Figure 16.

a) The overall illustration of the common face masks that are exposing to PMs, bacteria and viruses from the saliva and sweat of humans. b) Photograph and a cross‐section SEM image of the hybrid three‐layer filer. c) Simple description of the rule of each later. d) Embedding this three‐layer filter in a commercial facemask and recording the infrared image after applying a voltage of 3 V. e) Step for the filtration experiments and determination of the heating and insulation effectiveness of each layer in a layer in the hybrid filter. f) The heating and insulation performance of the hybrid layer. Reproduced with permission.^{[ 95 ]} Copyright 2021, American Chemical Society.