The principle of color-changing glass
Color glass under the appropriate wavelength of light irradiation to change its color,and remove the light source is to recover its original color of the glass. Also called photochromic glass or light color glass.Add light color glass is the glass raw material material. This material has two different molecules or electronic structure state, in the visible light region there are two different absorption coefficient,in under the action of light, can shift from one structure to another kind of structure, cause of reversible color change,
common containing silver halide color glass, aluminum in sodium borate glass to add a small amount of silver halide (AgX) as a sensitizer, add trace copper and cadmium ions as a sensitizer, after melting made of glassWhen it is irradiated by ultraviolet or short-wave visible light,the silver ion is reduced to silver atoms, and some silver atoms gather into colloids to make the glass display color.Light stopped, the thermal radiation or longer wavelengths (red light or infrared), silver atoms into silver ions and fade. The characteristics of silver halide color glass is not easy to fatigue,after more than 300000 of light and shade change, still not failure, is a commonly used material color glasses. Color glass can also be used for information storage and display, image conversion, control and adjust the light intensity, etc.Contains silver bromide (or silver chloride) and trace copper oxide is a kind of color glass. When sunlight or ultraviolet light, the decomposition of silver bromide, produce silver atoms (AgBr = = Ag + Br.) attract visible silver atomic energyLight, when silver atoms is gathered in a certain number, shot in the forward part of the glass is absorbed, originally colorless transparent glass then it becomes a film. When the glass into the dark, after color change under the catalysis of copper oxide, silver and bromine atoms can combine into a silver bromide (Ag + Br = = AgBr), because silver ions do not absorb visible light, so the glass will become colorless transparent. This is the basic principle of color glass discoloration.
