What is Graphene?
Graphene is the name given to one of the honeycomb braided structures of the carbon atom. One of the most interesting elements in the periodic table is the Carbon atom. In addition to the well-known allotropes of carbon, such as graphite and diamond, there are also newly synthesized forms such as nanotubes and fullerenes. Graphene's groundbreaking character lies primarily in its two-dimensionality. Physically, it is a layer of single carbon atoms arranged in a hexagonal arrangement that visually resembles a honeycomb. Graphene is therefore an allotrope of carbon.
History of Graphene
In the 1940s, Phillip Russel Wallace developed the theoretical concept of creating a monoatomic carbon structure. However, this idea has been rejected by most scientists for many years. Sixty years later, it has not been transformed into real, tangible material. Gejm and Nowosiolow at the University of Manchester managed to isolate graphene from a graphite stack by transferring carbon atoms to a silicon dioxide (SO 2 ) layer using an adhesive tape. Silica played an important role in this process, insulating a sheet of graphene with a neutral electrical charge. This method is currently used on a small scale for research purposes only.
Graphene is a form of carbon in which carbon atoms are arranged hexagonally and consist of two-dimensional surfaces. It can be used in many products due to its flexible structure. As a single-atom-thick, 2-dimensional nanomaterial, it is shown as one of the most critical components of nanotechnology.
Graphene's Unusual Properties
Graphene has proven to be an extremely good conductor of heat and electricity. It is also characterized by low active resistance. In this respect, it is a competitor for copper and silicon. At room temperature, graphene electrons show mobility not seen in other materials. Their high speed, up to 1/300th of the speed of light, opens up interesting possibilities for use in diagnosis. Graphene is also nearly transparent – it absorbs 2.3% of white light. Therefore, the extraordinary electric potential goes hand in hand with the optical one. It also provides a high level of flexibility (stretchability up to 20% in length or width). An oxidized graphene membrane is completely impermeable to gases but permeable to water, so it can be used for filtration. The antimicrobial properties of the material are also noteworthy. Although it is very light, it has a structure 200 times stronger than steel. It conducts electricity very well.
Since 2014, graphene has been produced on a larger scale for commercial purposes. New micromechanical techniques provided a significant price reduction in material. Currently, the leading producers are the USA and China, where substantial quantities of inexpensive amorphous graphite can be found. Premium graphene desired in the electronics field must be produced from graphite of sufficient quality, and this requires flat, ordered crystals obtained in special machining. The price of the material is correspondingly higher. Korean researchers have succeeded in developing an efficient and cost-effective way to produce graphene by chemical vapor deposition (CVD). The disadvantage of this solution is lower material quality and higher error frequency. However, in some applications, this is not a problem. Poles also contributed to the development of innovative graphene production methods. The Institute of Electronic Materials Technology in Warsaw holds a patent for producing the material from silicon carbide. In 2015, researchers from the University of Lodz in Poland developed a breakthrough HGSM technology that enables the production of high-quality large-format sheets from the liquid phase.
Is Graphene Safe?
As a relatively new material, graphene raises understandable doubts regarding its possible effects on human health. There are even claims that graphene's thin and light structure easily enters the lungs and poses a threat comparable to dust and even asbestos fibres. Chinese studies even suggest that two-dimensional carbon nanoparticles could lodge in internal organs. There is also a theoretical risk that graphene could enter surface and ground waters and be harmful to plants and animals. Fine particles can settle at the edges of water bodies and increase water hardness levels. However, according to current information, graphene is not toxic and has nothing to do with hazardous materials. Their amount, and thus potential exposure, is also extremely low or even negligible. It does not show irritant properties in contact with skin. Also, international studies show that inhalation does not cause adverse immunological reactions.
Below you can examine the images of graphene taken with AFM produced by NanoMagnetics Instruments.