Errr, the linked study directly contradicts your point: > In both respirators, large decreases in the dipole charge density were observed after several heat tr

Errr, the linked study directly contradicts your point: > In both respirators, large decreases in the dipole charge density were observed after several heat treatments. However, there was no significant drop in filtration efficiency because multiple parameters (i.e., mechanical filtration) were involved in the filtration performance.