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Ionic polymers open door to greener, safer explosives
Chemistry World ^ | 13 January 2012 | Phillip Broadwith

Posted on 01/18/2012 12:02:09 AM PST by neverdem

Highly sensitive explosives could become safer and greener by exploiting newly characterised ionic polymer structures, say chemists in the US. Such materials could replace explosives based on toxic heavy metals like lead and mercury salts.

Sensitive materials are routinely used as primary explosives in detonators to set off larger amounts of less sensitive high explosives in mining or military applications. The challenge is to make them stable enough to be handled safely in the field, but also sensitive enough to detonate reliably, packing as much energetic punch as possible. 'It's a very fine balance,' says Louisa Hope-Weeks of Texas Tech University (TTU) in Lubbock, who led the research.

'We wanted to make an optically activated material,' explains Hope-Weeks, 'so that if, for example, a bomb squad want to blow up a car they suspect has a terrorist device inside, they would have something they could remotely place under the car and then activate it with a laser, rather than someone having to go in there and wire it up.' 

While none of the materials the group has so far made has reached this goal, by making and solving the x-ray crystal structures of three materials based on metal hydrazine polymers, the team can relate the materials' properties to their structures.  

However, this kind of research obviously comes with significant hazards. These compounds are the same ones that caused a serious explosion in Hope-Weeks's lab in 2010, seriously injuring Preston Brown, one of the contributors on this paper. 'There was a lot learned from that accident, both from the students' point of view and my own,' comments Hope-Weeks. 'I've changed the way I manage my whole lab, and TTU has responded across the board.'

All this made for some nerve-racking moments in the crystallography lab. 'In the case of nickel hydrazine perchlorate, which we knew was very sensitive, we did need to cut a crystal to get one the right size,' Hope-Weeks says. 'I did that myself.' However, she points out that no particularly special crystallographic equipment was needed, since the size of crystals used - had they exploded - would not have caused significant damage to the diffractometer.

Thomas Klapötke, an energetic materials expert from the University of Munich in Germany, is impressed by the team's efforts at crystallising and characterising the materials. 'This is not easy, as these kinds of polymers often tend to crash out of solution as powders,' he says.

Explosion with chemical structures

Structural differences between nickel hydrazine perchlorate (left) and nickel hydrazine nitrate (right) can explain their sensitivity and energetic properties

© Adapted from J. Am. Chem. Soc.

The knowledge Hope-Weeks has gained should help her understand, tune and refine the stability and energetic properties of related compounds. For example, in nickel hydrazine nitrate - which is already used as a primary explosive, but whose crystal structure was unknown - each metal atom is linked to the next by three bridging hydrazine ligands. However, in nickel hydrazine perchlorate, only one hydrazine bridges between metal centres, with four more hydrazines coordinated to each nickel. This means the whole polymer is less strongly held together, making it significantly more sensitive. And when it does explode it can release more energy, because of the potential to produce more nitrogen gas per metal atom and form more thermodynamically stable products like nickel chloride rather than nickel metal. Changing the metal to cobalt produced a material with the same structure, but that was significantly less sensitive

One of the advantages of this class of materials is their tunability, explains Hope-Weeks. 'We can try different metals, different anions and other ligands,' she says, 'which might allow us to tweak the properties just enough.'

Klapötke agrees that there are many options to explore. 'These ionic polymers are very interesting, especially because they are not hygroscopic and non-toxic,' he points out. 'This gives them a long shelf-life because they don't react with water, which might alter their sensitivity and make them unreliable.'

 

 

References

O S Bushuyev et alJ. Am. Chem. Soc., 2012, DOI: 10.1021/ja209640k

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TOPICS: Culture/Society; News/Current Events; Technical; Testing
KEYWORDS: banglist; chemistry; ionicpolymers
Ionic Polymers as a New Structural Motif for High-Energy-Density Materials
1 posted on 01/18/2012 12:02:17 AM PST by neverdem
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To: neverdem
'We wanted to make an optically activated material,' explains Hope-Weeks, 'so that if, for example, a bomb squad want to blow up a car they suspect has a terrorist device inside, they would have something they could remotely place under the car and then activate it with a laser, rather than someone having to go in there and wire it up.'

Hoo boy, it would seem safer to have something with a string you could pull. Granted not likely someone's going to be playing around with a laser pointer there, but still....

2 posted on 01/18/2012 12:09:58 AM PST by HiTech RedNeck (Sometimes progressives find their scripture in the penumbra of sacred bathroom stall writings (Tzar))
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To: neverdem

Is this like how we need safer bullets?


3 posted on 01/18/2012 12:15:06 AM PST by LukeL (Barack Obama: Jimmy Carter 2 Electric Boogaloo)
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To: neverdem

bookmark


4 posted on 01/18/2012 12:22:51 AM PST by DarthVader (That which supports Barack Hussein Obama must be sterilized and there are NO exceptions!)
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To: HiTech RedNeck

Am I nuts, or are they giving the goods away to the bad guys?


5 posted on 01/18/2012 12:26:45 AM PST by Thebaddog (Remember, Obama said he's only 60% done with his agenda.)
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To: Thebaddog

There are so many publicly known ways to make explosives today, green or brown. A suicide bomber is hardly going to worry about a little mercury. BUT — if this is a new, more powerful stuff than anything known before, or easier to sneak on an airplane, that might be a problem.


6 posted on 01/18/2012 1:05:51 AM PST by HiTech RedNeck (Sometimes progressives find their scripture in the penumbra of sacred bathroom stall writings (Tzar))
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To: neverdem

Thanks Doc.....


7 posted on 01/18/2012 2:01:56 AM PST by Squantos (Be polite. Be professional. But have a plan to kill everyone you meet)
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To: LukeL

I tell my liberal friends I am very a environmentally aware recycler, I kill with a crossbow. Their minds are so fun to play with.


8 posted on 01/18/2012 2:13:13 AM PST by momincombatboots (Back to West by G-d Virginia.)
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To: neverdem

I hope their green explosives work better than Diamond green-headed Green Strike Anywhere kitchen matches. They suck. One out of three just fizzle without ever creating a flame and that’s striking them on the box.


9 posted on 01/18/2012 3:20:18 AM PST by TigersEye (Life is about choices. Your choices. Make good ones.)
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To: Thebaddog

So I guess the tree huggers and the jihadist symathizers will be happy to know that the terrorists now can be green, safe and more humaine while the victims can rest easier knowing thier murderers are compliant with government regulations.


10 posted on 01/18/2012 3:55:54 AM PST by ronnie raygun (V)
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To: Squantos; Tijeras_Slim

things that go boom ping


11 posted on 01/18/2012 4:27:48 AM PST by Tainan (Cogito, ergo conservatus sum)
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To: phockthis

sfl


12 posted on 01/18/2012 5:41:13 AM PST by phockthis (http://www.supremelaw.org/fedzone11/index.htm ...)
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To: momincombatboots

Try telling them you only kill baby seals with a wooden club and with them blow out their doughnut.


13 posted on 01/18/2012 6:01:09 AM PST by IMR 4350
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To: IMR 4350
Hmmm -- seems I have seen this incomprehensible post elsewhere this morning...

(Not questioning the premise -- just that of the senseless expression thereof...) Please re-state WTH you were trying to say -- in good clear English.

14 posted on 01/18/2012 11:22:15 AM PST by TXnMA ("Allah": Satan's current alias...)
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To: neverdem

15 posted on 01/18/2012 11:31:10 AM PST by bert (K.E. N.P. +12 ..... Crucifixion is coming)
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To: IMR 4350

I like that.. it has a neanderthal environmentalist slant to it. :) So I guess we will call it “ethically sourced wood”.


16 posted on 01/18/2012 11:52:58 AM PST by momincombatboots (Back to West by G-d Virginia.)
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To: Thebaddog; HiTech RedNeck; Squantos; Travis McGee; Tainan; bert
Am I nuts, or are they giving the goods away to the bad guys?

This stuff is about as stable as the compound made from acetone and hydrogen peroxide by the jihadi bombmakers who lose their hands in the process. It's more like fulminate of mercury used in primers for small arm cartridges. Using it as the main charge isn't too smart. Since chemistry was my major in college, I wanted to see nickel hydrazine perchlorate's formula and structure, but I had no luck, even at ChemSpider.

While scanning those Yahoo links, I found that Hope-Weeks's lab was working under a Dept. of Homeland Security contract, IIRC. Hope-Weeks gave instructions to her grad students not to make more than 100 milligrams of it at a time. That's one tenth of a gram. One idiot decided to make 10 grams of it, IIRC. He was left handed, and lost three fingers from his left hand after he started using a mortar and pestle on it!

17 posted on 01/18/2012 1:29:48 PM PST by neverdem (Xin loi minh oi)
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To: Tainan

Printed out for future confusion.....:o)

Grateful....


18 posted on 01/18/2012 3:15:28 PM PST by Squantos (Be polite. Be professional. But have a plan to kill everyone you meet)
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To: neverdem

If was easy ......:o)


19 posted on 01/18/2012 3:25:27 PM PST by Squantos (Be polite. Be professional. But have a plan to kill everyone you meet)
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To: neverdem

Thanks. There’s a lot of intillectual horsepower here.


20 posted on 01/18/2012 4:01:46 PM PST by Thebaddog (Remember, Obama said he's only 60% done with his agenda.)
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To: El Gato; Ernest_at_the_Beach; Robert A. Cook, PE; lepton; LadyDoc; jb6; tiamat; PGalt; Dianna; ...
How Terahertz Waves Tear Apart DNA (Technology to be used in NYC street scanners)

10 Surprising Health Benefits of Beer

Red-Wine Researcher Charged With 'Photoshop' Fraud (Accused Dr. blames "racial hatred")

Diet, nutrient levels linked to cognitive ability, brain shrinkage

FReepmail me if you want on or off my health and science ping list.

21 posted on 01/19/2012 12:58:18 AM PST by neverdem (Xin loi minh oi)
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To: neverdem

1. green bullets
2. green fuel
3. gay sensitivity training for US Marines in the field
4. green explosives

Ummm......I see a pattern.


22 posted on 01/19/2012 1:05:42 PM PST by gaijin
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To: Squantos; Tainan; archy; Jack Hydrazine
I finally thought there probably were other nickel hydrazine complexes, and I found this.

Novel Polynuclear Nickel(II) Complex: Hydrazine, Sulfato, and Hydroxo Bridging in an Unusual Metal Hexamer. Crystal Structure and Magnetic Properties of [Ni6(N2H4)6(SO4)4(OH)2(H2O)8](SO4)(H2O)10

The sulfate anion, that's the yellow sulphur atom bound to four red oxygen atoms, has a charge of minus two. The perchlorate anion has a charge of minus one. So my guess is that there are twice as many perchlorate anions in nickel hydrazine perchlorate that use an oxygen to oxygen bond, like you find in hydrogen peroxide, bonding adjacent perchlorate anions, IMHO, so that the net charge of the molecule is zero. (The pale green Ni atoms are nickel. The dark blue N atoms are nitrogen. The unmarked dark atoms bound to nitrogen are hydrogen.)

What Is A Coordination Compound?

Hydrazine gives the best performance as a rocket fuel, but it has a high freezing point and is too unstable for use as a coolant.

Perchlorates can be very strong oxidizing agents, e.g. The mixture of a perchlorate and any organic material may result in explosion that may be touched off by friction...

23 posted on 01/19/2012 2:11:26 PM PST by neverdem (Xin loi minh oi)
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To: gaijin
Have you ever used small-arms ammunition equipped with lead-free primers?

I have.

From a shooting perspective, they went "bang" every time, hit the target, and showed the same muzzle velocity for bullet weight as similar lead styphnate primed ammunition.

From a reloader's perspective ... looks like I don't have to tumble the brass. It comes out of the weapon already clean.

24 posted on 01/19/2012 2:20:47 PM PST by ArrogantBustard (Western Civilization is Aborting, Buggering, and Contracepting itself out of existence.)
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To: AdmSmith; AnonymousConservative; Berosus; bigheadfred; Bockscar; ColdOne; Convert from ECUSA; ...

I was really worried about that. There was a news story online about how the Russians have built an even more powerful version of the US’ MOAB, and tried to sell it as green technology by pointing out that it doesn’t generate nuclear fallout.

It also isn’t very powerful compared with a nuke, of course. And it’s not as if they’ve scrapped their nuclear arsenal.

Thanks neverdem.


25 posted on 01/19/2012 6:31:13 PM PST by SunkenCiv (FReep this FReepathon!)
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To: neverdem

I have more family than I realized!


26 posted on 01/19/2012 6:55:17 PM PST by Jack Hydrazine (It's the end of the world as we know it and I feel fine!)
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