deltaH
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Fuel perhydrate clathrate energetics?
Methane clathrate is a flammable ice-like material where methane molecules have been trapped in the crystal structure of an ice of sorts. A typical
empirical formula is CH4·5.75H2O. See https://en.wikipedia.org/wiki/Methane_clathrate for more info.
Now I was wondering if one could form methane clathrates with hydrogen peroxide, since hydrogen peroxide also forms strong hydrogen bonds? That might
make a neat frozen rocket monopropellant?
Sadly my google foo is failing me, no luck finding anything on hydrogen peroxide clathrates of any gas, but surely they exist???
SM please help!
[Edited on 9-10-2015 by deltaH]
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deltaH
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Doing some background reading on clathrates, they typically need high pressure and cold to form but then afterwards they are metastable, so you can
remove the pressure and handle the ice so long as you keep it cold?
With chlorine though, you can form a gas hydrate simply by bubbling chlorine gas through water 0°C < T < 10°C under light pressure and you
will get transparent slightly yellow crystals of the hydrate.
Now hydrogen peroxide is supposed to form stronger hydrogen bonds than water AFAIK, but then chlorine has a much higher boiling point than methane.
What one would need is a fuel molecule that is very inert, small, not very volatile and be slightly soluble in cold H2O2 ideally at ambient pressure.
hmm... any ideas, I will also think on it.
IDEAS SO FAR:
dimethyl ether, it's a type of LPG/diesel additive
I think it's suitable because: b.p. −24°C so not too volatile
Solubility in water: 71g/l at 25°C, that's slightly soluble.
Ok so a possible hypotherical route, bubble DME gas through a slush of partially frozen hydrogen peroxide. Filter clathrate ice crystals and compact
into final shape while keeping it cold?
dimethyl ether cannot form explosive peroxides, so it should be safe from that point of view, though the peroxide perhydrate clathrate may well be
explosive and of unknown sensitivity.
That would make this a Sprengel like explosive most likely and probably a heck of a lot more sensitive than the methane version, so not useful for
rockets 
[Edited on 9-10-2015 by deltaH]
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deltaH
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Aha, according to this abstract, DME can form two clathrate hydrates with water, so it seems a good candidate.
They require lower temperatures than expected, BUT this might be higher with hydrogen peroxide because it's a larger molecule and forms stronger
hydrogen bonds.
Also not that the clathrates have a relatively large ratio of dimethyl ether to water, that would be good for potentially energetic profile of the
peroxide version.
Reference:
http://pubs.acs.org/doi/abs/10.1021/j100538a004
Since 50 wt.% H2O2 solution has a m.p of -51°C, it can simply be immersed in a salted ice bath and then have the DME gas sparged through it slowly to
yield the perhydrate 'ice'?
[Edited on 9-10-2015 by deltaH]
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deltaH
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Another version:
acetone and H2O2... avoiding forming acetone peroxide, rather trying to form acetone perhydrate.
Possible route: Cool acid free conc. H2O2 in CaCl2-ice slush bath, then add acetone and recover crystallized acetone perhydrates while still extremely
cold and do not store?
This version would probably be a sensitive but powerful energetic (not a good combination). As a side note, the density of solid hydrogen peroxide is
1.64g/cm3, but the hydrates will probably be a little less dense.
[Edited on 9-10-2015 by deltaH]
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Detonationology
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I'm curious of the shock and friction sensitivity of this stuff.... hmmm 
“There are no differences but differences of degree between different degrees of difference and no difference.” ― William James
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deltaH
Dangerous source of unreferenced speculation
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The acetone version, while probably easiest to try to make, would probably be too sensitive, but I think less so than the 'formal' cyclic acetone
peroxides.
But I'm most interested in the dimethyl ether version for some reason (maybe my gut suggest it might be less sensitive).
Also, I think it might form at ambient pressure by bubbling DME though very cold 50% H2O2. Aside for a CaCl2 ice bath, one might simply throw in dry
ice to 50% peroxide to get it partially frozen... something CaCl2/ice can't do, so dry ice would be preferable.
The only problem, DME is neither easy to make nor obtain. Well maybe 10 years from now, it's touted as the next big thing in fuels, LPG and
refrigerants.
[Edited on 9-10-2015 by deltaH]
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