Sol-Gel Synthesis of FHA Nanoparticles and CDHA Agglomerates from a Mixture with a Nonstochiometric Ca/P Ratio

2008 ◽  
Vol 396-398 ◽  
pp. 607-610 ◽  
Author(s):  
R. Jahandideh ◽  
Aliasghar Behnamghader ◽  
M. Rangie ◽  
A. Youzbashi ◽  
S. Joughehdoust ◽  
...  
Keyword(s):  
Sol Gel ◽  
Calcium Nitrate ◽  
Triethyl Phosphite ◽  
Ammonium Fluoride ◽  
Powder Morphology ◽  
Dispersed Particles ◽  
Ft Ir ◽  
Xrd Patterns ◽  
Average Size ◽  
Sol Gel Synthesis

The aim of this study was to investigate the sol gel synthesis of HA/FA nanoparticles and the possible formation of TCP phase or unstoichiometric calcium deficient hydroxyapatite (CDHA) from the precursors with a Ca/P ratio of 1.62. In order to prepare the sol, the solutions of Triethyl phosphite, ammonium fluoride and calcium nitrate in ethanol were used respectively as P, F and Ca precursors. The crystallinity, particle and crystallite size, powder morphology, chemical structure and phase analysis were investigated by SEM, XRD, FT-IR and Zeta sizer experiment. A multiphase compound containing hydroxyapatite (HA) and fluoroapatite (FA) nanoparticles and calcium deficient hudroxyapatite (CDHA) agglomerates was obtained. The size of the crystallites estimated from XRD patterns using Scherrer equation and the crystallinity of HA phase were about 5 nm and 66% respectively. The zeta sizer experiments for the dispersed particles in its own conditions showed an average size of 98 nm.

Preparation and Characterization of BaFe12O19 Hollow Nanocrystalline Aggregations

2010 ◽  
Vol 152-153 ◽  
pp. 121-124 ◽  
Author(s):  
Hai Qing Huang ◽  
Guo Xuan Xiong
Keyword(s):  
Saturation Magnetization ◽  
Raw Materials ◽  
Sol Gel ◽  
Nano Particles ◽  
Soft Template ◽  
Ft Ir ◽  
Xrd Patterns ◽  
Average Size ◽  
Primary Crystals

M-type BaFe12O19 nanocrystalline aggregations were prepared by the citrate sol-gel method, using Fe(NO3)3 and Ba(NO3)2 as raw materials, urea and ethanol as the soft template. The samples were investigated by SEM, TEM, FT-IR, XRD and VSM. SEM and TEM micrographs show the product is hollow nanocrystalline aggregations with microporous. XRD patterns indicate M-type BaFe12O19 aggregations with mesoporous are purity and well crystallinity, the average size of the primary crystals of the aggregations is 48nm. Saturation magnetization and coercivity of the aggregations is 55.3emu/g and 5403Oe, respectively, which are higher than these of previous BaFe12O19 nano-particles reported in the literature.

The effect of silver concentration and calcination temperature on structural and optical properties of ZnO:Ag nanoparticles

2015 ◽  
Vol 29 (01) ◽  
pp. 1450254 ◽  
Author(s):  
M. Shayani Rad ◽  
A. Kompany ◽  
A. Khorsand Zak ◽  
M. E. Abrishami
Keyword(s):  
Calcination Temperature ◽  
Sol Gel ◽  
Visible Emission ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Zno Nps ◽  
Calcination Temperatures ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Average Size

Pure and silver added zinc oxide nanoparticles ( ZnO -NPs and ZnO : Ag -NPs) were synthesized through a modified sol–gel method. The prepared samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. In the XRD patterns, silver diffracted peaks were also observed for the samples synthesized at different calcination temperatures of 500°C, 700°C, 900°C except 1100°C, in addition to ZnO . TEM images indicated that the average size of ZnO : Ag -NPs increases with the amount of Ag concentration. The PL spectra of the samples revealed that the increase of Ag concentration results in the increase of the visible emission intensity, whereas by increasing the calcination temperature the intensity of visible emission of the samples decreases.

Influence of Li2+ Doping on the Structural and Optical Properties of CaO Synthesized by Sol–Gel Process

2019 ◽  
Vol 07 (01n02) ◽  
pp. 1950002
Author(s):  
Nadir Lalou ◽  
Ahmed Kadari
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Lithium Nitrate ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Sol Gel Process ◽  
Ft Ir ◽  
First Time

This work proposes the synthesis of nanocrystalline calcium oxide (CaO) pure and doped with different concentrations of lithium (Li[Formula: see text]) ions by sol–gel process. Calcium nitrate (Ca(NO[Formula: see text]4H2O; 99.99%) and lithium nitrate (LiNO3; 99.99%) were used as precursors. The synthesized powders were characterized by several techniques such as: UV-Vis transmission spectroscopy, Fourier Transform Infra-red spectroscopy (FT-IR) and X-ray diffraction (XRD). The main objective of this paper is to study the influence of lithium (Li[Formula: see text] ratio) on the structural and optical properties of synthesized powders. The band gap values decreased with the increasing of Li[Formula: see text] ions in CaO lattice; the slight change in the band gap was directly related to the energy transfer between the CaO excited states and the 2s levels of Li[Formula: see text] ions. The influence of Li[Formula: see text] doping on the physical properties of CaO nanocrystalline will be studied for the first time in this work; no literature has previously published this kind of impurities.

Homogeneity in the Polyether Alkoxide Sol‐Gel Synthesis of YBa2Cu3O7-δ

1994 ◽  
Vol 346 ◽  
Author(s):  
Carol S. Houk ◽  
Gary A. Burgoine ◽  
Catherine J. Page
Keyword(s):  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Mapping Techniques ◽  
Starting Solutions ◽  
Average Size ◽  
Sol Gel Synthesis ◽  
Elemental Maps

ABSTRACTWe have investigated the homogeneity of sol‐gel derived YBa2Cu307‐s from the solution phase to the final product using transmission electron microscopy (TEM), x‐ray diffraction (XRD), and Energy Dispersive X‐ray (EDX) lateral mapping techniques. The starting solutions contain stoichiometric amounts of the metal 2‐(2‐methoxyethoxy)ethoxide components in 2‐(2‐methoxyethoxy)ethanol and appear to be homogeneous by TEM with a uniform distribution of particles having an average size of less than 40 â. Through elemental mapping we see elemental segregation in the high temperature (950 °C) products, which are orthorhombic by XRD. In elemental maps of gel samples fired to 700 °C, which are tetragonal by XRD, we also see elemental inhomogeneity within particles and phase zoning in maps of products from finely ground gels. A comparison of elemental maps and x‐ray diffraction patterns of the products from gel processing and conventional solid state processing is made.

scholarly journals Synthesis of SiO2-TiO2:Yb3+ glass-ceramics and characterization of structure and optical properties

2017 ◽  
Vol 1 (T1) ◽  
pp. 114-121
Author(s):  
Thanh Tat Huynh ◽  
Van Thi Thanh Tran
Keyword(s):  
Sol Gel ◽  
Glass Ceramics ◽  
Xrd Analysis ◽  
Silica Matrix ◽  
Photoluminescence Intensity ◽  
Raman Spectroscopic ◽  
Characteristic Emission ◽  
Ft Ir ◽  
Average Size ◽  
20 Nm

In this work, the monoliths of 85 % SiO2-15 % TiO2 doped Yb3+ ions at different contents have been prepared by sol-gel method. The measurement of FT-IR, Raman spectroscopic and XRD analysis show the formation of anatase TiO2 nanocrystals with average size about 15–20 nm in silica matrix. Moreover, the pyrochlore crystals of Yb2Ti2O7 begin to form in the samples when content of Yb3+ reaches to 1 mol %. TiO2 Yb3+ 2F7/2 2F5/2 truyền năng lƣợng kích thích UV EV EC mức khuyết tật 974 nm The energy transferred from TiO2 crystals to Yb3+ ions is proven by the characteristic emission spectrum of Yb3+ at the wavelength of 980 nm when the samples are excited by the wavelength of 300 nm. The photoluminescence intensity is highest at 0.1% mol of Yb3+ and gradually decreases with doping content

scholarly journals Structural and Magnetic Properties of Nanoparticles of NiCuZn Ferrite Prepared by the Self-Combustion Method

2010 ◽  
Vol 168-169 ◽  
pp. 333-340 ◽  
Author(s):  
Silvia E. Jacobo ◽  
Juan C. Aphesteguy ◽  
N.N Shegoleva ◽  
G.V. Kurlyandskaya
Keyword(s):  
Annealing Temperature ◽  
Spinel Phase ◽  
Sol Gel ◽  
Combustion Method ◽  
Ferrite Nanoparticles ◽  
Network Analyzer ◽  
Cell Parameters ◽  
Nicuzn Ferrite ◽  
Xrd Patterns ◽  
Average Size

NiCuZn ferrites were prepared by the sol-gel self-combustion method. Nanosized, homogeneous and highly reactive powders were obtained at relatively low temperatures. In present work the variations of structural, magnetic, and microwave properties of NiCuZn ferrite nanoparticles were studied as a function of the annealing temperature. The analysis of XRD patterns showed that only the spinel phase is present. Cell parameters slightly vary with thermal treatment while a crystalline size increases. Magnetic nanoparticles were mixed with an epoxy resin for reflectivity studies with a microwave vector network analyzer using the microwave-guide method in the range of 7.5 to 13.5GHz. Static saturation magnetization value (measured by SQUID) and microwave absorption show clear dependence on the annealing temperature/particle size and the absorption maximum moves towards the higher frequencies with an increase in the average size of the particles.

scholarly journals Silica hybrid biomaterials containing gelatin synthesized by sol-gel method

2010 ◽  
Vol 8 (4) ◽  
pp. 870-876 ◽  
Author(s):  
Georgi Chernev ◽  
Borislava Borisova ◽  
Lyudmila Kabaivanova ◽  
Isabel Salvado
Keyword(s):  
Sol Gel ◽  
Bacterial Cells ◽  
Bet Analysis ◽  
Structure Surface ◽  
Potential Applications ◽  
Ft Ir ◽  
Degradation Activity ◽  
Sol Gel Synthesis ◽  
Hybrid Biomaterials ◽  
Silica Hybrid

AbstractThis work reports the sol-gel synthesis of silica hybrids. We determined the effect of the type and quantity of silica precursors and organic compounds on the resulting structure, surface area, nanostructure design and size, and potential applications. The structure of the synthesized hybrids was analyzed using FT-IR, XRD, BET-Analysis, SEM, and AFM. We demonstrate the immovilization of whole living thermophilic bacterial cells with cyanocompound degradation activity in the synthesized silica hybrid biomaterials by entrapment, chemical binding, and adsorption.

scholarly journals Synthesis of SnO2 nanopowders by a sol-gel process using propanol-isopropanol mixture

2008 ◽  
Vol 6 (4) ◽  
pp. 651-656 ◽  
Author(s):  
Ali Hassanzadeh ◽  
Behrang Moazzez ◽  
Hossein Haghgooie ◽  
Mohsen Nasseri ◽  
Mir Golzan ◽  
...  
Keyword(s):  
Sol Gel ◽  
Nanometer Scale ◽  
Preparation Process ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Sno2 Powder ◽  
Sol Gel Synthesis

AbstractA simple sol-gel process is proposed for synthesizing SnO2 nanopowders utilizing normal propanol and isopropanol mixture instead of just using normal alcohols such as ethanol, propanol or butanol for Sol preparation. No surfactant was used in this Sol preparation process. The structure of sol is studied by FT-IR-ATR technique. On altering propanol to isopropanol ratio, three different nanopowders were obtained. X-ray powder diffraction, high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction pattern (SAED) and BET techniques were used to characterize prepared powders. Results show that smaller grain size was obtained via altering alcohols ratio. In addition, Merck commercial SnO2 powder was also used as a reference material for comparing purposes; because it has nanometer scale (ca. 60 nm). HRTEM images show that obtained nanopowders were polycrystalline and their average diameters fall into the range of 6–80 nm. Finally, the effect of alkoxide ligand size through sol-gel synthesis on product particle size is discussed.

Calcined Powder of the Sol-Gel Synthesis Hydroxyapatite

2013 ◽  
Vol 284-287 ◽  
pp. 41-45
Author(s):  
Chich Kuan Chen
Keyword(s):  
Sol Gel ◽  
Calcium Nitrate ◽  
Molar Ratio ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sintering Time ◽  
Bioactive Properties ◽  
Gel Preparation ◽  
Sol Gel Synthesis

The bioactive properties of hydroxyapatite [HA, Ca10(PO4)6(OH)2] have been demonstrated to be akin to osseous tissue, and provide quick fixation in prosthesis and orthopedics. In this study, sol-gel preparation of hydroxyapatite were arranged for Ca/P=1.67 molar ratio in calcium nitrate [Ca(NO)3.4H2O ] and triethylphosphate [TEP, C6H15PO4] and then dilute in the solvent of ethylene glycol mono-methyl ether [HOCH2CH2OCH3]. Consequently, sintering process was carried out at different temperature for various sintering time to materialize this inorganic polycrystalline phosphate. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) are applied to investigate the as dried amorphous and calcined hydroxyapatite. Results reveal calcinations at 1000oC prolonged for 30 minutes in air can exhibit crystalline hydroxyapatite.

Effect of fuel content on formation of zinc aluminate nano and micro-particles synthesised by high rate sol–gel autoignition of glycine-nitrates

2016 ◽  
Vol 70 (3) ◽  
Author(s):  
Shiva Salem
Keyword(s):  
Thermal Analyses ◽  
Sol Gel ◽  
High Rate ◽  
Zinc Aluminate ◽  
X Ray Diffraction ◽  
Micro Particles ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Average Size ◽  
20 Nm

AbstractThe autoignition technique using glycine as fuel and related nitrate salts as an oxidiser is able to produce zinc aluminate spinel. The precursors were synthesised with lean and rich fuel at pH of 7.0 and the materials so obtained were calcined at various temperatures ranging from 600-1200°C. The autoignition process of precursors was studied by the simultaneous thermo-gravimetric and differential thermal analyses to determine the ignition mechanism. The calcined powders were characterised by X-ray diffraction, Brunauer-Emmett-Teller technique and transmission electron microscopy. The product contains nano-sized particles with an average size of approximately 20 nm. The XRD patterns showed the formation of ZnO in the powder obtained by the fuel-rich precursor and calcined at 600°C which disappears at 800°C due to solid-state reaction and proper crystallisation after heat treatment. The results presented here can be useful in manufacturing nano and micro-sized ZnAl

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