Abstract
The suitability of ultraviolet-C (UV-C) irradiation for the decontamination of a surgical face mask was studied by decontamination experiments and carried out using Staphylococcus aureus and MS2 microbes. A moderate dosage level of 0.22J/cm² achieved within 2 min led to an over 6-log10 reduction in viable microbe contamination of the inner filtering layer. The underlying reason for this effective decontamination of fibers with small external UV-C dosage was explored with ray-tracing optical simulations, supported by optical measurements on reflection and transmission. The model 3D fiber network was constructed from X-ray tomography images of the layered mask structure consisting of polypropylene fibers. Both simulations and optical measurements indicated that UV light was able to penetrate even the deepest material regions. The simulations show that, despite radiation reflection from the outer mask layer, microbes in the actual filtering layer are affected by the radiation with increased probability due to multiple refraction and scattering of UV light from the inner fibers.
| Original language | English |
|---|---|
| Article number | 6523 |
| Pages (from-to) | 6523-6531 |
| Number of pages | 9 |
| Journal | Applied Optics |
| Volume | 63 |
| Issue number | 25 |
| DOIs | |
| Publication status | Published - 1 Sept 2024 |
| MoE publication type | A1 Journal article-refereed |
Funding
Research Council of Finland (340385). This work was supported by the Academy of Finland (Project “Citizen Shield–technological, behavioural and societal solutions for protective actions to tackle pandemics”). We are also grateful for the support from the FinnCERES Materials Bioeconomy Ecosystem.