This rare and versatile composite fabric is reusable and restorable, making it a promising material to be used in face masks and other protective clothing.
Which mask should I be using? What makes one mask better than the other? When should I be using my mask and how many? Over the course of the pandemic, these questions have been frequently asked, answered, and re-answered. From cloth masks and surgical masks to N95 and face shields, experts and governments worldwide have frequently revised mask mandates to accommodate the new information gathered about the virus. For doctors and medical staff, these guidelines are even more stringent as they require protective clothing that can efficiently and reliably guard them against the virus at all times. Unfortunately, the production of such gear remains insufficient to adequately protect the general public.
In a novel study by researchers from Northwestern University, they have developed a versatile composite fabric that can deactivate not only biological threats such as SARS-CoV-2 but also chemical threats like those used in chemical warfare. The material is scalable and reusable, only requiring a simple bleach treatment to restore the fabric to its original state after exposure to biological and/or chemical threats. The porous nanomaterial can also be easily coated on textile fibres, making it a promising fabric to be used in face masks and various protective gear.
“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.
To create this MOF/fibre composite, Farha’s team built upon an earlier study in which they developed a nanomaterial that deactivates toxic nerve agents. With some minor adjustments, the team was able to easily incorporate anti-viral and anti-bacterial agents into the material as well. This is because metal-organic frameworks, akin to “sophisticated bath sponges,” are porous and can capture gases, vapours, and other agents. Since its production requires only basic textile processing equipment used in industrial settings, Farha believes that the composite material is highly scalable.
For the purpose of fighting biochemical treats, the pores of the metal-organic frameworks were integrated with catalysts that can deactivate toxic chemicals, viruses, and bacteria. With this addition, the MOF/fibre composite demonstrated rapid biocidal activity against SARS-CoV-2, E. coli, and S. aureus. The active chlorine-loaded MOF/fibre composite also rapidly degraded sulphur mustard gas and its chemical simulant, 2-chloroethyl ethyl sulphide.
When incorporated into a face mask, the material is expected to protect the mask wearer from any lingering virus in his or her vicinity as well as protect the individuals who come into contact with an infected person who is wearing the mask. Given the versatility of the new material, the team believes that it shows promising potential to be incorporated into masks. But besides these optimistic findings, the researchers were also able to develop an in-depth understanding of the material’s active sites down to the atomic level, thereby allowing them to uncover structure-property relationships that may lead to the creation of other MOF-based composites.
Source: Cheung et al. (2021). Immobilized Regenerable Active Chlorine within a Zirconium-Based MOF Textile Composite to Eliminate Biological and Chemical Threats. Journal of the American Chemical Society.