CARBON NANOTUBES
INTRODUCTION
The advancement of material science over the past decade has allowed the scientists to create two structures of carbon namely carbon nanotubes and carbon nanowires. Nanowires are small wires with a diameter as small as 1 nanometre. These are being used to build tiny transistors with higher efficiency for computer chips and other electronic devices. In the last couple of years the carbon nanotubes have somewhat overshadowed the nanowires. A carbon nanotube is a cylinder full of carbon atoms. To put it into simpler words, nanotubes are simply sheet of carbon atoms in hexagonal shape. If this sheet is rolled into a form of a cylinder, you have a carbon nanotube. The properties of this carbon nanotube are based on how the sheet is rolled. Although they are formed from the same graphite sheet, their properties are dependent on the variations in length, thickness, type of helical structure and number of layers.
Carbon nanotubes with their amazing properties in terms of strength, thermal and electrical are composed to have a significant impact on future material sciences, electronics and nanotechnology. Due to their specialized structures, Carbon nanotubes can be used in creating very thin energy storage devices which could provide a new dimension and replace the capacitors and batteries which exist now. Research in carbon nanotubes is moving ahead discovering new forms, applications and Solar thermal storage is a result of one such research.
TYPES OF CARBON NANOTUBES
Single wall carbon nanotubes (SWNT)
A sheet of graphite rolled into a tube with a singular cylindrical wall is called a SWNT. These are normally capped off at the ends. They have a diameter of close to 1nm. However they come in diffe...
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...nd the length of time they could store it and these can be controlled independently.
The basic principle of thermo chemical storage of solar energy is that it uses a molecule whose structure changes on exposure to sunlight and which can remain stable in that form for as long. On disturbing it with a stimulus or a catalyst or a small temperature change or a flash of light, it can quickly regain its original shape releasing its stored energy in the form of heat.
The prime advantage of this approach to harnessing solar energy is that the process is simplified by combining energy gathering and storage into a single step. This process is robust, stable and cheap. One limitation of this process is, while this is useful for heating applications, production of electricity would require another step using thermoelectric devices or producing steam to run a generator.
Due to the varied properties and the scope of application which the CNTs possess, it is of paramount importance that CNTs are produced sufficiently at a competitive cost with the existing technology. The research over two decades, since the discovery of CNTs at Iijima’s Laboratory in 1991, has not helped in reduction of cost or production of CNTs of well-defined properties on a massive scale (Kumar, n.d.). This is mainly because of the complexity in the growth mechanism of CNTs. Extra ordinary properties and applications cannot be unleashed without the fundamental understanding of the growth mechanism of Carbon Nanotubes (Kumar, n.d.). There are several methods to produce Carbon Nanotubes in a laboratory setup. Some of widely used techniques include
Solar energy is energy taken from the light that reaches earth's surface from the sun. There are four different kinds of solar energy, which are active solar systems, passive solar systems, photovoltaic cells and concentrating power systems. An active solar systems is a system that captures solar energy by mechanical means. Common active solar systems are often in buildings or homes. Some examples are roof collectors and water heating. Low Intensity and high variability have limited the use of active solar energy in Canada. A pass...
absorb the energy from the sun, but it does absorb some of the heat energy
Preview: Today I will discuss the potential that solar power has to become this country’s main supply of energy and the latest research that can make solar power more efficient and cost effective. I will also present the environmental benefits that come with using solar power over other and more harmful forms of energy.
How Efficient is Solar Energy Technology? Engineering Challenges. n. d. a. d. a. d. d. 8 April 2014. http://www.engineeringchallenges.org/cms/8996/9082.aspx>. How do Nuclear Plants Work?”
They can be seen as a collection of rolled sheets of graphene. CNTs demonstrate superconductivity with very large temperature transition. Electrons transport and resistance of CNTs do not depend on the sizes of CNTs. Carbon nanotubes electrodes are constructed by combining graphite powder and multiwall carbon nanotubes in a pestle and a mortar. Then, paraffin is added to the mixture by a syringe before the mixture is packed in a glass tube. After the construction, its electrochemistry is tested to verify its electro-activity by using standard solution of Fe(CN)63-/Fe(CN)64. Care is taken on information about electrode interfaces; mass transiport needs to be minimized in order to be used in catalysis, sensing and electrodeposition (Elrouby, 2013).
the discovery of carbon nanotubes, the strongest material known to man, a possible solution has been found.
Graphene has received great mass media coverage since Geim and Novoselov published their foundlings about monocrystalline graphitic films in 2004, which won them the Nobel Prize in Physics in 2010. (Novoselov et al, 2004) It has been described as the wonder substance or super material by the mass media, not only because it is the thinnest material ever known and the strongest ever measured, but also due to its excellent electrical, thermal, mechanical, electronic, and optical properties. It has high specific surface area, high chemical stability, high optical transmittance, high elasticity, high porosity, tunable band gap, and ease of chemical functionalization which helps in tuning its properties (Geim et al, 2007) Moreover, graphene has a multitude of amazing properties such as half-integer room-temperature quantum Hall effect (Novoselov et al, 2007), long-range ballistic transport with almost ten times greater electron mobility than that of silicon, and availability of charge carriers that behave as massless relativistic quasi particle, known as Dirac fermions. (Geim et al, 2007) The outstanding electrical conductivity and the transparency and flexibility of graphene-based material have led to research and development of some future technologies, such as flexible and wearable electronics. In addition, graphene can also be used for efficient energy storage materials, polymer composites, and transparent electrodes. (Geim et al, 2007) This paper presents a
Carbon Nanotubes could make t-shirts bulletproof. Retrieved March 11, 2014, from Nano Werk: http://nanowerk.com/spotlight/spotids1054.php. Fecht, S. (n.d.). Lighter, stronger bulletproof clothing. Retrieved April 8, 2014, from Popular Mechanics: http://popularmechanics.com/science/health/med-tech/6spidersilksuperpowers.htm.
Although Solar Energy is a flexible source of where energy could be directly or indirectly converted into forms of energy, it’s still not perfect. With its inefficiency, scientists are trying to find alternative solution to store solar cells for as long as possible. The main process of capturing solar energy happens at the nanoscale. With solar cells, it gets more efficient the tinier it gets. The converting rate of solar energy is equally price competitive as fossil fuel, with a dollar per watt of solar energy. With the help of nanotechnology, it could help raise solar energy conversion efficiency and help lower costs making it the ultimate method of raw energy conversion. To make sure the process of generating energy is kept at a low cost and energy output...
Siegel, RP. "Solar Thermal: Pros and Cons - Part 1: Solar Heating and Cooling." Triple Pundit RSS. N.p., 21 May 2012. Web. 04 Mar. 2014. .
Solar is a viable alternative energy source with solar panels becoming more affordable and more efficiently designed.
American Chemical Society. "Carbon nanotubes twice as strong as once thought." ScienceDaily, 16 Sep. 2010. Web. 5 Dec. 2013.
Graphite is another form of carbon. It occurs as a mineral in nature, but it can be made artificially from amorphous carbon. One of the main uses for graphite is for its lubricating qualities. Another is for the "lead" in pencils. Graphite is used as a heat resistant material and an electricity conductor. It is also used in nuclear reactors as a lubricator (Kinoshita 119-127).
Hot Water Heaters: The easiest way to exploit solar radiation is as thermal energy. One way to harness this solar energy is to heat water. Aro...