工业TiCl4水溶液水解制备金红石型二氧化钛纳米粒子

报道了以盐酸法制备的工业四氯化钛水溶液为原料,采用外加纳米晶种升温水解的方法, 较低温度下制备了锐钛型,金红石型纳米二氧化钛及其混晶。实验发现产物的晶型与水解时间密切相关,水解时间小于50min,产物是以金红石型为主锐钛型为辅的二氧化钛混晶,当水解时间大于70min 时,产物全部转化为金红石型纳米二氧化钛晶体。晶体的平均粒径为5 nm左右,经BET法测定其表面积为155m2／g。     

四氯化钛强迫水解制备金红石型纳米二氧化钛

以廉价的四氯化钛为原料，探索出一条制备金红石型纳米二氧化钛粉体的简便工艺。通过对沉淀产物进行XRD、TEM、TGA和DTA等分析表征表明，四氯化钛的盐酸溶液在沸腾回流水解中直接生成金红石相质量分数高达97．2％的沉淀产物，经干燥或进一步在较低温度(约500℃)下煅烧即可得到金红石型二氧化钛粉体，制得的粉体粒子呈椭圆形，粒径为10～30nm，且分散性好，比表面积大。该工艺具有原料成本低、能耗少的优点。     

Preparation of hollow alumina microspheres by microwave-induced plasma pyrolysis of atomized precursor solution

Hollow alumina microspheres have been prepared by microwave-induced (MI) plasma pyrolysis of atomized aerosols of precursor solutions and subsequent calcination at 1300 °C for 2 h. When an aqueous solution of 0.5 mol dm⁻³ Al(NO₃)₃ without any additives was used as a precursor, hollow -Al₂O₃ microspheres with a thick shell wall were prepared after post-calcination at 1300 °C. The addition of a polypropylene (PO)–polyethylene(EO) blockcopolymer (molecular weight: 2900–6500) to the precursor solution was effective for increasing the yield of hollow microspheres, but resulted in the formation of many cracks and holes in the thinned shell wall. Hollow alumina microspheres with a thin, but strong, shell layer could be prepared by the simultaneous addition of tetraethylorthosilicate.     

在乙二醇甲醚溶液中合成前驱体水解法制备Zn2SnO4超细粉末

在无隔膜电解槽中,加入0.15 mol/L( Bu4N)Br的乙二醇甲醚溶液,保持电解温度30℃、电流密度20 mA.cm-2时,先电解锡片4h,再电解锌片4h,制得锌、锡醇盐配合物,电流效率为90.3%.采用红外、拉曼光谱对其进行了表征.结果表明,前驱体结构为Zn2 Sn( OCH2CH2OCH3)8,可以有效克服团...     

Preparation of soluble TiCl3 catalysts by reduction of TiCl4 with Grignard reagents and their use for copolymerization of ethylene with propylene

Summary Preparations of soluble TiCl₃ catalysts by reduction of TiCl₄ with some types of Grignard reagents were carried out in halogenated hydrocarbon solvents by using appropriate ethers as donor. The soluble TiCl₃·MgX₂·ether complex catalysts and triisobutylaluminum as co-catalyst showed high activities for the copolymerization of ethylene with propylene. It was first found that the soluble TiCl₃·MgX₂·ether complex catalysts enhance the activities for the copolymerizations in the same manner as solid titanium catalysts supported on MgCl₂ which show high activities for homopolymerizations of olefin monomers. The copolymers obtained possessed low crystallinities. Also, the copolymers seem to contain microblock sequences and have outstandingly high tensile strength and elongation at break compared to copolymers by the conventional VOCl₃/Al(Et)_1.5Cl_1.5 catalyst system.     

Dimerization of 1-isopropenyl anthracene by TiCl4

Summary 1-isopropenyl anthracene was dimerized by reaction with TiCl₄ in CH₂Cl₂ and the structure of the dimer studied by ¹H NMR spectroscopy. The spectrum was assigned and is in agreement with simulation. The structure results from the attack of carbocation on carbon 9.     

隔膜电解法制备氯金酸及其机理探究

以金为阳极、石墨为阴极、饱和甘汞电极为参比电极、盐酸溶液为电解质,采用离子膜电解法制备了氯金酸。探究了制备过程中金的阳极行为以及实验条件氯离子浓度、pH、双氧水含量对制备过程的影响,并对反应机理进行了分析探究。结果表明：实验所得样品化学式为HAuCl₄.4H₂O,实验过程中基本上无金的损失,产率可达94%以上;电化学测试表明,金被电解为Au₃₊^发生在0.8-1.3V之间,致钝电压为1.3V;在pH为1.0的情况下最佳制备条件为电解电压1.25V,双氧水加入量5mmol,;在电解过程中减小电解液pH、增大电解液中氯离子浓度可以促进金的电解,此外峰电位随着pH的减小而降低;奈奎斯特图表明制备过程受电荷转移与扩散混合控制,随着溶液中Cl_-^{浓度的增大与双氧水的加入},扩散控制影响减弱由混合控制向电荷转移控制过渡。与传统工艺比较,隔膜电解法制备氯金酸具有无污染、易操作、安全性高、盐酸损失小等优点。关键词：氯金酸;电解法;金;盐酸中图分类号：TG146 文献标识码： A 文章编号：1003-5214 (2020) 01-0000-00     

Preparation of alumina by aqueous gelcasting

The alumina ceramic was prepared by aqueous gelcasting. The effects of zeta potentials, solid loading, dispersant content and milling time on the alumina suspension were studied systematically. The dispersant content has remarkable effects on the viscosity of the suspension. The appropriate dispersant concentration for alumina aqueous slurry with the solid loading of 55 vol.% is 0.6 wt.%. It can be seen that all suspensions (50–56 vol.% solid loading) exhibited a shear-thinning behavior and relatively low viscosity, which was suitable for casting. The degree of shear thinning and the viscosity at high shear rates increased with increasing volume fraction of solid. As the milling time prolongs, viscosity of the suspension decreases first, then the plateau appears and the average diameter keeps changeless. When the milling time was shorter than 20 h, the viscosity of slurries decreased gradually as the time of milling increased. After 20 h milling, the viscosity of the slurry tended to be consistent. Therefore, the ball milling time should be equal to or more than 20 h to obtain a stable suspension at equilibrium. The time available for casting the slurry (idle time) can be controlled by the amounts of initiator and catalyst added to the slurry as well as by the processing temperature. Micrograph of the gelcast green body was homogeneous.     

Dimerization of 9-isopropenyl phenanthrene by TiCl4

Summary 9-isopropenyl phenanthrene was dimerized by reaction with TiCl₄, in CH₂Cl₂ and the structure of the dimer studied by ¹H NMR spectroscopy. The structure results from the attack of carbocation on carbon 9.     

熔盐电解法制备硼粉的研究

对熔盐电解法制备硼粉的方法进行了论述,比较了各熔盐体系的优点和缺点,得出了氯化钾或氯化钾和氟化钾混合物的熔盐体系最适宜。用冷却曲线法对KF-KCl-KBF4体系熔盐体系的初晶温度进行了研究,研究表明:KF-KCl-KBF4体系的初晶温度为1 023—1 033 K,即750—760℃之间,当电解温度高于初晶温度20—30℃时,电解效率最高。这就为熔盐电解法制备元素硼提供了依据。     

铝矾土制备活性氧化铝掺合料的研究

研究了煅烧铝矾土制备活性氧化铝掺合料的过程。结合产物种类、结晶状态和比表面积,研究煅烧温度和煅烧时间对氧化铝活性的影响。采用XRD检测煅烧后铝矾土产物的种类及结晶状态,用激光粒度仪对产品进行比表面积的测定,并通过快速砂浆棒法检测煅烧所得活性掺合料对碱骨料膨胀反应的抑制效果。结果表明,获得活性氧化铝掺合料的最佳煅烧温度和煅烧时间分别为500 ℃和1.0 h,在此条件下制备的活性氧化铝掺合料对碱骨料膨胀反应的抑制效果较好,掺加质量分数为30%的活性氧化铝掺合料能使砂浆棒养护14 d的膨胀率从0.32%降至0.087%,其膨胀率低于0.1%,已经被控制在安全范围内。     

铝阳极氧化法制备Al2O3纳米线

采用二次铝阳极氧化法在草酸体系中制备多孔铝阳极氧化膜,用逆电剥离技术将氧化膜从铝基体上剥离：经超声清洗后,放入磷酸溶液中去除阻挡层,使纳米孔贯通。再将膜放入c=1mol／L的NaOH溶液和w=6％的铬酸、w=1．8％的磷酸混合溶液中进行溶解,可获得Al2O3纳米线。纳米线长度为40μm,与模板厚度一致,直径为10～20nm.通孔前后铝阳极氧化膜的形貌由SEM进行表征,纳米线的形貌由SEM和TEM表征．此外,本文还结合模板在溶解过程中的实验现象,对Al2O3纳米线的形成机理进行了初步分析。     

Preparation of laminated safety glass based on high strength polyurethane film by solution annealing

Compared with the traditional polyvinyl butyral (PVB) laminated glass, the polyurethane (PU) based laminated glass has the advantages of higher impact strength and longer service life. Thus, aromatic polyurethane films have attracted more attentions in recent years due to their high light transmittance, adhesion and functionality. In this paper, the tensile strength of polyurethane films based on bis(4-isocyanatocyclohexyl)-methane (HMDI) have been increased from 27 to 51 MPa and their elongation at break have been increased from 330% to 525% after solvent annealing in toluene. It is attributed to molecular segments with high crystallization and hydrogen bond formation of PU, which are confirmed by FT-IR and XRD characterization. Based on this, laminated glasses with higher impact strength based on the thermoplastic polyurethane films are constructed successfully.     

电子级四丁基氢氧化铵的离子膜电解法制备

讨论了以四丁基溴化铵为原料,离子膜电解法制备电子级四丁基氢氧化铵的条件。实验结果表明,在电解前金属离子的脱除中,WU-64树脂具有最好的提纯效果;在电解处理单元中,当电流密度为1000A·m-2、原料浓度为0.7mol·L-1时电流效率最高;在产品的后处理过程中,可采用两室一膜电解法对产品中阴离子进行去除,可得到溴含量为0.138mg·kg-1、氯含量为0.784mg·kg-1的质量分数为15%的四丁基氢氧化铵溶液。研究结果对于微电子工业有着重要的参考价值。     

以TiCl4为原料制备纳米TiO2技术的研究进展——液相法

介绍了以TiCl4为原料,用液相法制备纳米TiO2的几种方法;详述了其制备原理;分析了水解工艺对产品结构和质量的影响.     

直接电解氯酸盐制备二氧化氯的研究

介绍了直接电解氯酸盐制备ＣｌＯ＿２的方法。讨论了电解液温度、电流密度、氯酸盐浓度、硫酸酸度、ＣｌＯ＿２剩余浓度等对电化反应的影响。在最佳条件下，ＣｌＯ＿２的纯度可达９８．４４％。     

Decomposition voltage for the electrolysis of alumina at low temperatures

The apparent decomposition voltage for the electrolysis of alumina in an equimolar Na₃AlF₆-Li₃AlF₆ electrolyte was measured over a temperature range of 800 to 1000° C by the extrapolation of voltagecurrent plots to zero current. Temperature coefficients of –1.9 and –2.4 mV° C^–1 were determined for conditions of variable alumina activity (constant concentration) and unit activity (saturated), respectively. The overvoltage contribution to the temperature dependency was estimated to be about –1.6mV° C^–1 (versus a –0.6 mV° C^–1 dependency for the reversible decomposition voltage). Reduced alumina solubility at low temperatures also appeared to increase the overvoltage, but was of secondary importance.Based on work partially supported by the US Department of Energy (Contract DE-AC03-76CS40215: Energy Savings Through the Use of an Improved Reduction Cell Cathode).     

溶胶--凝胶法制备多晶氧化铝纤维的研究

本文探讨了溶胶－凝胶法制备多晶氧化铝过程中影响体性能的因素,成纤方法与工艺参数,热处理工艺制度及晶相转移关系等一系列问题。实验得到了以莫来石为主晶相长期使用温度超过１６００℃的多晶氧化铝纤维。     

Preparation of adherent films of poly-p-xylylenes on aluminum by electrolysis

The electrolysis of solutions of p-methylbenzyltrimethylammonium nitrate or, better, p-xylylenebis(trimethylammonium nitrate) or p-xylylenebis(triphenylphosphonium chloride or bromide) in a polar organic solvent with an aluminum cathode and a platinum anode results in the formation of adherent coatings of poly-p-xylylene on the cathode. The mechanism of this reaction involves the electrochemical generation of p-xylylene and its subsequent polymerization on the aluminum cathode. Competing reactions are formation of p-xylene and reduction of the solvent.