Recharging and rejuvenation of decontaminated N95 masks

Emroj Hossain; Satyanu Bhadra; Harsh Jain; Soumen Das; Arnab Bhattacharya; Shankar Ghosh; Dov Levine

doi:10.1063/5.0023940

Recharging and rejuvenation of decontaminated N95 masks

Phys Fluids (1994). 2020 Sep 1;32(9):093304. doi: 10.1063/5.0023940.

Authors

Emroj Hossain¹, Satyanu Bhadra¹, Harsh Jain¹, Soumen Das¹, Arnab Bhattacharya¹, Shankar Ghosh¹, Dov Levine²

Affiliations

¹ Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai 400005, India.
² Department of Physics, Technion-IIT, 32000 Haifa, Israel.

Abstract

N95 respirators comprise a critical part of the personal protective equipment used by frontline health-care workers and are typically meant for one-time usage. However, the recent COVID-19 pandemic has resulted in a serious shortage of these masks leading to a worldwide effort to develop decontamination and re-use procedures. A major factor contributing to the filtration efficiency of N95 masks is the presence of an intermediate layer of charged polypropylene electret fibers that trap particles through electrostatic or electrophoretic effects. This charge can degrade when the mask is used. Moreover, simple decontamination procedures (e.g., use of alcohol) can degrade any remaining charge from the polypropylene, thus severely impacting the filtration efficiency post-decontamination. In this report, we summarize our results on the development of a simple laboratory setup allowing measurement of charge and filtration efficiency in N95 masks. In particular, we propose and show that it is possible to recharge the masks post-decontamination and recover filtration efficiency.