Figure 1.

Influence of particle size (nano vs. bulk) on % solubility of MnO₂, ZnO, CeO₂, Al₂O₃, and Fe₂O₃ after 48 h of incubation in water and DMEM. Initial metal-oxide concentration was 100 mg/L. Results presented as mean (standard deviation) of triplicates. All pH values are reported in Tables S5A and S10, and Table S8 (Supplementary Materials) shows additional information. nd = Not detected. For a given metal-oxide and medium, ‘*’ and ‘***’ indicate significant differences between nano vs. bulk at α = 0.05 and 0.001, respectively, based on the Student’s or Welch’s t-test.