Graphene Structure, Physical Properties, And Fabrication Methods

In 1779, Carl Wilhelm Scheele showed another allotrope of carbon graphite, which were known as a form of lead in early times. He found out that graphite was almost identical to charcoal except a small admixture of iron, and when it oxidized with nitric acid, it gave out “aerial acid” (carbon dioxide). In 1786, the French scientists Claude Louis Berthollet, Gaspard Monge and Vandermonde confirmed that graphite was mostly carbon by oxidizing with oxygen in the same way

Carbon has six total electrons; two of the electrons it has are in its first electron shell while the other four are its valence electrons. Due to its four valence electrons, it rarely gains and/or loses electrons and/or form ionic bonds due to the fact it would have to give away or take four other electrons. In order to complete its outer shell, carbons shares its valence electrons with other atoms by having four separate covalent bonds. The carbon atom then becomes the crossing point where each molecule branches off into four separate directions.Carbon’s electron configuration allows it to bond frequently with oxygen, hydrogen, nitrogen, and phosphorus. If the carbon atom forms only a single covalent bond, The electrons form so that its bonds angle towards an imaginary tetrahedron.

You must have a picture that shows the structure of the element (number of protons, neutrons, and electrons) and the shell pattern of the electrons.

This paper will discuss the new glassy carbon discovery. This is done by giving a brief background about the glassy carbon and its uses, as well as the diamonds that can be made of

Ever since graphene has been found, scientists began to wonder how the substance will play a huge role in our future. Predicting which sector graphene can improve is easy. With the prior knowledge from previous experiments, the characteristics found could be used to formulate a list of industrial sectors where the specific characteristics would be useful. However, the experimentation for these hypotheses require countless amount of experimentation. In most cases, graphene would be mixed with several other useful materials to create a composite material. These added materials could make the composite material stronger, lighter, harder, etc. Unfortunately, these added materials may also bring in unfavorable changes. Furthermore, nobody

2a) Many characteristics allows carbon to be the base of biological molecules. Due to the four valance electrons carbon can bond with up to four other electrons in covalent bonds. This allows carbon to become the central point for many macromolecules. Carbon is also relatively small in size and is readily available on Earth. Carbon can also bin to other carbon atoms and can make single, double, or triple bonds. Due to this, long strings of carbon atoms can be created with seemingly no limit. The carbon-carbon bonds easily allow similar macromolecules with different functional groups. The shape of carbon-based macromolecules also easily vary. Shapes such as chains, rings, and branches are commonplace. With variance of shape, carbon can be the base for isomers; molecules with the same formula but different structures. Carbon is the only element on the periodic table that uniquely has all these characteristics.

A single layer of graphene does not create significant photoresponsivity, however, with two layers and a tunnel barrier in between, the top layer becomes electrically charged and transfers this response to the bottom layer as seen in Figure 2. This anomaly is known as a photogating effect and it produces a unique photoresponsivity over an extensive spectral range (Zhong 1). It is capable of absorbing 2.3% of white light in just one layer of graphene. The charge that it creates in the top layer is amplified and these charged electrons tunnel through the insulating barrier performing a quantum tunneling effect.

What is graphene? According to Merriam-Webster, graphene is defined as “an extremely electrical conductive form of elemental carbon that is composed of a single flat sheet of carbon atoms arranged in a repeating hexagonal lattice

Different structural arrangements in the carbon atoms determine the outcome of the mineral. Diamonds are the hardest mineral; they are formed under a covalent bond which is very strong. Graphite on the other hand is one of the softest; it is held with a softer bond. Despite the difference in structure, both of these minerals are made from the same substance, pure carbon.

Graphene is the basic structural element of carbon allotropes such as graphite, charcoal, carbon nanotube and

The three forms of carbon found freely in nature are the amorphous, graphite, and diamond, and each form has vastly different properties.

Diamond is made up of repeating units of carbon atoms joined to four other carbon atoms by a covalent bond

Carbon is able to form covalent bonds with hydrogen and other atoms because it has four valence electrons. Because carbon needs eight total electrons when its orbital is filled, it needs to form four more bonds with other atoms. Also, since it is able to form bonds with four other atoms, carbon has the potential to form single, double, or triple bonds.

Graphene is a form of carbon which has recently been receiving a great deal of attention. Some have come to call it “the wonder material” due to its many extraordinary properties. Although isolated in 2004, graphene's properties had been calculated decades earlier. It consists of a single layer of carbon atoms arranged in a hexagonal lattice. A single sheet of graphene is stronger than steel and yet remains very flexible, retaining all of its properties despite being bent and unbent multiple times. It is able to sustain extremely high electric current densities, is impermeable to all gasses, has a thermal conductivity double that of diamond and a very high electron mobility at room temperature. It is also easily chemically functionalized,

The existence in the same physical state of two or more structural forms of the same element is known as allotropy. Allotropes of carbon are the ability of carbon to exist in various forms in the same physical state. Carbon can exist in three different allotropic forms. These are diamond, graphite, and amorphous or non crystalline. Diamond and graphite form the crystalline carbon.