Morphology and Electro-Optic Study of Polymer Stabilized Liquid Crystal Dispersed Composites

Abstract

First chapter begins with introduction of liquid crystal phases and structure–property relationships of the LC monomers with polymers. We reviewed their physical properties, electro-optic properties; effect of alignments, molecular architecture and past literature of the work is discussed in this chapter and an effort has been made to explore the experimental study related to nanoparticles doped Polymer/Liquid Crystal soft templates and their uses for developing novel electro-optic shutter devices. The effects of photo sensitive CdSe quantum dots and silica nanoparticles on the morphology and electro-optic properties of an optically active polymer stabilized liquid crystal shutter was investigated with the help of various charachterization techniques such as scanning electron microscopy (SEM), polarizing optical microscopy (POM), Polarized photoliminescence (PL). The dopant nanomaterial manuplates the PL intensity of fluorescence during emission fluorescent polymer stabilized liquid crystal gel, which was tuned electrically. It presents the electricaly induced liquid crystal orientations and hence make them suitable for switchable electro-optic device. Our results showed the birefringence in liquid crystal, director configuration and droplet shape can be controlled with the help of dopant nanoparticles concentration, which explores the dependence of fluorescence scattering, dielectric and electro-optic properties of liquid crystal displays. Also novel Guest–host polymer stabilized ferroelectric liquid crystal composite films have been developed to create molecular ordering in fibrils network by polymerization-induced phase separation process. Ordered twisted fibril morphology was clearly observed through optical polarizing microscope and thus we determined the order parameter from the dichroism measurements with the help of polarized fluorescence spectroscopy, which impacts the significant contribution of dye molecules into the smectic layers of the host polymer stabilized ferroelectric matrix. The electrical and dielectric properties of polymer stabilized ferroelectric liquid crystal mixture and its guest–host derivatives were well studied. Our results showed that an optimum dye concentration (0.1 wt%) enhances the dielectric permittivity as well as spontaneous polarization of the guest host PSFLC material in the SmC*phase. In summarize, we have developed many supramolecular Polymer/LC/nanomaterials composites which bridges nanotechnology with liquid crystal display technology. This coupling of polymer, liquid crystal and nano-science can create a promising new fields aiming at the discovery of novel soft materials, which can be helpful in designing novel electro-optic switchable displays.