INFLUENCE OF B4C TO TTIP MOLAR RATIO ON SYNTHESIS OF NANO TITANIUM DIBORIDE POWDERS VIA SOL-GEL METHOD

2012 ◽  
Vol 05 ◽  
pp. 219-226
Author(s):  
HAMED SINAEI POUR FARD ◽  
HAMIDREZA BAHARVANDI ◽  
HOSSEIN ABDIZADEH
Keyword(s):  
Titanium Diboride ◽  
Electrode Materials ◽  
Sol Gel ◽  
Sem Analysis ◽  
Molar Ratio ◽  
Gel Method ◽  
Sol Gel Method ◽  
Heat Treated ◽  
Xrd Patterns ◽  
Titanium Diboride Powders

Titanium diboride ( TiB 2) has attracted great interests for its excellent mechanical properties, chemical resistance and good thermal and electrical conductivities. So it is widely applied as cutting tool composites, wear resistant parts, metal melting crucibles and electrode materials. This paper presents synthesis of nano titanium diboride powders via sol-gel method using a mixture of TTIP and B 4 C as precursors. In the hydrolysis step, B 4 C to TTIP molar ratio varied from 1.3 to 2.5. Solution samples stirred well and after aging and drying process, they were heat treated in an argon atmosphere. X-ray diffraction (XRD) patterns and Scanning electron microscopy (SEM) analysis showed that the percentage of synthesized TiB 2 increased gradually as the molar ratio of B 4 C to TTIP reached to 2.3, afterward increasing the B 4 C to TTIP molar ratio caused decreasing of titanium diboride percentage.

Synthesis of TiO2/Zno Core/Shell Type Nanocomposite via Sol-Gel Method

2011 ◽  
Vol 471-472 ◽  
pp. 993-998 ◽  
Author(s):  
Mohammad Reza Golobostanfard ◽  
Reza Ebrahimifard ◽  
Hossein Abdizadeh
Keyword(s):  
Sol Gel ◽  
Average Diameter ◽  
Photoluminescence Spectroscopy ◽  
Gel Method ◽  
Sol Gel Method ◽  
Tio2 Particles ◽  
Heat Treated ◽  
Composition Structure ◽  
Xrd Patterns ◽  
Nanocomposite Powders

TiO2/ZnO Nanocomposite powders with different Zn/Ti ratios were synthesized via sol-gel method. The as prepared and calcined Titania nanopowders were added to the ZnO sols. Also the as prepared and calcined ZnO nanopowders were separately added to the TiO2 sols. However, in the latter case, the nanocomposite never formed due to the high acidity of the sols. After gelation, the powders were dried and calcined at 500°C for 1h. The phase composition, structure, morphology and optoelectrical properties of the powders were characterized by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), UV-Vis photospectroscopy and photoluminescence spectroscopy (PL). The XRD patterns confirm the presence of TiO2 and ZnO crystalline phases in the TiO2 particles/ZnO sol samples. The FESEM micrographs show that TiO2/ZnO nanocomposites heat treated at 500°C were formed with average diameter of about 250nm with 50nm ZnO particles on clusters of 40nm TiO2 particles. It was found that the optoelectronic properties of the nanocomposites were improved according to the UV-Vis and photoluminescence spectroscopy.

STRUCTURAL STUDIES OF ALUMINUM-DOPED LANTHANUM BORATES

2002 ◽  
Vol 16 (23n24) ◽  
pp. 915-921
Author(s):  
S. SIMON ◽  
M. POP ◽  
GH. BORODI ◽  
D. DJURADO
Keyword(s):  
Rietveld Refinement ◽  
Sol Gel ◽  
Structural Data ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Heat Treated ◽  
Xrd Patterns

Powder X-ray diffraction structural studies on aluminum-doped lanthanum borates La 4-y Al y B 4 O 12 were carried out on samples with y = 1, 2 starting compositions heat-treated at temperatures between 860°C and 1200°C. The samples were prepared by the sol-gel method. The structural data were obtained by the Rietveld refinement of the XRD patterns.

scholarly journals Silica synthesis by the sol-gel method and its use in the preparation of multifunctional biocomposites

2014 ◽  
Vol 12 (2) ◽  
pp. 173-184 ◽  
Author(s):  
Łukasz Klapiszewski ◽  
Michał Królak ◽  
Teofil Jesionowski
Keyword(s):  
Electrode Materials ◽  
Sol Gel ◽  
Statistical Design ◽  
Morphological Properties ◽  
Statistical Design Of Experiments ◽  
Organic Precursor ◽  
Gel Method ◽  
Sol Gel Method ◽  
Non Invasive ◽  
Silica Synthesis

AbstractThis study focuses on the optimization process of silica synthesis using the sol-gel method while applying a statistical design of experiments which was based on a multilevel mathematical model. The product obtained in the process of optimized synthesis, characterized by the best dispersive and morphological parameters, was used for the preparation of organic/inorganic composites. The organic precursor was Kraft lignin, a high-molecular natural polymer. Synthesis of silica/lignin biocomposites was carried out by three proposed methods. The physicochemical properties and dispersive-morphological properties of each product were determined using the following available methods: Scanning Electron Microscopy — SEM, Non-Invasive Back-Scattering — NIBS, Fourier Transform Infrared Spectroscopy — FT-IR, Thermogravimetric analysis — TG and others. The electrokinetic and thermal properties of the biocomposites sufficed to be applied for example, as a cheap and biodegradable polymer filler. Further areas of application of these composites were sought, especially in electrochemistry as the advanced electrode materials.

scholarly journals Monoclinic Li2TiO3 Nano-particles via sol-gel method: Structure and impedance spectroscopy

2019 ◽  
Vol 8 (3) ◽  
pp. 209
Author(s):  
Fatima Zahra Krimech ◽  
Salaheddine Sayouri ◽  
Taj-Edine Lamcharfi ◽  
Fatima Zahra Ahjyaje
Keyword(s):  
Impedance Spectroscopy ◽  
Sol Gel ◽  
Low Frequency ◽  
Transport Processes ◽  
Nano Particles ◽  
Secondary Phases ◽  
Conventional Solid State Reaction ◽  
Gel Method ◽  
Sol Gel Method ◽  
Heat Treated

<p>Pure phase Li<sub>2</sub>TiO<sub>3 </sub>nano-particles were synthesized by the sol-gel method and the structural properties were examined with X-ray diffraction (XRD) technique. The latter showed that these materials, heat treated at relatively low temperature 900°C during 4h compared to the conventional solid-state reaction which calcination temperature is about 900–1100°C for 10 h; crystallize in the monoclinic phase without the presence of secondary phases. The microstructure of the LT ceramic (sintered at 1100°C) were determined by SEM and a good crystalline nature was observed with an average of granular size 2 μm. Moreover, the impedance spectroscopy showed at a higher temperature of 500°C the low-frequency arc due either to the grain boundary or sample-electrode charge transport processes.</p>

Iron-Zircon Pigments Prepared by Non-Hydrolytic Sol-Gel Method at Low Temperature

2011 ◽  
Vol 412 ◽  
pp. 223-226 ◽  
Author(s):  
Wei Hui Jiang ◽  
Yan Hui Yang ◽  
Qing Xia Zhu ◽  
Jian Min Liu
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Ferric Chloride ◽  
Lithium Fluoride ◽  
Sol Gel ◽  
Zircon Crystal ◽  
Molar Ratio ◽  
Gel Method ◽  
Sol Gel Method ◽  
Anhydrous Ferric Chloride

ron-zircon pigment has been synthesized by non-hydrolytic sol-gel method using zirconium chloride and tetraethoxysilane as precursors, anhydrous ferric chloride as colorant, lithium fluoride as mineralizer and anhydrous ethanol as solvent. Iron-zircon pigment has been characterized by means of DTA-TG, XRD, Colorimeter and TEM. The results show that only a small fraction of iron is incorporated in the zircon crystal structure while the remaining iron cations are trapped within the zircon matrix. The iron-zircon with the red value (a*) of 20.64 can be synthesized at 700°C with the optimum Fe/Zr molar ratio of 0.2.

Effects of Polyvinyl Pyrrolidone on Electromagnetic Properties of Hexagonal Ferrite Prepared by the Sol-Gel Method

2011 ◽  
Vol 197-198 ◽  
pp. 593-597
Author(s):  
Xiao Gu Huang ◽  
Jiao Chen ◽  
Peng De Han ◽  
Hong Zhou Wang ◽  
Shao Teng Yan ◽  
...  
Keyword(s):  
Sol Gel ◽  
Hexagonal Ferrite ◽  
Polyvinyl Pyrrolidone ◽  
Electromagnetic Properties ◽  
Hexagonal Ferrites ◽  
Gel Method ◽  
Sol Gel Method ◽  
Method Effects ◽  
Xrd Patterns ◽  
Particle Thickness

Ba(Zn0.3Co0.7)2Fe16O27hexagonal ferrites have been prepared by sol-gel method. Effects of polyvinyl pyrrolidone (PVP) on crystalline phase, natural surface and electromagnetic properties were analyzed. The XRD patterns of samples with and without PVP added both showed the single phase of hexagonal ferrite. The particle thickness increased when PVP was added. Moreover, Ferrites prepared with 2.0g PVP added into the sol solution had lower complex permittivity. Addition of PVP can be an effective way to obtain the electromagnetic match of hexagonal ferrites.

Iron and Iron-oxide on Silica Nanocomposites Prepared by the Sol-gel Method

2002 ◽  
Vol 17 (3) ◽  
pp. 590-596 ◽  
Author(s):  
G. Ennas ◽  
M. F. Casula ◽  
G. Piccaluga ◽  
S. Solinas ◽  
M. P. Morales ◽  
...  
Keyword(s):  
Sol Gel ◽  
Silica Matrix ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Gel Method ◽  
Sol Gel Method ◽  
Silica Nanocomposites ◽  
Transmission Electron ◽  
Nanometric Particles

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.

Characterization and Photocatalytic Activity of FeVO4 Photocatalysts Synthesized via a Surfactant-Assisted Sol-Gel Method

2011 ◽  
Vol 197-198 ◽  
pp. 926-930
Author(s):  
Min Wang ◽  
Qiong Liu ◽  
Chen Zhi Jiang
Keyword(s):  
Photocatalytic Activity ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Gel Method ◽  
Sol Gel Method ◽  
Photodegradation Rate ◽  
Photocatalytic Activities ◽  
Xrd Patterns ◽  
Surfactant Assisted

FeVO4photocatalysts were synthesized via a surfactant-assisted sol-gel method and characterized with X-ray diffraction (XRD), scanning electron microsoope （SEM）and specific surface area (BET). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under visible light. The XRD patterns of no-surfactant-assisted, PEG-assisted, CTAB-assisted and SDS-assisted FeVO4, indicate that diffraction peaks can be well indexed as triclinc FeVO4. And the crystalline sizes of samples were evaluated as 113, 69, 66, 76 nm for FVO, FVO-PEG, FVO-CATB and FVO-SDS respectively.The addition of surfactant woul greatly affect the morphology of FeVO4photocatalysts, which can lead to different photocatalytic activities between them. In the experimental conditions used, the PEG-assisted FeVO4product had a much higher photocatalytic activity (the photodegradation rate was about 77% or so in 14h) than the other three products.

Synthesis and Luminescent Properties of Mn2+-Doped Zinc Silicate Phosphors by Sol-Gel Method

2010 ◽  
Vol 434-435 ◽  
pp. 214-216 ◽  
Author(s):  
Ji Ming Zhang ◽  
Dong Lin Zhao ◽  
Zeng Min Shen
Keyword(s):  
Sol Gel ◽  
Green Light ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Nano Particles ◽  
Light Emitting ◽  
Gel Method ◽  
Sol Gel Method ◽  
Structural Details ◽  
Xrd Patterns

Abstract. Green light emitting Mn2+-doped Zn2SiO4 (Zn2SiO4:Mn2+) phosphor nano-particles were synthesized by sol-gel method combined with a furnace firing from the sol-gel solution made with ZnO, MnCO3 and tetraethoxysilan. The influences of annealing temperatures on the microstructures and photoluminescent properties of the Zn2SiO4:Mn2+ phosphors were investigated. The structural details of the phosphors were examined through XRD and SEM. The photoluminescent properties of the Zn2SiO4:Mn2+ phosphors were characterized by excitation and emission spectra. The results indicate that the XRD patterns of the Zn2SiO4:Mn2+ phosphors exhibit a willemite structure (-Zn2SiO4). Green photoluminescence whose emission peak is located at 525 nm were observed from the synthesized phosphor particles under UV excitation. The photoluminescent mechanisms of the Zn2SiO4:Mn2+ phosphors were discussed.

N-Doped Cu11O2 (VO4)6 Photocatalyst Prepared by Sol-Gel Method

2011 ◽  
Vol 393-395 ◽  
pp. 1287-1290
Author(s):  
Min Wang ◽  
Qiong Liu ◽  
Qi Xing
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Photodegradation Rate ◽  
Triclinic Phase ◽  
Synthesized Materials

The N-doped Cu11O2 (VO4)6 photocatalyst was prepared using the sol-gel method. Techniques of X-ray diffraction (XRD), scanning electron microscope (SEM) have been employed to characterize the as-synthesized materials. During liquid phase photocatalytic degradation of Methy lorange(MO) under the UV-light, the as-prepared N-doped Cu11O2 (VO4)6 exhibits higher activity than the pure Cu11O2 (VO4)6 without doped N. It found that the N-doped Cu11O2 (VO4)6 prepared with the molar ratio of citric acid to metal inons be 2:1, N/Cu molar ratio of 12%, pH=7 and calcinated under 500°C for 4 hours was pure triclinic phase. In this conditions, the sample had highest photocatalytic activity with the photodegradation rate was about 94.42% or so in 60min under 20W ultraviolet lamp.

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