Influence of ripening time on the properties of hydroxyapatite-calcium carbonate powders

Goldberg, M. A.; Смірнов, В. В.; Иевлев, В. М.; Баринов, С. М.; Kutsev, S. V.; Shvorneva, L. I.

doi:10.1134/s0020168512020094

Cited by 18 publications

(11 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The pH value of the reaction mixture was maintained at a level of 12.0–12.5 by adding 25% aqueous ammonia solution. Powders were ripened at mother solution for 21 days at a temperature of 25 °C for full crystallization of precipitate [ 19 ]. Obtained powders were filtered, washed in distilled water by triple times, and dried at 60 °C for 24 h.…”

Section: Methodsmentioning

confidence: 99%

“…Additionally, in [ 18 ], HA powder with a particle size of 20–40 nm was obtained using the sol-gel method. Our investigations previously demonstrated an increase in the S of composite materials in the HA-calcium carbonate system, which made it possible to obtain powders with a specific surface of more than 200 m 2 /g with the introduction of 20 wt.% calcium carbonate and the use of the ripening method in the mother liquor [ 19 ]. The same approach was applied when the Al-substituted HA powders were synthesized and the powders with 40–60 nm and S up to 91 m 2 /g were obtained [ 20 , 21 ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mesoporous Iron(III)-Doped Hydroxyapatite Nanopowders Obtained via Iron Oxalate

et al. 2021

View full text Add to dashboard Cite

Mesoporous hydroxyapatite (HA) and iron(III)-doped HA (Fe-HA) are attractive materials for biomedical, catalytic, and environmental applications. In the present study, the nanopowders of HA and Fe-HA with a specific surface area up to 194.5 m2/g were synthesized by a simple precipitation route using iron oxalate as a source of Fe3+ cations. The influence of Fe3+ amount on the phase composition, powders morphology, Brunauer–Emmett–Teller (BET) specific surface area (S), and pore size distribution were investigated, as well as electron paramagnetic resonance and Mössbauer spectroscopy analysis were performed. According to obtained data, the Fe3+ ions were incorporated in the HA lattice, and also amorphous Fe oxides were formed contributed to the gradual increase in the S and pore volume of the powders. The Density Functional Theory calculations supported these findings and revealed Fe3+ inclusion in the crystalline region with the hybridization among Fe-3d and O-2p orbitals and a partly covalent bond formation, whilst the inclusion of Fe oxides assumed crystallinity damage and rather occurred in amorphous regions of HA nanomaterial. In vitro tests based on the MG-63 cell line demonstrated that the introduction of Fe3+ does not cause cytotoxicity and led to the enhanced cytocompatibility of HA.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Mesoporous Iron(III)-Doped Hydroxyapatite Nanopowders Obtained via Iron Oxalate

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The pH value of the reaction mixture was maintained at a level of 11–12 by adding aqueous ammonia. Powders were ripened at mother solution for 21 days at a temperature of 25 °C for full crystallization of the precipitate . The obtained powders were filtered, washed with deionized water three times, and dried at 60 °C for 24 h. The powders were heat-treated at 600 and 900 °C for 1 h in the air to crystallize the main phases and chemical composition analysis.…”

Section: Methodsmentioning

confidence: 99%

“…To obtain powder materials with various properties (phase composition, morphology, etc. ), the authors vary the synthesis conditions: temperature and pH values, the concentration of the initial aqueous solutions, ripening time, and the Ca/P ratio …”

Section: Introductionmentioning

confidence: 99%

Iron-Doped Mesoporous Powders of Hydroxyapatite as Molybdenum-Impregnated Catalysts for Deep Oxidative Desulfurization of Model Fuel: Synthesis and Experimental and Theoretical Studies

et al. 2021

View full text Add to dashboard Cite

Mesoporous iron-doped hydroxyapatite (HA) powders with a surface area up to 141 m 2 /g were synthesized and characterized by a variety of analytical and computational approaches, including X-ray diffraction (XRD) and X-ray fluorescence spectroscopy (XRF), atomic emission spectrometry with inductively coupled plasma (AES-ICP), Fourier transform infrared absorption (FTIR), nitrogen adsorption−desorption (BET), scanning and transmission electron microscopy (SEM and TEM), electron paramagnetic resonance (EPR), and density functional theory (DFT). Based on the data of TEM with mapping, the homogeneous distribution of Fe was evidenced. Fe 3+ ions were detected by EPR, and according to DFT, Fe 3+ occupied the Ca(2) position. The second part of the manuscript was dedicated to evaluating the catalytic properties of the developed HA powders for oxidative desulfurization, which is a promising alternative to hydrotreating for fuel purification. For this purpose, the molybdenum was impregnated on the HA, and iron-HA powders and the influence of its amount and the iron content were investigated. The optimal process parameters such as rotation speed, amount of H 2 O 2 , reaction time, temperature, and quantity of the catalyst were established and for the first time, to the authors' best knowledge, complete conversion of dibenzothiophene in the presence of an HA-based catalyst was achieved due to a combination of active sites of iron cations and molybdate anions.

show abstract

“…The pH of the reaction mixture was maintained at a value of 11.0-12.0 by adding aqueous ammonia. After the synthesis, the mixture was ripened for 21 days for the crystallization of the precipitate [53].…”

Section: Sample Synthesismentioning

confidence: 99%

Radiation-Induced Stable Radicals in Calcium Phosphates: Results of Multifrequency EPR, EDNMR, ESEEM, and ENDOR Studies

et al. 2021

View full text Add to dashboard Cite

This article presents the results of a study of radiation-induced defects in various synthetic calcium phosphate (CP) powder materials (hydroxyapatite—HA and octacalcium phosphate—OCP) by electron paramagnetic resonance (EPR) spectroscopy at the X, Q, and W-bands (9, 34, 95 GHz for the microwave frequencies, respectively). Currently, CP materials are widely used in orthopedics and dentistry owing to their high biocompatibility and physico-chemical similarity with human hard tissue. It is shown that in addition to the classical EPR techniques, other experimental approaches such as ELDOR-detected NMR (EDNMR), electron spin echo envelope modulation (ESEEM), and electron-nuclear double resonance (ENDOR) can be used to analyze the electron–nuclear interactions of CP powders. We demonstrated that the value and angular dependence of the quadrupole interaction for 14N nuclei of a nitrate radical can be determined by the EDNMR method at room temperature. The ESEEM technique has allowed for a rapid analysis of the nuclear environment and estimation of the structural positions of radiation-induced centers in various crystal matrices. ENDOR spectra can provide information about the distribution of the nitrate radicals in the OCP structure.

show abstract

Influence of ripening time on the properties of hydroxyapatite-calcium carbonate powders

Cited by 18 publications

References 7 publications

Mesoporous Iron(III)-Doped Hydroxyapatite Nanopowders Obtained via Iron Oxalate

Mesoporous Iron(III)-Doped Hydroxyapatite Nanopowders Obtained via Iron Oxalate

Iron-Doped Mesoporous Powders of Hydroxyapatite as Molybdenum-Impregnated Catalysts for Deep Oxidative Desulfurization of Model Fuel: Synthesis and Experimental and Theoretical Studies

Radiation-Induced Stable Radicals in Calcium Phosphates: Results of Multifrequency EPR, EDNMR, ESEEM, and ENDOR Studies

Contact Info

Product

Resources

About