A rare feat: Material protects against both biological and chemical threats

For the elimination of biological and chemical dangers, a programming-compatible crystalline sponge-textile combination. Credit: Northwestern University
Northwestern University researchers have developed a flexible composite fabric that can be used to deactivate biological threats such as COVID-19. It is rare to find a material that can deflect both types of threats.

It can also be re-used. The fabric can be easily restored to its original condition after it has been exposed to dangers by simple bleach treatment.

Omar Farha from Northwestern, an expert on metal-organic frameworks (MOFs), said that a bifunctional material can be used to activate both biological and chemical toxic agents. This is the foundation of the technology.

Farha, who is also a professor of Chemistry at the Weinberg College of Arts and Sciences in California, is the co-corresponding author of this study. Farha is also a member at Northwestern's International Institute for Nanotechnology.

The MOF/fiber composite is based on an earlier study by Farha and his team that created a nanomaterial which deactivates toxic nerve agent. Researchers were able to incorporate antiviral as well as antibacterial agents with a few minor modifications.

Farha explained that MOFs are "sophisticated bathtub sponges". Nano-sized materials have many holes that capture gases, vapors, and other agents in the same way as a sponge. The MOFs contain catalysts that can activate harmful chemicals, viruses, and bacteria. It is possible to coat the porous nanomaterial with textile fibers.

The Journal of the American Chemical Society (JACS) published the study.

Researchers found that the MOF/fiber composite was effective against both SARS-CoV-2 (E.coli) as well as gram-negative and gram positive bacteria (S. aureus). The active chlorine-loaded MOF/fiber combination rapidly reduced sulfur mustard gas as well as its chemical simulant (2,chloroethyl-ethyl-sulfide). The pores of the MOF fabric are large enough to allow water and sweat to escape.

Farha said that the composite material can be scaled as it requires only basic textile processing equipment. The composite material, when integrated into a mask, should work in both directions: it protects the wearer of the mask from viruses in the surrounding area and also protects anyone who comes in contact with infected persons wearing the mask.

Researchers were also able to understand the active sites of the material down to an atomic level. This allows them to create structure-property relationships which can be used to make other MOF-based compounds.

The paper's title is "Immobilized Regerable Active Chlorine in a Zirconium Based MOF Textile Component to Eliminate Biological & Chemical Threats." The paper's first authors are Yuk Ha Cheung from The Hong Kong Polytechnic University, and Kaikai Ma from Northwestern University. Ma is also a co-corresponding writer.

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Information: Yuk Hacheung et. al., Immobilized Regenerable Activity Chlorine in a Zirconium Based MOF Textile Component to Eliminate Chemical and Biological Threats, Journal of the American Chemical Society (2021). Journal Information: Journal of the American Chemical Society Yuk ha Cheung et. al., Immobilized Regenerable Active Chlorine in a Zirconium Based MOF Textile Component to Eliminate Biological And Chemical Threats. (2021). DOI: 10.1021/jacs.1c08576