- Type of One-dimensional Nanomaterial.
- Carbon is very abundant in nature. They exist in different forms from the rice you eat to the petrol burn to the diamond you wish to wear.
- Petrol, rice, diamond all appear different though they are made of same thing (at least in part).
- How is it possible? It’s all about how the atoms arrange that decides the formation of different substance you see.
- If you take carbon and heat it up to very high temperatures the carbon atoms arrange themselves like clusters each made of 60 carbon atoms. (they become stable by arranging themselves)
- If you make a cluster using 60 carbon atoms arranging them in the shapes of pentagon and hexagon you make a football like structure called fullerene or spherical buckyballs. (named after a scientist) Before this only forms of carbon know were graphite and diamond.
- These cage-like balls withstand high temperature and pressure. (you heat it more nothing happens)
- Now imagine stretching this buckyball/football into a sheet and rolling the sheet and cap it at both ends. This is carbon nanotube.
- If you have one layered tube it is called single-walled, 2 layers it is called double-walled CNTs, many more layers you call it multi-walled.
Properties of Carbon Nanotubes
- High strength with low-weight: Single-walled CNTs are 100 times stronger and 1/6th its weight. Thus, can be used to make light-but-strong materials.
- Hollow, tubular structure make it ideal as storage box. Gas, lithium, even drugs may be stored. (drug delivery)
- Very good conductors of heat and electricity.
- Can exist as both as semi-conductors and metals. In addition, we can manipulate CNTs to change from being a semiconductor to a metal and vice versa.
- Large length-to-width ratio
- Self-assembling properties: scientists have harness the ability of self-assembly of bio molecules for various applications.
- CNTs are attached to DNA and proteins to make novel materials that have unique properties.
- CNTs are mixed with other materials to make composites like conductive plastics or steel-like plastics.
- CNTs can be used to store hydrogen.
- About 2/3rd of CNTs are semiconducting and 1/3rd metallic. Separation is a problem hindering mass production
- CNTs are insoluble in water. This can be solved by attaching it with organic matter like starch.
Plant-Based CNT
- Conventionally we use petro-hydrocarbons such as methane and benzene thereby impacting its carbon footprint.
- CNTs can be made using camphor, a green plant product, turpentine, oil from linseed, mustard and cotton seed.
