Technology and innovation have driven us to a point where there is an overwhelming demand for resources and ultimately increasing negative effects on global climate change. So technology must strive to keep up with the demand, as we are in a system in which the demand for resources greatly outweighs the supply.
And to cope with demand, new resources are needed to fill in the gap in supply. Around three decades ago the world thought that it discovered the holy grail of material that was 100 times stronger than steel but still around four times lighter. In theory, these materials called carbon nanotubes (CNTs) were supposed to be a key material in leading humanity out of the carbon age.
Carbon is a very familiar element. It’s in everything we eat, sleep on and step over. It is the element that holds our DNA together. And we depend on it to build and fuel our bodies. It’s the basis of life as we know it. Its ubiquity in our lives is a result of its versatility. Its chemical properties allow it to take many different shapes, each impacting its material properties in diverse and unique ways.
CNTs are cylindrical molecules that consist of rolled-up sheets of single-layer carbon atoms, the same basis as graphene. The researchers who created it were working with a material that holds much broader promises. That hasn’t quite happened, but the researchers did create another material that no one saw coming.
A Japanese physicist, Sumio Iijima, conducted a momentous experiment in 1991. Taking two graphite rods as electrodes and applied a current across the rods which spark arched between them and with it a cloud of carbon gas puffed into existence. As the carbon-laden air settled on the chamber walls it formed a thin layer of black soot, within it a strange new material appeared.
The new material was tiny single-layer straws of carbon. Sumio Iijima had just created carbon nanotubes. Laboratory testing of these mysterious little particles would reveal that these nanometer-wide hexagonal lattices of carbon had the strongest tensile strength known to man.
It soon became clear that carbon nanotubes had the potential to be the building block of futuristic new technologies. However, while these graphene-based tiny tubes have been overhyped as revolutionary for about 30 years, they haven’t made it to the market yet. But we’re seeing slow progress toward interesting use cases. So what is a carbon nanotube, and how does it work?
Contents
What are carbon nanotubes?
Carbon nanotubes also called buckytube is a thin, cylinder-shaped molecules made of hexagonal graphite molecules. The walls of this material are only one atom thick and are 100 times stronger than steel. That makes them useful in strengthening materials such as steel and other metals.
Carbon is a non-metallic element that plays a key role in nanotechnology. It can form a diverse range of molecules, including nanotubes. CNTs are stronger than steel, which is what makes them a basis for high-strength composite materials. Carbon also comes in the form of fullerene, which is a molecule that exists on the nm scale.
Buckytubes are very interesting to study due to their unique magnetic, electronic and mechanical properties. They’ve found applications in electronics, optics, nanotechnology and structural materials. It can also be found in car parts, Damascus steel, golf clubs, baseball bats and more.
Moreover, they’re actively added to polymers for their electrical and thermal conductivity and as a means of antistatic packaging. CNTs come in two basic types, single-walled and multi-walled. A multi-walled nanotube has several layers with continuously increasing diameters. Its outer wall may have one inner and one outer tube. Its walls maintain a distance by interatomic forces.
By contrast, a single-walled carbon nanotube (SWCNTs) has a single wall that is extremely thin. SWCNTs are a very important class of carbon nanomaterials that hold considerable commercial potential. Because of this, the National Institute of Standards and Technology (NIST) has been supporting the development of SWCNTs by producing documentary standards and reference materials.
Although a single carbon nanotube is extremely thin, its electrical conductivity is very high. This property is due to the tiny radius of curvature of the CNT. This characteristic makes this material a useful electron emitter in field emission displays, a new class of large-area flat-panel displays.
Why carbon nanotubes are important?
The simplest answer is that they’re extremely strong. In fact, their strength stems from the close bonds between the carbon atoms. Those tight bonds are what make carbon nanotubes so strong. These materials also have a unique electrical conductivity, making them ideal candidates for use in electronic components.
According to MIT, nanotubes could replace metals in manufactured goods, which would cut down on the overall cost of materials. Scientists also believe that CNTs could eventually replace silicon transistors in computer chips, which could help decrease energy use and double computer processing power every two years.
CNT is a fantastic wonder material. Their incredible mechanical properties are unmatched and they have a higher thermal conductivity than diamond, higher strength and superior weight-to-density ratio than steel. The hollow interior of a carbon nanotube shields it from the surrounding environment.
That property makes it an ideal candidate for nanomedicine and drug delivery. Other uses for buckytube include electrostatic discharge shielding. Because they are hollow, they can be filled with a variety of nanomaterials. Because of this, they’re also a good candidate for biosensors. You can even construct artificial blood capillaries from these tiny tubes.
Researchers have created transistors using SWCNTs. Their superior electrical properties and near-transparent contact with certain metals make them ideal candidates for high-performance electronics. They also feature tight pitch separation. These properties allow scientists to use carbon nanotubes in integrated circuits, functional systems and nanoelectronics.
These new materials could help fuel the development of new technologies such as LEDs and ultra-high-frequency semiconductor devices. These tiny tubes are also strong enough to shield the paint from corrosion while being lightweight and flexible. Their strength is similar to that of graphite fiber, but they are not as brittle as its counterpart.
They can be used in either a fabric-like form or as a composite material, depending on the desired properties. CNTs are extremely small fibers. They are formed by the polymerization of groups and are important for the construction of many materials. Polymers may be incorporated into carbon nanotube-based composites in several ways, including chemical vapor deposition (CVD).
However, they need to be made in bulk quantities and at uniform densities to make them useful. The task of creating such tiny graphite tubes is far more difficult than it sounds. The first step is to produce CNTs from carbon dioxide. One of the biggest hurdles to carbon nanotube electronics is the availability of high-quality, reliable contacts.
Fortunately, technology is advancing enough to overcome that hurdle. It is now possible to make transistors from buckytube using a nickel-based end contact. These advanced transistors could even lead to wearables, medical monitors and more. And because CNTs are extremely cheap and can be fabricated at low temperatures, this material can be used to make high-end devices.
These graphite nanotubes can withstand temperatures up to 2800 degrees Celsius in a vacuum. In contrast, silicon chip transistors operate at 150 degrees. A single CNT can carry one billion amperes per square centimeter, while a copper conductor would immediately burn out.
A carbon nanotube’s thermal conductivity is 6000 w/m/K, making it an excellent material for transferring heat. In comparison, a pure diamond can conduct heat at 3320 w/m/K, which is far higher than copper. The high ampacity of CNTs is critical in the fabrication of advanced electrical components, including microchips and nanowires.
They can also be used to fabricate complex multi-tiered current pathways on a nanoscale. The importance of carbon nanotubes in electronics cannot be overstated. This material will continue to play an important role in electronics. CNTs have a bright future in various flexible and stretchable devices.
From solar cells to thin-film transistors, buckytubes are already used in everything from display panels to loudspeakers. Scientists and engineers believe CNTs will help us create a more sustainable world and they hope to make carbon nanotubes a crucial part of that future. So what is the future of the carbon nanotube?
Future of carbon nanotubes
Scientists are studying this amazing substance for its many potential uses, including insulating textiles, biosensors and even the next-generation material and electric vehicles. Researchers are also experimenting with how to use it to make needles for injecting drugs and genes.
CNTs have great thermal and electrical conductivity, so they can be used as probes to study processes outside of cell membranes. Scientists are even working on developing a graphite nanotube transistor that can smell, by integrating a CNT with olfactory receptor proteins from mice.
Unlike the water-soluble substances, we’re familiar with, carbon nanotubes can be transported in environmental waters as colloids. These particles are larger than a dissolved substance’s molecules and can potentially penetrate cell walls. This means that buckytube can be used in laser treatments with far higher precision than current lasers.
In addition, they can be ingested to examine internal conditions in a person’s body. While the future of carbon nanotubes may not be visible today, we can expect a dramatic change in the world. Using this material in electronics and building structures could make them stronger and more lightweight.
These new materials can also be used to produce hydrogen and carbon. CNTs are smaller than human hair. Their unique properties make them highly durable and lightweight. They have incredible mechanical, electrical and thermal properties and may even play a key role in space elevators. So in the future, we may even be able to build space elevators.
Buckytubes have several potential applications in the field of sensing. In a recent study, researchers have developed a concept for a graphite nanotube-fitted sensor. The nanotube-outfitted sensor would register changes in electrical resistance caused by structural damage or fatigue.
These sensors could serve as crack gauges in aircraft, monitoring structural integrity and providing diagnostic information. Researchers are now working on scaling up these manufacturing processes to meet commercial production demands. In the future, CNTs may even be used to make space vehicles.
The world can use these new materials for wearable technology. From smartwatches to hospital garments to casual clothing, CNTs can be woven into fabric without changing its appearance. This would allow them to be used as conductive pathways or circuits for information and even feed information to a smartphone.
However, there are still some technical hurdles that need to be overcome before carbon nanotubes are fully developed. One important question is whether graphite nanotubes are safe for the environment. While manufacturers are working hard to develop safe nanotube products, there’s still a lot to learn about their effects on the environment.
Another major hurdle is purity. Because CNTs are made from different materials, they will behave differently in water. Their interactions with water will depend on their chirality. Different twisted tubes will exhibit slightly different surfactant molecules on their surface. Researchers have exploited this surface chemistry difference using ultracentrifuges to sort them by chiralities.
While nanotubes do not replace silicon-based electronics, they can certainly benefit the world in a number of ways. This could include making a new kind of computer that doesn’t rely on silicon chips. In addition to their usefulness, buckytubes can have a range of potential health risks. The presence of residual catalysts in these materials can accelerate decomposition.
Moreover, these materials can help improve the strength and dispersibility of composites. One study has found that composites consist of CNTs and copper. Multi-walled CNTs showed improved hardness and wear resistance when compared to copper. However, the material exhibited poor adhesion, as their lighter counterparts remained on the Cu particle surface.
There is a growing demand for materials with improved mechanical and thermal properties and the CNT-Cu composite is a promising solution. In addition to this, they are strong and have high thermal conductivity. These properties allow CNT-Cu composites can improve the overall mechanical and electrical properties of the material.
Therefore, CNT-Cu composites have the potential to improve a variety of applications, including structural surfaces, antennas and sensors. These applications will help fuel the development of the graphite nanotube as commercial material. To achieve this, we need to lower the cost of nanotube production while driving scale to volume.
And, ultimately, the carbon nanotube will be a defining component of future energy and materials technology. Scientists are using CNTs for biomedical applications. One Spanish research team has developed a biosensor using CNTs to detect yeast infections. When yeast and antibodies interact, CNTs vibrate and create heat.
Scientists are also researching CNTs for use in cancer treatment. It may even be possible to target tumors with a laser, which will activate the CNTs and produce a therapeutic effect. They will likely become a major competitor of carbon fiber and kevlar in high-end applications.
0 Comments