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Liquid Crystal Display Chemistry
The Williams domain PAA liquid crystal could be electrically controlled to produce dark and light, but had a nematic range of 117° to 134°C; Heilmeier’s DSM, although demonstrating that the APAPA liquid crystal could indeed serve as a display medium, also has a nematic liquid crystal phase melting temperature (Tm) of 116°C, requiring heated platforms, which made both liquid crystals clearly impractical for use in consumer products. Furthermore, they were not chemically stable when exposed to water and ultraviolet light, and they had relatively high viscosities.
These problems, together with Asada’s order to the Sharp engineers to develop a practicable calculator together formed an acknowledgment that the liquid crystal in a general use liquid crystal display must satisfy at least the following four criteria:
1. below zero to body temperature operating range;
2. hydrolytic and chemical stability;
3. low viscosity; and
4. colorless.
The four requirements can be abbreviated collectively as the “TSVC” (temperature-stability-viscosity-color) conditions. The objective was clear, but the search to find and develop a liquid crystal that could satisfy those criteria was to be long and arduous.
The Aromatic Compounds
The molecular structure of an organic compound is described by the line/angle formula, wherein the endpoints or intersections denote the presence of a carbon atom, and the associated hydrogen atom is denoted by an “H,” or its presence ...
