It is reported that foreign professionals are developing new types of glass through the following two approaches. The first is to change the material itself by changing the content of a component in the glass. The Asolvex type I glass recently created by Saint-Gobain was obtained by reducing the Al2O3 content in the
glass bottle. The second is to coat the surface of the glass with a thin coating of auxiliary properties to improve its surface functional properties. In recent years, with the increasingly fierce competition in the packaging materials market, the demand for glass products in the industry has also become higher and higher. It is a general trend to improve glass production processes and develop new types of glass.
Asolvex glass is a new type I glass. Type I glass is borosilicate glass and has chemical resistance. The content of Al2O3 in the glass component of Asolvex is reduced by 50% compared to the ordinary type I glass, and the content of silicon is increased accordingly, which makes the precipitation of Al2O3 greatly reduced. With normal non-ionized water, even a 75% reduction in sodium gluconate solution (Al2O3 precipitation rate corresponds to a 20 ml injection vial held at 125°C for 25 minutes).
This significant reduction in Al2O3 precipitation makes it possible to obtain new packaging materials because this property is applicable to products that are sensitive to trace metals, such as enzymes or products without preservatives and moderators. The application potential of this material is huge, especially for blood products, nutritional products, biological agents and genetic engineering drugs.
In addition, glass can be coated with any material such as metals, semiconductors, polymers, and the like. Coating a thin coating with a thickness ranging from 1 nm to 1 μm is a relatively simple and inexpensive method that can effectively change the properties of the glass surface, especially its cracking strength and moisture resistance.
Although the crack resistance of glass is relatively low, its internal fiber strength is very high. The reason why glass breaks down is that it is fragile because there is a very small (less than 1 micron) defect on the surface from which the cracks extend. Production can not completely avoid defects, but it can reduce or partially reduce this defect. This can be achieved by treating the glass surface with a very thin layer of a solution of a silicon-containing organic compound. Therefore, glass-like silicon molecules react with glass to form a solid network, which becomes a solid coating that adheres to the glass surface and can effectively fill surface cracks.
The tests showed that the cracking strength of these glass bottles increased by 1.5 to 2 times after the treatment of organic compounds containing silicon, and the existing research will further improve these treatment effects. In the future, mankind is expected to produce almost unbroken glass bottles. tank.
Some of the performance advantages of glass surfaces make the glass hydrophilic, which should be avoided in some cases. For example, in the field of pharmaceuticals, avoiding its hydrophilic nature can make it easier for people to empty all the medicines in glass bottles. Saint-Gobain has launched a research program to solve this problem. The surface of the glass was treated with a single layer of hydrophobic molecules having a number of C-F chemical bonds (thickness of the size of the molecular diameter) so that the water wetting angle reached 120°. The person concerned experimented with plant leaves, analyzed the surface under an electron microscope, and simulated the structure, adopting a nanometer-sized spiked structure to preserve the transparency of the glass surface. Experiments have found that water droplets (visible refractions) appear to be suspended on the glass surface, which is undoubtedly a good news for the development of non-wettable glass.
Reprinted: Chinese bottle net
December 01, 2022
