Evolved gas analyses of model inorganic compounds and apatites are described. The measurements ar... more Evolved gas analyses of model inorganic compounds and apatites are described. The measurements are performed on the system – a `thermochromatograph' (ThGC) – with a low-volume, thermal furnace, interfaced to a capillary gas chromatograph (GC) via a computer-controlled, pneumatic sample inlet device in the 70–600°C region. The `information content' performance of this inherently simpler system is comparable to that of
Evolved gas analyses of model inorganic compounds and apatites are described. The measurements we... more Evolved gas analyses of model inorganic compounds and apatites are described. The measurements were performed on a system comprising a `thermochromatograph', with a low-volume thermal furnace, interfaced to a capillary gas chromatograph via a computer-controlled, pneumatic sample inlet device in the temperature region 70–600°C. The performance of this inherently simpler system is comparable to that of thermogravimetry but is superior
The sorption mechanism of Ru3+ ions on hydroxy (HAp), carbonate (CO3HAp), and fluor apatites (FAp... more The sorption mechanism of Ru3+ ions on hydroxy (HAp), carbonate (CO3HAp), and fluor apatites (FAp) has been studied in detail. Ru apatites were obtained by reaction of the apatites with RuCl3 in aqueous solution. The structure and composition of the ruthenium-modified apatites were studied by several techniques: elemental analysis, XRD, EXAFS, IR, NMR, SEM-EDS, TEM, and thermal analysis. The amount of Ru in the modified apatite varies from 7.8 to 10.5 wt% and is not related to the initial composition or the specific surface area of the apatite. The different characterization techniques show that in the Ru-modified apatites Ru is surrounded by six oxygen atoms and do not contain any chlorine. For Ru-HAp and Ru-CO3HAp the new phase is amorphous whereas it is crystalline for FAp. The catalytic oxidation ability is higher for Ru-HAp and Ru-CO3HAp compared to Ru-FAp apatite in the oxidation of benzylic alcohol.
We describe the synthesis of two-dimensional {[MnIICrIII(C2O4)3]C} bimetallic networks that inclu... more We describe the synthesis of two-dimensional {[MnIICrIII(C2O4)3]C} bimetallic networks that include as template cations C stilbazolium salts 4-[4-(N,N-dimethylamino)-alpha-styryl]-N-alkylpyridinium with alkyl = methyl (DAMS), 4-[4-methoxy- alpha-styryll-N-isopentylpyridinium (MIPS), and DAZOP, which is a DAMS analogue with the central [C=C] core replaced by an azo N=N] moiety. These networks are obtained in their optically active forms, using the resolved - or Lambda- [CrIII(C204)3]3-
Phosphorus, Sulfur, and Silicon and the Related Elements, 2004
The thermal reactions in the mixtures of hydroxylapatite or fluorapatite and (NH4)2SO4up to 500°C... more The thermal reactions in the mixtures of hydroxylapatite or fluorapatite and (NH4)2SO4up to 500°C were studied with the purpose of elaborating the conditions of obtaining calcium–ammonium cyclophosphate that could be used as fertilizer. Thermal analysis with a simultaneous FTIR analysis of the evolved gases as well as the analyses of chemical and phase composition of solid products were performed. The thermal changes in the mixtures could be divided into three steps: (1) decomposition of (NH4)2SO4and reactions of apatite with these products at 250–420°C, (2) calcium ammonium polyphosphate formation at 290–450°C, and (3) reaction of CaSO4with CaNH4P3O9at 320–500°C. Higher concentrations of NH3in the gas phase promote the formation of CaNH4P3O9and increase its stability. Calcination at temperatures above 350°C causes decomposition of CaNH4P3O9with a decrease in the content of water-soluble phosphorus and evolvement of SO2.
The reaction between phenyl phosphonic dichloride (C6H5P(O)Cl2) and synthetic calcium hydroxy- an... more The reaction between phenyl phosphonic dichloride (C6H5P(O)Cl2) and synthetic calcium hydroxy- and fluorapatite has been investigated. The presence of mono- or polymeric (C6H5PO) fragment bound to hydroxyapatite was evidenced by IR, and solid-state 31P NMR spectroscopy. X-ray powder analysis has shown that the apatitic structure remains unchanged during the reaction. In contrast, no reaction was found using fluorapatite. According to
The sorption mechanism of Ru3+ ions on hydroxy (HAp), carbonate (CO3HAp), and fluor apatites (FAp... more The sorption mechanism of Ru3+ ions on hydroxy (HAp), carbonate (CO3HAp), and fluor apatites (FAp) has been studied in detail. Ru apatites were obtained by reaction of the apatites with RuCl3 in aqueous solution. The structure and composition of the ruthenium-modified apatites were studied by several techniques: elemental analysis, XRD, EXAFS, IR, NMR, SEM-EDS, TEM, and thermal analysis. The amount of Ru in the modified apatite varies from 7.8 to 10.5 wt% and is not related to the initial composition or the specific surface area of the apatite. The different characterization techniques show that in the Ru-modified apatites Ru is surrounded by six oxygen atoms and do not contain any chlorine. For Ru-HAp and Ru-CO3HAp the new phase is amorphous whereas it is crystalline for FAp. The catalytic oxidation ability is higher for Ru-HAp and Ru-CO3HAp compared to Ru-FAp apatite in the oxidation of benzylic alcohol.
Journal of Thermal Analysis and Calorimetry - J THERM ANAL CALORIM, 1999
The reaction of SO2 with synthetic apatites was studied by TG, XRD and IR analyses at 400-1000C. ... more The reaction of SO2 with synthetic apatites was studied by TG, XRD and IR analyses at 400-1000C. Due to an interaction of apatite with SO2, destruction of apatite and formation of CaSO4 and diphosphate up to 750C takes place. The further calcination leads to the formation of β-Ca3(PO4)2 and a part of the SO2 bound is lost again. The amount of SO2 bound with apatite at calcination depends on the substitution ((F- ↔ OH-, PO4 3- ↔ CO3 2-, Ca2+ ↔ Mg2+) in its structure.
... tee 5, 19086 Tallinn, Estonia 32 Centre for Materials Research, Tallinn University of Technol... more ... tee 5, 19086 Tallinn, Estonia 32 Centre for Materials Research, Tallinn University of Technology, Ehitajate tee 5, 19086 ... to the mineral components of natural bones, and is used as substitute material for human hard tissues. ... 1. AH Choi, B. Ben-Nissan, Nanomedicine 2 (2007) 51 ...
... using -[tris(tetrachlorobenzenediolato)- phosphate(V)] as a chiral counter-ion Michel Grusell... more ... using -[tris(tetrachlorobenzenediolato)- phosphate(V)] as a chiral counter-ion Michel Gruselle,* a Ren Thouvenot, a R gis Caspar, a Kamal Boubekeur, a Hani Amouri, a Mikhael Ivanov b and Kaia ... 4(a) D. Hesek, Y. Inoue, SRL Everitt, H. Ishida, M. Kunieda and MGB Drew, Inorg. ...
Evolved gas analyses of model inorganic compounds and apatites are described. The measurements ar... more Evolved gas analyses of model inorganic compounds and apatites are described. The measurements are performed on the system – a `thermochromatograph' (ThGC) – with a low-volume, thermal furnace, interfaced to a capillary gas chromatograph (GC) via a computer-controlled, pneumatic sample inlet device in the 70–600°C region. The `information content' performance of this inherently simpler system is comparable to that of
Evolved gas analyses of model inorganic compounds and apatites are described. The measurements we... more Evolved gas analyses of model inorganic compounds and apatites are described. The measurements were performed on a system comprising a `thermochromatograph', with a low-volume thermal furnace, interfaced to a capillary gas chromatograph via a computer-controlled, pneumatic sample inlet device in the temperature region 70–600°C. The performance of this inherently simpler system is comparable to that of thermogravimetry but is superior
The sorption mechanism of Ru3+ ions on hydroxy (HAp), carbonate (CO3HAp), and fluor apatites (FAp... more The sorption mechanism of Ru3+ ions on hydroxy (HAp), carbonate (CO3HAp), and fluor apatites (FAp) has been studied in detail. Ru apatites were obtained by reaction of the apatites with RuCl3 in aqueous solution. The structure and composition of the ruthenium-modified apatites were studied by several techniques: elemental analysis, XRD, EXAFS, IR, NMR, SEM-EDS, TEM, and thermal analysis. The amount of Ru in the modified apatite varies from 7.8 to 10.5 wt% and is not related to the initial composition or the specific surface area of the apatite. The different characterization techniques show that in the Ru-modified apatites Ru is surrounded by six oxygen atoms and do not contain any chlorine. For Ru-HAp and Ru-CO3HAp the new phase is amorphous whereas it is crystalline for FAp. The catalytic oxidation ability is higher for Ru-HAp and Ru-CO3HAp compared to Ru-FAp apatite in the oxidation of benzylic alcohol.
We describe the synthesis of two-dimensional {[MnIICrIII(C2O4)3]C} bimetallic networks that inclu... more We describe the synthesis of two-dimensional {[MnIICrIII(C2O4)3]C} bimetallic networks that include as template cations C stilbazolium salts 4-[4-(N,N-dimethylamino)-alpha-styryl]-N-alkylpyridinium with alkyl = methyl (DAMS), 4-[4-methoxy- alpha-styryll-N-isopentylpyridinium (MIPS), and DAZOP, which is a DAMS analogue with the central [C=C] core replaced by an azo N=N] moiety. These networks are obtained in their optically active forms, using the resolved - or Lambda- [CrIII(C204)3]3-
Phosphorus, Sulfur, and Silicon and the Related Elements, 2004
The thermal reactions in the mixtures of hydroxylapatite or fluorapatite and (NH4)2SO4up to 500°C... more The thermal reactions in the mixtures of hydroxylapatite or fluorapatite and (NH4)2SO4up to 500°C were studied with the purpose of elaborating the conditions of obtaining calcium–ammonium cyclophosphate that could be used as fertilizer. Thermal analysis with a simultaneous FTIR analysis of the evolved gases as well as the analyses of chemical and phase composition of solid products were performed. The thermal changes in the mixtures could be divided into three steps: (1) decomposition of (NH4)2SO4and reactions of apatite with these products at 250–420°C, (2) calcium ammonium polyphosphate formation at 290–450°C, and (3) reaction of CaSO4with CaNH4P3O9at 320–500°C. Higher concentrations of NH3in the gas phase promote the formation of CaNH4P3O9and increase its stability. Calcination at temperatures above 350°C causes decomposition of CaNH4P3O9with a decrease in the content of water-soluble phosphorus and evolvement of SO2.
The reaction between phenyl phosphonic dichloride (C6H5P(O)Cl2) and synthetic calcium hydroxy- an... more The reaction between phenyl phosphonic dichloride (C6H5P(O)Cl2) and synthetic calcium hydroxy- and fluorapatite has been investigated. The presence of mono- or polymeric (C6H5PO) fragment bound to hydroxyapatite was evidenced by IR, and solid-state 31P NMR spectroscopy. X-ray powder analysis has shown that the apatitic structure remains unchanged during the reaction. In contrast, no reaction was found using fluorapatite. According to
The sorption mechanism of Ru3+ ions on hydroxy (HAp), carbonate (CO3HAp), and fluor apatites (FAp... more The sorption mechanism of Ru3+ ions on hydroxy (HAp), carbonate (CO3HAp), and fluor apatites (FAp) has been studied in detail. Ru apatites were obtained by reaction of the apatites with RuCl3 in aqueous solution. The structure and composition of the ruthenium-modified apatites were studied by several techniques: elemental analysis, XRD, EXAFS, IR, NMR, SEM-EDS, TEM, and thermal analysis. The amount of Ru in the modified apatite varies from 7.8 to 10.5 wt% and is not related to the initial composition or the specific surface area of the apatite. The different characterization techniques show that in the Ru-modified apatites Ru is surrounded by six oxygen atoms and do not contain any chlorine. For Ru-HAp and Ru-CO3HAp the new phase is amorphous whereas it is crystalline for FAp. The catalytic oxidation ability is higher for Ru-HAp and Ru-CO3HAp compared to Ru-FAp apatite in the oxidation of benzylic alcohol.
Journal of Thermal Analysis and Calorimetry - J THERM ANAL CALORIM, 1999
The reaction of SO2 with synthetic apatites was studied by TG, XRD and IR analyses at 400-1000C. ... more The reaction of SO2 with synthetic apatites was studied by TG, XRD and IR analyses at 400-1000C. Due to an interaction of apatite with SO2, destruction of apatite and formation of CaSO4 and diphosphate up to 750C takes place. The further calcination leads to the formation of β-Ca3(PO4)2 and a part of the SO2 bound is lost again. The amount of SO2 bound with apatite at calcination depends on the substitution ((F- ↔ OH-, PO4 3- ↔ CO3 2-, Ca2+ ↔ Mg2+) in its structure.
... tee 5, 19086 Tallinn, Estonia 32 Centre for Materials Research, Tallinn University of Technol... more ... tee 5, 19086 Tallinn, Estonia 32 Centre for Materials Research, Tallinn University of Technology, Ehitajate tee 5, 19086 ... to the mineral components of natural bones, and is used as substitute material for human hard tissues. ... 1. AH Choi, B. Ben-Nissan, Nanomedicine 2 (2007) 51 ...
... using -[tris(tetrachlorobenzenediolato)- phosphate(V)] as a chiral counter-ion Michel Grusell... more ... using -[tris(tetrachlorobenzenediolato)- phosphate(V)] as a chiral counter-ion Michel Gruselle,* a Ren Thouvenot, a R gis Caspar, a Kamal Boubekeur, a Hani Amouri, a Mikhael Ivanov b and Kaia ... 4(a) D. Hesek, Y. Inoue, SRL Everitt, H. Ishida, M. Kunieda and MGB Drew, Inorg. ...
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