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以硝酸镧、硝酸锶、硝酸钴为金属源,柠檬酸为络合剂,采用水热法于180℃下保温24 h合成镧锶钴复合氧化物.XRD分析表明产物为斜方六面体钙钛矿结构的La0.8Sr0.2CoO3-δ晶相.SEM分析表明产物为球状颗粒,尺寸约0.5~1μm.红外吸收光谱表明产物主要为La0.8Sr0.2CoO3-δ,此外还残留部分柠檬酸和... 相似文献
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The behavior of liquefaction of Shengli (SL) lignite with NaOH-methanol was studied. Based on high content of water in lignite and the economy of the process (amounts of NaOH used), the effects of NaOH concentration, methanol content and water content on the liquefaction behavior of SL lignite were preliminarily investigated. The results show that SL lignite has a good reaction activity, and its conversion and product yield reach 98% and 99% at 300 °C for 1 h respectively, when the ratio of SL lignite, NaOH and methanol is for 1 g:1 g:10 ml. NaOH participates in the reaction. The increase of the amount of NaOH significantly increases the amount of tetrahydrofuran soluble (THFS) fraction. Methanol plays a promotion role in the liquefaction, which makes the product yield increase for about 16-23%. Water content has little effect on the SL lignite conversion, product yield and the product distribution. Solvent-extraction components of liquefaction products of SL lignite with NaOH-methanol are mainly THFS, toluene soluble (TS), hexane soluble (HS) and water soluble fractions (WS). The FTIR analyses of solvent-extraction components show that all of the fractions contain OH group, aromatic structure, carbonyl group and aromatic ether oxygen group. 相似文献
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YI Tingfenga ZHOU Anna ZHU Yanrong ZHU Rongsun HU Xinguo 《稀有金属(英文版)》2008,27(5):496-501
Spinel lithium manganese oxide cathode materials were synthesized using the ultrasonic-assisted sol-gel method. The synthesized samples were investigated by differential thermal analysis (DTA) and thermogravimetry (TG), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), and the charge-discharge test. TG-DTA shows that significant mass loss occurs in two temperature regions during the synthesis of LiLa0.01Mn1.9903.99F0.01. XRD data indicate that all samples exhibit the same pure spinel phase, and LiLa0.01Mn1.9903.99F0.01 and LiLa0.01Mn1.9904 samples have a better crystallinity than LiMn2O4. SEM images indicate that LiLa0.01Mn1.9903.99F0.01 has a slightly smaller particle size and a more regular morphology structure with narrow size distribution. The charge-discharge test reveals that the initial capacities of LiMn2O4, LiLa0.01Mn1.99O4, and LiLa0.01Mn1.99O3.99F0.01 are 130, 123, and 126 mAh·g^-1, respectively, and the capacity retention rates of the initial value, after 50 cycles, are 84.8%, 92.3%, and 92.1%, respectively. The electrode coulomb efficiency and CV reveal that the electrode synthesized by the ultrasonic-assisted sol-gel (UASG) method has a better re- versibility than the electrode synthesized by the sol-gel method. 相似文献
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In this work, we demonstrated a new precursor route to synthesize CoFe2O4 one-dimensional (1D) nanorods. CoFe2O4 nanorods were prepared via the thermal decomposition of CoFe2(C2O4)3 nanorod precursor, which was prepared by solvothermal method without the assistance of template or surfactant. The microstructure and magnetic property of the obtained products were characterized by x-ray powder diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), thermogravimetric (TG) and differential thermal analysis (DTA) and vibrating sample magnetometer (VSM). The results showed that the as-prepared CoFe2O4 nanorods were built by magnetic nanoparticles after calcining the precursor nanorods at different temperatures, and the size variation of magnetic nanoparticles with calcination temperatures leaded to variable magnetic properties. 相似文献
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Montmorillonite, organically modified by octadecylammine salt, has been adopted to successfully fabricate the exfoliated organic montmorillonite/poly(3,4‐ethyldioxythiophene) (OMMT/PEDOT) nanocomposites by in situ polymerization in aqueous media. Hydrochloric acid, 1,5‐naphthalenedisulfonic acid, and sodium benzenesulphonate have been employed to activate the polymerization of 3,4‐ethyldioxythiophene by offering active sites on the layers of montmorillonite. The resulting exfoliated nanocomposites have been characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, thermogravimetric analysis, and electrical conductivity measurement and showed controllable conductivity in the range of 10?7 to 10?2 S/cm and improved thermal stability compared with pure PEDOT. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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基于硫酸介质中钌(Ⅲ)对高碘酸钾氧化灿烂绿(BG)的催化反应,建立了动力学光度法测定痕量钌的新方法.钌在5.0×10-10~1.0×10-7g/mL范围内与催化反应速率有良好的线性关系,相关系数为0.994 1,方法的检出限为1.9×10-10g/mL.大部分常见离子不干扰测定.该体系灵敏度高、稳定性好,直接用于水样中... 相似文献
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By sol-gel method, (Ca0.54, Sr0.34)(Mo0.2, W0.8)O4: Eu3+0.08 luminescent materials can be synthesized. X-ray diffraction analysis indicates that it owns tetragonal scheelite structure, belonging to I-center with space group I41/a [88], Z = 4. The emission spectra, excitation spectra and fluorescence decay curves are measured, and the partial Judd-Ofelt parameters and, under 395 nm excitation, quantum efficiency of Eu3+ 5D0 energy level are calculated. The results indicate that Eu3+ 5D0-7F2 red luminescence can be excited by 395 nm, 465 nm and 535 nm in the hosts, respectively, and its quantum efficiency can be improved in space and it has potential application for white light emitting diodes as the red luminescent materials. 相似文献
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采用熔融共混技术,将Al(H2PO2)3引入聚氨酯热塑性弹性体,制备了一系列次磷酸铝/聚氨酯弹性体复合材料(Al(H2PO2)3/TPU)。采用极限氧指数(LOI)、垂直燃烧(UL-94)、锥形量热测试、TG和SEM研究了Al(H2PO2)3对Al(H2PO2)3/TPU复合材料阻燃性能及热稳定性的影响,采用力学测试研究Al(H2PO2)3对其力学性能的影响。阻燃测试表明,Al(H2PO2)3可以有效提高Al(H2PO2)3/TPU复合材料的阻燃性能。当Al(H2PO2)3添加量为20wt%时,Al(H2PO2)3/TPU复合材料UL-94级别达到V-0级,LOI达到30.5vol%。热重测试表明,Al(H2PO2)3的加入会导致复合材料热分解温度降低,但其残炭率有明显升高。锥形量热测试表明,Al(H2PO2)3的加入有效降低复合材料热释放速率峰值(pHRR)和总热释放(THR),并明显提高其火灾安全性能,其中20wt% Al(H2PO2)3/TPU的pHRR和THR相对纯TPU分别下降65.7%和20.2%。SEM表明,Al(H2PO2)3/TPU复合材料炭渣致密性有明显提高。在此基础上,采用TGA-FTIR联用分析Al(H2PO2)3/TPU复合材料阻燃机制,研究发现,Al(H2PO2)3在燃烧过程中可以有效促进TPU裂解产物成炭,降低可燃性气体生成量,从而提高复合材料阻燃性能。 相似文献
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