Study on Mullite Whiskers Preparation via Non-Hydrolytic Sol-Gel Process Combined with Molten Salt Method

2016 ◽  
Vol 848 ◽  
pp. 295-300 ◽  
Author(s):  
Kai Lin Fu ◽  
Wei Hui Jiang ◽  
Jian Min Liu ◽  
Guo Feng ◽  
Mu Pan
Keyword(s):  
Molten Salt ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Molten Salt Method ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
Anhydrous Aluminum Chloride ◽  
Oxygen Donor ◽  
Sol Gel Process ◽  
Mullite Whiskers

Mullite whiskers were prepared via non-hydrolytic sol-gel process combined with molybdate molten salt using tetraethoxysilane and anhydrous aluminum chloride as precussor, anhydrous ether as oxygen donor, molybdate as molten salt. The effects of heat treatment temperature, molten salt amount, holding time on synthesis and morphology of mullite whiskers were investigated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The results show that the mullite whiskers appeared at the lowest temperature of 800°C, and optimized mullite whiskers could be prepared at 900°C for 8 h with the mass ratio of xerogel and molybdate as 1:2, the diameter of the whiskers was in the range of 0.15-0.22 μm with the aspect ratio of more than 40.

Low Temperature Synthesis of Mullite Whisker by Nonhydrolytic Sol-Gel Process Combined with Molten Salt Method

2012 ◽  
Vol 538-541 ◽  
pp. 2346-2349 ◽  
Author(s):  
Wei Hui Jiang ◽  
Qian Wu ◽  
Jian Min Liu ◽  
Qing Xia Zhu ◽  
Li Feng Miao
Keyword(s):  
Low Temperature ◽  
Molten Salt ◽  
Sol Gel ◽  
Crystal Phase ◽  
Molten Salt Method ◽  
Anhydrous Aluminum Chloride ◽  
Low Temperature Synthesis ◽  
Mixed Powder ◽  
Oxygen Donor ◽  
Sol Gel Process

Using tetraethyl orthosilicate and anhydrous aluminum chloride as precursors, ethyl ether as oxygen donor, LiF as mineralizer, and Na2SO4-NaCl as compound molten salt, mullite whisker was synthesized in the low temperature by nonhydrolytic sol-gel process combined with molten salt method. The phase transformation of mixed powder composed of mullite xerogel and molten salt during the heat treatment and the microstructure of mullite whisker corresponding to different temperature were characterized by means of DTA-TG, XRD SEM and TEM. The results show that mullite crystal phase can be formed via non-hydrolytic sol-gel process combined with the molten salt method at 750°C. The synthetic effect of mullite get better as the temperature increased to 850°C, while NaAlSiO4 crystal phase is also detected. Mullite whisker, with diameters ranging from 300~500 nm and lengths of 3~5μm, is prepared at the temperature of 850°C.

Low Temperature Preparation of Mullite Whisker via Non-Hydrolytic Sol-Gel Process Combined with Molten Salt Method

2014 ◽  
Vol 936 ◽  
pp. 975-980 ◽  
Author(s):  
Kai Lin Fu ◽  
Wei Hui Jiang ◽  
Guo Feng ◽  
Jian Min Liu ◽  
Qian Wu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Low Temperature ◽  
Molten Salt ◽  
Sol Gel ◽  
Growth Direction ◽  
Treatment Temperature ◽  
Molten Salt Method ◽  
Low Temperature Preparation ◽  
Sol Gel Process ◽  
Temperature Preparation

Mullite whisker was prepared at low temperature via non-hydrolytic sol-gel (NHSG) process combined with molten salt method. The influence of heat treatment temperature was studied on the morphology and the microstructure of whisker, and its growth mechanism was also described. The results show that the mullite whisker appears at the lowest temperature of 750 °C, and optimized mullite whisker can be prepared at 850 °C with the growth direction of [00, whose diameter is in the range of 170~300 nm with the aspect ratio of >30.

Preparation of Zircon Whiskers via Non-Hydrolytic Sol-Gel Process Combined with Molten Salt Method

2014 ◽  
Vol 936 ◽  
pp. 970-974
Author(s):  
Hong Da Wang ◽  
Wei Hui Jiang ◽  
Guo Feng ◽  
Jian Min Liu ◽  
Qian Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molten Salt ◽  
Calcination Temperature ◽  
Raw Materials ◽  
Sol Gel ◽  
Molten Salt Method ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
The One

Zircon whiskers were prepared via non-hydrolytic sol-gel process combined with molten salt method, using Si (OC2H5)4 (TEOS) and ZrCl4 as raw materials, LiF as mineralizer, and Na2WO4 as molten salt. The phase composition, morphology and microstructure of the samples were characterized by X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The influence of introducing molten salt and calcination temperature on the synthesis and morphology of zircon crystals was investigated. The results show that the introduction of Na2WO4 contributes to the one-dimensional preferential growth of zircon. Zircon whiskers elongated along the c-axis, with diameter of ~100nm and aspect ratio of more than 15, are achieved at the temperature of 850 °C, and neither over low nor over high calcination temperature is conducive to the growth of zircon whiskers.

Effect of Heat Treatment on the Preparation of Zircon Whiskers

2016 ◽  
Vol 848 ◽  
pp. 289-294
Author(s):  
Tao Zhang ◽  
Wei Hui Jiang ◽  
Jian Min Liu ◽  
Guo Feng ◽  
Quan Zhang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Molten Salt ◽  
Sol Gel ◽  
Sodium Molybdate ◽  
Heat Treating ◽  
Molten Salt Method ◽  
Zirconium Tetrachloride ◽  
Treatment Mode ◽  
Heat Treatment Mode ◽  
Sol Gel Process

Zircon whiskers were synthesized via non-hydrolytic sol-gel process combined with molten salt method by using anhydrous zirconium tetrachloride as zirconium source, TEOS as silicon source, anhydrous ethanol as solvent, and sodium molybdate as molten salt. The effects of heat treatment mode and cooling rate on the synthesis of zircon whiskers have been studied by means of XRD, FE-SEM, TG and TEM. The results indicate that well-developed whiskers can be prepared through heat treating the sample at 850°C for 3 h followed by a furnace cooling process. The zircon whiskers which were fabricated by this heat treatment mode grew along the [001] direction and showed diameter of 50~100 nm and aspect ratio of 20~30.

Synthesis of ZrTiO4 and MgAl2O4 Powders via Non-Hydrolytic Sol-Gel Route Using Alcohol as Oxygen Donor

2011 ◽  
Vol 284-286 ◽  
pp. 1471-1474
Author(s):  
Heng Yong Wei ◽  
Rui Sheng Wang ◽  
Jun Hong Zhao ◽  
Jing Long Bu ◽  
Rong Lin Wang ◽  
...  
Keyword(s):  
Sol Gel ◽  
Milling Process ◽  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel ◽  
Zirconium Titanate ◽  
X Ray Diffraction ◽  
Laser Scattering ◽  
X Ray ◽  
Oxygen Donor ◽  
Sol Gel Process

Zirconium titanate and magnesium aluminate spinel precursors were prepared by non-hydrolytic sol-gel method using ethanol as oxygen donor. The gels and calcined powders were investigated by differential thermal analysis (DTA), thermogravimetry analysis (TG), X-ray diffraction (XRD). The results show that the ZrTiO4and MgAl2O4crystallized at low temperature of 550 °C and 700 °C, respectively. It indicated that the highly homogeneous zirconium titanate and magnesium aluminate gels were aslo obtained by nonhydrolytic sol-gel process using ethanol as oxygen donor. The particle size distribution measured by laser scattering exhibit that ZrTiO4and MgAl2O4powders were large soft agglomerates which could be broken through milling process.

Luminescent Properties of Zn2SiO4:Eu3+,Dy3+ Phosphors via Sol-Gel Process

2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi
Keyword(s):  
Thermal Analysis ◽  
Ir Spectra ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.

The Preparation and Photocatalytic Activity of SWNTs Doped ZnO/TiO2 Compound Films

2010 ◽  
Vol 97-101 ◽  
pp. 1611-1615 ◽  
Author(s):  
Qing Wang ◽  
Xin Li Li ◽  
Wei Nie ◽  
Yong Mei Xia ◽  
Jian Feng Dai
Keyword(s):  
Photocatalytic Activity ◽  
Absorption Spectra ◽  
Sol Gel ◽  
Composite Films ◽  
Wavelength Region ◽  
Tio2 Films ◽  
X Ray Diffraction ◽  
Sol Gel Process ◽  
Doped Zno ◽  
Walled Carbon Nanotubes

The ZnO/TiO2 composite films were deposited over glass using spin coating technique by sol-gel process. Single-walled carbon nanotubes (SWNTs) were used to modify the ZnO/TiO2 films successfully in this paper. The structure and composition of the ZnO/TiO2 composite and SWNTs doped ZnO/TiO2 composite were characterized by X-ray diffraction (XRD). The morphology of samples was characterized by scanning electron microscopy (SEM). The photocatalytic activity was investigated by photocatalytic degradation of aqueous methyl orange under ultraviolet (UV) radiation. The UV-vis absorption spectra of the ZnO/TiO2 films and SWNTs doped ZnO/TiO2 films in the wavelength region 200~800 nm were obtained. The results indicate that the SWNTs addition can decrease the grain size of ZnO/TiO2, which can enhance the photocatalytic activity. UV-vis absorption spectra of SWNTs-ZnO/TiO2 showed obvious blue shifts compared with ZnO/TiO2. The optimal amount of doping SWNTs is 1% according to this research. The enhanced mechanism of the SWNTs for the photocatalytic activity in ZnO/TiO2 films was analyzed in this article.

Sol-Gel derived Bi4-xNdxTi3O12 Thin Films and Their Characterization

2002 ◽  
Vol 737 ◽  
Author(s):  
R.E. Melgarejo ◽  
M.S. Tomar ◽  
A. Hidalgo ◽  
R.S. Katiyar
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Complete Solid Solution ◽  
Sol Gel Process ◽  
Ferroelectric Memory ◽  
Initial Results

ABSTRACTNd substituted bismuth titanate Bi4-xNdxTi3O12 were synthesized by sol-gel process and thin films were deposited on Pt substrate (Pt/TiO2/SiO2/Si) by spin coating. Thin films, characterized by X-ray diffraction and Raman spectroscopy, shows complete solid solution up to the composition x < 1. Initial results indicate that the ferroelectric polarization increases with increasing Nd content in the film with 2Pr = 50μC/cm2 for x = 0.46, which may have application in non-volatile ferroelectric memory devices.

Synthesis and Characterizations of Strontium Substituted Hydroxyapatite Thin Films

2010 ◽  
Vol 93-94 ◽  
pp. 231-234
Author(s):  
B. Hongthong ◽  
Satreerat K. Hodak ◽  
Sukkaneste Tungasmita
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Chemical Composition ◽  
Spin Coating ◽  
Phase Structure ◽  
Sol Gel ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process

Strontium substituted hydroxyapatite(SrHAp) were fabricated both in the form of powder as reference and thin film by using inorganic precursor reaction. The sol-gel process has been used for the deposition of SrHAp layer on stainless steal 316L substrate by spin coating technique, after that the films were annealed in air at various temperatures. The chemical composition of SrHAp is represented (SrxCa1-x)5(PO4)3OH, where x is equal to 0, 0.5 and 1.0. Investigations of the phase structure of SrHAp were carried out by using X-ray diffraction technique (XRD). The results showed that strontium is incorporated into hydroxyapatite where its substitution for calcium increases in the lattice parameters, and Sr3(PO4)2 can be detected at 900°C. The SEM micrographs showed that SrHAp films exhibited porous structure before develop to a cross-linking structure.

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