Carbon Nanotubes

1. Carbon Nanotubes Created by Theresa Lincheck

2. A little bit about the Carbon Atom… • Carbon is the 6th most abundant element in the universe and is estimated to be involved in some way in almost 95% of known compounds • Carbon is capable of bonding with up to 4 other atoms at a time, including other carbon atoms making it a very unique element

3. The ‘Amazing’ Carbon Atom • Carbon can form substances with completely different properties based solely on its crystalline structure • Ex: Graphite-one of the softest natural materials known vs. Diamond-one of the hardest natural materials known

4. The ‘Amazing’ Carbon Atom Diamond-a really hard carbon-based material formed from carbon bonded in pyramid-like structures Graphite-a really soft carbon-based material formed from carbon bonded in flat sheets

5. Introduction to Carbon Nanotubes • We know that carbon can form into different materials based on its lattice structure including graphite and diamond, but carbon atoms can also be arranged to form another material, called carbon nanotubes (CNTs)…

6. What are Carbon Nanotubes? • Carbon nanotubes-carbon atoms bonded together, arranged in tubular cylinders • Carbon nanotubes contain extraordinary mechanical, electrical, thermal, optical, and chemical properties

7. Carbon Nanotubes-Properties • Carbon nanotubes exhibit amazing strength • An individual carbon nanotube can exhibit 200x the strength and 5x the elasticity of steel • It can contain 5x the electrical conductivity, 15x the thermal conductivity, and 1,000x the current capacity of copper Graph taken from http://www.nasa.gov/vision/space/gettingtospace/16sep_rightstuff.html

8. Carbon Nanotubes-Properties

9. Carbon Nanotubes-Properties • Carbon nanotubes typically have diameters ranging from 1 nm to 50 nm • Individual nanotubes are normally so small as to be a couple ten-thousandths the thickness of a human hair

10. Carbon Nanotubes-Variations • Carbon nanotubes have many possible structural variations, including differences in length, thickness, type of helicity, and number of layers • Although they are formed from the same materials in the same type of lattice structure, their electrical characteristics can change depending on these variations, acting as either metals or as semiconductors

11. Carbon Nanotubes-Variations • There are two main types of carbon nanotubes; • Single-walled Carbon Nanotubes (SWCNTs) • Multi-walled Carbon Nanotubes (MWCNTs)

12. How are CNTs formed? • The global demand for carbon nanotubes is constantly increasing for production of stronger products, causing their production to skyrocket in recent years. • When carbon nanotubes are created, they are usually formed in ‘forests’ or ‘arrays’ on a plate that’s been exposed to extremely high temps for a couple of hours.

13. How are CNTs formed? • CNT’s are often produced in labs for testing. Their creation usually invloves; • A small silicon plate coated with iron particles • A special mix of gases containing carbon atoms such as acetylene • A special oven that can produce heat at over 800° C; it heats the silicon plate and mixture of gases, causing a reaction and the formation of CNTs

14. Formation of CNT’s • The silicon plate is usually removed from the oven after a couple of hours, and a small ‘forest’ of carbon nanotubes is present on it • On one small, inch-long plate over 1 billion CNT’s are usually present in a newly created forest

15. Formation of CNT’s • After a forest of CNT’s are formed, they are usually ‘spun’ into a long thin thread • Its spun by pulling out one CNT from the forest, and then the others follow to form a CNT ribbon or thread This picture shows a forest of carbon nanotubes being pulled into a thread

16. Formation of CNT’s • In carbon nanotube forests, the nanotubes like to stick together due to strong Van Der Waals forces that are present at the nanoscale • When a CNT is pulled out, the Van Der Waals forces causes the surrounding CNT’s to be ‘snagged’ with it, which is why the CNT’s seem to be pulled out forever when pulling from a CNT forest and why it forms an extremely long ongoing thread • The resulting CNT threads are usually 1/1000th the thickness of human hair and stronger than steel

17. Applications of Carbon Nanotubes • Because of their enhanced properties, CNTs have a surprisingly large amount of possible real-world applications, especially in improving efficiency and strength of current technology • Ex 1: due to its electrical conductivity, carbon nanotubes can be used to improve the efficiency of electrically run technology and save energy and resources • Ex: Carbon nanotubes can possibly help in improving battery life of lithium batteries • Ex 2: The high strength and elasticity of CNT’s can be very useful for probe tips on very high-resolution scanning probe microscopy

18. Properties of CNT’s (cont.) Ex 2: This above diagram shows the possible advantages of using carbon nanotubes in technology by comparing a probe’s capabilities with and without an added CNT tip.

19. Properties of CNT’s (cont.) • CNT’s thermal conductivity abilities is being taken advantage of to try and create better nanoscale electronics, sensing and actuating devices, and reinforcing fibers in functional composite materials • Ex 3: If CNT’s can conduct electricity and heat in subzero temperatures, they can help to improve electronics working capabilities in extreme cold • CNT’s strength and size capabilities can be taken advantage of to improve health and consumer products • Ex 4: CNT based water and air filtration systems have already been produced by companies which can block some of the smallest particles and possibly kill bacteria as well, which can help better health conditions of homes and living spaces

20. Applications of CNT’s (cont.) • As far as scientist know about CNTs currently, CNTs have almost no environmental or physical degradation issues, like that of which are common to metals • This includes thermal expansion/contraction, corrosion and sensitivity to radiation; all of these factors which can result in greater system failure in performance-sensitive applications in areas like aerospace and defense, aviation, automotive, energy, and consumer products • By using carbon nanotubes in place of metals and other materials, there is a very good chance that all of these factors above can be lessened

21. Conclusion • Carbon atoms are very special atoms that can form multiple different materials with unique and very beneficial properties, including carbon nanotubes • CNT’s have many amazing properties, including their high strength, high conductivity, and extremely small size • CNT’s are easy to produce and very strong in forces, despite their nanoscale size • Carbon nanotubes have an ever-increasing window of real-world applications that can help to increase human technology and efficiency, and they are also more environmentally friendly as of current knowledge

22. References • http://www.livescience.com/28698-facts-about-carbon.html • http://phys.org/news/2014-03-carbon-nanotubes-real-world-applications.html • http://cheaptubes.com/cntapplications.htm • http://www.nanocyl.com/jp/CNT-Expertise-Centre/Carbon-Nanotubes • http://www.nanocomptech.com/what-are-carbon-nanotubes • http://science.howstuffworks.com/nanotechnology2.htm • http://www.understandingnano.com/nanotubes-carbon.html • https://www.youtube.com/watch?v=19nzPt62UPg • https://www.youtube.com/watch?v=3QqR8UcoJ-c

23. Catalog Entry • “Discover what carbon nanotubes are and how they work, what its origins are, how to make a nanotube, and what they can be possibly used for today! Throughout this short powerpoint, you will gain a basic understanding and background of carbon nanotubes and all of the cool little things that makes a carbon nanotube a carbon nanotube!”