Journal ArticleDOI
Chemical characterization of silicon-substituted hydroxyapatite.
TLDR
Chemical analysis confirmed the proposed substitution of the silicon (or silicate) ion for the phosphorus (or phosphate) ion in hydroxyapatite and demonstrated that phase-pure silicon-substituted hydroxyAPatite may be prepared using a simple precipitation technique.Abstract:
Bioceramic specimens have been prepared by incorporating a small amount of silicon (0.4 wt %) into the structure of hydroxyapatite [Ca10(PO4)6(OH)2, HA] via an aqueous precipitation reaction to produce a silicon-substituted hydroxyapatite (Si-HA). The results of chemical analysis confirmed the proposed substitution of the silicon (or silicate) ion for the phosphorus (or phosphate) ion in hydroxyapatite. The Si-HA was produced by first preparing a silicon-substituted apatite (Si-Ap) by a precipitation process. A single-phase Si-HA was obtained by heating/calcining the as-prepared Si-Ap to temperatures above 700 degrees C; no secondary phases, such as tricalcium phosphate (TCP), tetracalcium phosphate (TeCP), or calcium oxide (CaO), were observed by X-ray diffraction analysis. Although the X-ray diffraction patterns of Si-HA and stoichiometric HA appeared to be identical, refinement of the diffraction data revealed some small structural differences between the two materials. The silicon substitution in the HA lattice resulted in a small decrease in the a axis and an increase in the c axis of the unit cell. This substitution also caused a decrease in the number of hydroxyl (OH) groups in the unit cell, which was expected from the proposed substitution mechanism. The incorporation of silicon in the HA lattice resulted in an increase in the distortion of the PO4 tetrahedra, indicated by an increase in the distortion index. Analysis of the Si-HA by Fourier transform infrared (FTIR) spectroscopy indicated that although the amount of silicon incorporated into the HA lattice was small, silicon substitution appeared to affect the FTIR spectra of HA, in particular the P-O vibrational bands. The results demonstrate that phase-pure silicon-substituted hydroxyapatite may be prepared using a simple precipitation technique.read more
Citations
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Journal ArticleDOI
Phosphate Recovery from Human Waste via the Formation of Hydroxyapatite during Electrochemical Wastewater Treatment.
TL;DR: Pilot-scale and bench-scale experiments demonstrated that electrolysis can remove phosphate by cathodic precipitation as hydroxyapatite at no additional energy cost, suggesting that phosphate removal can be viewed as an ancillary benefit of electrochemical wastewater treatment, adding utility to the process without requiring additional energy inputs.
Journal ArticleDOI
Effects of silicate and carbonate substitution on the properties of hydroxyapatite prepared by aqueous co-precipitation method
L. T. Bang,Singh Ramesh,Judha Purbolaksono,Yern Chee Ching,B.D. Long,Hari Chandran,Radzali Othman,Radzali Othman +7 more
TL;DR: In this paper, the effects of silicate and carbonate substitutions in hydroxyapatite (HA) on phase retention, physical properties, and in vitro biological response were investigated.
Journal ArticleDOI
Carbonate Hydroxyapatite and Silicon-Substituted Carbonate Hydroxyapatite: Synthesis, Mechanical Properties, and Solubility Evaluations
TL;DR: The results revealed that the silicate and carbonate ions competed to occupy the phosphate site and also entered simultaneously into the hydroxyapatite structure and resulted in a better solubility compared to that of Si-free CO3Ap.
Journal ArticleDOI
Recent developments in processing and surface modification of hydroxyapatite
TL;DR: In this article, a review of the developments in the fields of bioceramic materials and laser surface microstructuring of materials is presented, with the advantages of producing nanocrystalline material via emulsion routes.
Journal ArticleDOI
Synthesis of Si-substituted hydroxyapatite by a wet mechanochemical method
TL;DR: Si-substituted hydroxyapatites with up to 2.0% Si content have been prepared by a wet mechanochemical method to obtain improved biocompatibility as discussed by the authors.
References
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Journal ArticleDOI
Bioceramics: From Concept to Clinic
TL;DR: The mechanisms of tissue bonding to bioactive ceramics are beginning to be understood, which can result in the molecular design of bioceramics for interfacial bonding with hard and soft tissues.
Journal Article
Bioceramics : from concept to clinic
TL;DR: The mechanisms of tissue bonding to bioactive ceramics are beginning to be understood, which can result in the molecular design of bioceramics for interfacial bonding with hard and soft tissues.
Journal ArticleDOI
Silicon: A Possible Factor in Bone Calcification
TL;DR: Silicon, a relatively unknown trace element in nutritional research, has been uniquely localized in active calcification sites in young bone and is suggested to be associated with calcium in an early stage of calcification.