Right now with carbon nanotube drug delivery systems, problems arise like the lack of solubility, clumping occurrences, and halflife. Carbon nanotubes for power applications sciencedirect. Carbon has four electrons in its valence shell carbon is group ppt. Carbon nanotubes free download as powerpoint presentation. Holt et al, science, 312, 1034 2006 noy et al, nano today, 2, 22 2007. As in the case of single and doublewalled carbon nanotube growth, catalyst particles can be located on fig. The synthesis of carbon nanotubes can be accomplished in a wide variety of methods that involve the catalytic decomposition of a carbon containing gas or solid.
These nanotubes have enhanced set of characteristics that make them stronger than steel, with a large reduction of weight. They can be thought of as a sheet of graphite a hexagonal lattice of carbon. Nanotubes iijima, 1991 1d graphene geim, novoselov, science 306, 666 2004 graphene is a perspective material for atomicthin metallic fieldeffect transistors which would have smaller size, lesser power consumption, higher operation frequencies. On one hand they have molecular size and morphology. Our new crystalgraphics chart and diagram slides for powerpoint is a collection of over impressively designed datadriven chart and editable diagram s guaranteed to impress any audience. Carbon is the chemical element with atomic number 6 and has six electrons which occupy 1 s 2, 2 s 2, and 2p 2 atomic orbital. These are large macromolecules that are unique for their size, shape, and remarkable physical properties. Also showed how to produce nanohorns at room temperature and with high yield nanohorns had been previously discovered by peter harris. Ndoped carbon nanotubes containing a high concentration. Most synthesis methods also produce a range of nanotube sizes and structures.
Introduction to carbon nanotubes carbon nanotubes were discovered in 1991 by sumio iijima of nec and are effectively long, thin cylinders of graphite, which you will be familiar with as the material in a pencil or as the basis of some lubricants. As the nanotube grows longer, its structure stays consistent. Graphite is made up of layers of carbon atoms arranged in a hexagonal lattice, like chicken wire see. In continuation of the previous work, this article addresses the key issues on hand in carbon nanotube technology. Ppt carbon nanotubes powerpoint presentation free to.
Metallic or semiconducting, depending on chirality. Carbon nanotube membranes for energyefficient carbon. White 1993 structural rigidity of carbon nanotubes g. It also assesses the opportunities and challenges for increased commercialization and manufacturing of carbon nanotubes in the years ahead. Jun 17, 2004 carbon nanotubes supplied by approved carbon nanotube supplier thomas swan carbon nanomaterials buckytubes also have applications in a variety of fuel cell components. For the tube we assigned as 11, 2 or 12, 2, the ldos is finite and constant between. Discoveries of very constant nanometer size sp 2 carbon bonded materials such as graphene, fullerenes, and carbon nanotubes have encouraged to make inquiries in this field. It is a zerooverlap semimetal with both holes and electrons as charge carriers with very high electrical conductivity. Carbon nanotubes seminar report by shuhabutariq 1si03ec109 5 nanotubes are cylindrical fullerenes. Discovered carbon nanotubes in 1991 by demonstrating that the carbon fibers produced by a carbon arc were hollow. Generally, synthesis methods of carbon nanotubes can be classified into two main categories corresponding to different temperatures. Scientists dont know everything about carbon nanotubes or cnts for short, but they do know that they are very thin lightweight hollow tubes made up of carbon atoms. All carbon nanotubes involve a hexagonal aromatic rings all t i i l t iti t t th d h t lall atoms are in equivalent positions except at the ends where pentagonal rings are required.
There are also doublewall carbon nanotubes dwcnt which have a second layer of graphene. Carbon nanotubes carbon nanotubes, long, thin cylinders of carbon, were discovered in 1991 by sumio iijima. Hydrogenation of single walled carbon nanotubes anders nilsson stanford synchrotron radiation laboratory ssrl and stockholm university. Because of their tube structure, carbon nanotubes can be made with or without end caps, meaning that without end caps the inside where the drug is held would be more accessible. The high temperature routes, such as the electricarc discharge technique. Carbon nanotube c nt is a tabular form of carbon with diameter as small as 1nm. One of the main applications of carbon nanotubes is super strong bullet proof jackets. Binding sites for a carbon nanotube are preferentially defined at the ends of the tube on the pentagonal ring. Discovered in 1991 by sumiyoiijima, a japanese scientist working at the nec corporation. International journal of engineering research and general. A ndoped carbon nanotube catalyst containing a high concentration of single fe atoms was prepared by a simple and scalable atomic isolation.
Carbon nanotubes cnts are cylindrical large molecules consisting of a hexagonal arrangement of hybridized carbon atoms, which may by formed by rolling up a single sheet of graphene singlewalled carbon nanotubes, swcnts or by rolling up multiple sheets of graphene multiwalled carbon nanotubes, mwcnts. Mar 31, 2014 no one disputes that carbon nanotubes have the potential to be a wonder technology. Carbon has four electrons in its valence shell carbon is in group 1. Global carbon nanotubes market 2 carbon nanotubes are a form of carbon molecules that exist in the form of a tube like structure. Potential applications of carbon nanotubes wikipedia. Narrow graphene nanoribbons from carbon nanotubes nature. Industrial applications of carbon nanotubes 1st edition. Ppt carbon nanotube synthesis powerpoint presentation. Hagopian optical physicist nasa gsfc stephanie getty, manuel quijada, patrick roman, james butler, georgi georgiev, cleophus hunt, alejandro maldonado. Meet the wonder material that could revolutionize the world. Graphene ppt powerpoint presentation carbon nanotubes topics for seminar april 15, 2014.
Bullet proof jackets are formed by the carbon nano fibers which are made up of millions of tiny carbon nano tubes is starting to reveal exciting properties. Carbon nanotubes seminar report by shuhabutariq 1si03ec109. The medicine of tomorrow and nano medicine aristotle university of thessaloniki. As a group, carbon nanotubes typically have diameters ranging from nanotubes much longer, and measured in centimeters. Carbon nanotube membranes cnts have very high gas permeability because of the inherent smoothness of cnt surface aligned doublewalled carbon nanotube dwnt, 1.
Multiwalled carbon nanotubes mwcnt for stray light. As mentioned in the above section, ccvd is probably the only method suitable for the mass production of multi walled carbon nanotubes. Multiwalled carbon nanotubes mwcnt for stray light suppression in space flight instruments john g. They were discovered independently by iijima and ichihashi and bethune et al. Cnt are of high technological interest because they can be produced or refined to possess specific properties such as high.
Widely recognized as the quintessential nanomaterial, cnts have already compiled an impressive list of superlatives since their discovery in 1991. Feb 25, 2011 carbon nanotubes and their methods of synthesis slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Carbon nanotubes cnts are cylinders of one or more layers of graphene lattice. Singlewalled carbon nanotubes 207 iv data recorded along the two tubes discussed earlier exhibit very different features fig.
Carbon nanotubes what they are, how they are made, what. It is important to explain that carbon nanotubes and graphene have the same molecular structure geometry. Field emission of carbon nanotubes tharanga kariyawasam department of physics,university of cincinnati,cincinnati, ohio 45221 abstract carbon nanotubes, a novel form of carbon discovered in 1991, have been rapidly considered as one of the most promising electron. 161636 november 2005 with,959 reads how we measure reads. Cheap compounds found in kitchen cupboards can act as catalysts for making carbon nanotubes in your class download a oneslide summary of this article for use in your classroom ms powerpoint or pdf. The process coats along the height of carbon nanotubes with a sufficiently thin ptfe coating, unlike conventional methods in which greater minimum coating thicknesses 10 m can smooth out the surface texture. In the article carbon nanotubes, the synthesis, structure, properties, and potential applications of multiwalled and singlewalled variants of carbon were discussed extensively. Characterizing carbon materials with raman spectroscopy. Physics of carbon nanotubesphysics of carbon nanotubes maximum tensile strength 30 gpa density normalized strength of a carbon nanotube is 56 times that of steel wire cnt can carry large currents with little heating source. Is a tubular form of carbon with a diameter as small as 0. Single walled carbon nanotubes swcnts are a single cylinder of carbon atoms forming a tube. Carbon nanotubes grown using kitchen chemicals news.
Graphene is chemically the most reactive form of carbon. Graphene nanoribbons gnrs are materials with properties distinct from those of other carbon allotropes 1,2,3,4,5. Like their building block graphene, cnts are chemically bonded with sp 2 bonds, an extremely strong form of molecular interaction. They have a number of properties including high surface area and thermal conductivity that make them useful as electrode catalyst supports in pem fuel cells.
Among all the nanomaterials, a material by name carbon nanotubes has led the way in terms of its captivating structure and also its ability to furnish specific applications ranging from the electronics to the energy. Carbon nanotubes were purified by reflux with concentrated hydrochloric acid for 24 h. Growth of halfmeter long carbon nanotubes based on schulz. The most common way of producing nanotubes industrially is the carbon vapor deposition, or cvd, process, in which carbon bearing gases deposit carbon atoms on a growing nanotube.
Chart and diagram slides for powerpoint beautifully designed chart and diagram s for powerpoint with visually stunning graphics and animation effects. Carbon nanotubes are essentially rolled up graphene sheets that have been sealed to form hollow tubes. One single atom thick graphene is the worlds strongest, thinnest and most conductive known to exist. Perfect cnts have all carbons bonded in a hexagonal lattice except at their ends, whereas defects in massproduced cnts introduce pentagons, heptagons, and other imperfections in the sidewalls that generally degrade. The ptfe coating is applied onto the forest of carbon nanotubes through a hot filament chemical vapor deposition hfcvd process17,18.
Metallic and semiconducting carbon nanotubes generally coexist in asgrown materials. Optical properties of carbon nanotubes carbon nanotubes are hollow tubes made entirely from carbon with diameters in the nanometer range such as the one shown in the picture below. A graphene sheet can be rolled more than one way, producing different types of carbon nanotubes. If you continue browsing the site, you agree to the use of cookies on this website. Over the past many decades there has been a sudden growth in the field of research and advancement related to the nanomaterials.
Since carbon nanotubes cnts were discovered by iijima in 19911, they have become the subject of many studies because of their unique electrical, optical, thermal, and mechanical properties 26. Cnt is configurationally equivalent to a two dimensional graphene sheet rolled into a tube. A demonstration should be shown or made into another 5 minute activity with the paper printed graphene sheets showing. Carbon allotropes and derivatives occupy a unique place in terms of their ability to conduct heat. A carbon nanotube is like a sheet of graphite that is rolled into a cylinder, with distinctive hexagonal latticework making up the sheet. Carbon nanotubes cnts have been under scientific investigation more than fifteen years since their unique properties predestine them for numerous potential applications. Nanotubes iijima, 1991 1d graphene geim, novoselov, science 306, 666 2004 graphene is a perspective material for atomicthin. Scribd is the worlds largest social reading and publishing site. In this study, the development of cementitious nanocomposites reinforced with multiwall carbon nanotubes mwcnts at watercement ratios of 0. The field of nanotechnology and nanoscience push their investigation forward.
Thermal properties of graphene, carbon nanotubes and. These tubes of carbon are usually only a few nanometres wide, but they can range from less than a micrometre to several millimetres in length. Carbon nanotubes cnts are seamless cylinders of one or more layers of graphene denoted singlewall, swnt, or multiwall, mwnt, with open or closed ends 1, 2. Image showing growth of nanotubes from substrate such as zeolite. Lengthtodiameter ratio of a carbon nanotube can be as large as 28,000,000. High youngs modulus y 1 tpa high tensile strength 60 gpa remarkable flexibility. Nanotubes are promising candidates for nanoscale lightemitters and many other optical applications, especially in the infrared wavelength. Jun 21, 2012 carbon nanotubes are most often produced in combination with a range of fullerenes and amorphous carbon separating the desirable nanotubes from this other matter can be problematic. Cnts can be visualized as a sheet of carbon atoms rolled up into a tube with a diameter of around tens of nanometers. Carbon nanotubes cnts are tubes made of carbon with diameters typically measured in nanometers. Ppt carbon nanotube transistors powerpoint presentation.
Single wall carbon nanotube swnt graphene and carbon nanotubes a a x y a 2. With this process, 100% of purely semiconducting nanotubes were obtained and connected in parallel for highcurrent transistors. Functionalization of carbon nanotubes and its application in. Some of the most common techniques are chemical vapor deposition, arcdischarge, and laser vaporization synthesis 2, 3.
Singlewall carbon nanotubes swcnt are cylindrical tubes with a single outer wall with diameters that are usually only 1 2 nm. Carbon nanotubes cnts are big carbon molecules which have a very high lengthtodiameter ratio, somewhat similar to polymer molecules. Selective etching of metallic carbon nanotubes by gas. Carbon nanotubes cnt belong to a large group of hollow fiberlike carbon based nanomaterials with diameters mostly below 100 nm and very high aspect ratios. We present a gasphase plasma hydrocarbonation reaction to selectively etch and gasify metallic nanotubes, retaining the semiconducting nanotubes in nearpristine form. This combined with the high operating temperature and pressure make this method highly inefficient for producing large amounts of carbon nanotubes. Carbon nanotubes metal hydrides solar h 2 production photoelectrochemical h 2 production.
Diameters of singlewalled carbon nanotubes swnts and multiwalled carbon nanotubes mwnts are typically 0. Nanohorns have since proven useful in nextgeneration fuel cells because they have very. They can be thought of as a sheet of graphite a hexagonal lattice of carbon rolled into a cylinder. The nanotubes consisted of up to several tens of graphitic shells socalled multiwalled carbon nanotubes mwnts with adjacent shell separation of 0. The production of carbon nanotubes can be done by plasma based synthesis method or arc discharge evaporation method, laser ablation method, thermal synthesis process, chemical vapor deposition and. The yield of carbon nanotubes is also much higher, with very little amorphous carbon produced, but the overall amount generated is very small. They are normally around 1nm in diameter, but may be up to 5nm.