Insights into the kinetics of thermally induced crystallization of amorphous calcium phosphate
Authors
Uskoković, Vuk
Marković, Smilja

Veselinović, Ljiljana

Škapin, Srečo Davor

Ignjatović, Nenad

Uskoković, Dragan

Article (Accepted Version)
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Transformations between amorphous and crystalline apatite mechanistically govern some of the most essential processes in bone metabolism, including biomineralization and bone remodeling. Fundamental understanding of this phase transition can help us gain control over the formation and dissolution of boney tissues in vivo and utilize that knowledge for various therapeutic ends. Crystallization of hydroxyapatite (HAp) and two tricalcium phosphate (TCP) polymorphs from the metastable precursor, amorphous calcium phosphate (ACP) was here studied kinetically and mechanistically using thermal analyses, X-ray diffraction and Fourier-transform infrared spectroscopy. Crystallization was detected in the differential thermal analysis as the exothermic peak at 639.5 °C at the slowest heating regimen of 5 °C min−1, while a combination of different kinetics models, including Augis–Bennett, Borchardt–Daniels, Johnson–Mehl–Avrami, Kissinger, Ozawa and Piloyan, yielded activation energies in the 435–45...0 kJ mol−1 range. Dehydrated ACP required a significant energy input to transform to HAp, thus indirectly proving the key role that structural water plays in this process in a biological setting. The phase transformation at high temperatures involved preformed nuclei and was solely due to their 3D growth, contrasting the edge-controlled nucleation derived earlier as the mechanism of growth in the solution. Crystallization was in both cases accompanied by the formation of needle-shape crystals of HAp through aggregation of ultrafine spherical units of ACP. Relationship between crystallinity and the heating rate was detected only for the initially amorphous structure, indicating a more intense and coherent lattice ordering process in annealed ACP than in HAp. Despite that, crystallization disobeyed the rule of inverse proportionality between the thermal energy required for the relaxation of defects and the level of strain, as the recovery rate of the initially poorly crystalline HAp was higher than that of ACP.
Source:
Physical Chemistry Chemical Physics, 2018, 20, 29221-29235Publisher:
- Royal Society of Chemistry (RSC)
Funding / projects:
- United States National Institutes of Health (NIH) / National Institute of Dental and Craniofacial Research (NIDCR), Grant K99-DE021416
- Molecular designing of nanoparticles with controlled morphological and physicochemical characteristics and functional materials based on them (RS-45004)
Note:
- This is the peer-reviewed version of the article: Uskoković, V., Marković, S., Veselinović, L., Škapin, S., Ignjatović, N., Uskoković, D.P., 2018. Insights into the kinetics of thermally induced crystallization of amorphous calcium phosphate. Phys. Chem. Chem. Phys. https://doi.org/10.1039/C8CP06460A
DOI: 10.1039/C8CP06460A
ISSN: 1463-9076; 1463-9084
WoS: 000453935400022
Scopus: 2-s2.0-85057266300
Institution/Community
Институт техничких наука САНУ / Institute of Technical Sciences of SASATY - JOUR AU - Uskoković, Vuk AU - Marković, Smilja AU - Veselinović, Ljiljana AU - Škapin, Srečo Davor AU - Ignjatović, Nenad AU - Uskoković, Dragan PY - 2018 UR - https://dais.sanu.ac.rs/123456789/4514 AB - Transformations between amorphous and crystalline apatite mechanistically govern some of the most essential processes in bone metabolism, including biomineralization and bone remodeling. Fundamental understanding of this phase transition can help us gain control over the formation and dissolution of boney tissues in vivo and utilize that knowledge for various therapeutic ends. Crystallization of hydroxyapatite (HAp) and two tricalcium phosphate (TCP) polymorphs from the metastable precursor, amorphous calcium phosphate (ACP) was here studied kinetically and mechanistically using thermal analyses, X-ray diffraction and Fourier-transform infrared spectroscopy. Crystallization was detected in the differential thermal analysis as the exothermic peak at 639.5 °C at the slowest heating regimen of 5 °C min−1, while a combination of different kinetics models, including Augis–Bennett, Borchardt–Daniels, Johnson–Mehl–Avrami, Kissinger, Ozawa and Piloyan, yielded activation energies in the 435–450 kJ mol−1 range. Dehydrated ACP required a significant energy input to transform to HAp, thus indirectly proving the key role that structural water plays in this process in a biological setting. The phase transformation at high temperatures involved preformed nuclei and was solely due to their 3D growth, contrasting the edge-controlled nucleation derived earlier as the mechanism of growth in the solution. Crystallization was in both cases accompanied by the formation of needle-shape crystals of HAp through aggregation of ultrafine spherical units of ACP. Relationship between crystallinity and the heating rate was detected only for the initially amorphous structure, indicating a more intense and coherent lattice ordering process in annealed ACP than in HAp. Despite that, crystallization disobeyed the rule of inverse proportionality between the thermal energy required for the relaxation of defects and the level of strain, as the recovery rate of the initially poorly crystalline HAp was higher than that of ACP. PB - Royal Society of Chemistry (RSC) T2 - Physical Chemistry Chemical Physics T1 - Insights into the kinetics of thermally induced crystallization of amorphous calcium phosphate SP - 29221 EP - 29235 VL - 20 DO - 10.1039/C8CP06460A UR - https://hdl.handle.net/21.15107/rcub_dais_4514 ER -
@article{ author = "Uskoković, Vuk and Marković, Smilja and Veselinović, Ljiljana and Škapin, Srečo Davor and Ignjatović, Nenad and Uskoković, Dragan", year = "2018", abstract = "Transformations between amorphous and crystalline apatite mechanistically govern some of the most essential processes in bone metabolism, including biomineralization and bone remodeling. Fundamental understanding of this phase transition can help us gain control over the formation and dissolution of boney tissues in vivo and utilize that knowledge for various therapeutic ends. Crystallization of hydroxyapatite (HAp) and two tricalcium phosphate (TCP) polymorphs from the metastable precursor, amorphous calcium phosphate (ACP) was here studied kinetically and mechanistically using thermal analyses, X-ray diffraction and Fourier-transform infrared spectroscopy. Crystallization was detected in the differential thermal analysis as the exothermic peak at 639.5 °C at the slowest heating regimen of 5 °C min−1, while a combination of different kinetics models, including Augis–Bennett, Borchardt–Daniels, Johnson–Mehl–Avrami, Kissinger, Ozawa and Piloyan, yielded activation energies in the 435–450 kJ mol−1 range. Dehydrated ACP required a significant energy input to transform to HAp, thus indirectly proving the key role that structural water plays in this process in a biological setting. The phase transformation at high temperatures involved preformed nuclei and was solely due to their 3D growth, contrasting the edge-controlled nucleation derived earlier as the mechanism of growth in the solution. Crystallization was in both cases accompanied by the formation of needle-shape crystals of HAp through aggregation of ultrafine spherical units of ACP. Relationship between crystallinity and the heating rate was detected only for the initially amorphous structure, indicating a more intense and coherent lattice ordering process in annealed ACP than in HAp. Despite that, crystallization disobeyed the rule of inverse proportionality between the thermal energy required for the relaxation of defects and the level of strain, as the recovery rate of the initially poorly crystalline HAp was higher than that of ACP.", publisher = "Royal Society of Chemistry (RSC)", journal = "Physical Chemistry Chemical Physics", title = "Insights into the kinetics of thermally induced crystallization of amorphous calcium phosphate", pages = "29221-29235", volume = "20", doi = "10.1039/C8CP06460A", url = "https://hdl.handle.net/21.15107/rcub_dais_4514" }
Uskoković, V., Marković, S., Veselinović, L., Škapin, S. D., Ignjatović, N.,& Uskoković, D.. (2018). Insights into the kinetics of thermally induced crystallization of amorphous calcium phosphate. in Physical Chemistry Chemical Physics Royal Society of Chemistry (RSC)., 20, 29221-29235. https://doi.org/10.1039/C8CP06460A https://hdl.handle.net/21.15107/rcub_dais_4514
Uskoković V, Marković S, Veselinović L, Škapin SD, Ignjatović N, Uskoković D. Insights into the kinetics of thermally induced crystallization of amorphous calcium phosphate. in Physical Chemistry Chemical Physics. 2018;20:29221-29235. doi:10.1039/C8CP06460A https://hdl.handle.net/21.15107/rcub_dais_4514 .
Uskoković, Vuk, Marković, Smilja, Veselinović, Ljiljana, Škapin, Srečo Davor, Ignjatović, Nenad, Uskoković, Dragan, "Insights into the kinetics of thermally induced crystallization of amorphous calcium phosphate" in Physical Chemistry Chemical Physics, 20 (2018):29221-29235, https://doi.org/10.1039/C8CP06460A ., https://hdl.handle.net/21.15107/rcub_dais_4514 .