24 facts about silver
Silver is one of the first metals discovered by man, it has been known since antiquity. The Egyptians valued them more than gold. It was used to make ...
This increasingly popular material, which is a flattened form of carbon arranged in cubic structures, may revolutionize our world and the state of current science. Its very wide properties give it almost unlimited applications. Thanks to graphene, lighter and more durable materials can be created for the space, aviation, automotive, and construction industries. It also plays a significant role in electronics, telecommunications, medicine, environmental protection, etc. Graphene has been difficult to obtain for a long time. In 2008, its market price reached $100 million per 1 square centimeter, making it the most expensive substance on earth.
Allotropy is the phenomenon of the existence of different varieties of the same chemical element in the same state of matter, differing in their physical and chemical properties. Allotropic varieties of an element may differ in their crystal structure or the number of atoms in the molecule.
In nature, it occurs in large quantities in basically only three allotropic varieties: graphite, diamond, and amorphous carbon (hard coal, soot). They differ in the arrangement of carbon atoms in the crystal lattice-in each of these varieties, the carbon atoms are connected differently.
As a result, diamond is a transparent, non-reactive insulator, and graphite is a black conductor, susceptible to chemical modifications.
In graphite, each carbon atom is connected to three other atoms and all these bonds lie in one plane, creating a spatial network resembling a honeycomb (carbon atoms connect to form hexagons). Such layers spontaneously stack one above the other, and the distance between them is about two and a half times greater than the length of the carbon-carbon bond. Therefore, these layers are easy to separate from each other. This happens when we use a pencil - each trace of it is exfoliated layers of graphite, and graphene is such an exfoliated layer.
The term “graphene” appeared in the 1960s. In 1961-1962, Hans-Peter Boehm published a study of extremely thin graphite flakes and termed them “graphene” for the hypothetical single-layer structure.
This was only proven through research at the beginning of the 20th century, In 1947, the first theoretical description of graphene was created by Philip Russel Wallace. However, due to the two-dimensional nature of graphene, it was believed that this type of material could not function in nature.
They isolated layers of graphene from graphite using ordinary adhesive tape. They placed a graphite crystal on adhesive tape and repeatedly connected and separated different pieces of it until the thickness of the graphite reached only one atomic layer. For this discovery, both scientists received the Nobel Prize in physics in 2010.
Research has expanded and divided into many different subfields, examining various unique properties of graphene-quantum mechanics, electrical, chemical, mechanical, optical, magnetic, etc.
In 2014, the National Graphene Institute was established at the University of Manchester for this purpose. Two commercial manufacturers began production in the north-east of England, and Cambridge Nanosystems is a large-scale graphene powder production facility in the east of England.
The key date is 2011 when the Institute of Electronic Materials Technology together with the Faculty of Physics of the University of Warsaw confirmed the development of a modern technology for obtaining large sheets of very high-quality graphene.
In 2015, the Lodz University of Technology officially presented its device for producing graphene from the liquid phase. This technology was patented in the European Union and the USA in 2016.
China and the United States are currently leading the graphene market, which is worth billions.
This is a major obstacle to graphene finding mass application in many fields. For now, only small amounts are produced.
Graphene can be used to produce new types of screens (touch or liquid crystal), solar panels, and computers.
All modern devices are based on silicon semiconductors, but it is expected that the industry will soon reach the end of the ability to miniaturize silicon systems, and then graphene will become necessary.
Very high-quality graphene could be combined with other materials, e.g. rubber or plastics, which would give these materials completely different values-e.g. adding graphene to rubber would make it conduct heat.
It shows therapeutic potential as a drug carrier. It can also be used in tissue engineering because it has antibacterial properties, which makes it a suitable material for use in various biomedical fields, such as tissue differentiation, regeneration, and treatment of inflammation.
This property is used in an innovative method of pain treatment (local heating of tissues to a temperature of about 80 degrees Celsius destroys nerves responsible for pain in the human body).
Pain-relieving graphene heating pads, heated graphene clothing, and other graphene thermal devices are already being produced. Their use helps, among others: patients suffering from back or knee pain.
By adhering to cancer cells, it creates a thin layer around them, which cuts off oxygen and nutrients. This ultimately leads to the death of cancer cells.
It records brain activity at frequencies below 0.1 Hz. Tests of brain activity in such ranges provide a high possibility of predicting the probability of an epileptic seizure and stroke. This device is biocompatible, so it guarantees proper functioning in the body. The graphene sensor can also switch to stimulation mode during operation, which is used during speech rehabilitation.
Graphene can be used to create microprocessors a thousand times more efficient than those we know today. Its transparency and excellent conductivity make graphene suitable for producing transparent, rolled-up touch displays and for producing renewable energy from photovoltaic modules and storing it in high-performance batteries or supercapacitors.
Graphene sensors can register the presence of a single molecule of a harmful substance, which is why they are used, for example, in monitoring or environmental protection.
