The versatile MOF-based fibrous composite designed here has the potential to serve as protective cloth against both biological and chemical threats.
Multifunctional and regenerable N-chlorine based biocidal and detoxifying textile uses a robust zirconium metal–organic framework (MOF)
The fibrous composite exhibited rapid biocidal activity against both Gram-negative bacteria (E. coli) and Gram-positive bacteria (S. aureus) with up to a 7 log reduction within 5 min for each strain
The active chlorine loaded MOF/fiber composite selectively and rapidly degraded sulfur mustard and its chemical simulant 2-chloroethyl ethyl sulfide (CEES) with half-lives less than 3 minutes
A Northwestern University research team has developed a versatile composite fabric that can deactivate both biological threats, such as the novel coronavirus that causes COVID-19, and chemical threats, such as those used in chemical warfare.
The material 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 in the Weinberg College of Arts and Sciences, is a co-corresponding author of the study. He is a member of Northwestern’s International Institute for Nanotechnology.
The MOF/fiber composite builds on an earlier study in which Farha’s 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.
MOFs are “sophisticated bath sponges,” Farha said. The nano-sized materials are designed with a lot of holes that can capture gases, vapors 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 fibers.
The researchers found that the MOF/fiber composite exhibited rapid activity against SARS-CoV-2 and both gram-negative bacteria (E. coli) and gram-positive bacteria (S. aureus). Also, the active chlorine-loaded MOF/fiber composite rapidly degraded sulfur 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 his or her vicinity as well as protecting individuals who come into contact with an infected person wearing the mask.
The researchers also were able to develop an understanding of the material’s active sites down to atomic level. This allows them and others to derive structure-property relationships that can lead to the creation of other MOF-based composites.
Immobilized Regenerable Active Chlorine within a Zirconium-Based MOF Textile Composite to Eliminate Biological and Chemical Threats. Journal of the American Chemical Society, 30 September 2021.