Sodium-Doped Hydroxyapatite Nanopowder through Sol-Gel Method: Synthesis and Characterization

2011 ◽  
Vol 694 ◽  
pp. 128-132 ◽  
Author(s):  
Erlani Pusparini ◽  
Iis Sopyan ◽  
Mohd. Hamdi ◽  
Singh Ramesh

The nanocrystalline HA powders were produced through sol-gel method which employed calcium nitrate tetrahydrate [Ca(NO3)2.4H2O] and diammonium hydrogen phosphate [(NH4)2HPO4] as calcium and phosphorous precursors. Sodium ion (Na+) is one of the trace elements found in biological apatite and believed to have important effect in its performance. The concentrations of sodium dopant were varied from 0 mol% until 15 mol% by using sodium nitrate (NaNO3) as the source of dopant. Characterization of nanopowders was investigated by using X-ray diffraction (XRD), Fourier transform infra red (FTIR) and Transmission Electron Microscope (TEM). XRD analysis revealed that there are no other phases exist in the synthesized powder, evinced single phase of HA and a trend shows an increase of cristallinity with increase of sodium dopant concentration. While the TEM images showed evidence that the particle sizes were bigger with the increasing sodium concentration, showing the effect of sodium dopant on the densification of the powder.

2010 ◽  
Vol 13 (1-2) ◽  
pp. 85 ◽  
Author(s):  
S. Manocha ◽  
Parth Joshi ◽  
Bhavini Patel ◽  
L.M. Manocha

<p>Hydroxyapatite (HAp) is a unique material having high adsorption capacity of heavy metals, high ion exchange capacity, high biological compatibility, low water solubility, high stability under reducing and oxidizing conditions, availability and low cost. Hydroxyapatite nanoparticles have been synthesized by Sol-gel method using Calcium nitrate tetrahydrate [Ca(NO<sub>3</sub>)<sub>2</sub>•4H<sub>2</sub>O] and Phosphorus pentaoxide (P<sub>2</sub>O<sub>5</sub>) as starting reactants. The addition of Phosphorus pentaoxide to Calcium nitrate tetrahydrate was carried out slowly with simultaneous stirring. After addition, solution was aged for 10 minutes for maturation. The precipitate was dried at 80 °C overnight and further heat treated at 550 °C for 2 hours. The dried and calcined particles were characterized by X-ray diffractometry, Fourier transform infra-red spectroscopy and Thermo gravimetric analysis. The particle size and morphology were studied using transmission electron microscopy. TEM examination of the treated powders displayed particles of polygon morphology with dimensions 20-50 nm in length. The FT-IR spectra for sample confirmed the formation of hydroxyapatite.</p>


2018 ◽  
Vol 24 (8) ◽  
pp. 5523-5526 ◽  
Author(s):  
B Shalini ◽  
A. Ruban Kumar ◽  
A. Mary Saral

Hydroxyapatite (HAp) is the most widely accepted biomaterial for the repair and reconstruction of bone tissue defects. The current study is based on HAp was synthesized using sol–gel method. The drug was loaded in presence and absence of gelatin with pure HAp. Precursors like calcium nitrate tetrahydrate and diammonium hydrogen orthophosphate were used and ammonia solution was added to maintain the pH value at 10.5 throughout the reaction. The synthesized HAp, drug loaded HAp and drug loaded HAp with gelatin were characterized using PXRD, FTIR, SEM, Drug loading, drug release studies. Results shows that the average crystallite size of the prepared HAp and drug loaded HAp with gelatin are 30 to 60 nm and 100 to 300 nm respectively was calculated using PXRD and morphology of pure HAp and drug loaded HAp with polymer was found using SEM. Drug loading and release percentage was calculated.


2006 ◽  
Vol 309-311 ◽  
pp. 317-320 ◽  
Author(s):  
Ill Yong Kim ◽  
Chikara Ohtsuki ◽  
Masanobu Kamitakahara ◽  
Masao Tanihara ◽  
S.B. Cho

CaO-SiO2 gels for bioactive organic-inorganic composites were prepared from tetraethoxysilane (TEOS) and calcium nitrate tetrahydrate (Ca(NO3)2⋅4H2O) by a sol-gel method with the addition of polyethylene glycol (PEG) and methacryloxypropyltrimethoxysilane (MPS). The effects of PEG and MPS on morphology and bioactivity of the gel were investigated. The samples with the nominal compositions of Ca(NO3)2:TEOS:MPS = 30:70:0 and 30:63:7 (in molar ratio) were prepared with or without coexistence of PEG at a molar ratio of (TEOS+MPS):PEG = 70:0.16. Spherical powders were obtained regardless of the addition of MPS after removal of PEG by washing, whereas the samples prepared without PEG gave crack-free bulk bodies. Incorporation of MPS was confirmed form the results of Fourier transform infrared spectroscopy (FT-IR). All the samples, regardless of addition of PEG and MPS, formed apatite on their surfaces in simulated body fluid (SBF), when washing time was 3 h during the preparation. These results show that the bioactive spherical powder of CaO-SiO2 gel modified with MPS can be obtained by the present method. It is expected to induce the increase of the chemical bonding with surrounding organic matrix when it was used as fillers for composite materials.


2016 ◽  
Vol 840 ◽  
pp. 156-159
Author(s):  
Shah Rizal Kasim ◽  
Siti Noor Fazliah Mohd Noor ◽  
Zainal Arifin Ahmad

In this research, the effect of stirring and aging time on the formation of β-tricalcium phosphate (β-TCP) powder was studied. β-TCP powder was synthesized using calcium nitrate tetrahydrate (Ca(NO3)2.4H2O) (0.6M) and diammonium hydrogen phosphate (NH4)2HPO4) (0.4M) via wet precipitation method. The mixture was stirred with different duration (1, 3, 5 and 7 hours) then centrifuged before washed with distilled water (twice) and ethanol followed by drying in oven (80°C, 24 hours). The cake was ground to form powder. The as prepared powder was analyzed using thermo-gravimetric (TGA) to determine the suitable calcinations temperature. TGA results show that the proper calcinations temperature was 800°C. The formation of β-TCP was characterized using X-ray Diffraction (XRD) analysis. Sample with optimum formation of β-TCP phase will choose for further study on the effect of aging time (0.5, 1, 20 and 24 hours). XRD analysis confirmed that sample stirred for 7 hours and aging for 24 hours produced β-TCP as major phase. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) proved that β-TCP powder form as agglomerated particles


2017 ◽  
Vol 31 (12) ◽  
pp. 1750083 ◽  
Author(s):  
Nandeibam Nilima ◽  
Mamata Maisnam ◽  
Sumitra Phanjoubam

Li–Ni–Co ferrite samples with compositional formula Li[Formula: see text]Ni[Formula: see text]Co[Formula: see text]Fe[Formula: see text]O4 with [Formula: see text] ranging from 0.00 to 0.1 in steps of 0.02 were prepared by sol–gel method. X-ray diffraction (XRD) analysis confirmed the formation of single phase with spinel structure in all the samples. The lattice constant evaluated from XRD data was found to increase with increase of Co[Formula: see text] substitution and crystallite size was observed in the range of 30–59 nm. The microstructure of the samples was studied by using scanning electron microscopy (SEM). Nanocrystalline nature of ferrites was also confirmed by transmission electron microscopy (TEM). [Formula: see text]–[Formula: see text] measurements were made using a vibrating sample magnetometer and hysteresis parameters such as saturation magnetization and coercivity were obtained for all compositions. The frequency variations of initial permeability and permeability loss showed a dispersive behavior for all compositions and an increase in initial permeability is observed with increase of Co[Formula: see text] substitution. The results obtained and mechanisms involved are discussed in the paper.


Nanopages ◽  
2019 ◽  
pp. 1-11
Author(s):  
G. M. Taha ◽  
M. N. Rashed ◽  
M. S. El-Sadek ◽  
M. A. Moghazy

Abstract BiFeO3 (BFO) nanopowder was synthesized in a pure form via a sol- gel method based on glycol gel reaction. Effect of drying and preheating temperature on preventing other phases was studied. Many parameters were studied as calcination temperature and time & stirring temperature as well. The prepared powder was characterized by X-Ray Diffraction of powder (XRD) and Transmission Electron Microscope (TEM). High pure BiFeO3 was obtained by preheated process at 400 °C for 0.5 h and calcination at 600 °C for 0.5 h without any impurities compared to dry at110 °C.


2018 ◽  
Vol 41 (3-4) ◽  
pp. 53-62 ◽  
Author(s):  
Behnaz Lahijani ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi

Abstract In this work, the PbFe12O19 nanoparticles were prepared by the simple and optimized precipitation method with different organic surfactants and capping agents. In the next step, the TiO2 nanoparticles were synthesized using the sol-gel method. At the final step, the PbFe12O19-TiO2 nanocomposites were prepared via the sol-gel method. The effect of the precipitating agent on the morphology and particle size of the products was investigated. The prepared products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The results obtained by the vibrating sample magnetometer show the magnetic properties of the ferrite nanostructures. The photocatalytic effect of the PbFe12O19-TiO2 nanocomposite on the elimination of the azo dyes (acid black, acid violet and acid blue) under ultraviolet light irradiation was evaluated. The results indicate that the prepared nanocomposites have acceptable magnetic and photocatalytic performance.


2004 ◽  
Vol 03 (06) ◽  
pp. 749-755 ◽  
Author(s):  
YING LI ◽  
SUO HON LIM ◽  
TIM WHITE

The properties influencing the photocatalytic activity of TiO 2 particles have been suggested to include the surface area, crystallinity, crystallite size and crystal structure. Therefore, manipulation of the microstructure of titania, especially of nanocrystalline powders, is very important in the preparative process. In this study, nanocrystalline TiO 2 powders with controlled particle size and phase composition were synthesized at low temperature (<80°C) by a modified sol–gel method. The effects of gelation temperature were systematically investigated. It was found that this parameter played a critical role in determining the crystallinity of single phase anatase. With increasing gelation temperature, the crystallinity of anatase improved initially and then decreased if the temperature was raised to 80°C. These nanomaterials were characterized comprehensively by powder X-ray diffraction (including Rietveld analysis), high-resolution transmission electron microscopy, DSC/TGA thermal analysis and UV–Vis spectrometry.


2002 ◽  
Vol 17 (3) ◽  
pp. 590-596 ◽  
Author(s):  
G. Ennas ◽  
M. F. Casula ◽  
G. Piccaluga ◽  
S. Solinas ◽  
M. P. Morales ◽  
...  

γ–Fe2O3/SiO2 and Fe/SiO2 nanocomposites, with a Fe/Si molar ratio of 0.25, were prepared by the sol-gel method starting from ethanolic solutions of tetraethoxysilane and iron (III) nitrate. After gelation the xerogels were oxidated or reduced. Samples were investigated by transmission electron microscopy, x-ray diffraction, differential scanning calorimetry, and thermogravimetry. Magnetic properties of the samples were investigated at room temperature (RT) and at 77 K. Nanometric particles supported in the silica matrix were obtained in all cases. Bigger particles (10 nm) were obtained in the case of Fe/SiO2 nanocomposites with respect to the γ–Fe2O3/SiO2 samples (5–8 nm). A slight effect of sol dilution on particle size was observed only in the case of γ–Fe2O3/SiO2 nanocomposites. A superparamagnetic behavior was shown at RT only by γ–Fe2O3/SiO2 nanocomposites. Iron-based composites exhibited coercivity values higher than 700 Oe at RT.


2004 ◽  
Vol 449-452 ◽  
pp. 1121-1124 ◽  
Author(s):  
Do Won Seo ◽  
J.G. Kim ◽  
Yun Hae Kim ◽  
Chin Myung Whang

Bioactive ORMOSILS (organically modified silicate), PDMS-CaO-SiO2-P2O5 with five different P2O5 content (0, 0.01, 0.03, 0.06, 0.09 mol%) have successfully been synthesized by sol-gel process. The hybrids have been prepared with polydimethylsiloxane (PDMS), tetraethoxysilane (TEOS), calcium nitrate tetrahydrate [Ca(NO3)2 4H2O] and triethyl phosphate (TEP) as starting materials and subsequently soaked into the simulated body fluid (SBF) for different period of time and the bioactivity of hybrids was determined by examining the apatite formation on the surface of the specimen by FT-IR, Thin-Film X-ray Diffraction, and Scanning Electron Microscopy (SEM). All of the prepared samples with different P2O5 content showed in vitro bioactivity. It was observed that the increase in P2O5 content up to 0.03 mole % increases the apatite formation compared to P2O5- free hybrids. However, further increase in P2O5 concentration slows down the formation of the apatite layer most probably due to the decrease of pH of SBF by dissolution of a large amount of phosphate ions.


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