Question

what are the methods of preparation of carbon nanotubes?​

Answer 1

Answer:

This is the correct answer

Answer 2

Carbon nanotubes are prepared by methods Current ARC method, Laser ablation , Steam Chemical Deposition Method etc.

• carbon nanotubes were observed in 1991 by Sumio Lijima (LIJIMA, 1991) during surface studies of graphite electrodes used in an electric discharge method for fullerene synthesis.

• It was discovered that this material has excellent mechanical, electrical and thermal properties, high surface area, among other properties, curiosities and a huge range of applications
• Carbon nanotubes are generated in cylindrical form by means of graphite layers (ROCHA), and can be divided into two groups, single wall carbon nanotubes (SWNTs) and multiple wall carbon nanotubes

Current ARC Method (Arc Discharge)

• The arc and current method was used by Lijima in the discovery of carbon nanotubes.

• It consists of an electric discharge of two electrodes (anode and cathode) of graphite inside a steel chamber, containing inert gas at high pressure

Method by Laser Ablation

• This process consists in the evaporation of a graphite billet by the application of a high power laser beam in an inert gas chamber (He or Ar) at a temperature of up to 1200 ° C.
• With the laser reaching the graphite billet, occurs the evaporation of the carbon, following the gas flow until it is deposited in the copper collector (cooler part of the quartz shell) or in the tube walls

Steam Chemical Deposition Method (CVD)

• The CVD (Chemical Vapor Deposition) method enables the production of large-scale carbon nanotubes (ZARBIN; OLIVEIRA, 2013).
• It consists of the catalytic deposition of the carbon that is generated from a carbon containing gas inside an oven with temperatures of 500 °C to 1100 °C in the presence of a metal catalyst.
• As in the laser ablation method, CVD also occurs inside a quartz tube.

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