Probing the surface structure of hydroxyapatite through its interaction with hydroxyl: a first-principles study

Wang, Xian; Zhang, Li; Liu, Zeyu; Zeng, Qun; Jiang, Gang; Yang, Mingli

doi:10.1039/c7ra13121f

Cited by 26 publications

(17 citation statements)

References 68 publications

(85 reference statements)

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“…The fact that this transition is possible under ambient conditions in water suggests that the process is kinetically influenced by the particle/solution interfacial dynamics, proving both the key role of dissolution/reprecipitation phenomena and the intimate ties between these surface events and the internal crystal structure of the particles. Mechanistically, OH − groups, which play an important role in defining the surface activity of Hap 56 and which traverse the crystal structure of HAp in threads 57 , may have a key role in connecting the surface and the bulk and enabling this process to occur relatively promptly in the solution. This role is justified by the model proposed to hold for the transformation of Posner’s clusters, the flexibly structured 58 basic prenucleation building blocks of CP precipitates 59 , to apatitic crystalline units.…”

Section: Resultsmentioning

confidence: 99%

Insights into the kinetics of thermally induced crystallization of amorphous calcium phosphate

Uskoković

Marković

Veselinović

et al. 2018

Phys. Chem. Chem. Phys.

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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, 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 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.

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Section: Resultsmentioning

confidence: 99%

Insights into the kinetics of thermally induced crystallization of amorphous calcium phosphate

Uskoković

Marković

Veselinović

et al. 2018

Phys. Chem. Chem. Phys.

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“…Crystal orientation of hydroxyapatite along with the role exerted by citrate bridges and collagen between HAp platelets in bone have been carefully described as well [14][15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Habit Change of Monoclinic Hydroxyapatite Crystals Growing from Aqueous Solution in the Presence of Citrate Ions: The Role of 2D Epitaxy

2018

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Calcium hydroxyapatite (HAp) has been crystallized from aqueous solutions in the presence of citrate ions, in two temperature intervals. At lower temperature, where citrate could form the stable 3D-ordered phase Ca-citrate-tetrahydrate (Ca-Cit-TH), only the monoclinic (P2 1 /c) HAp polymorph occurs and assumes the shape of fence-like aggregates, built by sharply [010] elongated lamellae dominated by the pinacoid {001}. This pronounced anisotropic growth habit is compared with the usually considered rod-like pseudo-hexagonal occurring in pure aqueous solution growth. The habit change is interpreted by assuming that 2D islands of Ca-citrate-tetrahydrate can be adsorbed as epimonolayers of thickness d 001 onto the different growth forms: {001}, {100}, 102 , {010}, and 101 of HAp. A comparison is made among the corresponding coincidence lattices, in order to explain on reticular basis the selective adsorption of citrate on the {001} HAp form. The role exerted by the 2D-epitaxially adsorbed Ca-Cit-TH as a "mortar" in the monoclinic HAp "brick" assembly is outlined as well.

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“…Based on this result and RB speciation, it can be assumed that there was no cation exchange or electrostatic attraction between the negatively charged surfaces of CFA-HAp1-4 and the uncharged dye molecule. Although the surfaces of the hydroxyapatites [107] and aluminosilicates [108] are characterized by the presence of numerous hydroxyl groups, strong deprotonation inhibits the formation of hydrogen bonds. For this reason, we considered a different basis for RB adsorption onto the composites.…”

Section: Cu(ii) and Rb Adsorption Equilibriummentioning

confidence: 99%

Characterization of the Physical, Chemical, and Adsorption Properties of Coal-Fly-Ash–Hydroxyapatite Composites

et al. 2021

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(1) Hydroxyapatite (Hap), which can be obtained by several methods, is known to be a good adsorbent. Coal fly ash (CFA) is a commonly reused byproduct also used in environmental applications as an adsorbent. We sought to answer the following question: Can CFA be included in the method of Hap wet synthesis to produce a composite capable of adsorbing both heavy metals and dyes? (2) High calcium lignite CFA from the thermal power plant in Bełchatów (Poland) was used as the base to prepare CFA–Hap composites. Four types designated CFA–Hap1–4 were synthesized via the wet method of in situ precipitation. The synthesis conditions differed in terms of the calcium reactants used, pH, and temperature. We also investigated the equilibrium adsorption of Cu(II) and rhodamine B (RB) on CFA–Hap1–4. The data were fitted using the Langmuir, Freundlich, and Redlich–Peterson models and validated using R2 and χ2/DoF. Surface changes in CFA–Hap2 following Cu(II) and RB adsorption were assessed using SEM, SE, and FT-IR analysis. (3) The obtained composites contained hydroxyapatite (Ca/P 1.67) and aluminosilicates. The mode of Cu(II) and RB adsorption could be explained by the Redlich–Peterson model. The CFA–Hap2 obtained using CFA, Ca(NO3)2, and (NH4)2HPO4 at RT and pH 11 exhibited the highest maximal adsorption capacity: 73.6 mg Cu/g and 87.0 mg RB/g. (4) The clear advantage of chemisorption over physisorption was indicated by the Cu(II)–CFA–Hap system. The RB molecules present in the form of uncharged lactone were favorably adsorbed even on strongly deprotonated CFA–Hap surfaces.

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Probing the surface structure of hydroxyapatite through its interaction with hydroxyl: a first-principles study

Cited by 26 publications

References 68 publications

Insights into the kinetics of thermally induced crystallization of amorphous calcium phosphate

Insights into the kinetics of thermally induced crystallization of amorphous calcium phosphate

Habit Change of Monoclinic Hydroxyapatite Crystals Growing from Aqueous Solution in the Presence of Citrate Ions: The Role of 2D Epitaxy

Characterization of the Physical, Chemical, and Adsorption Properties of Coal-Fly-Ash–Hydroxyapatite Composites

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