Foam News: Copper PPE masks

We're taking a look at innovation from Georgetown University, Washington D.C., where a team of researchers have been developing more efficient and durable air filtration systems for PPE masks. As we have seen during the Covid-19 pandemic, health and safety equipment such as face masks, gloves and aprons have faced unprecedented demands. However, during this time, we have learned that there is a range of different face masks on offer, all of which provide varying levels of protection and quality of air purification.

With a lack of medical-grade facemasks available at the start of the pandemic, many of us turned to use cotton or other cloth fabric solutions. In some countries such as France, Germany and Austria, medical standard masks are now compulsory in public spaces, including shops and transportation, and homemade and cloth options are now banned. However, we are again seeing a shortage of medical masks available for professionals and other healthcare workers. The research undertaken by groups including that from Georgetown University holds promise for those desperately seeking durable and efficient medical-grade PPE solutions.

The recent innovation from Georgetown University concerns the creation of a lightweight foam made of copper nanowires. Copper has long been recognised as a recyclable and durable material that can be easily decontaminated and therefore holds promise in its use in air filtration systems. When we consider PPE masks' purpose, these need to be capable of filtering small airborne particles, as a person with Covid-19, for example, can spread the disease via droplets smaller than 0.3μm. This is where a material such as copper is beneficial, as it is an anti-microbial material that can trap tiny bacteria-laden particles.

Other materials like glass fibres and carbon nanotubes have been used in the past. However, they have not been durable enough to withstand repeated decontamination procedures required for reusable PPE masks commonly found in medical settings. The team at Georgetown University has worked copper into a metallic foam with microscopic pores that is stronger and more resistant to cleaning solvents, temperatures, and deformation. The research began to remove microscopic aerosols and droplets from materials while also being durable enough to be decontaminated and reused. Initial results have found that the copper foams the team has developed are as breathable and comparable in effectiveness to the N95 masks, which are currently commercially available.

Through this vital research, the viability of metal-infused foams has been realised. The industry is already considering how such materials can impact other applications aside from PPE masks. The researchers at Georgetown University created these foams by harvesting copper nanowires and applying them into a 'free-standing 3D network' then solidified by heat to develop strong bonds. An incredibly thin second layer of copper material was added to strengthen the mask to finish the product.

We at Easyfoam are pleased to see the continued research into the potential of foams in fighting against the Covid-19 pandemic.