The current COVID-19 pandemic has prompted extensive research into materials capable of neutralizing the deadly SARS-CoV-2 virus. At the same time, in an uncertain world where the threat of chemical warfare looms, a material capable of countering these agents is essential. Now scientists have reported the development of a versatile composite fabric that can neutralize biological and chemical threats.
In a new international study, researchers have described a multifunctional, regenerable, biocidal and detoxifying material. It has been found to inactivate bacteria such as Escherichia coli and Staphylococcus aureus, and the SARS-CoV-2 virus. The composite material could also cancel out the deadly sulfur mustard gas.
“Having a bifunctional material that has the ability to deactivate both chemical and biological toxic agents is crucial because the complexity of integrating multiple materials to do the job is high,” said Dr. Omar Farha, co-author of the ‘study, in a statement. The results were published in the Journal of the American Chemical Society.
A multi-absorbent ‘sponge’
The metal-organic (MOF) / fiber composite is built on a previous study where the team developed a nanomaterial that can deactivate toxic nerve agents. By making some modifications to the material, the authors were able to incorporate antibacterial and antiviral agents into them. MOF uses zirconium, a metal with chemical and physical properties similar to titanium.
According to Dr. Farha, MOFs are “sophisticated bath sponges”. Nanoscale materials are designed with many holes or cavities that can capture vapors, gases and other agents; much like the way water is absorbed by a sponge. In the new composite tissue described in the study, the MOF cavities contain catalysts capable of neutralizing toxic chemicals as well as bacteria and viruses. It is important to note that textile fibers can be easily coated with the porous nanomaterial.
Neutralize biological and chemical threats
The team learned that the MOF / fiber composite exhibited rapid biocidal activity against both Gram-positive bacteria (S. aureus) and gram-negative bacteria (E. coli), with a reduction of up to 7 log in 5 min for either strain. Importantly, the team also found that it also showed rapid antiviral action against the SARS-CoV-2 virus. A 5 log reduction in coronavirus was noted in 15 min.
Additionally, the MOF / fiber composite – which is loaded with active chlorine – degraded sulfur mustard gas and its chemical simulant (2-chloroethyl ethyl sulfide, CEES), quickly. “The versatile MOF-based fibrous composite designed here has the potential to serve as a protective fabric against biological and chemical threats,” wrote authors.
Scope for easy scalability
In addition to being able to fight effectively against several agents, the equipment is reusable. Following exposure of the fabric to chemical and biological threats, the material can be returned to its original state with a simple bleaching treatment. Dr Farha said the composite material also offers the ease of scalability, as the basic textile processing equipment currently in use is the only requirement.
The fabric could also be incorporated into face masks and other protective clothing. When integrated into a face mask, the material can perform a two-way function: protecting the wearer from viruses such as the novel coronavirus present in their environment, and also protecting people who come into contact with infected people wearing the mask.
In addition, the nanopores of the MOF material are large enough to allow water and sweat to escape. In addition, scientists were able to glean the active sites of the material at the atomic level. This allows the derivation of structure-property relationships that can aid in the development of other MOF-based composites.