Introduction of glass

Glass is an amorphous inorganic non-metallic material, generally made of a variety of inorganic minerals (such as quartz sand, borax, boric acid, barite, barium carbonate, limestone, feldspar, soda ash, etc.) as the main raw material, and a small amount of auxiliary raw materials are added. of.

Its main components are silicon dioxide and other oxides. [1] The chemical composition of ordinary glass is Na2SiO3, CaSiO3, SiO2 or Na2O·CaO·6SiO2, etc. The main component is silicate double salt, which is an amorphous solid with irregular structure.

It is widely used in buildings to separate wind and transmit light. It is a mixture. There are also colored glass that is mixed with certain metal oxides or salts to show color, and tempered glass made by physical or chemical methods. Sometimes some transparent plastics (such as polymethyl methacrylate) are also called plexiglass.

For hundreds of years, people have always believed that glass is green and cannot be changed. Later, it was discovered that the green color came from a small amount of iron in the raw materials, and the compounds of divalent iron made the glass appear green. After adding manganese dioxide, the original divalent iron turns into trivalent iron and appears yellow, while the tetravalent manganese is reduced to trivalent manganese and appears purple. Optically, yellow and purple can complement each other to a certain extent, and when mixed together to become white light, the glass will not cast color. However, after several years, the trivalent manganese will continue to be oxidized by the air, and the yellow will gradually increase, so the window glass of those ancient houses will be slightly yellow.

General glass is an amorphous solid with irregular structure (from a microscopic point of view, glass is also a liquid). Its molecules do not have a long-range orderly arrangement in space like crystals, but have a short-range order similar to liquids. sequence. Glass maintains a specific shape like a solid, and does not flow with gravity like a liquid.


Post time: Sep-14-2021

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