Chirality in Liquid Crystals - from Bent-cores to Chromonics

Chirality in Liquid Crystals - from Bent-cores to Chromonics PDF Author: Leah Elaine Bergquist
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Languages : en
Pages : 0

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Book Description
Chirality is a central scientific concept but its superstructural and nanoscale manifestation are not well understood, severely limiting the potential of materials in a range of emerging applications. In the first part of this dissertation, we examine a lyotropic chromonic liquid crystal (LCLC) forming a nematic phase for its more intense response to gold nanoparticles capped with chiral L-cysteine ligand molecules than to their free molecular counterparts. We show that such nanoparticles induce a tighter chiral twist within, and similar among, the stacks of nematic LCLCs but with several orders of magnitude fewer chiral molecules. The second part of this dissertation focuses on the SmCP phase and the development of an optically isotropic antiferroelectric liquid crystal (OI-AFLC) display mode. This report describes in detail the synthesis and characterization of a series bent-core liquid crystal (LC) systems. Multi-component mixtures of these compounds achieved room temperature switching between optically isotropic and birefringent states; several mixtures displayed a modulated SmCaPA phase extending from below -40 °C up to about 100 °C. Requiring high fields and showing slow switching speeds, their utility is found in non-video-rate switching applications requiring high contrast.