Borosilicate glass
K S Sugi 14 -5 -16
1 Introduction:
Glass is a non-crystalline amorphous solid that is often transparent and have widespread applications.
The most familiar, and historically oldest, type of glass is "silicate glass.”
Most common type of silicate glasses are
Fused quartz
Soda-lime-silica glass
Lead-oxide glass
Aluminosilicate glass
2
Borosilicate glass:
Borosilicate glass is a type of glass with silica and boron trioxide as the main glass- forming constituents.
It contains silica 81% + boric oxide (B2O3) 12% + soda (Na2O) 4.5% + alumina (Al2O3) 2.0%. Classification:
Non-alkaline-earth borosilicate glass(borosilicate glass 3.3)
Boron trioxide is 12 –13% and SiO2 80%.
High chemical resistance and low thermal expansion (3.3 × 10–6 K−1) makes this a multitalented glass material.
3 Alkaline-earth-containing borosilicate glass
SiO2 - 75% and B2O3 – 8 –12%, alkaline earths and alumina (Al2O3) 5% .
Softer glasses which have thermal expansion in the range (4.0–5.0 × 10–6 K−1).
High-borate borosilicate glass
B2O3 – 15 –25% , SiO2 – 65 –70%, and smaller amounts of alkalis and Al2O3 as additional components.
low thermal expansion.
4 History:
First developed by German glassmaker Otto Schott in the late 19th century and was sold under the brand name Duran since 1893.
Later Corning Glass Works introduced Pyrex in 1915, the name became a synonym for borosilicate glass in the English-speaking world.
Now, borosilicate glasses are known under trade names Otto Schott (1851 – such as Simax, Borcam, Borosil, Suprax, Kimax, Heatex, Pyrex, 1935), the pioneer of Endural, Schott, or Refmex, Kimble. modern glass science and technology
5 Manufacturing process: Manufacturing process depends on the product geometry.
Floating
Molten raw Fed to tin Floating glass Annealed and cut materials bath ribbon using machine
Vello process
For preparation of tubes.
6 Moulding/Molding
Precision glass moulding is a process used for Molten glass which is collected in production of high precision optical components hollow pipes is expanded by blowing from glass without grinding and polishing. process through pipes.
7 Physical properties:
The common type of borosilicate glass used for laboratory glassware has a very low thermal expansion coefficient (3.3 × 10−6 K−1), about one-third that of ordinary soda-lime glass.
Thermal shock resistance.
Resistant to chemical corrosion, making it perfectly suitable for laboratory experiments.
The temperature differential that borosilicate glass can withstand before fracturing is about 165 °C (329 °F) whereas soda lime glass only a 37 °C (99 °F).
8 Material Optical crown glass Borosilicate glass Fused quartz
Refractive Index 1.5251 1.473 1.4 – 1.5
2.2 g/cm3 2.55 g/cm3 2.23 g/cm3 Density
E=71.5 x103 N/mm2 E=64 x103 N/mm2 Modulus of elasticity 73x106 Kpa
Coefficient of Thermal 33 x 10-7/K 5.3 x 10-7/K 95 x 10-7/K Expansion
170 to 2700 nm 320 to 2500 nm Useable optical range 334 to 2500 nm
9 Applications:
In medical field they are used as ampoules, dental cartridges implantable medical devices such as prosthetic eyes, artificial hip joints, bone cements, dental composite materials.
Pipe coolants in electronic equipments.
Semiconductor industry for the development of MEMS.
Microwave- and dishwasher-safe cook wares.
Used as envelope for high intensity lamps.
Used to make mirror components and lenses of optical instruments.
Tubing made of borosilicate glass protects an advanced camera that shoots in 360 degrees.
10 Gorilla glass is a brand of specialized toughened glass developed and manufactured by Corning, designed to be thin, light and damage-resistant. They are used in smart phones and rear windshields.
Crown glass is a type of optical glass used in lenses and other optical components. It has relatively low refractive index (≈1.52) and low dispersion.
Kodial glass used as view ports of UHV is a borosilicate glass.
Disadvantages:
.Can react with NaH to form NaBH4.
.Borosilicate glass can still crack or shatter when subjected to rapid or uneven temperature variations.
.Hydrofluoric acid can etch borosilicate glass.
.Cant heat with phosphoric acid or strong alkaline solutions. 11 References:
https://en.wikipedia.org/wiki/Borosilicate_glass
https://apaviata.com/advantages-of-borosilicate-glass/
http://www.glasswaretales.com/what-is/borosilicate-glass
http://www.schott.com/magazine/english/sol109/sol109_01_125years.html
https://www.google.co.in/#q=crown+glass
http://www.corninggorillaglass.com/
12 13