 
Free radicals in the body, as suggested by the word ¡®radical¡¯, contain an odd number of electrons. |
Interactivity
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Glossary
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A Short Background on Nanotubes
From what I know, nanotubes are originally inspired by buckyballs
(short for "buckminsterfullerene"), that contain 60 carbon molecules
through covalent bonding. The shape of the ball is the uniqueness of its
structure in which 1 carbon atom is bonded to 3 other carbon atoms, giving
it physically its spherical structure. The most important thing to note
for now is that a buckyball is a sphere with approximately 1 nanometer
in diameter, and that they can be bonded to various types of atoms. (A
carbon atom contains 4 electrons in its outermost shell so it could either
take in or give away electrons depending on the element it is bonded to.
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Let me touch a bit on the usage of
these buckyballs as a medical application. As the carbon atom is hugely
versatile, buckyballs can neutralize free radicals in the body by
pairing up with the unpaired electrons in free radicals using their
delocalized electrons. Free radicals, through the word "radical"
often used in Math, contain an odd number of electrons. Due to this
reason, they are mostly very reactive and unstable. If large numbers
were present in the body, certain diseases will be caused. As they
bind to the buckyballs, their reactivity significantly decreases,
while achieving an octet structure. This stops the radical ions from
causing further damage to cell molecules. However, as the carbon atoms
in buckyballs are bonded through covalent bonding, one of the properties
of covalent bonding is that the compound cannot be dissolved in water.
As our body is mostly made up of water, buckyballs are not soluble
in the bloodstream. By covalently bonding a water-soluble molecule
to one of the carbon atoms, buckyballs can then be soluble in the
bloodstream. The process of bonding an atom to a buckyball to change
its chemical properties is called functionalisation. |
Despite its effectiveness, we observe that the number of carbon atoms in buckyballs is too few, as there are just 60 atoms in each buckyball. To lengthen the amount of carbon atoms, we cannot use a spherical shape. Researchers have found that through adding metal nano-particles to carbon atoms, carbon atoms could dissolve into the metal. As the metal nano-particles become saturated with carbon, carbon will form on the exterior of the metal particle. Through this, carbon atoms will be attached to the metal nano-particles, forming carbon chains on the particles. They will be rendered unable to assume the regular spherical shape. As we control the lengths of the metal particles, we can also manipulate the length of the carbon chains to suit our needs. Iron is often used as the metal nano-particle in the various methods of obtaining nanotubes. |
