Polymer scientists have developed a fabric made of nanotubes that has the ability to switch from a breathable state to a protective one, in response to an environmental threat, without the need for an external control system.
The scientists at the University of Massachusetts Amherst and other institutions received a five-year $1.8 million grant from the U.S. Defense Threat Reduction Agency to design the material that will be used in military uniforms. The material could be ready for use in the field in fewer than 10 years, according to a press release from the university.
The material will be able to block a chemical threat while maintaining a good breathability level. “The uniform will be like a smart second skin that responds to the environment,” says Francesco Fomasiero of the Lawrence Livermore National Laboratory, a team leader.
In essence, the material puts polymers and nanoparticles together to produce hybrid functional materials. The key to the fabric’s reversibility is the highly breathable membranes that have pores a few nanometers wide and the vertically aligned carbon nanotubes that have surface layers designed to response to chemical warfare agents, says James Watkins, a polymer scientist at UMass Amherst. The press release explains further how the material works:
The threat response would be triggered by direct chemical warfare agent attack. The fabric would switch to a protective state by closing the pore entrance or by shedding the contaminated surface layer.
Soldiers need clothing that breathes so they don’t suffer from heat stress. The composite material will take advantage of the unique transport properties of the nanotube pores. These offer gas transport rates two orders of magnitude faster than any other pore of similar size, the university claims.
Biological agents and viruses are close to 10 nanometers in size. The membrane pores on the uniforms will be only a few nanometers wide, so they will block the agents from entering the material. There still is a challenge, though. The press release explains:
Chemical agents such as mustard gas and nerve gas can be much smaller and require the membrane pores to be able to react to block that threat. To create a multifunctional membrane, the research team plans to modify the surface of the original prototype carbon nanotube membranes with chemical threat responsive functional groups. These functional groups sense and block the threat like gatekeepers on entrance.
“Development of chemical threat responsive carbon nanotube membranes is a great example of a novel material’s potential to provide innovative solutions for the Department of Defense (chemical and biological) needs,” says Tracee Harris, science and technology manager for the Dynamic Multifunctional Material for a Second Skin Program. “This futuristic uniform would allow our military forces to operate safely for extended time periods and successfully complete their missions in environments contaminated with chemical and biological warfare agents.”
Source: “UMass Amherst Research Develops ‘Second Skin’ Military Fabric to Repel Chemical and Biological Agents,” UMass Amherst press release, 11/27/12
Image by Piotr Wlodarczyk.