, created in the liquid crystal bulk, as well as in the presence of flexoelectric polarization are
among those employed for achieving of fast switching modes in LCDs. Proper assembling and electronic driving of two
parallel liquid crystal cells, arranged in a double cell configuration, is another approach enabling a fast switching mode
between bright and dark state of the device. We discuss these modes in terms of device performance and their suitability
for application in LCDs.