The synthesis of novel liquid crystal materials designed for electro-optic displays

Carr, Neil

Abstract

Liquid crystals represent a fourth state of matter whose properties are intermediate between those of a crystalline solid and an amorphous isotropic liquid. Over recent years, the general area has progressed from a small academic field to the present situation involving worldwide interest from many different standpoints, primarily because of the applications of thermotropic nematic liquid crystals in electro-optic displays.
Nematic liquid crystals are well suited for such applications as they uniquely combine the fluid nature of an isotropic liquid with the anisotropic properties of more ordered systems, and it was within the general area of nematics that this work was undertaken.
The current micro-electronic revolution has meant that the new materials of the early 1970's now present significant problems and limitations relating to their use in some of the more sophisticated display applications. Consequently, there is a great demand for a superior generation of liquid ’crystals to meet this need.
The broad objectives of this work involved the synthesis of novel materials to try and improve the properties of existing systems, and to carry out this work in a reasonably systematic manner such that the properties (physical and electro-optic) could, as far as possible, be related to molecular structure.
Over twenty-five different structural types were examined, and in many cases useful properties were observed. These structural types were derived from variations in .the ring system [benzene, naphthalene, biphenyl, trans-cyclohexane, bicyclo(2.2.2] octane), the terminal (alkyl, alkoxy, hydrogen, cyano) and lateral (hydrogen, fluorine) substituents, and the inter-ring linkage (-CH2O-, single bond, -C0.0-, -CH2CH2-). The best of these materials do in fact exhibit superior properties compared with some commercial materials. Furthermore, in some cases, it has been possible to relate the properties to molecular structure, whilst in other cases ideas are developed concerning those properties that are less well understood.

Citation

Carr, N. The synthesis of novel liquid crystal materials designed for electro-optic displays. (Thesis). University of Hull. https://hull-repository.worktribe.com/output/4240447

• Thesis Type: Thesis
• Deposit Date: Mar 15, 2023
• Publicly Available Date: Mar 15, 2023
• Keywords: Chemistry
• Public URL: https://hull-repository.worktribe.com/output/4240447
• Additional Information: Department of Chemistry, The University of Hull
• Award Date: 1984-06