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How does boric oxide change the properties of borosilicate glass?
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Examining a superhydrophobic glass surface that resists fog and glare and is self-cleaning.
Boric oxide (BβOβ) significantly alters the properties of borosilicate glass by acting as a flux, which lowers the working temperature of the glass during production.1
When incorporated into a silica-based glass, boric oxide provides several key physical and chemical advantages:
- Thermal Stability: It imparts a low coefficient of thermal expansion, making the glass much less susceptible to fracture from thermal shock compared to standard soda-lime-silica glass.12
- Chemical Durability: The substitution of boric oxide, along with small percentages of alkali and alumina, increases the chemical stability of the material.1
- Electrical Properties: Borosilicate glass exhibits high dielectric strength.1
- Mechanical and Optical Traits: It maintains a high softening temperature and, when present, allows for the transmission of X-rays.1
In industrial applications, such as the manufacturing of domestic cookware or laboratory equipment, these properties are achieved by replacing a portion of the sodium oxide (a flux) and lime with boric oxide and alumina.12