Figure 3

TGA-DTG curve for (a) untreated facemasks under a 100 cm³min⁻¹ flow air, (b) untreated facemasks under a 100 cm³min⁻¹ flow carbon dioxide. DTG signals are denoted as dashed lines. TGA measurements to 900 °C under Ar and to 1200 °C under CO₂ atmospheres for (c) GCI coal (solid line) compared to GCI coal/20 wt.% facemask blend (dashed line) and (d) Charcoal (solid line) compared to charcoal/20 wt.% facemask blend (dashed line).