borosilicato

Borosilicate glass, sometimes referred to as borosilicato in some languages, is a type of glass in which a portion of the silicon dioxide (SiO2) is replaced by boron trioxide (B2O3). This modification yields a glass with a relatively low coefficient of thermal expansion and improved resistance to thermal shock, compared with conventional soda-lime glass.

Key properties include a low thermal expansion (roughly 3 × 10^-6 per kelvin), high resistance to thermal stress, good chemical durability, and clear optical transmission in the visible range. It also offers high heat resistance, allowing containers and components to withstand rapid temperature changes common in laboratory and industrial settings.

Manufacture and composition: Borosilicate glass is made from silica with boron oxide as a glass former, along with small amounts of alkali metal oxides and aluminum oxide to tune properties. It is formed using standard glass-making techniques such as melting, blowing, pressing, and then annealed to relieve stress.

Applications: It is widely used for laboratory glassware (flasks, test tubes, condensers), chemical processing equipment, and specialty cookware in some markets. It is also employed in lighting, electronics components, and certain architectural glazing where thermal stability is advantageous.

History and branding: The development of borosilicate glass is attributed to 19th–early 20th century glassmakers, including Otto Schott. It gained prominence under brands such as Corning's Pyrex and SCHOTT's DURAN, which market borosilicate grades for scientific and industrial use. Today it remains a standard material for applications requiring thermal and chemical resistance.