Structural parameters observed for a selection of PuO2 references and nanoparticles.
| PuO2 NP category | PuO2 NP characteristics (synthesis route) | Characteristics of the best fits | Pu–O | Pu–Pu | Ref. | ||||
|---|---|---|---|---|---|---|---|---|---|
| R Pu–O (Å) | CN Pu–O | DWFPu–O (×10−3 Å2) | R Pu–Pu (Å) | CN Pu–Pu | DWFPu–Pu (×10−3 Å2) | ||||
| Bulk reference | PuO2.00 (thermal conversion of Pu(iv) oxalates, 650 °C, 1 h, 10–20 m2.g−1) | Single O-shell | 2.33(1) | 8 | 6.5(4) | 3.81(1) | 12 | 4.9(1) | 196 |
| S 0 2 = 0.9, k = 2.4–14 Å−1 | |||||||||
| PuO2 ref (thermal conversion of oxalates, 650 °C) | S 0 2 = 0.9, k = 2.5–15 Å−1 | 2.33a | 8a | 5.9 | 3.81(1) | 10.5(19) | 3.5(6) | 94 | |
| Colloids and nanoclusters | Pu38 nanocluster | — | 2.33a | 8a | 14.9(12) | 3.80(1) | 4.4(14) | 10(1) | 94 |
| PuO2 in contact with H2O | Single O-shell | 2.321(4) | 8 | 9.0(5) | 3.816(2) | 12 | 3.5(2) | 115 | |
| Pu(iv) intrinsic colloids (addition of NaOH to Pu(iv) solution) | Single O-shell | 2.294(8) | 8 | 8.1(5) | 3.793(3) | 3.9(5) | 3.6(9) | ||
| Aged Pu(iv) intrinsic colloids (addition of NaOH to Pu(iv) solution) | Single O-shell | 2.267(3) | 8 | 15.2(6) | 3.779(4) | 1.7(3) | 1.9(13) | ||
| Pu(iv) intrinsic colloids (controlled hydrolysis)b | Single O-shell | 2.33a | 8a | 14.9(7)–16.7(10) | 3.80(1)–3.81(1) | 5.0(17)–5.7(13) | 5.9(7)–6.7(8) | 94 | |
| Fourier filtered S02 = 0.9, k = 2.5–15 Å−1 | |||||||||
| Pu(iv) intrinsic colloids (sonication of PuO2 nanopowder) | Single O-shell | 2.33a | 8a | 7.8(6) | 3.82(1) | 8.6(18) | 3.7(10) | 94 | |
| Fourier filtered S02 = 0.9, k = 2.5–15 Å−1 | |||||||||
| Pu(OH)4 (Am) (addition of NaOH to Pu(iv) solution) | Single O-shell | 2.32 | 4.0 | 10.4 | 3.87 | 2.4 | 6.6 | 83 | |
| S 0 2 = 1.0, k = 2.7–12.5 Å−1 | |||||||||
| R f = 0.016 | |||||||||
| Pu(iv) intrinsic colloids (addition of H2O, NaOH or NaCl solution to Pu(iv) solution) | Two O-shells | 2.20–2.24 | 0.7–3.3 | 0.4–8 | 3.86–3.9 | 2.1–4.9 | 7.5–9.0 | 83 | |
| S 0 2 = 1.0, k = 2.7–12.5 Å−1 | 2.38–2.42 | 0.8–5.6 | 5.9–13.6 | ||||||
| R f = 0.004–0.013 | |||||||||
| Dispersed or associated nanoparticles | PuO2 nanopowder (thermal conversion of hydroxides, 485 °C) | Single O-shell | 2.33a | 2.41a | 8.9(10) | 3.80(2) | 9.5(13) | 4.9(7) | 116 |
| S 0 2 = 0.9, k = 2.0–14 Å−1 | |||||||||
| R f = 0.045 | |||||||||
| Nano-dots and nano-rods (solvolysis in BnOBn/OA/OAm mixture) | Single O-shell | 2.31(1) | 6.6(0.8) | 9(2) | 3.81(1) | 8.1(15) | 2(1) | 117 | |
| S 0 2 = 0.9, k = 2.8–10.9 Å−1 | |||||||||
| R f = 0.025 | |||||||||
| Monodisperse PuO2 (addition of NH3·H2O to Pu(iii–v) solutions) | Single O-shell | 2.30(1)–2.32(1) | 7.2–7.8 | 10a | 3.79(1)–3.81(1) | 3.2–4.5 | 4.3(5)–7.1(5) | 111 | |
| S 0 2 = 0.95, k = 2.0–14 Å−1 | |||||||||
| Two O-shells | 2.26(1)–2.30(1) | 5.5–7.4 | 7.6(5)–9.7(5) | 3.79(1)–3.81(1) | 3.2–4.5 | 4.3(5)–7.1(5) | 111 | ||
| S 0 2 = 0.95, k = 2.0–14 Å−1 | 2.39(1)–2.44(1) | 0.6–2.5 | 1.0(5)–4.3(5) | ||||||
| Three O-shells | 1.81(1)–1.84(1) | 0.2–0.5 | 1.0(5) | 3.79(1)–3.81(1) | 3.2–4.5 | 4.3(5)–7.1(5) | 111 | ||
| S 0 2 = 0.95, k = 2.0–14 Å−1 | 2.28(1)–2.29(1) | 3.7–6.1 | 3.2(5)–8.3(5) | ||||||
| 2.42(1)–2.44(1) | 1.5–2.3 | 1.0(5)–5.3(5) | |||||||
| Nanostructured oxides | Nanostructured PuO2 powder (thermal conversion of oxalates, 485 °C) | Single O-shell | 2.33a | 2.41a | 7.0(11) | 3.81(1) | 11.8(18) | 5.6(6) | 116 |
| S 0 2 = 0.9, k = 2.0–14 Å−1 | |||||||||
| R f = 0.045 | |||||||||
a
Fixed values.
b
Taken from a series of hydrolytic colloids showing different Pu : HNO3 ratios (5–10 mM : 21–42 mM).