Phosphorus-31 spin–lattice NMR relaxation in bone apatite and its mineral standards

Kaflak, Agnieszka; Kołodziejski, Wacław

doi:10.1016/j.ssnmr.2007.04.005

Cited by 27 publications

(33 citation statements)

References 33 publications

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“…In this way, the discussion comes to the point, in which one has to consider particular properties of water in biological apatites [15,26,30,33,34] and to figure out how those peculiar features are reflected in the presented results. The most interesting problem is that the two-component CP kinetics is only demonstrated by synthetic CHA-B and bone samples B1-B6 (Table 2).…”

Section: Discussionmentioning

confidence: 99%

“…This, in turn, implies adequate resemblance between the apatite structures, in accordance with many earlier publications, including our NMR works. [1,24,34,48] They showed that the bone apatite is in fact carbonatoapatite and that it is deficient in the structural OH groups. If the apatite crystals are very small, e.g.…”

Section: Discussionmentioning

confidence: 99%

“…[24,34,35,48] Stoichiometric HA was synthesized by the wet chemical method with the Ca/P ratio of 1.67. [49] It was predried in air to give as-synthesized sample HAh.…”

Section: Methodsmentioning

confidence: 99%

“…The latter parameter reflects the 1 H-31 P dipolar couplings [51] and in the former publications [1,24,34,44,51,52] it has been designated by T 2 . For a rigid lattice λ = (n + 1) −1 , where n is the number of protons in close neighborhood of the observed 31 P nucleus.…”

Section: Theorymentioning

confidence: 99%

“…We found that the 31 P spin-lattice relaxation in bone can be explained by the existence of surface P-OH groups and surface phosphate centers hydrated by strongly adsorbed water. [34] There are already first solid-state NMR studies showing how the organic matrix is bound to the apatite mineral. [41 -43] Various solid materials, including bone, can be successfully characterized using kinetics of NMR cross-polarization (CP), that is the dependence of a CP signal intensity on the contact time.…”

Section: Introductionmentioning

confidence: 99%

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Kinetics of ¹H → ³¹P NMR cross‐polarization in bone apatite and its mineral standards

Kaflak

Kołodziejski

2008

Magnetic Reson in Chemistry

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Kinetics of NMR cross-polarization (CP) from protons to phosphorus-31 nuclei was studied in the following samples: mineral of whole human bone, apatite prepared from bone, natural brushite, synthetic hydroxyapatite (hydrated and calcined), and synthetic carbonatoapatite of type B with 9 wt% of CO(3) (2-). In order to avoid an effect of magic angle spinning on CP and relaxation, the experiments were carried out on static samples. Parameters of the CP kinetics were discussed for trabecular and cortical bone tissue from adult subjects in comparison to the synthetic mineral standards. It was found that carbonatoapatite shows similar CP behavior to the bone mineral. Both materials undergo two-component CP kinetics. The fast-relaxing classical component is from the surface of apatite crystals and the slow-relaxing nonclassical component comes from the crystal interior. The components have been unambiguously assigned using inverse CP from phosphorus-31 to protons. The study provides information on a structured water layer, which covers crystal surface of carbonato- and bone apatite. The layer encompasses ca 40% of apatite phosphorus and its thickness is more than ca 2 nm.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

“…[24,34,35,48] Stoichiometric HA was synthesized by the wet chemical method with the Ca/P ratio of 1.67. [49] It was predried in air to give as-synthesized sample HAh.…”

Section: Methodsmentioning

confidence: 99%

Section: Theorymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Kinetics of ¹H → ³¹P NMR cross‐polarization in bone apatite and its mineral standards

Kaflak

Kołodziejski

2008

Magnetic Reson in Chemistry

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Synergistic Effect Between Ca₄V₄O₁₄ and Vanadium‐Substituted Hydroxyapatite in the Oxidative Dehydrogenation of Propane

et al. 2021

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The present work reports on a new type of V-based catalysts, namely V-substituted hydroxyapatites, and the influence of the synthesis conditions on their catalytic performance in the oxidative dehydrogenation of propane (ODHP) reaction. V xsubstituted hydroxyapatite materials prepared with the periodic addition of ammonia during the maturation step (V x -HAp-pHper) were shown to exhibit a Ca 4 V 4 O 14 phase in addition to the V-substituted hydroxyapatite phase for x greater than or equal to 3.5. TEM characterization of the biphasic samples allowed us to demonstrate that the Ca 4 V 4 O 14 phase was grown epitaxially on the V x -HAp nanorods. The close intimacy between the two phases was confirmed by NMR suggesting the involvement of V 4 + species. Consistently EPR data of the fresh and spent samples showed that V 4 + species may be stabilized at the boundaries of these two phases. The strong promotion of the oxidative dehydrogenation reaction to propene observed from 723 K for the V 4 -HAp-pH-per composition is attributed to a synergistic effect between the V x -HAp nanorods that enable the activation of propane and the Ca 4 V 4 O 14 phase that helps the redox exchanges. This synergy may be attributed to an easier electron delocalization on the V 4 O 14 units located at the phases' boundaries.

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A ³¹P NMR Investigation of the CoPi Water‐Oxidation Catalyst

Harley

Mason

McAlpin

et al. 2012

Chemistry A European J

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Phosphorus-31 spin–lattice NMR relaxation in bone apatite and its mineral standards

Cited by 27 publications

References 33 publications

Kinetics of ¹H → ³¹P NMR cross‐polarization in bone apatite and its mineral standards

Kinetics of ¹H → ³¹P NMR cross‐polarization in bone apatite and its mineral standards

Synergistic Effect Between Ca₄V₄O₁₄ and Vanadium‐Substituted Hydroxyapatite in the Oxidative Dehydrogenation of Propane

A ³¹P NMR Investigation of the CoPi Water‐Oxidation Catalyst

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Phosphorus-31 spin–lattice NMR relaxation in bone apatite and its mineral standards

Cited by 27 publications

References 33 publications

Kinetics of 1H → 31P NMR cross‐polarization in bone apatite and its mineral standards

Kinetics of 1H → 31P NMR cross‐polarization in bone apatite and its mineral standards

Synergistic Effect Between Ca4V4O14 and Vanadium‐Substituted Hydroxyapatite in the Oxidative Dehydrogenation of Propane

A 31P NMR Investigation of the CoPi Water‐Oxidation Catalyst

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Product

Resources

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Kinetics of ¹H → ³¹P NMR cross‐polarization in bone apatite and its mineral standards

Kinetics of ¹H → ³¹P NMR cross‐polarization in bone apatite and its mineral standards

Synergistic Effect Between Ca₄V₄O₁₄ and Vanadium‐Substituted Hydroxyapatite in the Oxidative Dehydrogenation of Propane

A ³¹P NMR Investigation of the CoPi Water‐Oxidation Catalyst