How much do you know about all kinds of glass in your life?
With the development of the modern information society, people's lives are inseparable from the optical fiber that transmits signals. At present, the optical fiber used is generally quartz glass fiber. The main method for producing the glass material is to melt high-purity quartz glass into a melt in a high-temperature furnace, and then to extrude the melt into a hollow having a diameter of about 100 μm. The elongated filaments give the optical fibers. When light is incident on the glass fibers at a suitable angle, the light travels along the curved glass fibers, so it is called an optical fiber. In 1966, British-Chinese scientist Gao Wei theoretically proved the feasibility of using optical fiber as a medium to realize optical propagation signals. Today, optical fiber has become a widely used communication material.
Light-related glass also has photochromic glass. The photochromic glass changes from a colorless and transparent state to a dark color under sunlight or strong light; the discolored glass is placed in a dark place and becomes a colorless and transparent state again. The secret of its color change is the addition of silver bromide (or silver chloride) and traces of copper oxide to the glass. Silver bromide decomposes under strong light to produce silver atoms and bromine atoms (or chlorine atoms). Silver atoms can absorb visible light. When the amount of silver atoms produced reaches a certain amount, most of the visible light that is irradiated on the glass will not be Absorption, at this time the glass is grayish black; the blackened glass is placed in the dark, and the silver atom and the bromine atom (or chlorine atom) combine to form silver bromide (or silver chloride) under the catalytic action of copper oxide. The glass again becomes a colorless and transparent state. Photochromic glass is often used as a lens for color-changing glasses, and it can also be used to make windows that soften the sunlight entering the room during the summer. In recent years, there has also been a new type of color-changing glass, electrochromic glass, which can be stably and reversibly discolored under the action of an electric field. This glass can change color under human control. There are already glass curtain walls made of electrochromic glass in buildings.
There is also a glass that is essential in our lives, that is, borosilicate glass. Speaking of the name of this glass, you may not be familiar with it, but the utensils made with it are what we use every day, that is, the glass of water that people drink. Compared with ordinary glass, borosilicate glass has the advantages of high temperature resistance, low expansion ratio, high strength and high hardness. Therefore, a water cup made of borosilicate glass is not easily broken in the case of rapid cooling and rapid heat. Moreover, the main material for making the glass pot is also borosilicate glass.