A team of researchers from universities in Australia and South Korea has developed a liquid gallium-based coating that could help us contain the next local epidemic before it becomes a global pandemic. As they describe, this new coating adheres strongly to fabrics such as those used on face masks and can help create an environment that is toxic to pathogens.
Anything dangerous that happens to be captured by the face mask is eradicated within minutes. This makes the mask reusable and safer against viruses and bacteria, so this could be a game-changing discovery.
The researchers placed liquid gallium into an ethanol solution and then bombarded it with sonic waves to break it down to nanoparticles. This solution is then sprayed onto the fabric, and after ethanol is evaporated, the gallium particles remain deeply enwoven. The next step is to dip the fabric into a copper sulfate solution to create a galvanic replacement reaction which results in the formation of a coating made out of metal copper alloy nanoparticles.
Testing this against Staphylococcus aureus, Escherichia coli, and Candida albicans which are all known to grow quickly on untreated face masks showed amazing performance. A characteristic 99% of all pathogens injected into the treated fabric was killed in just five minutes.
The researchers state that silver could be used instead of copper, which is also renowned for its anti-microbial properties, but this is, of course, a more expensive material. The main case with gallium is that it offers a simple, low-cost way into creating semi-permanent metal coatings on fabrics.
As for the toxicity of copper, silver, or remnants of gallium for the mask wearer, all these metals are considered safe to humans when the exposure is limited and short-term. In fact, gallium is widely used in pharmaceutical and radiopharmaceutical medicine as well as several novel anti-cancer treatments.
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Article Source: Advanced Materials
