Polymer-stabilized thermotropic liquid crystal device

Abstract

A resizable polymer-stabilized, thermotropic liquid crystal device formulation is used in passive or active light-regulating and temperature-regulating films, materials and devices, including construction materials. Implementations of the device may be composed of five basic elements: one or more transparent substrates, a transparent surface treatment, a liquid crystal mixture, a stabilizing polymer, and spacer beads. The polymer-stabilized liquid crystal is coated and cured on at least one substrate. The transparent surface treatment and the stabilizing polymer network are selected to provide phase separation, curing, and adhesion within the LC mixture. The substrate or substrates may be polarizing or nonpolarizing.

What is claimed is: 
     
         1 . A resizable polymer-stabilized, thermotropic liquid crystal device comprising
 a transparent substrate;   a mixture of liquid crystal components coating the substrate and having a clearing point within a typical range of atmospheric temperatures and a freezing point below an expected minimum atmospheric temperature;   a means to define a thickness of the coating of the mixture of liquid crystal components; and   a stabilizing polymer provided in conjunction with the mixture of liquid crystal components on the substrate that cures under the influence of an external stimulus and that is distributed throughout the mixture of liquid crystal components to form a plurality of walls that define a plurality cells, each wall enclosing a portion of the mixture of liquid crystal components within the cell that is defined by the wall.   
     
     
         2 . The device of  claim 1  further comprising a surface treatment provided on the substrate that promotes polymer adhesion with the substrate and that is wholly or partially transparent or translucent to one or more wavelength bands. 
     
     
         3 . The device of  claim 1 , wherein the stabilizing polymer adheres to the substrate, the surface treatment, or both. 
     
     
         4 . The device of  claim 1 , wherein the means to defineing the thickness comprises a plurality of micro-scale spacers distributed within the mixture of liquid crystal components. 
     
     
         5 . The device of  claim 1  further comprising
 a transparent opposing substrate; and 
 a surface treatment provided on the substrate and the transparent opposing substrate that promotes polymer adhesion with the substrate and the transparent opposing substrate and that is wholly or partially transparent or translucent to one or more wavelength bands; wherein the means to define the thickness comprises a plurality of micro-scale spacers distributed within the mixture of liquid crystal components; and 
 the opposing substrate is placed over the mixture of liquid crystal components, the micro-scale spacers, and the stabilizing polymer on the substrate and adhered to the stabilizing polymer. 
 
     
     
         6 . The device of  claim 2 , wherein the surface treatment functions as an alignment layer for the mixture of liquid crystal components. 
     
     
         7 . The device of  claim 2 , wherein the surface treatment is an integral feature of the substrate. 
     
     
         8 . The device of  claim 2 , wherein the surface treatment comprises an application of one or more of the following materials to the substrate: ethyl cyanoacrylates, methyl cyanoacrylates, thiol-ene adhesives, diacrylates, triacrylates, methacrylates, urethane acrylates, acrylated epoxies, polyimides, polystyrenes, vinyl polymers, fluoropolymers, ionenes, polyalkenes, nylons, and polyesters. 
     
     
         9 . The device of  claim 1 , wherein the stabilizing polymer is distributed throughout the mixture of liquid crystal components. 
     
     
         10 . The device of  claim 1 , wherein the stabilizing polymer is formed in a pattern on the substrate. 
     
     
         11 . The device of  claim 9 , wherein the mixture of liquid crystal components is miscible with the stabilizing polymer and the stabilizing polymer forms a matrix within which the mixture of liquid crystal components is retained. 
     
     
         12 . The device of  claim 1 , wherein the stabilizing polymer is phase separated from the mixture of liquid crystal components. 
     
     
         13 . The device of  claim 5 , wherein the stabilizing polymer is positioned about an outer perimeter of the mixture of liquid crystal components and seals an outer edge between the substrate and the opposing substrate. 
     
     
         14 . The device of  claim 1 , wherein the means to defineing the thickness comprises patterned protrusions on a surface of the substrate. 
     
     
         15 . The device of  claim 1 , wherein the external stimulus comprises one or more of light, heat, or ultraviolet radiation. 
     
     
         16 . The device of  claim 1 , wherein the mixture of liquid crystal components is stable upon exposure to ultraviolet radiation. 
     
     
         17 . The device of  claim 5 , wherein the stabilizing polymer network provides partial or total retention of the mixture of liquid crystal components within the substrate and the opposing substrate. 
     
     
         18 . The device of  claim 1 , wherein the mixture of liquid crystal components is suitable for use in guest-host devices. 
     
     
         19 . The device of  claim 1 , wherein the mixture of liquid crystal components has a clearing point between 0° C. and 50° C. 
     
     
         20 . The device of  claim 1 , wherein the stabilizing polymer includes a photoinitiator or a thermal initiator.