共查询到18条相似文献,搜索用时 78 毫秒
1.
采用炭吸附沉淀法,以氯化锶、五硼酸铵为原料,制备了硼酸锶纳米催化剂。利用热重/差热分析仪(TG-DTA)、X射线衍射仪(XRD)、透射电镜(TEM)和紫外可见光谱仪(UV-Vis)等对所得催化剂的焙烧温度、物相、微粒尺寸及光吸收性能进行表征。结果表明:炭黑的吸附有效阻止了纳米硼酸锶催化剂在制备过程中的团聚和烧结, 600 ℃下焙烧的纳米硼酸锶粉体具有良好的分散状态,平均晶粒尺寸为13 nm,比表面积为83.26 m2/g。罗丹明B紫外光催化反应结果表明,在60 min内罗丹明B在硼酸锶催化剂上几乎完全分解。 相似文献
2.
3.
4.
5.
6.
五硼酸钾的形成机理及其生产工艺的研究 总被引:2,自引:0,他引:2
在详细研究五硼酸钾形成机理和条件的基础上创建了从含有大量氯化钠、氯化钾、硼酸或硼砂及一定量氯化钙、氯化镁的复杂溶液中直接析出K[B_5O_6(OH)_4]·2H_2O的新工艺。其主要特点是首次以硼砂或石灰乳提供的微弱碱性使溶液中的氯化钾能以氧化钾形式进入产品,通过一次结晶或重结晶即可得到质量较高的五硼酸钾。产品用以代替硼酸和碳酸钾于玻璃生产,具有良好的经济效益。 相似文献
7.
8.
9.
10.
11.
纳米钛酸锶粉体制备及其表面改性工艺研究 总被引:1,自引:0,他引:1
钛酸锶(SrTiO3)是制备陶瓷电容器和热敏电阻器等电子陶瓷的重要原料,在电子工业上的应用非常广泛。以四氯化钛和氯化锶、氢氧化钠为原料,采用直接沉淀法合成纳米钛酸锶粉体,重点研究了表面活性剂十二烷基苯磺酸钠(SDBS)在合成过程中对纳米钛酸锶粉体性能的影响,并应用XRD,TEM,SEM,BET等一系列手段对其微观结构进行表征。结果表明表面活性剂SDBS的添加浓度有一最佳值(0.15 mol/L)。通过SDBS改性后的纳米钛酸锶粉体,其晶型结构没有发生改变,颗粒的形状为球形,平均粒径约为25 nm,粒度分布较窄,团聚现象也大为改善。 相似文献
12.
Single-crystalline barium strontium titanate nanocubes were synthesized via the solvothermal synthesis using TiCl4-BaCl2 as precursors in the mixed solvent of water-ethanol-ethylene glycol monomethyl ether. The products were characterized by XRD, TEM and XRF. The well-dispersed barium strontium titanate nanocubes with narrow particle size distribution may be attained by this simple solvothermal method and the particle morphology and size of powders are dependent on Sr/(Sr + Ba) mole ratio in reactants. 相似文献
13.
Ming Feng Guorong Ji Yaqiao Wu Guomin Li Kaiyue Wang Yuming Tian 《International Journal of Applied Ceramic Technology》2022,19(3):1293-1299
Ceramics with aluminum borate whiskers (ABWs) were prepared from H3BO3 and Al2O3 reagent, with and without 6 wt% MnO2 used as an addition. The microstructures, phase composition, and crystal structure of the ceramics were analyzed via scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction, respectively. The results show that MnO2 is an effective addition for enhancing the flexural strength of ceramics. The MnO2 could lead to the distortion of lattice, and improve the mechanical strength via a solid solution strengthening mechanism. Moreover, the content of H3BO3 and the sintering temperature were also key factors in the manufacture of optimal ceramics. The ceramic made from 6 wt% MnO2 addition, 25 wt% H3BO3, and sintered at 1200°C, showed the highest flexural strength of 88.5 (±1.9) MPa, and had a bulk density of 1.64 g/cm3 and porosity of 44.2%. 相似文献
14.
以六水合氯化镁和硼酸为原料,在水热条件下合成了碱式硼酸镁[MgBO2(OH)]晶须,将其焙烧得到硼酸镁(Mg2B2O5)晶须。采用X射线衍射(XRD)、扫描电镜(SEM)和热重-差热分析(TG-DTA)手段,对前驱体和焙烧产物的物相和形貌进行表征。主要考察了反应物浓度对前驱体物相和形貌的影响,并分析前驱体的形成过程。结果表明,前驱体的制备过程与反应物浓度直接相关,在Mg2+浓度为2.0 mol/L,硼酸浓度为0.75 mol/L的条件下,可合成形貌良好的碱式硼酸镁晶须,将其在较低焙烧温度650 ℃下焙烧3 h,可得到组分单一、直径为40~70 nm、长度为500~1 500 nm、长径比为10~20的硼酸镁晶须。 相似文献
15.
16.
17.
以硼砂和氯化钙为原料,采用超临界流体干燥技术(Supercritical Fluid Drying简称SCFD)制备纳米级硼酸钙。其过程主要包括制备水溶液中的胶体,经过过滤,用正丁醇、石油醚的混合溶液置换胶体中的水,然后进行超临界干燥。考察了制备沉淀过程中的反应物浓度和干燥条件对硼酸钙粒径大小的影响。采用SCFD技术可制备出大孔、高比表面积、低密度气凝胶超细粉。采用吸附法对其物性进行表征测定。该方法制备的纳米级硼酸钙超细粉体,表观密度可达到0.13g/mL,比表面积可达到388.8m^2/g。 相似文献
18.
In this study, it was aimed to prepare polyvinyl borate/polyvinyl alcohol blend nanofibers by electrospinning process. Polyvinyl borate was synthesized by the condensation reaction of polyvinyl alcohol and boric acid. Polyvinyl borate itself was not suitable for electrospinning process. To improve fiber formation capability, polyvinyl borate was blended with polyvinyl alcohol before electrospinning process. A series of nanofibers with various polyvinyl borate concentrations in polyvinyl alcohol were prepared. Homogeneous and highly porous mat containing 100–250 nm diameter nanofibers were obtained by electrospinning process. According to the FTIR results, boron atoms were found to be integrated into the polymer network. There is not any significant effect of polyvinyl borate content on fiber morphologies according to SEM images. The blend composition with the highest polyvinyl borate content was found to be suitable for thermally stable nanofiber formation according to the TGA results. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献