What are the Advantages and Applications of Carbon Nanotubes
A carbon nanotube is a tubular nano-carbon material with graphite crystals. As a nanomaterial, it is very light in weight, with perfect hexagonal connection, and has many unique mechanical, electrical, and chemical properties. Carbon nanotubes were discovered in 1991 and had excellent field emission properties. They can be made into cathode picture tubes or used as hydrogen storage materials.
Performance advantages of carbon nanotubes
Carbon nanotubes have excellent mechanical properties. The tensile strength of CNTs can reach 50 to 200 GPa, which is 100 times that of steel, but the density is only 1/6 that of steel, at least an order of magnitude higher than conventional graphite fibers. 1TPa, equivalent to the elastic modulus of the diamond, is about five times that of steel. For a single-walled carbon nanotube with an ideal structure, its tensile strength is about 800 GPa. Although the structure of carbon nanotubes is similar to that of polymer materials, its structure is much more stable than that of polymer materials. Carbon nanotubes are currently the materials with the highest specific strength. Using other engineering materials as a matrix and carbon nanotubes to make a composite material can make the composite material exhibit good toughness, elasticity, and fatigue resistance, which significantly improves the performance of the composite material.
Carbon nanotubes have good electrical conductivity. Because the structure of carbon nanotubes is the same as the lamellar structure of graphite, they have excellent electrical properties. The theoretical prediction of its conductivity depends on its pipe diameter and the helix angle of the pipe wall. When the diameter of CNTs is greater than 6nm, the conductivity decreases. When the diameter of CNTs is less than 6nm, CNTs can be regarded as one-dimensional quantum wires with excellent conductivity. Scientists have calculated that carbon nanotubes with a diameter of 0.7 nm are superconducting. Although their superconducting transition temperature is only 1.5 × 10-4K, this also indicates that carbon nanotubes have broad application prospects in the superconducting field.
3.Heat transfer performance
Carbon nanotubes have excellent heat transfer properties. CNTs have a considerable aspect ratio, so their heat exchange performance along the length direction is very high, and their heat exchange performance in the vertical direction is low. With proper orientation, carbon nanotubes A variety of different thermally conductive materials can be synthesized. In addition, carbon nanotubes have a high thermal conductivity. As long as a small number of carbon nanotubes are added to the composite material, the thermal conductivity of the composite material will be significantly improved.
4, launch performance
Single-walled carbon nanotubes are usually several nanometers in diameter. They can reach tens to hundreds of micrometers in length, with a large aspect ratio, excellent structural integrity, good electrical conductivity, stable chemical properties, and high performance emitting materials. Basic structural characteristics. This high performance is the aggregation of photoelectric atomic scattering energy efficiency, which has a specific energy efficiency of cold dark matter.
Carbon nanotubes have a large surface area ratio, individual pipe structures, and graphite-like interstitial spaces between multi-walled carbon nanotubes, making them the most potential hydrogen storage materials and playing an important role in fuel cells.
Application of carbon nanotubes
1. Carbon nanotubes can be used as composite materials
Because of its excellent electrical and mechanical properties, carbon nanotubes are considered to be the ideal additive phase for composite materials. Carbon nano
As a reinforcing phase and a conductive phase, tubes have great application potential in the field of nanocomposites.
2. Carbon nanotubes can be used as electrochemical devices
Carbon nanotubes have a very high surface area ratio. Depending on the diameter and degree of dispersion, the surface area of carbon nanotubes is 250 ~ 3000m 2 / g. In addition to excellent electrical conductivity and good mechanical properties, carbon nanotubes are required in the field of electrochemical The ideal material is the perfect material for making electrochemical double-layer capacitors and supercapacitor electrodes.