There are many different types of glass with different properties achieved through different types of forming.
Some of the types of glass used in windows are:
Heat resistant glass used in windows has aluminium added.
Radiation resistant glass has barium added.
Electrical/Chemical resistant glass has the sodium removed.
Also, glass used in light bulbs has magnesium added, and glass used for containers has aluminium added.
Frosted glass is an opaque glass used for privacy made through the process of either sand blasting or acid etching (often hydrofluoric acid), however some frosted glass also known as privacy glass can be turned on and off using an electrical current; two plates are placed on either side with micro-droplets in between, when a current is put through the plates the micro-droplets align themselves one end to the positive plate and one to the negative, this allows light to pass through, however once turned off the micro-droplets scatter which blocks the light from passing through.
There is also the new ‘smart glass’ on Boeing 787 planes that has the special property of being dimmable, this type of glass is achieved by placing a clear gel between two pieces of glass, and by pushing an electrical current through that gel the chemical structure is changed. Quite often the chemical used in the gel is tungsten oxide.
There are also oxide glasses, most of which use oxygen to form links in the network
Then there is transition lenses, transition lenses use a special kind of glass and chemical mixture to obtain a type of glass that is sensitive to ultraviolet light.
Glass is also a non-crystalline structure comprised of 90% crystal making it ideal for use in science, for things such as, chemical glassware, lenses for micro and telescopes as well as for valves in electronics.
Regular glass is comprised of mainly silica (SiO2) and soda (Na2O) and can hold most acids except for hydrofluoric acid.
It can hold this acids because of its very low level of reactivity. This type of glass is clear.
Transition lenses use a chemical compound known as naphthopyrans which change when in the presence of ultraviolet light
(fig 2.2); when UV light is present the molecule exhibits photochromism by which the O-CR1R2 bond is separated. Then
once the ultraviolet light is removed they return to their original state with the O-CR1R2 bond returned.
Using a gel consisting of an electrosensitive chemical that as the current and voltage increases so too does the level and degree of tint, this type of glass is most commonly found on board the new Boeing 787 Dreamliner.
Electric Frosted Glass
Using two electrically charged plates and micro-droplets, the electrical plates when stimulated aligns all of the micro-droplets which allows light to seamlessly pass through, when that stimulus is removed, often in the form of electricity, the micro-droplets scatter into random patterns which in turn block 80% of light from passing through, this achieves an opaque effect.
The different types of glass have shown to have different properties as a result of different molecular structures.
Every type of glass has positives and negatives, for instance bulletproof glass has the property of being bullet resistant, however, it is quite heavy; or privacy glass is quick to change and has the ability to be both opaque and transparent, however, it requires an electrical current to be on in order for it to be transparent.
These different types of glass allow us to use one type of molecule, in this case glass, for a range of different things that’s why glass is such a crucial part of chemistry and day-to-day life worldwide.
Glass is a great compound/molecule used in many areas of the world around us, from radiation glass in outer space to the simple window on the front of your house, glass is used in everything. Glass is one of our main building materials due to its transparent properties as well as it unreactive nature. We then add or subtract different elements which in turn also change the properties of the glass, e.g. adding barium makes regular glass radiation resistant, or removing the sodium makes it electrical resistant. We have so many uses for glass worldwide and yet we have only dipped our foot in the giant ocean of possibilities for glass.
There are many different types of glass in our world ranging from bullet-proof (resistant) to transition lenses, all of which have their own properties and chemical structures.
Glass is a structure formed using liquid sand which is mainly comprised of silicon dioxide. Liquid glass is achieved by melting sand at its average melting point of 1700ºC. The process that gives glass the property of changing shape is known as melt-quenching. Once both of these have been achieved and the glass has reached molten point, the glass is then shaped using the mould from which that glass is for, alternatively the extra’s are added for the different types of glass in order to obtain desired properties as mentioned below.
...(download the rest of the essay above)