h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: Evaporating Thin Films of Carbon60 - A685857
Author: Researcher 175309 - U175309

This is a description of the tricky process of evaporating C60 (a type of carbon). It's quite difficult and I've never seen it in any literature. I learned this process through word of mouth by a mentor and I thought that it should be published somewhere.

why is it expensive?

carbon 60 (or buckyballs) can be simply made by using a carbon arc in 1/7th of an atmosphere of inert gas.

you then purify it using a standard laboratory solvent (I can't recall which one at the moment).

This should make the stuff relatively cheap.

so where does the expense come in (or is that due to the required purity)?

The "carbon arc in helium" method is the best way of making it and it produces between 20%-40% fullerines in all the soot. So all the soot has to be dissoled in benzene or chlorobenzene. It's easy and cheap so far... (although benzene use is severly restricted now 'cos it's so dangerous, mind you chlorobenzene isn't too nice either).

You then have to use chromatography to seperate out all the soot from the fullerines. This takes time and has to be done again and again until the required purity is reached and this is the exensive part.

At the moment you would pay about €200 per gram for 99.5% C60 which is the best price I've seen yet. It used to be $5000 per gram!

A c60/C70 mix 99% pure is much cheaper with 12% of the total being C70 although this is not too useful in most experiments, (not the ones I do anyways)

Barry
stop me if I'm boring you

I would have thought that there was a better way of doing this.

I don't know spesifically, but surely passing the stuff through a filter (like in reverse osmmosis) might select for size, or using asymetric catalysis should make it so that you can attach to the isomers? of the left and right forms of c-70 (or am I thinking of c-72) allowing you to extract those easily from the sample, thus causing increased purity.

or am I completely talking out of my hat as regards the current state of the art?

these sorts of techniques were being talked up a lot as having incredible potential in the early 90's.

Your entry makes no mention of is name of buckminster-fullerine, the links to C60 aren't appropriate. Also, you don't mention its history - vital to the story, surely? The entry could do with some headers, a bit on uses of the stuff, etc.

A good start, apart from that!

Whoami?

Was just pondering the link thing - presumably the entry is in standard text, and the dna parser has read them and recognised them as a guide page, and made them into links - to avoid this will putting the entry in guideML be enough, or will the tag need to be used? The formula C60 has to be written somehow after all.

vp

GuideML will do the trick. Still, I think it needs to expand into an entry on the bucky ball to give it some substance.

Whoami?

I have an entry on C60 itself in preperation. This article is only about the evaporation of such and nothing more.

Stay tuned for my C60 article which covers history and basic properties.

Barry
(a man, not a toy)

I'm pretty sure C60 does not have isomers, neither does C70 (both of them being highly symmetrical). Some of the other fullerenes might do, but I know little or nothing about them.

I am not a chemist but read solid state physics so..... but many companies such as Sigma and Hoescht all produce and purify this way, so I am told by one of the chemists in the lab.

Nanotubes could be a different matter though.

Barry
(A man, not a toy)

right. in that case, I amn definately thinking of c-72 which definately is chiral.

I still can't help thinking that making use of the active sites on the molecule with asymetrical catalysis would be a more effective way of seperating out the different forms.

Oh well, I will have to go away and think about it.

PS. if you use C-60 rather than C60 it seems not to get it wrong.

The secret on what you need to do is use guideML - visit the <./>GuideML-Clinic</.> for hints and tips. If you want, try going to <./>Test696260</.> and borrow the code from there. While GuideML isn't a must for recommendation, it's used for each and every Edited Entry, and if the author does it, they get to get the entry exactly how they envisage it - well, almost. There's a standard format, but you get more control, certainly.

Yes. I edited the article substituting C60 for Carbon60. Although this might end up being tedious to read...
I'm going to investigate GuideML and rewrite it using it, but I'm a bit busy at the moment. Hopefully I'll have the much demanded article on C60 history and basic properties up by the weekend.

Regarding purifying C60 by using active sites...all of the 60 free electrons on C60 are usualy delocalised so there are no active sites as such, unless you use charge, temperature, lattice imperfections or other methods to try and change this (I could be wrong here). But this is the extent of my knowledge as to what's going on electronically.

By using simple GuideML, you could use tags to get the appropriate subscript 60. A good subeditor would be happy to do this, but you might want to do it yourself just to make sure. If not, I'd be happy to pre-edit the code for you as a copy of the entry - you could just copy and paste then, and alterations would be yours to make. If you allow it, I'd be happy to sort it for you.

Whoami?
Scout, Sub-Editor

OK! Another revision. I done it in GML this time. Sorry about the delay in replying but I've to submit a paper by Thursday which could end up published in Chem-Phys Letters, so that had to take precedence.

Again, I'm planning to submit an actual C60 description over the weekend, but me being Irish and St. Patrick's Day coming up and all means I could end up drunk all of a sudden...

Anyways, further comments welcome...

Barry

Well done with the GuideML - you've done well. Overall, looking good, but I can't help feeling that some headers/subheaders under the idea of the 'What? When? Where? Who? Why?' variety might be useful.

Keep up the good work,

Whoami?

I'll work on it!