Carbon Nanotubes, What Are They?
The growth of carbon nanotubes is an intricate process that has many challenges. It is important to understand what carbon nanotubes are, there history, what their potential applications are and how they will be able to accomplish these task. Carbon nanotubes (CNTs) are one of a multitude of tiny materials that will help to define the future.
Carbon nanotubes have an unparalleled history. The first publication about these was written in 1952 by Raduskevich and Lukyanovich (Ren 8). These two Russian scientists provided the scientific community with the first distinct image of carbon nanotubes. Radushkevich and Lukyanovich 's publication had unobscured images showing multi-walled carbon nanotubes with a 50 nm
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These tubes that they found have likely been around since the time of Thomas Edison and were created as he was experimenting with carbon filaments for light bulb, which would eventually be his defining discovery, or even earlier on during the metal forging process. The reason CNTs would go unnoticed is do to their microscopic size (Ren . Their diameter can range between 1 and 50nm and with lengths that can out measure their diameter by 1000 times (Nanocyl). A nanometer is 10-9 meters or .000000001m. Even with the best optical microscopes, which magnify light rays reflected from objects, it wouldn’t have been possible to discern the fact that these cylindrical structures were hollow, if they could even see them.
Carbon nanotubes get all of their impressive properties from their physical structure. They are hexagons of covalently bonded carbon atoms. A covalent bond is a bond between two non-metals atoms. Two of these atoms are bonded to four others and form another hexagon and these other hexagons exist on all the sides of the first and off of each other. This would look like a sheet of hexagons that could then be "wrapped" into tubes. These tubes can be single walled (SWCNTs), and multi-walled (MWCNTs) depending on the number of layers they have. The carbon atoms in these nanotubes have S2P2 chemical bonds (Zhang 7). This means that the atoms have one
Recent advances in carbon nanotechnology have led to the discovery that single-walled carbon nanotubes (SWNT) fluoresce from 900 to 1600 nm1 a region that is particularly transparent to biological tissue and media. Single-walled carbon nanotubes have a particular advantage as sensing elements due to the fact that all atoms are surface atoms causing the nanotube to be especially sensitive to surface adsorption events (Paul W. Barone, 2005).
Carbon is the fundamental element for everything on Earth. All life on Earth depends on carbon. Carbon has different forms of allotropes including diamond, graphene and charcoal. Carbon is found in position 12, with 4 colvalent electrons. All the allotropes have different properties nd uses due to how the carbon atoms are bonded. Carbon is able to single, double and triple bond with other elements to form complex molecules. Carbon can also use its four electrons to form diamond, where it is strong and stable, or three electrons to form graphite found in pencils, buckyball or all forms of nanocarbon including carbon nanotube.
The discovery of graphene was given credit to the director of the center for Mesoscience and Nanotechnology at the University of Manchester, Andre Geim and his colleague Kostya Novoselev. The paper was published in October 2004 in Science Magazine. The title of the paper was "Electric field effect in atomically thin carbon films." The paper has become one of the most cited papers in material physics. Around the time of the discovery, carbon nanotubes was an interesting area of research. Geim was also interested in carbon nanotubes but had an idea about using them in an unfolded configuration. With the idea for the unfolded nanotubes he took a graphite block and polished it.
In the 21st century, human and technologies are inseparable. In past decades, there has been an astonishing amount of development in modern world’s technology. Nanotechnology is one of them. This technology is based on nano-scale and it can be used in many different areas because of its small sizes. (Metchis). However, there is a huge amount of uncertainties on the hazards of nanomaterial due to lack of research in this field in real world applications. There is a lot of things that need to be study on this technology. For this technology to be considered fully developed there is an immediate need for a balance between a free and unregulated market with some involvement from the government because both systems have its own strengths and weaknesses that will be discussed further.
The infinitesimal molecular structure of carbon 60 has provided a revolutionary solution for flight efficiency and advancement today. Through the use of an experimental material derived from carbon nanotube technology some of flights oldest conjectures will be solved. Manifested in the form of paper like sheets, these carbon molecules have been transformed into a material better known as
Graphene is a form of carbon which has recently been receiving a great deal of attention. Some have come to call it “the wonder material” due to its many extraordinary properties. Although isolated in 2004, graphene's properties had been calculated decades earlier. It consists of a single layer of carbon atoms arranged in a hexagonal lattice. A single sheet of graphene is stronger than steel and yet remains very flexible, retaining all of its properties despite being bent and unbent multiple times. It is able to sustain extremely high electric current densities, is impermeable to all gasses, has a thermal conductivity double that of diamond and a very high electron mobility at room temperature. It is also easily chemically functionalized,
Mother Nature generates sophisticated and complicated structures from the humblest of ingredients. Often their construction relies on the self-assembly of building blocks resulting in hybrid structures that combine both organic and inorganic materials. For example, Shewanella bacteria are capable of forming extracellular networks of arsenic-sulfide nanotubes with unique electrical and photoconductive properties1. Our ability to mimic these natural processes to create desirable nano- and
Nanotechnology is the study of particles on the nanoscale with, at least one dimension being less than 100nm. (Chen, Schluesener, 2008) Nanoscale particles can come in many shapes and sizes, ranging from 100 - 1 nm. These particles can be found as rods, cones, spheres and many more complex matrices and patterns as seen in figure 1.(Champion, Katare, Mitragotri, 2007) Nanosilver will form a roughly spherical shape as can be seen in figure 2. (Utopia Silver Supplements, 2012)
In light of these shortcomings, there has been an upsurge in eco-friendly materials and devices, all in an effort to recover and save the environment. Nanotechnology, which deals with matter on an atomic level, has played a significant role in this movement.
The carbon nanotube field-effect transistor (CNTFET) technology is a significant part of nanotechnology. It is to use carbon nanotubes as the channel material to build field-effect transistors (FETs) [2]. CNTFET technology takes advantage of the unique electronic structure of graphite, thereby forming hollow cylinder. It is
Before the discovery of graphene in real-life, scientists were skeptical with the idea of a 2D carbon-based
Nano computers have the potential to revolutionize the 21st century in the same way that the transistor led to the information age. Increased investments in nanotechnology could lead to breakthroughs such as molecular computers. Billions of very small, fast, and cheap computers networked together can fundamentally change the face of modern IT computing. This miniaturization has already spawned a whole series of consumer-based computing products: computerized clothes, smart furniture, and access to the internet that is a thousand times faster than the late 20th century’s dial-up technology.
“There’s plenty of room at the bottom”; this statement by Richard Feynman in 1959 during a presentation to a meeting of the American Physical Society, is widely accepted as the spark that initiated the present ‘nano’ age1. Nano, “dwarf” in Greek, is defined as one billionth, it follows that the nanoscale is measured in nanometres, or 10-9 m. To put this in perspective; the average strand of a human hair is roughly 75,000 nm in diameter, or from the other extreme 1 nm is the length of 10 hydrogen atoms lined up end to end.
To overcome the terminology and nomenclature issues, a standardization committee, ISO TC229 "Nanotechnologies", started in 2005, and a joint working group with IEC 113 "Nanotechnology Standardization for Electrical and Electronic Products and Systems"
As early as in my junior year, I was guided by Professor Jia Huang in Tongji University to conduct an innovative research project "Organic Field-Effect Transistor (FET) based Humidity Sensor", in which FET was prepared from an organic semiconductor material and its moisture electrical inductive was measured. This project triggered my research interest in this field and prepared me well for later research challenges. I was excited to conduct my graduation project involving the synthesis of single-molecule chained nanoparticles produced through photoreactions. I recall that my passion for solving problems and making