1 Introduction
2 Materials and methods
2.1 Materials
2.2 Synthesis of the sol
Sample code | Sample | Gelation at room temperature | Transparency | Bulk sample |
---|---|---|---|---|
PCNT1 | P40Ca25Na5Ti30
| ✓ | ✓ | Few cracks |
PCNT2 | P40Ca25Na10Ti25
| ✓ | ✓ | Few cracks |
PCNT3 | P40Ca25Na15Ti20
| ✓ | ✓ | Heavily cracked |
2.3 Characterization
2.3.1 X-ray diffraction
2.3.2 EDX analysis
2.3.3 XANES study
2.3.4 MAS NMR
2.3.5 FT-IR spectroscopy
2.3.6 Thermal analysis
2.3.7 Ion release study
3 Results
3.1 X-ray diffraction
3.2 EDX analysis
Sample code | P2O5 (mol%) | CaO (mol%) | Na2O (mol%) | TiO2 (mol%) |
---|---|---|---|---|
PCNT1 | 40 (36.2 ± 1.1) | 25 (26.7 ± 0.7) | 5 (6.3 ± 0.7) | 30 (30.8 ± 0.8) |
PCNT2 | 40 (35.8 ± 1.3) | 25 (26.9 ± 0.8) | 10 (11.6 ± 0.9) | 25 (25.7 ± 0.8) |
PCNT3 | 40 (35.6 ± 1.2) | 25 (26.9 ± 0.8) | 15 (16.4 ± 0.8) | 20 (21.1 ± 0.7) |
3.3 Ti K-edge XANES study
3.4 Solid state 31P MAS-NMR
Glass code | Sample | Position (ppm) (±0.2) | Qi species | Line width (ppm) (±0.2) | Abundance (%) (±1.0) |
---|---|---|---|---|---|
PCNT1 | P40Ca25Na5Ti30
| −1.2 | 0 | 7.7 | 2.0 |
−10.3 | 1 | 9.8 | 29.1 | ||
−14.8 | 1 | 9.9 | 40.8 | ||
−22.8 | 2 | 11.8 | 28.1 | ||
PCNT2 | P40Ca25Na10Ti25
| −0.8 | 0 | 7.4 | 3.4 |
−10.1 | 1 | 9.7 | 37.4 | ||
−14.4 | 1 | 9.9 | 35.7 | ||
−22.5 | 2 | 11.7 | 23.5 | ||
PCNT3 | P40Ca25Na15Ti20
| −0.2 | 0 | 6.8 | 4.1 |
−10.0 | 1 | 9.5 | 41.3 | ||
−14.1 | 1 | 9.6 | 33.2 | ||
−21.9 | 2 | 11.2 | 21.4 |
3.5 FTIR analysis
Wave number (cm−1) | Assignment | Associated Qi (where applicable) |
---|---|---|
745 | ʋs (P–O–P) | |
900 | ʋas (P–O–P) | Q2
|
970 | ʋs (PO3) | Q1
|
1,175 | ʋas (PO2) | Q2
|