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Nitrogen Fullerenes - Powerful Chemistry
wildsurf writes "A post in sci.energy points to recent confirmation of the stable existence of N60 , through supercomputer simulation. Large-scale synthesis of this material could form the basis for tremendously powerful rocket fuel. Here is an in-depth article on the subject. What would you do with a few million liters of this stuff?"
The stable existence of N60 was confirmed jointly by the National Institute of health care materials) and Chemical Research ( NIMCR ),(russian news agency) of Industrial Science and technology, and Nissan Motor Co., ltd.
Increasingly promising lately is the potential for N60, the molecule consisting of 60 nitrogen atoms bonded in a soccer-ball shape, to be
used as rocket fuel capable of generating the world's highest thrust.
Supercomputer simulation confirmed the existence of N60 as the ``nitrogen version'' of the newly emerging promising material, C60, made of 60 carbon atoms.
Although a ``considerable amount of time is required for synthesizing N60,'' its development has already begun.
NIMCR's Chief Researcher Takehiro Matsunaga, who proposed the N60 concept, says this: ``When I saw the crystalline structure of C60, I immediately sensed that the world ''s most powerful explosive could be made if the same structure could be applied to nitrogen atoms.''
NIMCR and Nissan Motor are jointly developing the next-generation rocket fuel.
The joint team has been in search of a compound capable of generating a sufficiently powerful thrust to propel heavy rockets faster and
farther.
Although nitrogen exists as a stable gas, its compounds can become powerful explosives.
TNT, today's most widely used explosive, is also a
nitrogen-containing compound.
Compared with oxygen and hydrogen, the atomic bonding force in nitrogen is greater, and therefore, when the bond is destroyed, larger energy is released.
In other words, if a compound can be synthesized from nitrogen atoms only, the compound can be a powerful explosive.
From that standpoint, the crystalline structure of the soccer-ball-like C60 was the ideal shape for explosive researchers.
The joint group of NIMCR and Nissan Motor computed the atomic radius and the molecular bonding energy and confirmed the existence of N60,
consisting of 60 nitrogen atoms, and N70, consisting of 70 nitrogen atoms.
Furthermore, the group computed the magnitude of thrust when these molecules are used as rocket fuel.
The currently most advanced propulsion technology involving the reaction between liquid hydrogen and liquid oxygen is to be used for space shuttles and the next Japanese-made large rocket H2, which is scheduled to be launched in february 1994 by the National Space Development Agency.
The technology makes use of the heat that is released when oxygen and hydrogen react.
Specific impulse, an index of a rocket ''s efficiency, for H2 is approximately 445 seconds.
By computation, the group obtained a specific impulse of approximately 550 seconds, approximately 20 percent better than the above value, for the predicted N60, despite the common knowledge that it is almost impossible to improve specific impulse by even one second with today's fuel technology.
Another advantage of N60 as rocket fuel is that it is a solid.
By applying high heat or impact, the energy accumulated in the material is released instantaneously.
The liquid fuel to be used for H2 is difficult to handle and has a potential for leaking.
It has been reported that the U.S. National Aerospace Agency has experienced more than 5000 accidents in the area of engine
development.
NIMCR's Chief Researcher Takehiro Matsunaga) says, ``there is no doubt in my mind that the new nitrogen compound, if synthesized, will be the new rocket fuel.''
There seems to be no clue to the synthesis method for the compound.
It took five years for the synthesis method for C60 to be found after the computer prediction had been made for the existence of the molecule.
Actually, the carbon molecule was isolated from soot produced by the electric discharge between carbon electrodes.
In contrast with the C60 molecule, which is in the shape of a nearly perfect soccer ball, the N60 molecule predicted by the joint group has an indentation involving more than 10 nitrogen atoms.
Because of this distorted shape, N60 molecule is said to be easily destroyed and difficult to synthesize.
C60 molecule was synthesized with a systematic approach by gradually increasing the number of carbon atoms on a molecule consisting of 12
carbon atoms that was already in existence.
On the other hand, nitrogen molecules containing four, six and 20 atoms showed excessive strain in simulation tests, and their stable existence was negated.
ection Chief Katsumi Tanigaki of the Exploratory Research Department, NEC Basic Research Institute, points out that ``unless an epoch-making synthetic method is found, it will be a long road before we see the actual N60 molecule.''
He suggests that the group should ``first scheck the possibility of synthesizing a molecule consisting of carbon and nitrogen. ''
According to the super-computer simulation, N60 molecule is supposed to generate the world 's greatest explosive force.
Although a long road of synthesis is ahead, we must hope for the best for future research.
As Section Chief Katsumi Tanigaki says, we must ``go for it, as long as its existence has been predicted.''