Figure 1 X-ray diffraction patterns for CaCO3 crystals precipitated at 25, 50, 70, and 80 °C.
Figure 2 Bar chart of different polymorphs fractions by mass obtained at the synthesis temperatures (25-80 °C).
Figure 3 SEM images of calcium carbonate crystals precipitated at (a) 25 °C,(b) 30 °C, (c) 40 °C, (d) 50 °C, (e) 60 °C, (f) 70 °C, and (g) 80 °C.
Table 1. Fractions of polymorphs of calcium carbonate formed at each temperature (25-80°C) by mass. |
|||||||
Temperature (°C) |
25 |
30 |
40 |
50 |
60 |
70 |
80 |
Vaterite |
0.961 |
0.925 |
0.698 |
0.014 |
0.424 |
0.794 |
0.742 |
Calcite |
0.039 |
0.075 |
0.302 |
0.986 |
0.576 |
0.154 |
0.258 |
Aragonite |
0 |
0 |
0 |
0 |
0 |
0.053 |
0 |
Table 1:Fractions of various polymorphs of calcium carbonate formed at each temperature (25-80 °C).