Properties of Carbon

Introduction: 

Carbon compounds can be found in everything, including the food we consume, the clothes we wear, and even the lead of the pencil we use to write. Carbon has an atomic number of 6 and a mass of 12.01gmol-1. The 14th group of elements in the Periodic Table is represented by the symbol C. It is the sixteenth most abundant element on the planet, according to the data. It can be found in both the free and combined states. 

Properties of carbon: 

Physical properties of carbon: 

1. Carbon is a one-of-a-kind element. It comes in a variety of shapes and sizes. Coal and soot are two examples of carbon in its purest form.

2. The colour is a smooth, drab grey or black.

3. Charcoal is one of the most important carbon compounds, which is generated when carbon is burned in the absence of air.

4. It can be found in a variety of allotropic forms. Allotropes are different types of an element having different physical and chemical properties.

5. The density of different kinds of carbon varies depending on their origin. 

Chemical properties of carbon: 

Carbon’s chemical characteristics govern how it reacts with other chemicals and transforms from one form to another. During chemical reactions, the chemical characteristics of carbon are detected. Carbon may be broken down into millions of different chemicals. Carbon is involved in four major reactions: 

1. Combustion reaction: When carbon is burned in the presence of oxygen, it produces carbon dioxide, heat, and light. The process of combustion is defined as the generation of heat and light by the burning of carbon in excess of oxygen. 

C (s) + ½O2 (g) → CO2 (g) + heat + light 

Unsaturated carbon creates soot and burns with a yellow flame, whereas saturated carbon burns with a blue flame. There are two types of combustion: complete combustion and partial combustion. 

2. Oxidation reaction: In the presence of oxygen, carbon and its compounds are oxidised. 

C (s) + ½O2 (g) → 2CO (g) 

Although all combustion reactions are oxidation reactions, they are not all oxidation reactions. 

3. Addition reaction: Carbon is capable of forming lengthy atom chains or strings. The additional reaction is what we call it. This process causes unsaturated substances to become saturated. 

C2H4 + H2 + (Nickel catalyst) → C2H6 

4. Substitution reaction: A substitution reaction occurs when one functional group in a molecule is replaced by a different functional group. 

CH3Cl + OH– → CH3OH + Cl– 

Anomeric carbon: 

The sugar’s hemiacetal or hemiketal carbon is the anomeric carbon. The addition of an alcohol to an aldehyde produces a hemiacetal carbon, which is attached to hydrogen, a R group, a hydroxyl group, and an alkoxy group (-OR). The addition of an alcohol to a ketone results in the formation of a hemiketal carbon, which is bonded to two R groups, a hydroxyl group, and an alkoxy group. During the cyclization reaction of a sugar from the open-chain to the cyclic form, the hemiacetal or hemiketal carbon is generated. 

Identification of anomeric carbon:

The Fischer projection and the Haworth projection are two popular projections for depicting sugars. A sugar in its open-chain form is shown using the Fischer projection. It is made up of a sequence of interconnected crosses, each with a stereocenter at its centre. A sugar in its cyclic form is depicted using the Haworth projection. It consists of a drawn ring with substituents pointing up or down perpendicular to the ring, thick lines flowing out of the page and thin lines going into the page. In a Haworth projection, groups projecting to the right in a Fischer projection will point down, while groups projecting to the left will point up. 

An anomeric carbon can be recognised in either the open-chain or cyclic form of the sugar. The anomeric carbon in the open-chain form is the carbon of the carbonyl group, which is either an aldehyde or a ketone depending on the sugar type. The carbon that was formerly part of the carbonyl group in the open-chain form but is now connected to a hydroxyl group and the ring oxygen in the cyclic form is known as the anomeric carbon. 

Carbon fibres: 

Carbon fibres are fibres with a diameter of 5–10 micrometres and are largely made up of carbon atoms. High stiffness, good tensile strength, low weight, high chemical resistance, high temperature tolerance, and minimal thermal expansion are only a few of the benefits of carbon fibres. Carbon fibre is widely used in aircraft, civil engineering, military, and motorsports, as well as other competitive sports, due to its unique qualities. However, when compared to similar fibres such as glass or plastic fibres, they are quite pricey. 

Structure of carbon fibres: 

Carbon fibre has an atomic structure similar to graphite, consisting of sheets of carbon atoms arranged in a regular hexagonal pattern (graphene sheets), with the distinction being how these sheets interlock. Graphite is a crystalline material in which the sheets are arranged in a regular pattern parallel to one another. The intermolecular forces between the sheets are Van der Waals forces, which give graphite its soft and brittle properties. 

Classification and types of carbon fibres: 

Carbon fibres are divided into three categories based on their precursor fibre materials: 

• PAN-based carbon fibres

• Pitch-based carbon fibres

• Mesophase pitch-based carbon fibres

• Isotropic pitch-based carbon fibres

• Rayon-based carbon fibres

• Gas-phase-grown carbon fibres  

Applications of carbon fibres: 

1. Carbon fibre  is most commonly used to strengthen composite materials, particularly the carbon fibre or graphite reinforced polymers class of materials. 

2. Carbon fibres can also be encased in non-polymer materials as a matrix. Carbon has had limited success in metal matrix composite applications due to the development of metal carbides and corrosion concerns. 

3. Reinforced carbon-carbon (RCC) is a high-temperature structural material made out of carbon fibre-reinforced graphite. 

4. Carbon fibre microelectrodes are created using carbon fibres. For biochemical signalling detection, carbon-fibre microelectrodes are utilised in amperometry or fast-scan cyclic voltammetry. 

Conclusion: 

Carbon is the only element that can form tightly bound chains that are separated by hydrogen atoms. These hydrocarbons are generally used as fuels because they are extracted naturally as fossil fuels (coal, oil, and natural gas). A tiny but significant portion is utilised as a feedstock in the petrochemical industry, which produces polymers, fibres, paints, solvents, and plastics, among other things.