Preparation and Characterization of Fluorohydroxyapatite Nanopowders Nonalkoxide Sol-gel Method (original) (raw)
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J Ceram Process Res, 2008
Nanocrystalline hydroxyapatite (HA) powder was synthesized by a simple heating process involving simple chemical reaction. The characterization of the produced powder showed that the powder is nanosize with particle in the range of 30-70 mm in diameter and almost evenly spherical in shape. The powder also has a high surface area of 43.16 m 2 /g. Field Emission Scanning Electron Microscopy (FESEM) observation showed the crystallite and particle size become bigger with an increment of calcination temperature, indicating increasing of crystallinity. FESEM observation showed the particle size become bigger with an increment of calcinations temperature. It is in agreement with the crystallite size analysis, obtained by Scherer's formula and particle size analysis, measured by Nano-Sizer. X-ray Diffraction (XRD) and Fourier Transform Infra Red Spectroscopy (FTIR) analyses exhibited the same result, where HA phase was clearly observed at at various temperatures up to 600˚C. However, at temperature more than 600˚C, Tri calcium phosphate (TCP) phase appeared suppressing the HA phase, producing biphasic calcium phosphate.
Synthesis of nano-fluorohydroxyapatite thin films by sol-gel method
Malaysian Journal of Science. Series B, Physical & Earth Sciences, 2010
It is realized that the surface of biomedical metallic implants covered by fluorohydroxyapatite,-alo(PO4)6(01-1, F)] (FHA) can create bioactivity of the implant and shorten healing time. In this work FHA, in the of powders and of thin films on titanium substrates, were synthesized by sol-gel spin coating method, using calcium nitrate tetrahydrate (Ca(NO3)2).4H20, phosphorous pentoxide (P205) and ammonium fluoride (NH4F) to vide Ca-precursor, P-precursor and fluorine reagent, respectively. The FHA powders were calcined and thin were fired at temperatures ranging from 500-800°C. The constituent of both powders and thin films were firmed as FHA using X-ray diffraction (XRD) and Fourier transform Infrared spectroscopy (FTIR). The thermal bility of FHA powders was studied by differential thermal analysis (DTA). The optimized calcination and firing temperature was 600 °C. Transmission electron microscopy (TEM) results with Debye-Scherrer equation gave the tie of the FHA particles in nano-scale range. The films were found to be quite uniform and dense by SEM.
Micro and Nano Letters, 2012
Several fluorine-substituted hydroxyapatite ceramics with the general chemical formula Ca 5 (PO 4) 3 (OH) 12x F x (0 ≤ x ≤ 1), where x ¼ 0.0 (hydroxyapatite; HA), x ¼ 0.41 (fluorhydroxyapatite; FHA1) and x ¼ 0.69 (fluorhydroxyapatite; FHA2) and x ¼ 0.98 (fluorapatite; FA), were synthesised via pH-cycling method. The powders were characterised by using scanning electron microscope, transmission electron microscopy (TEM), Fourier transform infra-red (FTIR), X-ray diffraction (XRD) and F-selective electrode. The TEM micrographs showed that the increasing of fluoride ion concentration will cause a reduction in the aspect ratio of the produced crystallites. The XRD analysis of the calcined powders showed that all of the synthesised powders were pure and their XRD patterns were similar together. Eventually, the FTIR results suggest that the fluorine has substituted instead of hydroxyl groups in the fluoridated hydroxyapatite samples.
Advances in Applied Ceramics, 2010
In this study, the effect of fluorine ion addition on the structural, thermal, mechanical and solubility characteristics of hydroxyapatite nanopowders was investigated. The fluorine substituted hydroxyapatite powders with compositions of Ca 5 (PO 4) 3 (OH) 12x F x [x50 (hydroxyapatite), x50?68 (fluorhydroxyapatite) and x50?97 (fluorapatite)] were prepared. The powders were uniaxially pressed and were formed as disc shape. Subsequently, sinterability and thermal stability of disc samples were compared together. Also the effects simultaneously of fluoride content and temperature on the lattice parameters, crystallites size, microstrain and microstructure of the samples were examined. The sintering density and flexural strength of these samples were evaluated with the sintering temperature. Finally, the in vitro dissolution studies of the apatite samples were performed at osteoclastic resorption conditions. The above mentioned experimental results showed that the fluorine content had significant impact on the sintering behaviour, densification and mechanical properties of the hydroxyapatite nanopowders.
Synthesis of Nano - Hydroxyapatite and Nano - Fluoroapatite Particles by Sol-Gel Method
2019
Background: Hydroxyapatite is a material which resembles the composition and crystal structure of hard tissues in human body. It is being used in dentistry as a bioactive material in dental implants and is a major constituent in the bone regenerative materials. Fluoroapatite is also a bioactive material and is more stable than Hydroxyapatite. The fluoride content is anti - bacterial and is working very efficiently as a component of dental restorative materials. Objective: The objective is to synthesize the nano Hydroxyapatite and nanoFluoroapatite powder via sol-gel method, and compare the FTIR and Raman Spectrums of synthesized material with the FTIR and Raman of nano Hydroxyapatite and Fluoroapatite. Methods: The materials were synthesized by sol - gel method and then evaluated by the FTIR and Raman spectroscopy to confirm the chemical structure of both the materials.Results: FTIR and Raman Spectroscopy of the synthesized Hydroxyapatite and Fluoroapatite are then evaluated and com...
Synthesis of hydroxyapatite/fluoroapatite solid solution by a sol–gel method
Materials Letters, 2001
Ž . A sol-gel method is developed to synthesize hydroxyapatite HA rfluoroapatite FA solid solution for providing a basis of preparation of the solid solution film or coating. Calcium nitrate-4 hydrate, phosphoric pentoxide and trifluoroacetic acid Ž . Ž . TFA were used as the precursors. Triethanolamine TEA was used as a promoter for incorporating fluorine into Ca phosphates. Mixed ethanol solutions of the Ca and P precursors in CarP ratio of 1.67 with different amounts of TFA and TEA were prepared; the mixed solutions were dried on a hot plate to convert them to the as-prepared powders. After the powders were calcined at temperatures up to 9008C, HArFA solid solutions were obtained. It was found that the fluorine contents in the apatite were dependent on the amounts of TFA and TEA in the mixed solutions. q
Synthesis of fluorapatite–hydroxyapatite nanoparticles and toxicity investigations
International Journal of Nanomedicine, 2011
In this study, calcium phosphate nanoparticles with two phases, fluorapatite (FA; Ca 10 (PO 4) 6 F 2) and hydroxyapatite (HA; Ca 10 (PO 4) 6 (OH) 2), were prepared using the solgel method. Ethyl phosphate, hydrated calcium nitrate, and ammonium fluoride were used, r espectively, as P, Ca, and F precursors with a Ca:P ratio of 1:72. Powders obtained from the sol-gel process were studied after they were dried at 80°C and heat treated at 550°C. The degree of crystallinity, particle and crystallite size, powder morphology, chemical structure, and phase analysis were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Zetasizer experiments. The results of XRD analysis and FTIR showed the presence of hydroxyapatite and fluorapatite phases. The sizes of the crystallites estimated from XRD patterns using the Scherrer equation and the crystallinity of the hydroxyapatite phase were about 20 nm and 70%, respectively. T ransmission electron microscope and SEM images and Zetasizer experiments showed an average size of 100 nm. The in vitro behavior of powder was investigated with mouse fibroblast cells. The results of these experiments indicated that the powders were biocompatibile and would not cause toxic reactions. These compounds could be applied for hard-tissue engineering.