Scientists develop chemical and biological-agent resistant fabric
18/10/2012
The material will undergo a rapid transition from a breathable to a protective state. The membranes will have pores made of a few-nanometer-wide vertically aligned carbon nanotubes that are surface modified with a chemical warfare agent-responsive functional layer. Response to the threat would be triggered by direct chemical warfare agent attack to the membrane surface, at which time the fabric would switch to a protective state by closing the CNT pore entrance or by shedding the contaminated surface layer.
"The uniform will be like a smart second skin that responds to the environment," said Francesco Fornasiero, LLNL's principal investigator for the Defense Threat Reduction Agency-funded project. "Without the need of an external control system, the fabric will be able to switch reversibly from a highly breathable state to a protective one in response to the presence of the environmental threat. In the protective state, the uniform will block the chemical threat while maintaining a good breathability level."
High breathability is a critical requirement for protective clothing to prevent heat-stress and exhaustion when military personnel are engaged in missions in contaminated environments.
"We have demonstrated that our small-size prototype carbon nanotube membranes can provide outstanding breathability in spite of the very small pore sizes and porosity," said Sangil Kim, another LLNL scientist in the Biosciences and Biotechnology Division.
Biological agents, such as bacteria or viruses, are about 10 nanometers in size. Because the membrane pores on the uniform are only a few nanometers wide, these membranes will easily block biological agents.
However, chemical agents are much smaller and require the membrane pores to be able to react to block the threat. To create a multifunctional membrane, the team will surface modify the original prototype carbon nanotube membranes with chemical threat-responsive functional groups. A second response scheme will be developed: Similar to how a living skin peels off when challenged with dangerous external factors, the fabric will exfoliate upon reaction with the chemical agent. In this way, the fabric will be able to block chemical agents such as sulfur mustard (blister agent), GD and VX nerve agents, toxins such as staphylococcal enterotoxin and biological spores such as anthrax.
The project is funded for $13 million over five years with LLNL as the lead institution.
The new uniforms could be deployed in the field in less than 10 years.
Share this story:
