| In the present dissertation, we have summarized the recent research progress of ionic liquid crystals (ILCs) and liquid crystalline ionomers (LCIs). Based on the molecular design of chemical structures and mesogenic groups, we have successfully synthesized a series of azobenzene-containing ILCs and LCIs as well as self-assembled supramolecular materials. The chemical structures of ILCs and LCI were carefully examined, and thermotropic liquid crystalline behaviors and self-assembled structures were investigated.1. Alkylammonium salts with variable alkyl chains were synthesized by reaction of an azobenzene mesogen with1-iodoalkanes. They were found to form thermotropic liquid crystals with various optical textures under polarized light. Their clearing temperatures decrease while melting temperatures increase with increasing the alkyl tails of AzoCn (n≤4), and tend to be constant with n>4. The ordering of lamellar organization for AzoCn gradually decreases with increasing the length of alkyl chain, and the textures of AzoCn salts transfromed from the smectic phase into the nematic phase.2. The resulting functional alkylammonium salts were coupled with poly(ethylene sulfonate) via ion exchange to acheive thermotropic LCIs. The smectic fan-like focal conic textures were clearly observed under polarized light. However, the ionic interaction limits the flow of mesogenic units. As a result, these LCIs directly changed from liquid crystal state to glass state upon cooling, and no clearing temperatures were observed during heating until they underwent thermal decomposition.3. The conjugated ionic compound containing perylene units (PTAS-AzoCl) has been successfully synthesized by ion exchange reaction of potassium perylenetetracarboxylicate with a typical ILC. Driven by the strong interaction of π-π stacking, PTAS-AzoCl molecules were self-assembled into multilayer supramolecular structures with the length of up to40μm and width of12μm in the thickness range of70to150nm. |
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