TITLE

Structural and compositional features of amorphous calcium phosphate at the early stage of precipitation

AUTHOR(S)
Zyman, Z. Z.; Rokhmistrov, D. V.; Glushko, V. I.
PUB. DATE
January 2010
SOURCE
Journal of Materials Science: Materials in Medicine;Jan2010, Vol. 21 Issue 1, p123
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Precipitates formed at an early stage (during the first 6 h) of the hydroxyapatite crystallization of a solution were studied. A nitrous synthesis was used (0.583M (NH4)2HPO4 and 0.35 M Ca(NO3)2·4H2O solutions at pH 11–12, 21°C, fast mixing, lyophilization of aliquots). Although XRD patterns indicated an amorphous calcium phosphate (ACP), IR spectra revealed apatite nanocrystals in the precipitates. Some amount of free calcium was found in the mother solution by mass spectrometrical analysis of the aliquots. This amount considerably decreased as the synthesis proceeded, however, the decrease had a slight effect on the crystallinity of the precipitates. A new suggestion on the nature of delayed crystallization (under conditions as those in the present study) was proposed. The free calcium adsorbed by the nanoparticles from the solution formed a shell around a particle because the calcium diffusion into the bulk was poor at the low synthesis temperature. As such, the encapsulation delayed the crystallization of the nanoparticles. Evidence for this suggestion was given. New possibilities were proposed for preparation of bioactive materials of desired composition based on the structural and compositional peculiarities of the X-ray diffractionamorphous calcium phosphates.
ACCESSION #
47481432

 

Related Articles

  • Synthesis of nanophase hydroxyapatite by aSerratiasp. from waste-water containing inorganic phosphate. Yong, P.; Macaskie, L. E.; Sammons, R. l.; Marquis, P. M. // Biotechnology Letters;Nov2004, Vol. 26 Issue 22, p1723 

    Synthesis of nanophase hydroxyapatite (HA) on a bacterial surface was achieved at the expense of CaCl2 and inorganic phosphate (Pi). After initial nucleation, calcium was precipitated on and around the cells as calcium phosphate at the expense of inorganic phosphate in the challenge solution,...

  • The Effect of Fluoride Ion on Apatite Formation From Amorphous Precursor. AOBA, TAKAAKI; MORIWAKI, YUTAKA // Journal of Dental Research;Jun1977, Vol. 56 Issue 6, p698 

    The article presents a study which examines the effect of fluoride ion upon the formation of apatite from amorphous precursor. The fact that amorphous calcium phosphate (ACP) and fluoride ions can aid in the transformation of ACP to hydroxyapatite (HA) is noted. The results of the study are also...

  • The Role of Brushite and Octacalcium Phosphate in Apatite Formation. Johnsson, Mats S.-A.; Nancollas, George H. // Critical Reviews in Oral Biology & Medicine;1992, Vol. 3 Issue 1, p61 

    Studies of apatite mineral formation are complicated by the possibility of forming several calcium phosphate phases. The least soluble, hydroxyapatite (HAP), is preferentially formed under neutral or basic conditions. In more acidic solutions phases such as dicalcium phosphate dihydrate...

  • Diffusion coefficient of Fe2+ in single-crystal ZnSe. Il'ichev, N. N.; Shapkin, P. V.; Gulyamova, E. S.; Kulevsky, L. A.; Nasibov, A. S. // Inorganic Materials;Feb2010, Vol. 46 Issue 2, p112 

    The diffusion coefficient of Fe in single-crystal ZnSe has been measured in the temperature range 886–995°C. The 995°C diffusion coefficient is (47 ± 5) × 10−11 cm2/s, and the average activation energy for Fe diffusion is 2.9 ± 0.3 eV.

  • Infrared absorption by sulfur-doped silicon formed by femtosecond laser irradiation. Crouch, C. H.; Carey, J. E.; Shen, M.; Mazur, E.; Génin, F. Y. // Applied Physics A: Materials Science & Processing;2004, Vol. 79 Issue 7, p1635 

    We microstructured silicon surfaces with femtosecond laser irradiation in the presence of SF6. These surfaces display strong absorption of infrared radiation at energies below the band gap of crystalline silicon. We report the dependence of this below-band gap absorption on microstructuring...

  • Synthesis and Structure of Magnesium-Substituted Hydroxyapatite. Fadeev, I. V.; Shvorneva, L. I.; Barinov, S. M.; Orlovskii, V. P. // Inorganic Materials;Sep2003, Vol. 39 Issue 9, p947 

    Magnesium-substituted calcium phosphates with the general formula Ca10 – xMgx(PO4)6(OH)2 (x < 1) are synthesized and characterized by IR spectroscopy and x-ray diffraction. The magnesium ion is found to destabilize the structure of hydroxyapatite: increasing the Mg content from 1 to 10...

  • Nanodimensional and Nanocrystalline Apatites and Other Calcium Orthophosphates in Biomedical Engineering, Biology and Medicine. Dorozhkin, Sergey V. // Materials (1996-1944);Dec2009, Vol. 2 Issue 4, p1975 

    Recent developments in biomineralization have already demonstrated that nanosized particles play an important role in the formation of hard tissues of animals. Namely, the basic inorganic building blocks of bones and teeth of mammals are nanodimensional and nanocrystalline calcium...

  • Traversing phase fields towards nanosized beta tricalcium phosphate. Gross, Karlis A.; Andersons, Juris; Misevicius, Martynas; Svirksts, Janis // Key Engineering Materials;2014, Vol. 587, p97 

    The difficulty of beta tricalcium phosphate (ß-TCP) crystallization in aqueous media opens the question whether ß-TCP can be produced using an alternative pathway. Amorphous calcium phosphate (ACP) is metastable in an aqueous environment and prefers a more stable apatite phase. Others have...

  • Magnesium Inhibition of Apatite Nucleation by Proteolipid. ENNEVER, J.; VOGEL, J. J. // Journal of Dental Research;Apr1981, Vol. 60 Issue 4, p838 

    The effect of magnesium on apatite nucleation by Bacterionema matruchotii proteolipid was determined. The ion, in metastable calcium phosphate solution at a concentration that did not reduce proteolipid calcium binding, prevented apatite crystallization. The data were compared with those...

Share

Read the Article

Courtesy of MICHIGAN ELIBRARY

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics