Researchers at Spain's IMDEA Materials Institute, Rey Juan Carlos University and Valladolid University have developed a new spray coating to improve the antiviral efficacy of personal protective equipment, notably face masks.
The team's system is based on nanoplatelets of graphene oxide (GO) spray coated via a simple one-step procedure over a poly(lactic acid) textile fabric, allowing a homogeneous coating. The incorporation of GO does not affect the textile structure nor its air permeability, while it increases its water contact angle, potentially preventing droplet trespassing.
The antiviral efficiency was tested against Influenza A virus (strain A/Hong Kong/8/68), reportedly reaching a high reduction with no cytotoxic effect observed.
"The antiviral properties of GO in solutions have been proved previously," explained IMDEA Materials researcher Jimena de la Vega, one of the authors behind the study. "However, this is the first time that an antiviral GO solution has been directly integrated into a biodegradable fabric to create a more effective and more environmentally friendly material for face masks."
"The pores of the fabric that we have used for these masks are also smaller than the size of the viral droplets. That means they prevent these droplets from being inhaled by the wearer, while the breathability of the mask is unaffected."
The research team behind the study includes Dr. Antonio Vázquez-López and Profs. Silvia Prolongo and Ignacio Collado from Rey Juan Carlos University (URJC), Profs. Pedro Prádanos and Francisco Javier Carmona (University of Valladolid [UVa]), and Jimena de la Vega and Prof. Dr. De-Yi Wang from IMDEA Materials.
Dr. Vázquez-López, himself a former IMDEA Materials researcher, said he had found inspiration for the breakthrough from the common practice of using wood ash as a pesticide to protect crops. "While the effectiveness of this practice is partially a myth, from this starting point I was led to the idea of using carbonaceous materials for their antibacterial and antiviral qualities," he explained. "Ideally, these materials had to be abundant and non-toxic."
"GO was one of several additives with these properties that was tried during this research and was one of the easiest to work with. However, GO dispersion can be quite difficult. Luckily, we were able to work with the Spanish company Antolin which has experience in providing GO in water suspension, which greatly simplified the process."
"There is existing research on using graphene or carbon nanotubes for antiviral coatings, but as far as I am aware, nothing related to using GO, and certainly not combined with a recyclable PLA-based fabric."
The utilization of an environmentally sustainable material such as PLA, underscores a commitment to addressing not only public health concerns in face mask production, but also environmental sustainability challenges.
Meanwhile, Dr. Vázquez-López is also confident of the potential scalability of the enhanced antiviral mask's fabrication process.
"One of my objectives with this research was to be able to automate the process as much as possible to streamline its manufacture," he said. "A water-dispersed GO solution is easy to work with, and can be easily applied to the material at an industrial level."