| Popis: |
Liquid crystal displays are widely used in many electronic devices. To produce an image the displays are electronically addressed through complex electrode patterning. The electrode patterning is costly due to the development of drive chips and software and adds to the bulk of the display in order to house the control circuitry and power supply. In effort to reduce the cost of cholesteric displays, the development of a photocontrolled cholesteric state was undertaken. Such a state would eliminate the need for electronic control, enabling the display to be optically addressed by the addition of a photochemically tunable chiral dopant. This work focuses on the synthesis of 4-({2,2'-[(4-hydroxyphenyl) diazenyl]-1,1'-binaphthalenyl} diazenyl)phenol and modified derivatives for use as photochemically tunable chiral dopants in cholesteric displays. In detail, the synthesis, characterization and preliminary evaluation of the materials as dopants are reported. Some doped mixtures exhibit a tunable Bragg reflection of over 2,500 nm, while others have been optimized to only have tunable reflection within the visible spectrum. The details of a prototype display based on the properties of these materials are also included. |
