The COVID-19 pandemic has resulted in significant changes in our daily lives, including the widespread use of face masks. Face masks have been reported to reduce the transmission of viral infections by droplets; however, improper use and/or treatment of these masks can cause them to be contaminated, thereby reducing their efficacy. Moreover, regular replacement of face masks is essential to maintaining their effectiveness, which can be challenging in resource-limited healthcare settings. The initial scarcity of face masks during the early stages of the pandemic led to the development of reusable face mask solutions. This research aimed to design a porous, standalone electrically heatable carbon veil (CV) layer that can be applied to commercial face masks without compromising their breathability. The main objective of this study is to directly inactivate aerosolized viruses using CV heaters powered by a direct current (DC). Prototype face mask samples with the CV were produced and tested using the aerosolized MS2 bacteriophage. After contamination of the face mask with the MS2 bacteriophage, the mask was treated by applying a direct current of 6 V and 1.17 A, which caused the surface temperature of the CV layers to reach over 70 °C within 10 s. This rapid temperature increase through Joule heating effectively inactivates the captured MS2 bacteriophage, with an average inactivation efficiency exceeding 99%. The findings of this study provide valuable insights into the potential application of engineered carbon layers for the decontamination of face masks and air filters from aerosolized viruses, thereby potentially enabling their reuse.
Keywords: Joule heating; aerosolized MS2 bacteriophage; direct inactivation; electrically heatable carbon veil layer; reusable face mask.