The Vibrational Spectra of Brushite, CaHPO<sub>4</sub>·2H<sub>2</sub>O

Casciani, F.; Condrate, R. A.

doi:10.1080/00387017908069196

Cited by 42 publications

(53 citation statements)

References 10 publications

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“…Also changes occurred in the υ4 O-P-O(H) bending mode, which is located at 578 cm −1 for brushite and 602 cm −1 for HAp. 51,52 These changes occurred more rapidly for samples formed with less initial seed material. After 168 h incubation, low concentration seeded composites had almost completely lost the vibrational modes associated with brushite and the resulting spectra resembled poorly crystalline HA; by comparison high concentration seeded samples, however, had only partially converted by this time.…”

Section: Bioactivity Of Alginate Composites In Sbfmentioning

confidence: 97%

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Controlled mineralisation and recrystallisation of brushite within alginate hydrogels

Bjørnøy¹,

Bassett²,

Ucar³

et al. 2016

Biomed. Mater.

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Abstract. Due to high solubility and resorption behaviour under physiological conditions, brushite (CaHPO 4 ·2H 2 O, calcium monohydrogen phosphate dihydrate, dicalcium phosphate dihydrate) has great potential in bone regeneration applications, both in combination with scaffolds or as component of calcium phosphate cements. The use of brushite in combination with hydrogels opens possibilities for new cell based tissue engineering applications of this promising material. However, published preparation methods of brushite composites, in which the mineral phase is precipitated within the hydrogel network, fail to offer the necessary degree of control over mineral phase, content and distribution within the hydrogel matrix. The main focus of this study was to address these shortcomings by determining precise fabrication parameters needed to prepare composites with controlled composition and properties. Composite alginate microbeads were prepared using a counter-diffusion technique which allows for simultaneous crosslinking of the hydrogel and precipitation of an inorganic mineral phase. Reliable nucleation of a desired mineral phase within the alginate network proved more challenging than simple aqueous precipitation. This was largely due to ion transport within the hydrogel producing concentration gradients that modified levels of supersaturation and favoured the nucleation of other phases such as hydroxyapatite and octacalcium phosphate which would otherwise not form. To overcome this, incorporation of brushite seed crystals resulted in good control over the mineral phase and by adjusting the amount of seeds and precursor concentration, the amount of mineral could be tuned. The material has been characterized with a range of physical techniques, including scanning electron microscopy, powder X-ray diffraction and Rietveld refinement, Fourier transform infrared spectroscopy and thermogravimetric analysis, in order to assess mineral morphology, phase and amount within the organic matrix. The mineral content of the composite material converted from brushite into hydroxyapatite when submerged in simulated body fluid, indicating possible bioactivity. Additionally, initial cell culture studies revealed that both the material and the synthesis procedure is compatible with cells relevant to bone tissue engineering.

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Section: Bioactivity Of Alginate Composites In Sbfmentioning

confidence: 97%

“…51 Changes in the FTIR spectrum occurred for all samples exposed to SBF, which indicated a change from HPO 2− 4 to PO 3− 4 . This can be seen in the disappearance of the υ3 P-O(H) stretching mode at 875 cm −1 and the appearance of a strong adsorption at 1025 cm −1 .…”

Section: Bioactivity Of Alginate Composites In Sbfmentioning

confidence: 99%

Controlled mineralisation and recrystallisation of brushite within alginate hydrogels

Bjørnøy¹,

Bassett²,

Ucar³

et al. 2016

Biomed. Mater.

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“…Its crystal structure contains compact sheets, consisting of parallel chains, in which calcium ions are coordinated by six phosphate oxygens, two oxygen atoms belonging to the water molecules. Two kinds of water molecules exist in brushite: the hydrogen bonding of the two molecules differs somewhat (3)(4)(5)(6). Figure 1 reports the structure of brushite.…”

Section: Introductionmentioning

confidence: 98%

Study of Protonic Mobility in CaHPO4·2H2O (Brushite) and CaHPO4(Monetite) by Infrared Spectroscopy and Neutron Scattering

Tortet

Gavarri

Nihoul

et al. 1997

Journal of Solid State Chemistry

126

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“…Condrate et al [33] have reported a polarized Raman study but did not mention the possible LO-TO splitting. In this work, we present a detailed study on the polarized Raman spectra of a single crystal of brushite, in order to characterize the crystal modes and to demonstrate the effect of LO-TO splitting on the A″ and A′ modes in the 800-1200 cm À1 wavenumber range.…”

Section: Introductionmentioning

confidence: 99%

“…In a single crystal, these spectra show significant differences according to the relative crystal orientation with the incident/scattered light. These changes due to the LO-TO effects provide a simple and efficient method for measuring this splitting.Several papers reported Raman spectra of brushite [33][34][35][36][37][38] and a proposal of assignments for the observed bands. Condrate et al [33] have reported a polarized Raman study but did not mention the possible LO-TO splitting.…”

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confidence: 99%

Polarized Raman spectra of brushite (CaHPO₄.2H₂O) crystal. Investigation of the phosphate stretching modes, study of the LOTO splitting

Quillard

Mevellec

Deniard

et al. 2016

J Raman Spectroscopy

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Polarized Raman measurements were recorded on a monoclinic brushite (CaHPO 4 .2H 2 O) crystal in the 800-1200 cm À1 spectral range, corresponding to the P-O stretching modes. This study is a continuation of the investigation of the phosphate stretching modes observed in polarized infrared reflectance spectra of brushite crystal. In such ionic non-centrosymmetric crystals, the splitting between the transverse and longitudinal components of the optic vibrations was observed in the polarized Raman spectra recorded at several scattering geometries. A″ symmetry modes of the brushite crystal were measured. Using a simple model based on the symmetry of the PO 4 group, the Raman intensities of the stretching modes are calculated and compared with experimental bands. IntroductionDi(basic) calcium phosphate dihydrate (DCPD; CaHPO 4 .2H 2 O) is also known as the rare mineral 'brushite'. This mineral was discovered in 1865 by G. E. Moore [1] who called it 'brushite' in honor of Professor George Jarvis Brush an American mineralogist (Yale University, New Haven, Connecticut, USA). DCPD can be found [2][3][4] in pathological calcifications and some carious lesions. In bone surgery, DCPD is used as calcium phosphate cements, [5][6][7][8] and in dentistry, [9][10][11][12][13] it is added to toothpaste both for caries protection and as a polishing agent. In the dairy industry, DCPD is used as a mineral supplement as its importance as a constituent of infant's food was discovered [14] as early as 1917. In the food industry, it serves as a texturizer, bakery improver and water retention additive. [15] Other applications [16,17] have been reported including flame retardant, slow-release fertilizer, anticorrosive and passivating pigment for some ground coat paints.The crystalline structure of DCPD has been investigated by several groups. [18][19][20][21] This compound as well as other isostructural ones (gypsum and pharmacolite [22,23] ) is described by a noncentrosymmetric monoclinic space group Ia with, for brushite, the following cell parameters a = 5.812 Å; b = 15.180 Å; c = 6.239 Å; β = 116.25°and Z = 4. Large tabular thin-plate transparent crystals can be obtained.Among the vibrations of this compound, the P-O stretching modes are located in the 800-1200-cm À1 wavenumber range where no other bands are expected. In Raman scattering, as in infrared (IR) spectroscopy, these bands are very intense and well separated; moreover, the spectra exhibit a strong molecular character associated with the internal modes of PO 4 group. [24] Finally, in several calcium orthophosphate compounds, changes in the structure strongly affect these modes, for example, calcium substitution by other cations. [25][26][27] That is why, the study of these bands is especially interesting, and we focused our work on these modes.Four P-O stretching, vibrations are combined in the phosphate tetrahedron to give four modes, numbered [28] Q 1 to Q 4 in increasing wavenumber order (with the pseudo-symmetry [29] C 3v ). Considering the space group Ia and the presenc...

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The Vibrational Spectra of Brushite, CaHPO₄·2H₂O

Cited by 42 publications

References 10 publications

Controlled mineralisation and recrystallisation of brushite within alginate hydrogels

Controlled mineralisation and recrystallisation of brushite within alginate hydrogels

Study of Protonic Mobility in CaHPO4·2H2O (Brushite) and CaHPO4(Monetite) by Infrared Spectroscopy and Neutron Scattering

Polarized Raman spectra of brushite (CaHPO₄.2H₂O) crystal. Investigation of the phosphate stretching modes, study of the LOTO splitting

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The Vibrational Spectra of Brushite, CaHPO4·2H2O

Cited by 42 publications

References 10 publications

Controlled mineralisation and recrystallisation of brushite within alginate hydrogels

Controlled mineralisation and recrystallisation of brushite within alginate hydrogels

Study of Protonic Mobility in CaHPO4·2H2O (Brushite) and CaHPO4(Monetite) by Infrared Spectroscopy and Neutron Scattering

Polarized Raman spectra of brushite (CaHPO4.2H2O) crystal. Investigation of the phosphate stretching modes, study of the LOTO splitting

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The Vibrational Spectra of Brushite, CaHPO₄·2H₂O

Polarized Raman spectra of brushite (CaHPO₄.2H₂O) crystal. Investigation of the phosphate stretching modes, study of the LOTO splitting