New composite material can defeat toxic nerve agents

A novel composite material based on a metal-organic framework that can destroy toxic nerve agents has been integrated with textile fibers

Original source: Materials Today

Scientists at Northwestern University have successfully combined a nanomaterial effective at destroying toxic nerve agents with textile fibers. This new composite material could one day be integrated into protective suits and face masks for use by people facing hazardous conditions, such as chemical warfare.

The material, a zirconium-based metal-organic framework (MOF), can degrade in minutes some of the most toxic chemical agents known to mankind, including VX and soman (GD), a more toxic relative of sarin.

“With the correct chemistry, we can render toxic gases nontoxic,” said Omar Farha, associate professor of chemistry in the Weinberg College of Arts and Sciences at Northwestern University, who led the research. “The action takes place at the nano-level.” Farha and his colleagues report their work in a paper in the Journal of the American Chemical Society.

The authors write that their work represents, to the best of their knowledge, the first example of the use of MOF composites for the efficient catalytic hydrolysis of nerve agent simulants without using liquid water and toxic volatile bases – a major advantage.

The new composite material integrates MOFs and non-volatile polymeric bases onto textile fibers. The scientists found that the MOF-coated textiles could efficiently detoxify nerve agents under battlefield-relevant conditions using just the gaseous water in the air. They also found that the material can stand up to degrading conditions such as sweat, atmospheric carbon dioxide and pollutants over a long period of time. These features bring the promising material closer to practical use in the field.

“MOFs can capture, store and destroy a lot of the nasty material, making them very attractive for defense-related applications,” said Farha, a member of the International Institute for Nanotechnology.

MOFs are well-ordered, lattice-like crystals. The nodes of the lattices are metals, while organic molecules connect the nodes. Within their very roomy pores, MOFs can effectively capture gases and vapors, such as nerve agents. It is these roomy pores that also pull enough water from the humidity in the air to drive the chemical reaction in which water breaks down the bonds of the nerve agent.

The approach developed at Northwestern seeks to replace the technology currently in use: activated carbon and metal-oxide blends, which are slower to react to nerve agents. Because the MOFs are built from simple components, the new approach is scalable and economical.