What do you know about glass?

What do you know about glass?
Glass is a common material in our life.
What common residence window glass uses is common glass, the main raw material of common glass is soda soda, limestone, quartz sand, this is the material that sodium silicate, calcium silicate and silica melt together to get.
When people produce ordinary glass, the raw materials are crushed, mixed in appropriate proportion and then put into the glass kiln to strengthen the heat. Complex physical and chemical changes take place after the melting of the raw materials.
Glass does not have a certain melting point, but is gradually softened over a range of temperatures.
When the glass is softened, it can be made into anything of any shape. Common glass bottles and glasses are made from ordinary glass.

Glass with different properties and uses can be made by adding different substances and adjusting their chemical composition in the process of glass production.
For example, the addition of boron oxide in the production of ordinary glass can improve the chemical stability of the glass, reduce the coefficient of thermal expansion, thus making it more resistant to high temperature and chemical corrosion, can be used in the manufacture of advanced chemical reaction containers.
In addition, the optical glass made by adding lead oxide has a high refractive rate and can be used to make eye lenses and lenses in cameras, telescopes and microscopes.
Also, colored glass can be made if certain metal oxides are added to the glass.
When cobalt oxide is added, the glass will appear blue.
When cuprous oxide is added, the glass will appear red.
Generally we see the ordinary glass is light green, this is because the raw material mixed with iron.

In addition, glass can be processed in a variety of processes.
For example, the ordinary glass turned into the toughening furnace heating, when close to the softening temperature, quickly removed from the furnace, and then with a cold wind blowing, can be made of toughened glass.
The mechanical strength of toughened glass is 4-6 times larger than ordinary glass, anti-seismic crack, not easy to break.
Toughened glass after broken, broken pieces without sharp edges and corners, not easy to hurt.

Color changing glass is used as window glass to soften the light coming through under the hot sun, and can also be used to make solar lenses.
Color changing glass is a glass containing silver bromide (or silver chloride) and a trace amount of copper oxide.
When the glass is irradiated by sunlight or ultraviolet light, the silver bromide in the glass will decompose to produce silver atoms, which can attract visible light. When the silver atoms gather in a certain number, most of the visible light shining on the glass will be absorbed.
At this time, the original colorless transparent glass will become gray black.
When the discolored glass is placed in a dark place, the silver and bromine atoms combine to form silver bromide, catalyzed by copper oxide.
Because the silver ions do not absorb visible light, the glass will again become colorless and transparent, which is the basic principle for changing color of glass.

Among them, the characteristics of photochromic glass is that the color and transmittance of glass automatically change with the intensity of sunlight.
Intensity of sunshine is high, the color of glass is dark and the transmittance is low.
On the contrary, the sunshine intensity is low, the color of the glass is light, and the transmittance is high.
Photochromic glass is generally used in doors, Windows and curtain walls of buildings.