Aim.
The aim of this paper is to show an alternative to tackle the problem with the computer area by being without computers in the future with more rapid. This is because the more processor speed has generated more heat, and just the current methods of cooling such as fans or rooms specially designed will not work.
On the other hand materials which are made with today’s processors will not further reduce its physical size, making it impossible to create smaller computers.
Here is where to play them so-called nanotubes conduct heat to power more rapidly than silicon and have a nanometer size opens the possibility of designing computers much smaller and powerful.
Definition.
Essentially Carbon Nanotubes are structures of layers of graphite rolled up on themselves, in which carbon atoms are arranged in a hexagonal shape. Different types of nanotubes: SWNT (Single-Walled Carbon Nanotubes) or monolayer and MWNT (Multi-Walled Carbon Nanotubes) or multilayer.
These have excellent properties, both mechanical, electronic, chemical and thermal. These properties can be varied by changing the diameter and number of concentric tubes.
Development.
Graphite is composed of carbon atoms arranged in a hexagonal pattern. These layers are arranged one above the other and each layer by itself is very stable, strong and flexible. Yet despite being so stable by itself, binds weakly to the neighboring leaves.
Although the individual scales are very strong and flexible, for example graphite used in pencils, is weak. This is because the layers can slide easily between them.
In carbon fibers, the individual layers of graphite are much larger and form a pattern long spiral. These fibers can be glued with a synthetic resin, forming an extremely strong compound, used in aircraft, rackets, bicycles, automobile suspensions etc..
There is another way to fix these leaves to make them even stronger. This involves wrapping the back over itself and join the edges. This will form a tube of graphite, ie a carbon nanotube.
These nanotubes are the strongest fibers known. A single perfect nanotube is about 10 to 100 times stronger than steel per unit weight.
To convert the nanotubes into useful materials is necessary to eliminate its weaknesses and the byproducts produced during its synthesis (amorphous carbon, graphite, fullerenes, metal nanoparticles that act as catalysts, etc..) It is necessary for their synthesis control the length, diameter and number concentric tube
Features.
The nanotubes are among others the following features:
-. High ratio radius / length allows tighter control of property
unidirectional resulting materials;
-. Electrons can behave as metallic, semimetallic or insulating depending on their diameter and helicity. It has demonstrated its quantum-dimensional electronic behavior. Recent studies suggest that could be used in flat screens for its good ability as electron emitters.
-. High mechanical strength. It has been shown to have higher mechanical strength and greater flexibility than the carbon fibers so that could be used in composites.
-. Their properties can be modified by encapsulating metals inside finally obtain electric or magnetic nanowires, or gases and may be used for hydrogen storage or as a system of separation
gas.
production methods.
-. Arc obtained:
Carbon nanotubes were first discovered in 1991, formed by an electrical discharge between two graphite electrodes.
The material evaporated from an electrode and deposited on the other shaped nanoparticle (60%) and nanotubes (40%).
Purification is achieved by oxidation in the gas or liquid phase. Unfortunately, despite optimization, yields still remain low and the cost may be $ 500 per gram, even before purification. This process still provides most of the material studied, as the tubes of high crystallinity
-. Laser Collection:
Another method to produce nanotubes is by laser ablation, which was demonstrated in 1996 by Smalley’s group and has prompted many interest. It was shown that the synthesis could be performed in a horizontal tube under an inert gas flow controlled pressure. In this arrangement the flow tube is heated to ~ 1200 ° C.
The laser pulses enter the pipe and attack a target that consists of a mixture of graphite and a metal catalyst such as Co or Ni. The nanotube is condensed from laser vaporization of and deposited into a collector outside the furnace area.
-. Catalytic Growth:
An alternative collection methods for arc and laser ablation is the catalytic growth of nanotubes. This method is based on the decomposition of a hydrocarbon gas over a transition metal and later obtain nanotubes in a chemical deposition reactor in vapor phase (CVD).
Conclusion.
In conclusion we can say that carbon nanotubes are a real possibility to move forward in making ever more powerful computers and so continue fulfilling Moore’s Law which states that processor speed doubles every 18 months.
Moreover nanotechnology and nanotubes also serve many other areas such as medicine, telecommunications, electronics, etc..