Graphene is pure carbon in the form of a very
thin, nearly transparent sheet, one atom thick. It is remarkably strong for its
very low weight (100 times stronger than steel) and it conducts heat and
electricity with great efficiency. While scientists had theorized about
graphene for decades, it was first produced in the lab in 2004. Because it is
virtually two-dimensional, it interacts oddly with light and with other
materials. Researchers have identified the bipolar transistor effect, ballistic
transport of charges and large quantum oscillations.
Technically, graphene is a crystalline allotrope of carbon with 2-dimensional properties. In graphene, carbon atoms are densely packed in a regular sp2-bonded atomic-scale chicken wire (hexagonal) pattern. Graphene can be described as a one-atom thick layer of graphite. It is the basic structural element of other allotropes, including graphite, charcoal, carbon nanotubes and fullerenes. It can also be considered as an indefinitely large aromatic molecule, the limiting case of the family of flat polycyclic artomatic hydrocarbons.
Graphene research has expanded quickly since the substance was first isolated in 2004. Research was informed by theoretical descriptions of graphene's composition, structure and properties, which had all been calculated decades earlier. High-quality graphene also proved to be surprisingly easy to isolate, making more research possible. Andre Geim and Konstantin Novoselov at the Univesity ofManchester
Graphene is the only form of carbon (and generally all solid materials) in which each single atom is in exposure for chemical reaction from two sides (due to the 2D structure). It is known that carbon atoms at the edge of graphene sheets have special chemical reactivity, and graphene has the highest ratio of edgy carbons (in comparison with similar materials such as carbon nanotubes). In addition, various types of defects within the sheet, which are very common, increase the chemical reactivity. The onset temperature of reaction between the basal plane of single-layer graphene and oxygen gas is below 260 °C and the graphene burns at very low temperature (e.g., 350 °C). In fact, graphene is chemically the most reactive form of carbon, owing to the lateral availability of carbon atoms. Graphene is commonly modified with oxygen- and nitrogen-containing functional groups and analyzed by infrared spectroscopy and X-ray photoelectron spectroscopy. However, determination of structures of graphene with oxygen- and nitrogen-containing functional groups is a difficult task unless the structures are well controlled.
In 2013,Stanford University
Technically, graphene is a crystalline allotrope of carbon with 2-dimensional properties. In graphene, carbon atoms are densely packed in a regular sp2-bonded atomic-scale chicken wire (hexagonal) pattern. Graphene can be described as a one-atom thick layer of graphite. It is the basic structural element of other allotropes, including graphite, charcoal, carbon nanotubes and fullerenes. It can also be considered as an indefinitely large aromatic molecule, the limiting case of the family of flat polycyclic artomatic hydrocarbons.
Graphene research has expanded quickly since the substance was first isolated in 2004. Research was informed by theoretical descriptions of graphene's composition, structure and properties, which had all been calculated decades earlier. High-quality graphene also proved to be surprisingly easy to isolate, making more research possible. Andre Geim and Konstantin Novoselov at the Univesity of
Chemical
Graphene is the only form of carbon (and generally all solid materials) in which each single atom is in exposure for chemical reaction from two sides (due to the 2D structure). It is known that carbon atoms at the edge of graphene sheets have special chemical reactivity, and graphene has the highest ratio of edgy carbons (in comparison with similar materials such as carbon nanotubes). In addition, various types of defects within the sheet, which are very common, increase the chemical reactivity. The onset temperature of reaction between the basal plane of single-layer graphene and oxygen gas is below 260 °C and the graphene burns at very low temperature (e.g., 350 °C). In fact, graphene is chemically the most reactive form of carbon, owing to the lateral availability of carbon atoms. Graphene is commonly modified with oxygen- and nitrogen-containing functional groups and analyzed by infrared spectroscopy and X-ray photoelectron spectroscopy. However, determination of structures of graphene with oxygen- and nitrogen-containing functional groups is a difficult task unless the structures are well controlled.
In 2013,
Applications
While as of 2014,
graphene is not used in commercial applications, many have been proposed and/or
are under development, in areas including electronics, biological engineering,
filtration, lightweight/strong composite materials, photovoltaics and energy
storage. Graphene is produced as a
powder and as a dispersion in a polymer matrix, or adhesive, elastomer, oil and
aqueous and non-aqueous solutions. The dispersion is stated by the manufacturer
to be suitable for advanced composites, paints and coatings, lubricants, oils
and functional fluids, capacitors and batteries, thermal management
applications, display materials and packaging, inks and 3D-printers’ materials,
and barriers and films.
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