During the Spring Festival of the Dog, the Chengdu Museum of Sichuan Province held a grand exhibition of "Afghanistan Treasures." It took only four days to attract more than 50,000 people to visit the site. This exhibition promotes the cultural exchange between the East and the West and the development of the Belt and Road Initiative. Among the exhibits, there are a large number of glassware from the archaeological site of Begram, Afghanistan. As a typical product of the Roman Empire, the patterns on these glassware were very beautiful, which fully demonstrated the outstanding craftsmanship of glassmaking at that time. In addition, imitation jade, jade, coral and other glass bottles, bowls, nose and other glassware, not only vivid colors, with a unique style and charm, its surface pattern is often bright spots. So how are the patterns on the surfaces of these glassware made? Stained glass products in the Afghan Treasure Show. (Network diagram) The glass is stable, not afraid of hydrochloric acid, sulfuric acid, and aqua regia. It also withstands alkali corrosion. At the same time, the glass itself is hard and it is generally cut with diamond or other alloys. Obviously, it is not easy to engrave patterns on glass. "One thing falls." When the glass hits hydrofluoric acid, it will be corroded. Because fluorine is an active element, it can react chemically with almost all elements. Fluorine and hydrogen combine to produce hydrogen fluoride, and hydrogen fluoride dissolves in water to become hydrofluoric acid. Hydrofluoric acid (HF) is an anaerobic acid formed by halogen elements. It has a very strong corrosiveness and chemical reactions occur when it encounters glass. How does hydrofluoric acid react with glassware? Originally, glassware was mostly made of soda lime silicate glass, and its main component was silicon dioxide. Silica is a colorless, transparent or white powder with a high melting point, hard and infusible, and insoluble in water. Natural silica, commonly known as silica, is one of the constituents of rock. Silica encounters hydrofluoric acid and generates volatile silicon tetrafluoride gas and water.
The glass is then eroded into frosted glass. The chemical formula of the reaction between the two is: SiO2+4HF==SiF4+2H2O The beautiful home glass etched on the surface. Hydrofluoric acid is the "craftsman" that etched glass. Using this characteristic of it, various beautiful patterns can be carved on the glass craftwork. The specific method is to dip the glassware into the molten paraffin first, then cut the pattern into a pattern with a knife, apply hydrofluoric acid, or put it into hydrogen fluoride gas for corrosion. When the residual hydrofluoric acid is washed away and paraffin is scraped off, a beautiful pattern is left on the glassware. This method is also used to scale or add to the inner surface of glass chemical instruments such as measuring cylinders and burettes. Laboratory glassware. (Network diagram) In the industry, acid polishing is widely used to make different effects on the glass surface. Before acid polishing, that is, before hydrofluoric acid is applied, the glassware is soaked in different acids to make it work better. . As a side note, because hydrofluoric acid can corrode glass, do not store hydrofluoric acid in glass containers.