摘要:
A method of forming a polymer dispersed liquid crystal (PDLC) film is disclosed which consists of forming a solution of LC dissolved in a monomer, photopolymerizing the solution to form a film having a dispersion of LC bubbles therein, establishing a correlation between the LC bubble size and selected characteristics of the film, selecting a LC bubble size corresponding to desired film characteristics, and controlling the conditions of photopolymerization to achieve said LC bubble size. The LC bubble size is controlled by means of the UV exposure intensity, exposure temperature, exposure wavelength, LC concentration and/or concentration of polymerization initiator. Correlations are noted between LC bubble size and the resulting film's threshold and operating voltages for optical transmission, contrast ratio, absolute transmissivity and electro-optical response times. Special types of films, including in situ gratings and holograms, are obtained by periodically varying the conditions of polymerization over the film to produce a corresponding periodic spatial variation in the LC bubble size; different processes used to achieve this result are noted. Films with LC bubbles in a new size regime that significantly decreases the operating voltage threshold, and with gradients in the bubble size, are also disclosed.
摘要:
A method of forming a polymer dispersed liquid crystal (PDLC) film is disclosed which consists of forming a solution of LC dissolved in a monomer, photopolymerizing the solution to form a film having a dispersion of LC bubbles therein, establishing a correlation between the LC bubble size and selected characteristics of the film, selecting a LC bubble size corresponding to desired film characteristics, and controlling the conditions of photopolymerization to achieve said LC bubble size. The LC bubble size is controlled by means of the UV exposure intensity, exposure temperature, exposure wavelength, LC concentration and/or concentration of polymerization initiator. Correlations are noted between LC bubble size and the resulting film's threshold and operating voltages for optical transmission, contrast ratio, absolute transmissivity and electro-optical response times. Special types of films, including in situ gratings and holograms, are obtained by periodically varying the conditions of polymerization over the film to produce a corresponding periodic spatial variation in the LC bubble size; different processes used to achieve this result are noted. Films with LC bubbles in a new size regime that significantly decreases the operating voltage threshold, and with gradients in the bubble size, are also disclosed.
摘要:
A liquid crystal cell useful in light valves is disclosed in which positive anisotropy liquid crystals are installed at an initial off-perpendicular alignment within the approximate range of 6.degree.-45.degree.. A light valve employing the cell is initially biased to a voltage approximately corresponding to a transmissivity peak; the selection of the exact bias voltage involves a trade-off between contrast and response speed. The cell surfaces are characterized by generally flat macrostructures and tilted surface microstructures, with an overcoat on the surfaces of a long chain alcohol with alkoxy groups derived therefrom bonded to the tilted surface microstructure. The alcohol molecules have the formula ROH, where R is a carbon chain having at least six carbon atoms therein.
摘要:
Liquid crystals are induced to assume substantially perpendicular alignment on the surfaces of substrates used to fabricate electro-optical device by causing long chain alcohols to react in the vapor phases with surface OH.sup.- inherently found on oxide coatings provided on the substrates. The process facilitates liquid crystal alignment in prefabricated electro-optical cells.
摘要:
A method for making batteries wherein the extraction step includes extracting plasticizer using phase shifting of supercritical carbon dioxide. In addition, contacting the extracting cells with pressurized carbon dioxide throughout the fabrication process encourages the formation of a solid electrolyte interphase layer.
摘要:
An improved package for photopolymerized recording materials is disclosed. The package consists essentially of a cover plate, a substrate spaced apart from said cover plate, at least one of the said cover plate or said substrate having a coating on an internal surface of a photopolymerizable compound or a catalyst therefore, and fluid ingress means for introducing fluid into the space between said cover plate and said substrate. In a particularly preferred embodiment the ingress means is associated with a collapsible vessel located outside the basic package. Also disclosed are methods for using the package such as in holographic nondestructive testing.