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How does alumina affect the properties of aluminosilicate glass?
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industrial glass
Examining a superhydrophobic glass surface that resists fog and glare and is self-cleaning.
In the context of industrial glass, alumina (aluminum oxide, ) acts as an intermediate oxide that significantly influences the properties of aluminosilicate glass. Its primary effects include:7
- Chemical Durability: The addition of small amounts of alumina (typically 2 to 3 percent) enhances the chemical durability of glass containers. Furthermore, aluminosilicate glasses with relatively high alumina content exhibit exceptional resistance to alkalis and can withstand exposure to hot sodium-metal vapors.12
- Thermal Properties: Alumina contributes to the high-temperature performance of glass. Aluminosilicate glasses are capable of standing higher operating temperatures compared to borosilicate glasses.2
- Structural Role: In the glass network, aluminum can occupy tetrahedral sites, allowing it to be incorporated into the silicate polymerization scheme, which helps stabilize the glass structure.3
While alumina is a key component in these specialized glasses, it is also used in the glass industry for refractories—the materials used to line furnaces for firing glass—due to its high melting point, strength, and volume stability at elevated temperatures.4