Silica is a major constituent of glass used in bottles, windowpanes, etc. But the glass used in specialized technical applications and fiber optics does not contain silica. In fact, it is the absence of silica that is making it useful in these applications.
The glass that does not contain silica includes chalcogenide glass, phosphate glass, borate glass, fluoride glass, and aluminosilicate glass. In addition to this classification, the glass is further classified into different types of oxide glass.
The distinction is made on the basis of the degree of components like intermediates, modifier and network formers. The network formers consist of germanium, boron and silicon. They help the formation of an extremely cross-linked network of chemical components. Zinc, magnesium, beryllium, aluminum, titanium and zirconium form the intermediate.
While modifiers and network formers do not share any similarity in their nature, the intermediates share commonalities. They can act both as modifier and as network former. The modifier consists of calcium, potassium, sodium, lead and lithium. It has the capacity to change the structure of the network used.
The constituent ions are present in this type of glass. Ions consists non-bridging oxygen atoms. The glass network in the combination is bound by a single covalent bond and helps it release the negative charge.
Basically, there is no glass called ‘hydrophobic glass.’ Any of the glass mentioned initially (chalcogenide glass, phosphate glass, borate glass or fluoride glass) can act as hydrophobic. Studies indicate that glass, which does not contain silica, will be compatible with any coating. So, it is easy to transform a non-silica glass into hydrophobic. Hydrophobic glass is applied on a glass through chemical processes.
Furthermore, the presence of non-bridging oxygen in non-silica glass makes it more useful in applications. There are multiple reasons for this. Non-bridging oxygen lowers the melting temperature of the glass. It also decreases the viscosity the glass.
Glass that consists of alkali metal ions has more applications because of its compatibility with electrical conductivity. The electrical conductivity of this type glass reaches the highest level when the glass is put at high temperature.
Hydrophobic glass is used in several modern applications such as port windows, camera lenses, etc. Get in touch with an expert at Optical Coatings for more technical details on the type of glass for your needs.