Fig. 2: Characterization of nanoparticles released from a kettle following different number of boils.

The particle size distribution of nanoparticles at a boil 1, b boils 75, and c boils 150 was detected by NTA. The black line represents the mean value, while the shaded area represents the deviation of the three measurements. The particle size distributions of nanoparticles at e boil 1, f boils 75 g boils 150 were detected by Sync. The particle count concentration of nanoparticles was detected by d NTA and h Sync with the contribution from the blank samples subtracted. See Supplementary Figure 4 for blank sample data.