ENM physico-chemical characterisation | TiO2 NM-105 | ZnO NM-111 | Ag Sigma 576832 | BaSO4 NM-220 | CeO2 NM-212 |
---|---|---|---|---|---|
Core composition and CAS | Titanium Dioxide CAS: 1317-80-2 | Zinc Oxide CAS: 1314-13-2 | Silver CAS: 7440-22-4 | Barium Sulfate CAS: 7727-43-7 | Cerium Dioxide CAS: 1306-38-3 |
Crystalline phases (XRD)a | 86.9% Anatase + 13.1% Rutile | Zincite | Metallic | Barite | Cerianite |
Surface coating | N/A | UV active silicon coating—triethoxycaprylsilane | PVP (polyvinylpyrrolidone) functionalized polymer | N/A | N/A |
Impurities (XRF) | None (purity > 99%) | P2O5, SiO2, CaO, CuO, Fe2O3, NiO (All < 1.0%) | Pd, Cl (< 1.0%) Rh, Fe, Cu, Ni (< 0.1%) (purity > 99.5%) | Na, Ca, Sr, F, Cl, organic contaminations (purity > 93.8%) | P2O5, CaO, Cl (< 1.0%) V2O5, SO3, CoO, MgO, SiO2, CuO, Fe2O3, ZnO (< 0.1%) |
Size (MinFeret; TEM)b | 25Â nm | 40.6Â nm | 30.0Â nm | 31.5Â nm | 13.7Â nm |
3D aspect ratio and circulatory (TEM)b | N/A | A.R: 1.88 ± 0.78 C: 0.80 ± 0.12 | A.R: 1.36 ± 0.30 C: 0.88 ± 0.09 | A.R: 1.22 ± 0.19 C: 0.98 ± 0.04 | A.R: 1.21 ± 0.25 C: 0.97 ± 0.06 |
Surface area (BET) | 51.0 m2/g | 12.0 m2/g | 6.4 m2/g | 33.0 m2/g | 27.0 m2/g |
Relative density (He pycnometer) | 3.95Â g/cm3 | 4.99Â g/cm3 | 8.36Â g/cm3 | 4.13Â g/cm3 | 7.2Â g/cm3 |
Chemical nature of the surface (XPS)c | Ti: 24.5% O: 65.0% C: 10.5% | Zn: 34.6% C: 22.2% O: 43.1% | Ag: 38.9% C: 47.6% O: 13.5% | Ba: 21.5% S: 12.5% O: 65.8% | Ce: 25.6% O: 74.4% |
Surface charge (zeta potential at pH 7 in 10 mM KCl water solution) | − 17.0 mv | N/A | − 30.0 mV | − 30.2 mV | + 35.2 mV |
Surface reactivity (FRAS) | 18.6 (nmol TEU/m2 ENM) | 20.3 (nmol TEU/m2 ENM) | 2240.0 (nmol TEU/m2 ENM) | 13.9 (nmol TEU/m2 ENM) | 16.7 (nmol TEU/m2 ENM) |
Surface reactivity (EPR DMPO and CPH spin count) | DMPO: 3.01e+12 CPH: 8.29e+12 | DMPO: 1.21e+13 CPH: 1.28e+13 | DMPO: 8.00e+11 CPH: 5.58e+13 | DMPO: 4.92e+12 CPH: 8.89e+12 | DMPO: 5.86e+12 CPH: 1.22e+14 |
Hydrophobicity (water contact angle) | Hydrophilic (60°) | Hydrophobic (152°) | Hydrophobic (141°) | Hydrophilic (< 10°) | Hydrophilic (60°) |
Dissolutiond | Low dissolution (in PBS) | High dissolution (in biological media DMEM + FCS) | Unknown | Low dissolution (in PBS) | Low dissolution (in biological media DMEM + FCS) |
Dissolution (24 h) in DMEM + 10% FBS + 1% Pen/Strep | Not detectable | 10.11 ± 0.31 µg/mL | 0.01 ± 0.01 µg/mL | 2.40 ± 0.01 µg/mL | Not detectable |
Biological clearance in vivo (t50)d | Physiological clearance (> 40 days) | Rapid clearance | Unknown | Accelerated clearance (< 40 days) | Decelerated clearance (> 40 days) |
Previous REACH grouping categoryd | 4—active, biopersistent, non-fibrous ENMs | 1—soluble, non-persistent ENMs | 1—soluble, non-persistent ENMs | 3—passive, biopersistent, non-fibrous ENM | 4—active, biopersistent, non-fibrous ENMs |