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Al2O3透明陶瓷薄膜的制备与结构研究 总被引:1,自引:0,他引:1
Al2O3透明陶瓷薄膜的制备与结构研究苏春辉*端木庆铎王艳隋智通(长春光学精密机械学院材料系长春130022)(东北大学冶金学院沈阳)关键词Al2O3,透明陶瓷,薄膜,制备,结构1997-03-25收稿,1997-09-01修回国家自然科学基金资助项... 相似文献
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以硝酸铝为铝源,十六烷基三甲基溴化铵和尿素为复合模板剂,采用溶胶-凝胶法制备了介孔氧化铝(1),其结构经TEM, XRD, TG-DTA和N2-BET表征。结果表明:1比表面积较大(>400 m2·g-1),孔径分布窄(3~5 nm),形成的蠕虫状孔道具有短程有序性。 相似文献
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Titanium-doped ordered mesoporous alumina with specific structural properties has been prepared by the evaporation induced self-assembly sol-gel method. The results show that the doped titanium helps to stabilize the ordered mesoporous alumina material without influencing the ordered mesoporosity. The textural properties of the obtained sample are related to the amount of doped titanium. When the molar ratio of aluminum to titanium(n(Al)/n(Ti)) is controlled as 10.2, the titanium-doped ordered mesoporous alumina exhibits high surface area(up to 218 m2 g-1), large pore volume(0.42 cm3 g-1) and narrow pore diameter(6.1 nm) after treating at 900 ℃, showing high thermal stability. Moreover, the obtained sample calcined at 900 ℃ still maintains ordered mesoporous structure and exhibits high thermal stability. 相似文献
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采用聚乙烯醇对碳纳米管表面进行改性,通过化学沉淀法将Al(OH)3均匀沉积在碳纳米管表面,然后在氮气气氛下于500 ℃煅烧2 h,制备出氧化铝/碳纳米管复合材料。采用TEM、TG、DTA、XRD、IR、氮吸附脱附(比表面积及孔结构分析)等对氧化铝/碳纳米管复合材料进行表征,结果表明:未经聚乙烯醇改性的碳纳米管,氧化铝与碳纳米管相互分离;经聚乙烯醇改性的碳纳米管,氧化铝与碳纳米管结合良好。经聚乙烯醇改性的碳纳米管表面均匀覆盖一层聚乙烯醇膜,通过聚乙烯醇的吸附作用, Al(OH)3沉积在碳纳米管表面形成一层连续的覆盖层。 相似文献
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担载多孔Al2O3膜的制备和表征 总被引:1,自引:0,他引:1
研究了溶胶—凝胶法在多孔陶瓷载体上制备多孔Al_2O_3膜的工艺条件,发现在孔径为1.1~1.6μm的多孔陶瓷载体上必须经过多次重复浸渍—干燥—焙烧过程,才能制备出担载均匀的多孔A1_2O_3膜,不过对溶胶和多孔陶瓷载体进行适当的化学改性后,能够减少重复以上过程的次数。用BET法和透气实验对Al_O_3膜的孔径大小和透气性能进行了表征。 相似文献
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L. Ben Hamouda A. Ghorbel F. Figueras 《Journal of Sol-Gel Science and Technology》2003,26(1-3):831-836
A series of sulfated mixed oxides of alumina and zirconia having a relative composition of 5% and 10% of ZrO2 was prepared by means of sol-gel methods using zirconium propoxide or zirconium acetylacetone as precursor. The characterization of the physicochemical properties was carried out using 27Al NMR, XRD, N2 adsorption at 77 K, thermogravimetry, FTIR analysis of adsorbed pyridine, 27Al NMR-MAS and XPS. The catalytic properties were studied by means of isomerization of n-hexane at 250°C. Results obtained allowed to propose that the use of Zr(acac)4 as a zirconium precursor leads to a better retention of sulfate species which seems to form polymeric superficial sites. The symmetry of aluminium undergo an increase from tetrahedral to octahedral coordination and Zirconium atoms seems to be located in the second coordination sphere of Al. XRD analysis indicated an amorphous structure of obtained solids calcined at 650°C. The sulfated solids presented both Lewis and Brönsted acidic sites. Catalytic results showed that both activity and selectivity towards isomerization products were better using Zr (acac)4 as precursor. Furthermore, the increase of the Zr loading affected considerably the catalytic properties of sulfated zirconia supported by alumina. 相似文献
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氧化铝中空纤维膜的制备与表征 总被引:4,自引:0,他引:4
介绍了铝氧化反应结合技术与干湿法纺丝工艺相结合制备氧化铝中空纤维膜的方法.采用热重分析、能量色散谱、X射线衍射、热机械分析和扫描电镜等手段对烧结过程中的反应行为、相转变及膜的微观结构进行了研究.结果表明,所制备的氧化铝中空纤维膜具有非对称结构的特点,其孔隙率高(50.1%)、孔径分布窄(平均孔径0.88μm)、机械强度高(压缩强度和弯曲强度分别为89.6和41.1MPa).气体的渗透实验结果表明,所制备的膜无针孔、裂纹等缺陷,并且具有良好的渗透性. 相似文献
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YANG Jing-hai GAO Ming ZHANG Yong-jun YANG Li-li LANG Ji-hui WANG Dan-dan WANG Ya-xin LIU Hui-lian FAN Hou-gang WEI Mao-bin LIU Fu-zhu 《高等学校化学研究》2008,24(3):266-269
ZnO nanorods were synthesized using the sol-gel method, and the effects of annealing temperature and Ce doping on the morphologies and optical properties of ZnO nanostructures were investigated in detail. The XRD measurements showed that the as-synthesized ZnO nanostructures had a hexagonal wurtzite structure. SEM images showed that uniform nanorods formed at 900 °C. Photoluminescence measurements showed an ultraviolet emission peak and a relatively broad visible light emission peak for the samples sintered at different temperatures. The UV emission peak bathochromically shifted when the annealing temperature rose from 850 to 1000 °C. Ce doping decreased the synthesized temperature of the ZnO nanorods to 500 °C, and the UV peaks hypsochromically shifted. 相似文献
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Titanium dioxide (TiO2) thin films have been deposited on silicon and glass substrates by the sol-gel process using titanium iso-propoxide [Ti(O-i-C3H7)4]. The bond configuration of the TiO2 thin films was analyzed by using FTIR in the wavenumber range from 400 to 4000 cm–1. The spectral transmittance of as-deposited TiO2 films deposited on fused silica glass was measured in the wavelength range from 200 to 900 nm. X-ray diffraction measurements were performed to determine the crystallinity of the TiO2 films. As-deposited films were amorphous. As the film was annealed at higher temperature, the structure was transformed from amorphous to the anatase crystalline state. The chemical composition of the deposited film was investigated using X-ray photoelectron spectroscopy (XPS). The films are essentially stoichiometric with carbon as the dominant impurity on the surface. Raman spectra show the characteristic of TiO2 anatase phase. The electrical properties of the TiO2 films were measured using capacitance-voltage (C-V) and current-voltage techniques. From C-V measurements, the dielectric constants were calculated to be approximately 26 for the as-deposited films and 75–82 for films annealed at 700°C in different atmosphere. For the as-deposited samples, the breakdown voltage was 2.7 MV/cm, and for an electric field of 1 MV/cm, the leakage current was 5 × 10–5 A/cm2 and the resistivity was 2.2 × 1010 -cm. 相似文献
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负载Ni金属有序介孔氧化铝催化剂的制备及表征 总被引:1,自引:0,他引:1
采用原位合成法和传统浸渍法以价格低廉的硝酸铝作为铝源, 聚乙二醇1540为模板剂, 硝酸镍为镍源, 制备出负载Ni金属有序介孔氧化铝催化剂, 并采用BET、TEM、XRD、TG多种测试技术对合成催化剂的物理化学性质和结构特征进行了表征. 实验结果表明, 两种方法均能制备出比表面积大(>210 m2·g-1)、孔径分布窄(4 nm左右)的负载Ni金属介孔氧化铝催化剂. 与浸渍法相比, 原位合成法所制备的负载Ni金属有序介孔氧化铝镍离子与载体具有更强的相互作用力, 且孔结构具有一定的有序性. 相似文献
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Microstructure Evolution of Nonhydrolytic Alumina Gels 总被引:2,自引:0,他引:2
Grader G.S. de Hazan Y. Cohen Y. Bravo-Zhivotovskii D. 《Journal of Sol-Gel Science and Technology》1997,10(1):5-12
Nonhydrolitic sol-gel processes of aluminum chloride and aluminum bromide with isopropyl ether and aluminum sec-butoxide were performed at various temperatures. Based on the Arrhenius type variation of the gelation time with temperature, activation energies for the gelation were found to be in the range 19–25 Kcal/mol range. The energies were found to be sensitive to the nature of the aluminum ligands and the chemical scheme. Due to the large activation energy, it is possible to stop the reaction at any time before gelation by cooling the sol to room temperature. Small angle X-ray scattering (SAXS) of sols from the AlClAlCl3/Pr
O system shows unique development of a fractal like structure with nanometer scale order, demonstrated by discrete peaks in the SAXS data. A fractal dimension D = 1.64 was found. An aggregation scheme is proposed to explain this phenomenon. A fractal dimension of 2.4 without small scale ordering found for xerogels prepared from the AlCl3/ASB system reflects the effect of the different precursors on the microstructure of nonhydrolytic gels. 相似文献
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Atheer Al Khudhair Karim Bouchmella Pierre Hubert Mutin Vasile Hulea Olinda Gimello Ahmad Mehdi 《Molecules (Basel, Switzerland)》2022,27(8)
The development of green and sustainable materials for use as heterogeneous catalysts is a growing area of research in chemistry. In this paper, mesoporous SiO2-Al2O3 mixed oxide catalysts with different Si/Al ratios were prepared via hydrolytic (HSG) and nonhydrolytic sol-gel (NHSG) processes. The HSG route was explored in acidic and basic media, while NHSG was investigated in the presence of diisopropylether as an oxygen donor. The obtained materials were characterized using EDX, N2-physisorption, powder XRD, 29Si, 27Al MAS-NMR, and NH3-TPD. This approach offered good control of composition and the Si/Al ratio was found to influence both the texture and the acidity of the mesoporous materials. According to 27Al and 29Si MAS NMR analyses, silicon and aluminum were more regularly distributed in NHSG samples that were also more acidic. Silica–alumina catalysts prepared via NHSG were more active in esterification of acetic acid with n-BuOH. 相似文献
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Sun Jiebing Xiong Rui Wang Shimin Tang Wufeng Tong Hua Shi Jing 《Journal of Sol-Gel Science and Technology》2003,27(3):315-319
This paper presents a new sol-gel process to prepare molybdenum oxide thin films. A molybdenum acetylacetonate sol was prepared by employing the system CH3COCH2COCH3/MoO3/C6H5CH3/HOCH2CH2OCH3. A molybdenum acetylacetonate gel was prepared by addition of aqueous NH3. Thermal gravimetry (TG) and differential thermal analyses (DTA) of the gel suggested that crystallization of MoO3 occurs in a 140 K temperature range around 508°C. MoO3 films were prepared on fused silica, Si (111) and Al2O3 (012) substrates by annealing spin coating films of the sol in oxygen environment at 508°C. X-ray diffraction (XRD) showed that all films crystallize in -MoO3 structure, and crystallites on fused silica substrate are arbitrarily oriented while those on Si (111) and Al2O3(012) substrates oriented in the (010) direction. SEM investigations showed that MoO3 grains of all films are randomly distributed, with a longitudinal dimension of about 1–5 m and the film thickness is about 1 m. 相似文献
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Xiaorong Fu Zhitang Song Guangming Wu Jipo Huang Xinzhong Duo Chenglu Lin 《Journal of Sol-Gel Science and Technology》1999,16(3):277-281
MgO thin films have been prepared on Si substrates by a novel and simple sol-gel method using magnesium nitrate and collodion as starting material. Solutions consisting of magnesium nitrate in a mixture of collodion and ethanol were spin-coated onto silicon substrates. It was found that collodion was a necessary component to form stable sols and the crystallization and structures were clearly dependent on the amount of the collodion and the annealing temperature. The MgO thin films with good crystallization were obtained after annealing at 800°C. Meanwhile, the microstructure of the MgO films was examined by transmission electron microscopy and atomic force microscopy. 相似文献
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溶胶凝胶法制备铜铁矿结构p型透明导电氧化物薄膜 总被引:1,自引:0,他引:1
王金梅|李达|邓赞红|朱雪斌|董伟伟|方晓东 《化学进展》2009,21(1):128-133
铜铁矿结构p型透明导电氧化物(transparent conducting oxide, TCO)薄膜是一类在电子学领域具有广泛应用前景的新材料,因其可与n-TCO薄膜形成真正意义上的“透明器件”而备受关注。本文介绍了铜铁矿结构p-TCO的结构特性以及溶胶凝胶法的基本原理和特点;系统地介绍了溶胶凝胶法制备铜铁矿结构p-TCO薄膜的工艺;分析比较了有机醇盐、无机盐溶胶体系的优缺点;最后讨论了进一步的发展方向,指出溶胶凝胶法是一种高效可行的制备p-TCO薄膜的方法。 相似文献