Evaluation of Physical Adsorption Properties of the Activated Carbon Layers Used in the Commercial Face Mask Inserts

When the coronavirus disease 2019 (COVID-19) pandemic spread globally, wearing face masks in public became one of the most effective protective measures. Subsequently, due to the increasing demand for face masks, researchers explored feasible approaches to optimize their efficiency. The outcome of this research provides insights into the adsorption performance of four commercial face mask filter inserts with activated carbon layers (ACL). The results showed that the ACL of the inserts has very low Brunauer, Emmett, and Teller (BET) surface areas (2-33 m2/g) and low carbon percentages (19-31%). Physical adsorption analysis revealed non-uniform micropore size distributions in all samples. In addition, non-woven structures were obtained through scanning electron microscopy (SEM). The experimental outcomes show that the ACL in the purchased face masks is low-quality adsorbent and not pure carbonaceous material; polymeric components may be predominant.