1
$\begingroup$

According to a web page I can no longer find, some brittle materials such as glass have a very high theoretical strength but they tend to have surface cracks which magnify tension at the tip greatly lowering the observed strength. I believe that when a substance has the ability to keep being pulled thinner, it is as ductile as possible and cannot undergo fatigue. I think a material is as malleable as possible when it can keep being squeezed thinner without breaking. If a material is as malleable as possible, that doesn't necessarily mean it is as ductile is possible. Pushing a material thinner in one direction is like pulling it thinner in two directions in a really high pressure environment and I guess really high pressure can make a material as ductile as possible that isn't normally. Therefore under normal conditions, being as ductile as possible is a stronger property than being as malleable as possible.

I'm looking to see if buckminsterfullerene, the substance composed of C60 molecules in the shape of a soccer ball is as ductile as metarials can possibly be under normal conditions, that is, it can keep being pulled thinner and thinner like gold. It might not only be as ductile as possible but also have an insanely high yield strength. In addition to that, I believe almost everything would have more cohesion than adhesion to it. I read that soot has C60 molecules in it and I also collected soot and observed with my own eyes that soot was hydrophobic so I'm wondering if soot is made of buckminsterfullerene particles. Since it's hydrophobic, that means water's adhesion to it is less than half its cohesion. It only has to be a tiny bit less than half. Then extreme roughness of the collected soot will be even more hydrophobic.

According to https://www.azonano.com/article.aspx?ArticleID=5158, buckminsterfullerene is very ductile. According to https://faculty.csbsju.edu/frioux/c60/BondingC60.pdf, each buckminsterfullerene molecule has 90 localized bonds between 2 carbon atoms and 60 electrons delocalized throughout the entire molecule. Probably 30 delocalized orbits each of which has 2 electrons. Also according to that pdf file, its molecules form a face centered cubic arrangement.

Because of the hybridization scheme of each molecule, I expect that if you have just two of them held together by Vanderwalls forces, it would take a lot less force to get one sliding along the surface of the other than it would to pull them apart from each other. Since they form a face centered cubic arrangement and can slide along one another so easily, I'm wondering whether with sufficient tension, that material will just keep being pulled thinner and thinner and just round the tips of any cracks and therefore be totally immune to fatigue.

However, it does not mean nothing can make it undergo brittle fracture. For example suppose you made it into the following shape. A sphere with ring hooks on its surface. Now add to the surface of it even smaller ring hooks all over its surface. Now add even smaller ring hooks all over the surface of this shape. Now if you start tugging on all of the hooks of any size, it will create tension in all 3 directions in the interior of the sphere and may lead to brittle fracture even if it can normally keep being pulled thinner and thinner.

I wonder what the ductility of C$_{60}$ is? In particular, have there been any quantum mechanical calculations of this ductility? If none have been done before, how would one go about doing this quantum mechanical calculation?

However, an answer to the second question cannot be used by me. I will not understand it but it doesn't hurt to ask it. Maybe a researcher will be able to read and understand the answer to that question and use it to help them invest in research on building materials. An answer on whether there was a lab report confirming by observation whether it can keep being pulled thinner and thinner will also do.

$\endgroup$
6
  • 1
    $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – Tyberius
    Jul 7 '20 at 1:57
  • $\begingroup$ I hardly know anything about quantum mechanics. I don't want to go through the bother of studying it so hard. It's a really long slow thing to learn. I'm just looking for an answer by somebody who makes the calculations for me and then just gives me the answer of how ductile it is. Maybe some day, I will read "Principals of Quantum Mechanics" but it's not on my mind now. $\endgroup$
    – Timothy
    Jul 7 '20 at 2:54
  • $\begingroup$ I know a small bit like the hybridization scheme of all the elements up to neon which I learned in a course called Physical Inorganic Chemistry. $\endgroup$
    – Timothy
    Jul 7 '20 at 2:56
  • 2
    $\begingroup$ You cannot ask people to do QM calculations for you here. That would be a research project. You can contact a professor by email and ask them to do a the calculation, but here you can only ask if it's been done before and how to do it (so I've rollbacked). $\endgroup$ Jul 7 '20 at 11:51
  • $\begingroup$ @NikeDattani Now I think it would have been better to instead ask a different question on whether there has been research on the ductility of C60. $\endgroup$
    – Timothy
    Jan 5 at 18:55