August 28, 2008

Study Makes Some Explosives More Stable

U.S. government scientists say they've developed a "green" method that makes some explosives safer and more stable.

The Lawrence Livermore National Laboratory researchers say they added unique green solvents -- ionic liquids -- to an explosive called TATB and improved its crystal quality and chemical purity.

"Improving crystal quality and purity leads to explosive materials that are (less likely to react violently) when subjected to mechanical impact or heat," said Larry Fried, the project's principal investigator.

The scientists said most explosives belong to a class of materials called molecular crystals that are bound by hydrogen-bonds, making the materials nearly insoluble in general organic solvents. That, in turn, hinders many technological applications.

The researchers, using quantum mechanical simulations, found a special class of ionic liquids -- a type of molten salt that becomes liquid under the boiling point of water-- that can dissolve hydrogen-bonded materials.

"The design of custom solvents through first principles modeling opens up new possibilities for the dissolution of materials that are hard to dissolve," Amitesh Maiti, the study's lead author, said.

The research appears in the Sept. 1 issue of the journal Physical Chemistry Chemical Physics.