Sciencemadness Discussion Board

Structural bond energy release

Fusionfire - 9-7-2011 at 14:45

Does anyone have more information or references to share about this interesting avenue of energetics research? :)

Somehow I find it hard to believe that solid-solid phase transitions can rival the energy output of conventional energetics which involve the breaking of weak bonds to form strong new ones with a large negative enthalpy, but I may stand to be corrected.

Also the change in entropy from a solid-solid phase transition can't be that great (compared to say solid -> gas for explosives), so I'd be suprised if the Gibbs Free Energy change is something substantially favourable/negative.
Quote:
There are many simple stable materials that can transition to lower energy states through a solid-solid phase transition. Under most conditions, these transitions are so slow that no useful work is obtained from the corresponding energy release. However, in principle, energy can be stored in the structure and released upon transition. This little known phenomenon is referred to as Structural Bond Energy (SBE) [Tananaev, et al., 1987; Dlott, 2004] and in some cases, the stored structural potential energy can be liberated so rapidly that explosion occurs, termed structural bond energy release (SBER) [Al’tschuler, 1990 and 1991]. First documented in the United States by P.W. Bridgman in 1927, these experiments generated intense interest in the former Soviet Union, as evidenced by the numerous static and shock loading experiments exploring potential SBE materials such as carbon, silicon, borides and nitrides [Al’tschuler, 1990 and 1991]. Reports generated by Bridgman detail unusual explosive behavior of various inert materials, such as chalk and ice, when the material was subjected to high-pressure and shear [Bridgman, 1927 and 1935]. Experimental research in the United States has been absent since the 1960s [Teller, 1962], and it has only been in the past few years that interest has been revived, due to the advent of computational and experimental resources to fully explore the feasibility of the phenomena.


Attachment: SBER_in_nanodiamonds_USARL.pdf (289kB)
This file has been downloaded 602 times

franklyn - 9-7-2011 at 16:23

An example would be Prince Rupert's glass , http://en.wikipedia.org/wiki/Prince_Rupert%27s_Drop

Materials that expand in volume when they undergo a solid state phase change
can fragment with some vigor though one can hardly term this an explosion.
http://www.lateralscience.co.uk/rupdrop/index.html

Shape memory alloys are the most common form of this phenomenon.
The most pronounced effect is seen in NITINOL ( Nickel Titanium Naval Ordinance Lab )
when ther material is heated beyond it's transittion temperature ( which depending on
alloy proportions can range from far below zero to over 200 ºC ) a 7 % change in the
length of one axis results. This property is exploited as a solid state heat engine.
http://www.sciencemadness.org/talk/viewthread.php?tid=5080#p...

Ballotechnics thread
http://www.sciencemadness.org/talk/viewthread.php?tid=8985#p...

P.S.
@ wizard
chime in here , you must have an item or two on this.

.

Fusionfire - 10-7-2011 at 00:08

Re: Prince Rupert's drops. Fascinating! :D

Thanks, I never knew about them until today :D

How 'bout...

The WiZard is In - 10-7-2011 at 12:04

Compounds that simple come unglued?!

Nitrogen iodide and nitrogen trichloride, ozone are examples.

I would suggest the only explosives that produce no permanent
gases .... the acetylides which simple revert to their elements —
producing a lot of heat really fast.

How 'bout the poorly understood molten metal - water
explosions?

Byda - Prince Rupert's drops are mechanical — not chemical.
They can be surprisingly difficult to make. Until you get
the knack.



djh
----
Nightsoil is probably the most valuable of
all the solid animal manures. It varies in
richness with the food of the inhabitants
of each district, * —chiefly with the quantify
of animal food they consume, — but when dry,
few other solid manures, weight for weight
can be compared with it in general efficacy.

This is said to be so well known in some of
the town in the centre of Europe, where
mixed population of Protestants and
Roman Catholics live together, that the
neighbouring farmers give a larger price
for the house-dung of the Protestant families.

JFW Johnson, M.A., F.R.SS. L. & E.
Elements of Agricultural Chemistry and Geology
CM Saxton Agricultural Book Publisher
New York 1855

PHILOU Zrealone - 11-7-2011 at 23:02

Some polymerisations may become explosive because of the heat generated by the loss of freedom levels on a molecular level and the contraction of the matrix. The heat generated becomes entrapped because the viscosity of the media increases with the molecular weight of the polymer (in other words with the advancement of the polymerisation).

If the quantity is big enough and that heat generates faster than it dissipates...a second reaction occurs because heat is strong enough to cause cracking.

A typical example is aged and concentrated H-C#N, it is endothermic and may polymerise explosively

Fusionfire - 12-7-2011 at 00:21

Quote: Originally posted by PHILOU Zrealone  

A typical example is aged and concentrated H-C#N, it is endothermic and may polymerise explosively


Would another example be the oligomerisation of acetylene?

By the way, can someone with institutional access please share the following articles on Prince Rupert's drops with Sciencemadness? :)

http://www.ingentaconnect.com/content/sgt/pcg/2006/00000047/...

http://dx.doi.org/10.1002/pssa.200925006
http://dx.doi.org/10.1098/rsnr.1986.0001

Copy and paste whole thing:
http://dx.doi.org/10.1016/0924-0136(92)90292-Z



[Edited on 12-7-2011 by Fusionfire]

The WiZard is In - 12-7-2011 at 06:50

Quote: Originally posted by PHILOU Zrealone  
Some polymerisations may become explosive because of the heat generated by the loss of freedom levels on a molecular level and the contraction of the matrix. The heat generated becomes entrapped because the viscosity of the media increases with the molecular weight of the polymer (in other words with the advancement of the polymerisation).

If the quantity is big enough and that heat generates faster than it dissipates...a second reaction occurs because heat is strong enough to cause cracking.

A typical example is aged and concentrated H-C#N, it is endothermic and may polymerise explosively




Once just Chemicals, and Now Bombs
NY Times 30ix88
By KEITH SCHNEIDER


NITRO, W.Va., Sept. 27 - The discovery of an explosive cylinder of deadly
hydrogen cyanide at an abandoned plant here has thrown into sharp
focus a potentially serious threat, posed by deteriorating chemicals, to
communities across the country.

The chemical contained in the four-foot-tall cylinder is at least 20 years old
and has undergone a slow process that has transformed a stable liquid
into a highly unstable solid believed to weigh about 30 pounds.

Ever since it was found Aug. 26 at the center of the 11-acre plant, owned
by the Artel Chemical Corporation, workers clad in white jumpsuits and
breathing from air tanks have been kept busy trying to isolate the cylinder
by carefully moving out of the way thousands of drums of chemicals that
are more stable but equally inflammable.

The Environmental Protection Agency hopes to evacuate virtually all of
this town's 8,000 residents next month and then destroy the cylinder and
its contents in a controlled explosion at the plant, which is only 1,500 feet
from Nitro's business center.

Threat to Town Centers
Federal officials here and in other regions say that cylinders of explosive
chemicals are being found at hundreds of abandoned hazardous waste
sites in communities across the country, many close to the center of town,
as in Nitro. In numerous cases, the chemicals have become so unstable
that a simple nudge can set off the blast, placing entire communities in the
path of uncontrollable fires and clouds of poisonous gases.

The plant here in Nitro is one of 1,177 hazardous waste sites for whose
cleanup Congress has already authorized $8.5 billion, with billions more to
be needed. Although it is not known how many of the sites have
deteriorating chemicals that are ready to explode, Federal inspectors and
local fire chiefs: say that their discovery of such wastes I is becoming
increasingly common.

"What we have in Nitro is typical of what we're finding now," said Stephen
Jarvela, chief of the emergency response section at the E.P.A.'s Philadel-
phia office. "Chemicals dry out, crystallize and become shock-sensitive.
Bumping, jarring, even opening them to find out what's inside, can heat
the molecules enough to-cause an explosion."


Fire Struck Elizabeth
What officials fear is an explosion and fire like the fierce blaze that
engulfed, the Chemical Control Corporation waste site in Elizabeth, N.J.,
on April 21, 1980. In that episode, two thirds of the 40,000 drums of
chemical wastes stored on an isolated two-acre site in an industrial area
along the Elizabeth River were destroyed. The cause of the fire, which
burned for 15 hours, has never been determined, although unstable
chemicals are the prime suspect. Fortunately a wind blowing eastward
carried clouds of toxic gases away from the, heart of Elizabeth, and the
clouds had largely' dissipated by the time they reached the next
population center, on Staten Island.

Here, along the eastern bank of the Kanawha River 11 miles ' west of
Charleston, workers under contract to the E.P.A. have been occupied for
months with averting a similar blaze. The Artel plant was abandoned late
last year after 35 years of operation, is thoroughly contaminated by
leaking chemicals and lies along the railroad tracks that run through the
heart of Nitro, a town that got its name from an enormous nitro-cellulose
gunpowder factory that was built by the Government in 1918.

Last June here, inspectors with the E.P.A. and the State Department ot
Natural Resources discovered hundreds of tanks and more than 4,000
drums of chemicals, many rusting an leaking. Among the chemicals
stacked in dilapidated warehouses and unsteady piles were drums of
sodium amide and chromyl chloride, both of which, when mixed with other
agents are inflammable and explosive. The inspectors also found a
railroad tank cat containing 9,000 gallons of methyl mercaptan, which is
added to natural gas to give it an odor and is as explosive as gasoline, as
well as drums that were labeled as containing phosgene, a deadly
component of nerve gas.

Federal officials, concerned that leaking chemicals might mix and produce
"an uncontrollable situation,' began to stabilize the site. But in late August,
workers stumbled upon something far more unstable, and thus fat more
dangerous, than the chemicals that had been discovered initially: It was
the cylinder of hydrogen cyanide leaning against a crumbling concrete
wall in a roofless storage shed. After building a curtain of sandbags
around the cylinder, Federal managers sought help from experts.

Manufactured for Two Decades
The cylinder and its contents were manufactured from 1948 to 1968 by
the American Cyanamid Company, one of the nation's largest chemical
manufacturers. Hydrogen cyanide was generally used as an insecticide by
exterminators, grain elevators and furriers But it was also useful in various
chemical processes, and Elmer A. Fike, from whom Artel acquired
controlling interest in the plant two years ago, said in an interview today
that he bought the cylinder of hydrogen cyanide to conduct laboratory
experiments there ir the 1960's.

Mr. Fike, who from November 1980 to February 1987 was cited 14 times
by state and Federal inspectors for numerous violations of environmental
laws, described himself in the inter view as "not a good housekeeper."

American Cyanamid was aware that hydrogen cyanide was unstable
and during the two decades when the chemical was on the market,
required customers to return cylinders every 90 days so that they could be
cleaned and refilled.

According to specialists at American Cyanamid, liquid hydrogen cyanide
forms a granular polymer over time. If a piece of the polymer is jarred
loose and falls into any liquid that may main, a violent chain reaction
results heating the contents, building enormous pressure and turning the
cylinder in a bomb.

Early Control Setbacks
After production of hydrogen cyanide was halted in 1968 in favor of
superior and more stable insecticides American Cyanamid tried to locate
and retrieve all the cylinders. one day in 1970, while company technician!
were drawing the liquid out of a cylinder found at a grain elevator in the
Middle West, the cylinder began to heat up, to such an extent that the
paint or its exterior blistered. Then it exploded. The technicians had
enough time it seek cover, and nobody was injured But the incident
Alerted the company to the unacceptable danger of trying it empty the
cylinders manually.

In 1976, the company tried another approach, involving explosives. But an
Army ordnance squad made *an error in disposing of two cylinders in
Stamford, Tex., and the resulting explosion caused extensive property
damage.

The company now uses a nine-year old method developed in part by
E.P.A Specialists in Dallas. The technique entails removing the ends of
the cylinder with explosive cutting charges, which are detonated in a pit
alongside containers of diesel fuel and gasoline. The chemical, which is
released as a gas is then instantly consumed in a fireball,


Jet Research Center Inc., an explosives manufacturer in Mansfield, Tex.,
is under contract to American Cyanamid to help destroy hydrogen
cylinders wherever they are found and has done so 14 times, in Canada,
Australia and the United States. The most recent occurrence was last
April, when two small cylinders were discovered in Minneapolis and blown
up in the nearby town of Anoka without incident.

Doug P. Fox, the E.P.A. official who is coordinating the cleanup in Nitro,
says he now hopes to destroy the cylinder here on Oct. 9. Twice this
month, after questions had arisen over the legal liability of companies that
help carry out such an operation, Mr. Fox was led to delay it.

The on-again, off-again evacuation has angered Nitro's Mayor, Don
Karnes. "They've put us all through a lot of pain," said Mr. Karnes, a
former mechanic and garage owner who took office in July. "It's costing us
thousands of dollars we can't afford to plan for the evacuation. I can't
believe that we're going through all of this to remove a little tank. I can't
see where it's such a big deal.”

But Mr. Fox, whose agency has already spent $2 million making the old
plant here safer, says residents do not understand the hazards. "We were
requested by the State of West Virginia to stabilize a situation that was
very dangerous," he said. "We intend to stay until the threat is gone."

quicksilver - 13-7-2011 at 06:12

Supercooling issues have some model similarities to focused detonations yet the depth of the model needs to be explored for that similarity to be more obvious. This was one of the REASONS for numeric modeling (of detonation) was explored. Without numeric modeling one would have singular test results , yet no theory to explore when new materials were developed.
Several people are familiar with the Fickett & Davis textbook "Detonation"; there are some examples therein. The models are very important when you have a primary (for example) that does not release a gas in it's detonation while others do so in the most obvious manner (an observable breakdown).

Morgan - 25-3-2013 at 08:18

Mystery of Prince Rupert's Drop at 130,000 fps - Smarter Every Day 86
https://www.youtube.com/watch?v=xe-f4gokRBs


[Edited on 25-3-2013 by Morgan]

AndersHoveland - 28-3-2013 at 18:33

There is also exploding antimony...
Quote: Originally posted by franklyn  
http://antimonyproperties.blogspot.com/2009/03/yellow-antimo...

Two unstable allotropic forms of antimony are yellow and explosive.

Much like its arsenic and phosphorus analogs, yellow antimony exhibits mostly nonmetal properties. The oxidization, either by air or oxygen, of liquid antimony hydride produces yellow antimony and black antimony. Yellow antimony is only stable below -90° C. At temperatures between -90° C and -50° C, the yellow allotrope will degrade into its black counterpart. At temperatures above -50° C, yellow antimony rapidly converts into regular metallic antimony.

Explosive antimony is produced by the electrolysis of the aqueous solution of antimony halide. It is believed that this is because of the presence high concentrations of antimony ions in the solution. Explosive antimony deposits on the cathode at a current density of 200 A/m2 in a hydrochloric acid solution containing 17 - 33% SbCl3. Explosive antimony has a steel-gray color and a smooth, soft surface. Its density is 5.64 -5.97 g/cm3. It will produce a vigorous explosion when it is gently struck, rubbed, treated with thermal radiation, or heated to 125° C. The explosion is the result of instant liberation of crystalline heat when a foreign force is applied and will occur even under water.



http://www.sciencemadness.org/talk/viewthread.php?tid=14271