Materials Chemistry and Physics

Materials science is one of the most quickly emerging sciences, that were formed in relatively recent times. Although materials have since always been a very important part in our lives, they become subject of more extensive scientific research in the 19th and 20th century. Throughout history humans have used materials that they found in the nature, for example stone and wood. With time, we learned to make and use metals, like copper and iron, and many alloys derived from these metals, like bronze. Some materials, like gold, were and are still used extensive in jewelry because of its unique coloration among metals, and the inability to corrode, which makes it stable for long periods of time. It is also important to mention steel as one of also relatively recent materials, that, we could say without exaggeration, started a whole new industrial revolution on its ow, because of many applications that were found for this material with time.

Today, we are using many new types of metals, like aluminium and titanium, and alloys that contain the mentioned metals, which are mostly very strong, and at the same time, have a relatively low density, so they are mostly very light. As a example of a typical metallic alloy, we will mention a material known as steel, which is a basically a material that, in most cases, contains up to 5% of carbon that, in the combination with iron, forms a very hard iron carbide. In the process of hardening, the metastable structure is created, which is the main reason of the hardness of steel. Steel is a metal that is produced in very large quantities and it is getting more and more difficult to produce enough of this material, and because of that, in its production, the steel industry leans towards easier and cheaper process. After leaving the furnace, steel almost always goes to the refining process in which impurities that might have a negative effect on its properties, are released. In doing so, some other metals can be added instead (if we have a case of further alloyed steels). Although there are some problems related to steel, it is still one of the most important and most commonly used materials that humans use as to this date.

Also, today, we have a great amount of organic materials like polyethylene (PE), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and many others. All these materials are products of extensive research done in the domain of materials science, but also the science of chemistry that is a very important part of materials science. As an example of a organic material, we could mention a plastic material known as celluloid which is considered to be the first man-made thermoplastic material. It can be easily shaped and molded, and in the start, it was most well known for being a replacement for ivory. The early types of celluloid were highly flammable and easily decomposed, which often presented a risk, but with time, new formulas have been created in which some additional compounds are added to reduce flammability of this plastic. However, with time it was replaced with many other types of plastics that have better properties. Regardless of this fact, it remains one of the most important materials in the history of material technology. It is also interesting to mention that today celluloid is most well known to be the most common material used in production of guitar picks and table tennis balls.

There are also a lot of composite materials that have very interesting properties. Basically, these materials are produced by combining several different materials. A common example for such a material is armed concrete, which is composed of two materials: concrete and iron or steel bars inside of it. Glass could also be mentioned as a composite material, because often, it consists of many different components that often surpass the essential compounds that form basic glass as a material. Glass is a material in which sodium and calcium silicate prevail. Glass is very viscous liquid with a non crytalline structure, and it has no defined melting point. It is a poor conductor of heat. As the surface of the glass is always cooled faster than the interior, tension within the glass matter is created. With the help of rapid cooling of glass, one can achieve an extremely hard surface of the glass object. This kind of glass is resistant to shock, but with some limits however. Although it is very hard, when it breaks, it gets shattered into thousands of small pieces. This feature is used in auto industry, where a glue layer is added to this kind of glass. Because of that, in the moment of glass breaking, the glass breaks into small pieces, but they are held together with the help of the mentioned glue layer.

And finally, we will mention one more interesting invention that has been created by combining various discoveries from the domain of materials science, chemistry and physics – self darkening materials. These materials basically work by reacting to ultraviolet rays that come from the Sun. This principle was invented during the middle of the last century. The most well known property of the early versions of this type of glass was the relatively slow darkening or lightening period, and often, the level of darkness of the lenses would remain at some constant level after a certain time period. This however, wasn’t desirable, so with time, better lenses were developed. Basically, the principle remained the same, but the materials used for the substrate of the self darkening material were changed, along with the material that causes the darkening by itself.

Materials chemistry and physics are truly interesting domains of science, with still many things to be explored, researched, and learned about chemistry and properties of materials, and it will be interesting to see how things will evolve in this new branch of science.

Posted in Uncategorized | Tagged , | Comments Off