Researchers from the City University of Hong Kong announced that they have successfully produced graphene face masks, which they claim have an anti-bacterial efficiency of 80 per cent, which can be enhanced to almost 100 per cent with exposure to sunlight for around 10 minutes. Graphene is believed to have a high level of anti-bacterial efficiency, which researchers attribute to either the damage of bacterial cell membranes by graphene’s sharp edges, or the hydrophobic (water-repelling) property of the substance.
"Initial tests also showed very promising results in the deactivation of two species of coronaviruses. The graphene masks are easily produced at low cost, and can help to resolve the problems of sourcing raw materials and disposing of non-biodegradable masks," according to a study published in scientific journal ACS Nano.
"Commonly used surgical masks are not anti-bacterial. This may lead to the risk of secondary transmission of bacterial infection when people touch the contaminated surfaces of the used masks or discard them improperly. Moreover, the melt-blown fabrics used as a bacterial filter poses an impact on the environment as they are difficult to decompose. Therefore, scientists have been looking for alternative materials to make masks," according to the university website.
"Previous studies suggested that COVID-19 would lose its infectivity at high temperatures. So the team carried out experiments to test if the graphene’s photothermal effect [producing heat after absorbing light] can enhance the anti-bacterial effect. The results showed that the anti-bacterial efficiency of the graphene material could be improved to 99.998 per cent within 10 minutes under sunlight, while activated carbon fibre and melt-blown fabrics only showed an efficiency of 67 per cent and 85 per cent respectively," according to a press statement.