Reusing surgical facemasks : probing the impact of soap on materials properties and masks recharging

Details

Supervisors

Kerckhofs, Greet

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil biomédical, à finalité spécialisée

Abstract

The emergence of the COVID19 pandemic required the fast implementation of sanitary measures to limit the rapid spread of the virus. The wearing of masks became, therefore, compulsory in enclosed spaces and populated areas, which created an exorbitant demand for disposable masks. The massive production with the environmental, economic and social consequences entailed, motivated the research towards the decontamination of surgical masks and respirators. This study, therefore, aims to provide further information on the filtration capacity of the following decontamination methods: immersion for 30 minutes in hot water at 60° and in low concentrated soap solution at 60° with and without a rinsing step. The first experiment of this work studied the filtration efficiency of surgical masks and filters treated by the different decontamination methods. The influence of five decontamination cycles on the filtration capacity was also investigated. The efficiency of the rinsing step was then assessed by using SEM and ToF-SIMS techniques through the investigation of residual presence of soap on the fibers. The last experiment of this work aimed at evaluating the impact of soap on the electrostatic charges of the samples. The study of the hot water samples showed a conservation of the filtration efficiency, identical to the reference samples, after 5 decontamination cycles. On the contrary, soap based samples showed an impaired of filtration efficiency, despite the insertion of a rising step. This rinsing step was found to be effective via SEM and ToF-SIMS, leading to the common conclusion of the absence of soap on the fibers. The electrostatic behavior of rinsed and hot water samples naturally dried showed an identical behavior on the charges after treatment and in their recharging capacity. Drying the masks by hair dryer showed, on the contrary, a higher recharging capacity for the hot water samples. As the protocol has limitations, further study is required before a causal relationship with filtration efficiency can be asserted. Further research is still needed to understand completely the origin of the high particle penetration in the rinsed soaped-based samples.