Solomon
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simple room temperature Carbon Nanotube synthesis
I am planning to synthesize carbon nanotubes and am wondering what gas mask I should use. Would any decent chemical mask from lowes be sufficient? Am
using the following method:
http://arxiv.org/pdf/1007.1062.pdf
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WGTR
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Personally, I would do this one in a fume hood, or with a big fan.
This link may provide a little bit of peripheral context to what you're planning to do. The nanotubes
are essentially rolled-up sheets of graphene oxide. The process releases yellow clouds of NO2.
Something to consider is that a mixture of chlorate, H2SO4, and fuming HNO3; needs to be kept
away from any and everything organic, except for your graphite. Even then, note that the
addition of chlorate is done carefully and slowly. This is definitely intentional.
My experience is with the improved method using KMnO4 instead of KClO3, so I don't know all of
the safety precautions needed for the chlorate method. In the situation with KMnO4, manganese
heptoxide is produced, which can spontaneously detonate above 55*C. That's why you only
heat the mixture up to 50*C. Unfortunately most papers don't mention this little fact, since it is
assumed that you already know how not to maim yourself.
Either method that you use, powerful oxidative conditions are present, and I'd encourage
you to read all that you can from different sources to get familiar with it first. If you can find a
paper that uses a H2SO4/H3PO4/KMnO4 method (and a room temperature one), this is probably
safer in regards to the amount of gasses that are being produced, and could be done safely
outside with the initial reaction kept loosely covered. Manganese is toxic by inhalation, as an FYI.
[Edited on 31-12-2013 by WGTR]
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Solomon
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http://www.homedepot.com/p/3M-Tekk-Protection-Professional-M... is the mask i will use. I hope it will provide adequate saftey. In addition, a
small fan will be used as a fume extractor. Should this be adequate? Would a common glass beaker or measuring cum suffice as reaction vessel?
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Solomon
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Would 99.5% pure graphite of 5 micron diamiter be adequate for the reaction procedure. I doubt it but could drain cleaner work for sulfuric acid as it
is only about 93% pure
[Edited on 1-1-2014 by Solomon]
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WGTR
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We'd really have to know the part number for the filter itself, so we could look up the specs for it.
I wouldn't trust a Home Depot ad.
I personally think that respirators with cartridges should only be used in situations where the fumes
would be a mere nuisance without the mask. In other words, don't depend on it. When I was
getting set up to paint my car, my first thought was to use one of the cartridge-type masks, since
they were cheap. The professional paints used these days contain isocyantates, and I found
that the small amounts that get through the cartridges were enough to cause serious problems,
to make a long story short. Anyway, I ended up having to buy a supplied air respirator, complete
with a 50 foot long air hose. It was very expensive, but it provided protection for my lungs
and eyes.
In my opinion, I think there's a better way to approach this. Instead of trying to make the air
breathable, put the extra effort into supplying fresh air to your work environment. For example,
you can make a simple chimney out of either a long cardboard box, or a wooden frame. It only
has to be strong enough to support the fan (and wind gusts), which would be used to pull air
over your stir plate, and out the top. Hey, if it's a wooden frame, it's even possible to cover
it with plastic wrap. In any case I'd recommend exhausting the air straight up, so it goes over
your head.
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WGTR
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Well, it calls for 45 micron powder size, so you won't get exactly the same results that they did.
Even if you follow their directions to the letter, you might not get the same results they did.
The exact way that oxidized graphite behaves can depend on quite subtle variables, and it may
take several tries to learn what to adjust to get a repeatable result. What will save you a lot
of lab time in the long run is to read up every journal you can that deals with the same general
procedure, and learn how each result varied from the others, and why. Sometimes you may
learn that there is a more common way of doing what you're trying to do, and that more
supporting literature is available if you go about things a little differently. I've found that to be
the case in my own personal research sometimes.
The extra 0.5% of impurity probably won't give you trouble in this synthesis, since the environment
is heavily acidic and oxidizing (i.e., heavily contaminated). The offending impurities are probably
nickel or iron, as these are quite common in natural graphite. Where it may give trouble is in your
final product, depending on what the nanotubes are being used for.
93% sulfuric acid may work, but the reaction is sensitive to extra water, so it won't work the
same way. Note that fuming HNO3 is >90% concentration, not the usual 68% stuff. This is one
reason why I suggest finding a journal that does this procedure, but with
(98%)H2SO2/(85%)H3PO4/KMnO4. Concentrated phosphoric acid is dangerous, but it doesn't
fume like fuming nitric does, and it's more easily obtained.
Edit:
I browsed the 'net for a bit, and didn't see a method that involved using KMnO4. That's rather
odd, as usually there would be at least one journal describing how someone tried it and it didn't
work. Anyway, sonochemical synthesis of carbon nanotubes is another attainable method, and
there actually are a number of papers on this method. Sonochemistry here is a fancy word
for sticking your test tube of chemicals into an ultrasonic cleaner. The starting chemicals
vary. Some used chlorobenzene, some dichlorobenzene; others ferrocene. I can provide links
next time I'm at work if there is any interest.
[Edited on 1-1-2014 by WGTR]
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Solomon
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I could simply react sulfuric acid and KNO3 for my nitric acid and order KClO3 online and hope for the best (the successful synthesis of CNTs without
dying)
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