01The difference and use of carbon and carbon

Due to the uniqueness of Chinese characters and the lack of attention paid to the difference and usage of "carbon" and "carbon" for a long time, people have been confused in the use of carbon and carbon for a long time, which can be seen clearly in many articles, books and the use of names. From a chemical point of view, carbon and carbon are strictly different in nature and use.

All pure compounds that can fully reflect the properties of carbon elements or carbon atoms, or that are composed of carbon atoms or carbon ions and other ions or ion groups, are always described and named with "carbon" beside the stone. Such as: carbon element, carbon atom, carbon 60, nano carbon, carbon isotope, carbide, aromatic carbon, naphthenic carbon, carbon mesh plane, aromatic carbon rate, primary carbon, terminal carbon, carbon dioxide, carbon content, carbon steel, carbon chain, carbon ring, carbohydrate, hydrocarbon, carburizing, calcium carbamate, carbonate, amorphous carbon, carbon element, other carbon compounds, etc.

For those that can not fully reflect the properties of carbon element or carbon atom, or the mixture composed of carbon atom or carbon compound, "carbon" is used in expression and name. Such as: charcoal, coal, coke, activated carbon, glass carbon, pyrolytic carbon, biochar, carbon brick, carbon block, carbon graphite material, carbon rod, carbon rod, carbon black, carbon paste, carbon plant, carbon technology, carbon process, carbon slag, carbon material, carbon society, carbon annual meeting, carbon electrode, carbon anode, carbon cathode, carbon paste, etc.

02Definition and classification of carbon materials

In a broad sense, carbon material is the general name of all pure carbon materials and carbon containing mixtures.

In a narrow sense, carbon material refers to the inorganic material obtained by using graphite or amorphous carbon as the main solid raw material, supplemented by other raw materials through a specific production process. In industry, the latter concept is generally adopted..

Carbon materials include carbon raw materials and carbon products.

Carbon raw materials mainly include coal, coke, petroleum coke, asphalt, coal tar, graphite, diamond, coal tar, etc.

There are many kinds of carbon products with different specifications, models and physicochemical properties. They are also widely used. Due to the different uses of the products, the raw materials and processing technology used are different, and the physical and chemical properties of the products are also significantly different.

According to the material, carbon products can be divided into carbon products, semi graphite products, natural graphite products and artificial graphite products. It can be divided into conductive materials, structural materials and special functional materials

（1）Conductive material

Such as graphite electrode for electric arc furnace, carbon electrode, natural graphite electrode, electrode paste and anode paste (self baking electrode), prebaked carbon anode, carbon cathode, graphite cathode, semi graphite cathode, graphite anode for electrolysis, mould materials for brush and EDM, carbon rod for dry battery, etc.

（2）Structural materials

For example, the lining of reduction furnace, ferroalloy furnace, calcium carbide furnace, side carbon brick of aluminum reduction cell, refining furnace and related refining furnace (also known as carbon refractory), deceleration material and reflective material of nuclear reactor, head or nozzle lining material of rocket or missile, corrosion-resistant equipment of chemical industry, wear-resistant material of mechanical industry, continuous casting of steel and non-ferrous metal smelting industry Graphite lining of crystallizer, carbon crucible, semiconductor and high purity material smelting device etc.

（3）Special functional materials

Such as biochar (artificial heart valve, artificial bone, artificial tendon), concealed aircraft materials, various types of pyrolytic carbon and pyrolytic graphite, recrystallized graphite, carbon fiber and its composites, graphite intercalation compounds, C60 family, nano carbon, etc.

03Three research hotspots of carbon materials

（1）Porous carbon materials

Porous carbon materials, from the perspective of energy, are mainly used in the electrode materials of electric double-layer capacitors and clean energy, and are the main carrier of clean energy hydrogen and natural gas storage. The former is to use the external voltage to effect metal ions to complete the storage function. This method can effectively convert the metal ions into electrochemistry by voltage, which greatly prolongs the cycle life of the metal ions and has a good development prospect. The latter uses the porous principle to adsorb its gas on the energy materials for storage. This method, especially at room temperature, can give full play to the storage function and realize its environmental storage.

（2）Carbon nanomaterials

Since the appearance of fullerenes, researchers have linked them with carbon nanotubes and studied them continuously, including hydrogen storage performance, electrochemical performance, field emission performance and filling enhancement performance. It is found that this kind of bonding material makes it have some properties field emission properties which are not possessed by traditional materials. Further attention should be paid to this kind of research. At present, the most research is the extraction and purification of nano carbon materials, the main principle is the use of acid and oxidation treatment.

The applications of carbon nanotubes include electronic devices, electrode materials, catalyst carriers, fillers, gas sensors, gas storage, noble metal extraction adsorbents, etc. It can be seen from the above that this kind of material will be used more and more widely, especially in the case of energy shortage, it can give full play to its effectiveness and get great attention.

（3）compound material

In the research of composite materials, the research on oxidation resistance is the most, which is consistent with the characteristics of carbon materials and the requirements of oxidation resistance in composite materials to a certain extent. Although carbon materials have certain oxidation resistance, with the increase of environmental temperature and oxidation resistance, the ablation rate of carbon materials increases significantly. As the ablation of carbon materials, its mechanical properties will gradually become worse and its service life will be shortened. At the same time, composite materials have excellent mechanical properties and heat resistance, and have been widely used in aerospace. In order to solve the problem of oxidation and ablation at high temperature, the current oxidation technology is mainly to add oxide layer on the surface of composite materials, mainly to carry out antioxidants on silicon carbide coating materials and composite coating composition.

The other important content of composite material research is its wear resistance, so as to improve the service life of composite materials, so that composite materials can be successfully applied to the research of friction materials. In order to achieve a good combination and enhance the physique, improve the comprehensive properties of the composite materials, enhance the surface modification treatment or the densification processing technology of chemical vapor infiltration composite materials in the use stage, which is also an important topic at present.