APPLIANCE WINDOWS COATED WITH THERMOCHROMIC POLYMER DISPERSED LIQUID CRYSTAL.

摘要

An appliance window coated with a thermochromic, polymer-dispersed liquid crystal (PDLC) material allows users of appliances containing such window to view the inside chamber of the appliance without opening the appliance door. The thermochromic material on the coated window also does not detract from the overall appearance of the appliance and is composed of phase-separated droplets of liquid crystal in a light-transmissive resin matrix. The liquid crystal has an optical index of refraction in the isotropic phase that is similar to the refractive index of the resin and an index of refraction in the liquid crystalline phase that is mismatched with the refractive index of the resin. The thermochromic coating is activated by the thermal energy released by the appliance during operation. The thermal energy raises the temperature of the coating to a sufficient value so as to cause the coating to switch from an opaque state to a clear state. When the temperature is reduced below a critical value, the coating switches back to the opaque state.