Assessing the influence of decontamination on the performance of face masks : a materials engineering approach

Details

Supervisors

Kerckhofs, Greet

Faculty

Ecole polytechnique de Louvain

Degree label

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

Abstract

With the COVID-19 sanitary crisis, surgical masks have become widely worn by the general population, resulting in a lot of waste. Decontaminating surgical masks could help to resolve this issue. We studied home decontamination methods that involve heating surgical masks in hot water, as the SARS-CoV-2 virus was shown to be inactivated when heated over 56°C for 15 min. The methods were to submerge the masks in hot water without soap for 30 min at 30, 60 and 100°C. The same method with the addition of soap at 60°C was studied and the last methods were to wash surgical masks with soap in a washing machine at 30 and 60°C. The methods at 30°C were not considered efficient to decontaminate the masks but were added as comparison. This work assesses the influence of these home decontamination methods on different properties of surgical masks that influence their performance. The first studied property was their particle filtration efficiency, which was evaluated with a physical experiment of particle flow. This filtration can be split into mechanical and electrostatic filtration. Mechanical filtration is mainly influenced by the structure of the mask, so we studied the morphometrics and the tortuosity of the decontaminated masks. Their electrostatic properties were also assessed. Breathability is the ability to let air flow through the mask, which ensures comfort and less leakage on the sides of the masks. This was assessed with both a physical experiment and a simulation. Lastly, water contact angles measurements were done to study hydrophobicity, an important parameter to filtrate droplets.