EVANSTON – A versatile composite fabric that can deactivate both biological threats, such as the coronavirus that causes Covid-19, and chemical threats, such as those used in chemical warfare, has been developed at Northwestern University.
The material is also reusable and can be restored to its original state after the fabric has been exposed to threats by a simple bleach treatment.
“Having a bifunctional material that has the ability to deactivate both chemical and biological toxic agents is crucial since the complexity to integrate multiple materials to do the job is high,” said Northwestern’s Omar Farha, an expert in metal-organic frameworks, or MOFs, which is the basis for the technology.
Farha, a Professor of Chemistry at the Weinberg College of Arts and Sciences, is a member of Northwestern’s International Institute for Nanotechnology. The MOF/fibre composite builds on an earlier study in which his team created a nanomaterial that deactivates toxic nerve agents. With some small manipulations, the researchers were able to also incorporate antiviral and antibacterial agents into the material.
Sophisticated bath sponges
“MOFs are sophisticated bath sponges,” Farha said. “The nano-sized materials are designed with a lot of holes that can capture gases, vapours and other agents the way a sponge captures water. In the new composite fabric, the cavities of the MOFs have catalysts that can deactivate toxic chemicals, viruses and bacteria. The porous nanomaterial can be easily coated on textile fibres.
The researchers found that the MOF/fibre composite exhibited rapid activity against SARS-CoV-2 and both gram-negative bacteria (E. coli) and gram-positive bacteria (S. aureus). The active chlorine-loaded MOF/fibre composite also rapidly degraded sulphur mustard gas and its chemical simulant (2-chloroethyl ethyl sulfide, CEES). The nanopores of the MOF material coated on the textile are wide enough to allow sweat and water to escape.
The composite material is scalable, Farha added, as it only requires basic textile processing equipment currently used by industry. When incorporated into a facemask, the material should be able to work both ways – protecting the mask wearer from virus in the vicinity as well as protecting individuals who come into contact with an infected person wearing the mask.
The researchers were also able to develop an understanding of the material’s active sites down to atomic level. This will allow structure-property relationships that can lead to the creation of other MOF-based composites to be further studied.
Omar Farha also has a financial interest in the startup company NuMat Technologies, which is seeking to commercialise metal-organic frameworks.