Logan Smestad's Carbon Nanotube Research
This page will be devoted to information about carbon nanotubes and the immense strength that is attributed to their structure. For more information about the background of carbon nanotubes and how they are shaped please visit this sister website that was created. Carbon Nanotube Website
Also in starting this project I read a scientific article which had some pretty good information and was a great starting point. Here is a link to this website.
Ultimate Strength of Carbon Nanotubes
The carbon nanotube is the strongest material that has been created and is reported to have a theoretical tensile strength of 120-150 Giga Pascals. They are 100 times stronger than that of steel with one sixth of the weight.
Due to the immense tensile strength of carbon nanotubes there are many helpful applications for it. For example scientists are working on creating nanotube sheets which may be used as solar sails to catch the solar wind from the sun. The current sails made of Mylar and Kapton are similar in strength to the carbon nanotube sheets however they pail in comparinson to their overall weight. In theory a square kilometer sheet of carbon naontube would weigh just 30 kilograms. This technology can create major breakthroughs in terms of space exploration.
For this part of the project I decided to stray from our main project about the intriguing way that carbon nanotubes interacts with water and study their strenght properties. To do this I was able to take advantage of a program called WebMO to do calculations having to do with the energy levels within the bonds of a carbon nanotube structure. In doing this I first started out by doing a small calculation with a benzene ring just to see what the energy output was. 
The output values showed that their bond energy was as follows.
Next I did this same calculation only using a small carbon nanotube made up of multiple benzene rings. To do this I first needed to do a geometry optimization for the model I created which turned out like this.
The output values in this model showed that the bond energies were as follows. The bond length within this molecule was 1.438 Angstroms.
Finally I took this model of the carbon nanotube and tweaked it by stretching some of the bonds within the structure. By doing this it weakened the overall molecule and I was given energies that were much higher than those when the molecule was stable. For this molecule the bond length was 2.761 Angstroms.
With this small change in bond length then energy of the molecule increased from 1545.2619 kcal/mol in the nanotube that was unstretched to 2175.90602 kcal/mol in the nanotube that was stretched. This is a change of 630.64370 kcal/mol with a change of only 1.323 Angstroms, a relatively high energy change for such a small bond length change. This is very interesting in the fact that it somewhat shows the strength of the carbon nanotube and its overall resistance to stretching/change.
Doing this was a fairly interesting process and learning about bond lengths and the structure of a molecule. It showed the overall importance of molecule's strength and helped model the overall rigidity of a carbon nanotube. For me it was an experience just to be able to use some of the programs such as Gaussain 03 as well as WebMO to draw and create models and then be able to run calculations on them. I felt that I was able to learn a great deal from this process.