硅钼黄和硅钼蓝测定三元复合驱采出水中硅的比较

三元复合驱采出水中硅含量的测定分别采用硅钼黄分光光度法和硅钼蓝分光光度法,并对两种测试方法进行了比较。实验结果表明,当样品的硅离子浓度较低时,采用硅钼蓝法的精密度要高于硅钼黄法。当硅离子浓度较高时,硅钼黄法精密度高于硅钼蓝法。因此,建议在测试三元复合驱采出水硅含量时,可根据样品的硅含量选取适当的分析方法。     

硅钼蓝比色法测定钼酸铵中微量硅

硅钼蓝比色法测定钼酸铵中微量硅袁玉琴，陈泽民（湖北省化学研究所，武汉４３００７４）硅钼蓝比色法是在微酸性溶液中，使硅与铅酸铵生成硅钼酸络离子，而硅钼酸络离子是氧化剂，可被合适的还原剂还原成钼蓝。在还原过程中，既不能使过剩的钼酸铰还原，又要保证硅钼酸络...     

硅钼蓝光度法快速测定SAPO-34分子筛中硅含量

建立一种以分光光度法测定SAPO-34分子筛中硅含量的分析方法。以硅和钼酸铵在盐酸介质中形成硅钼黄杂多酸,再以抗坏血酸将硅钼黄还原成硅钼蓝后,对硅含量进行测定。结果表明,体系中硅钼蓝的最大吸收波长为806 nm,绘制的标准曲线在0.100 0~6.000 mg/L内服从朗伯-比尔定律,所得相关系数为R2=0.999 5。该分析方法用于SAPO-34分子筛中硅含量的测定,精密度及稳定性良好,操作简单、快速。     

硅钼蓝分光光度法测定水中硫

在酸性介质中,硫离子可以定量地将硅钼黄还原为硅钼蓝,通过测定硅钼蓝的吸光度,可间接测定硫离子的含量,从而建立了硅钼蓝分光光度法测定水中硫的新方法。论文详细探讨了硅钼蓝分光光度法测定硫离子的各种影响因素。结果表明,显色体系的最大吸收波长为730nm,硫离子质量浓度在0.4000~8.000μg/mL范围内服从比尔定律,线性相关系数γ=0.9996。方法用于测定河水、山泉水、井水、温泉水中硫离子的含量,标准加入回收率分别为97.5%~105.0%、97.1%~101.0%、95.8%~96.7%、101.4%~102.1%。     

硅钼蓝光度法测定牙膏中二氧化硅含量的研究

牙膏经烘干后,经过氧化钠熔融,盐酸酸化后,在0.6~1.0 mol/L酸性溶液中,加入钼蓝显色剂将硅钼黄还原成硅钼蓝,在波长680 nm处测定其吸光值。用钼蓝分光光度法测定,方法精密度(RSD,n=12)为0.88%,回收率为96.8%~103.7%,方法稳定,测试结果可靠。     

粘土中二氧化硅的差示分光快速测定

粘土中二氧化硅的含量一般在50％左右,通常采用重量法或容量法测定。近年来,对采用硅钼蓝比色法的研究工作已取得了不少进展,并已逐渐被应用到较高二氧化硅含量的样品分析中。本文对硅钼黄显色的酸度、体积、温度等影响又作了进一步的研究,提出了在pH=1时,在小体积内进行硅钼黄显色,继后用抗坏血酸将其还原成硅钼蓝,且用差示分光法测定粘土中二氧化硅的快速方法。本法具     

高纯铪中微量硅的钼蓝分光光度法研究

研究制定了高纯铪中微量硅的钼蓝分光光度法,采用氢氟酸溶解样品,以饱和硼酸掩蔽氟离子。加入钼酸铵使硅酸根离子与钼酸铵形成黄色的硅钼杂多酸络合物,在酒石酸介质中用1-氨基-2萘酚-4磺酸还原成硅钼蓝,测量其吸光度并进行回收率测试。试验结果表明:该方法操作简便,方法稳定性、重现性、准确性好,能满足铪中微量硅的分析检测要求。     

硅钼蓝分光光度法测定磷矿石中的二氧化硅

对硅钼蓝分光光度法测定磷矿石中的二氧化硅进行了研究。研究了硅钼黄的显色条件及干扰因素,在本方法试验控制Ｈ２ＳＯ４浓度范围内硅与钼酸钠生成硅钼黄,经ＦｅＳＯ４还原成硅钼蓝,ＳｉＯ２含量在０～６００μｇ／１００ｍｌ范围内服从比耳定律。操作简便,重现性好,结果准确,测定磷矿石中的二氧化硅含量,结果满意。     

分光光度法测定生料中的二氧化硅

水泥生料中SiO2的测定通常采用硅钼蓝分光光度法,但由于形成的硅钼蓝络合物不稳定,显色后来不及测定颜色便消失或者出现浑浊现象等,使测定结果受到影响.本文通过试验,找出了最佳测试条件,不仅能满足水泥生料中硅含量的测定,也可用于其他物料中少量或微量硅的测定.     

硅钼兰比色法测定锅炉水中二氧化硅的优化

通过探讨分光光度法测定水中常量二氧化硅的方法,在盐酸浓度为0.12 mol/L的酸度条件下,水样中活性硅与钼酸铵生成为硅钼黄,酒石酸掩蔽磷酸根等干扰物质,用抗坏血酸还原生成硅钼蓝,生成硅钼蓝络合物的颜色深度与水样中硅浓度成正比,符合郞伯比尔定律。本方法适用于SiO_2含量较高的水样中SiO_2的测定,如原水、循环冷却水和炉水等。此方法操作简单,准确度高,具有推广价值。     

高纯三氧化二钛中微量硅的萃取分光光度测定

为了测定三氧化二钛中的微量硅，对萃取——分光光度测定法的某些操作步骤进行了改进和检验。利用Ｈ２ＴｉＯ３沉淀可将母体钛分离，硅的回收率大于９０％。稳定硅钼兰的还原状态后，可使分析的精密度大为提高。对钛氧化物中１０μｇ／ｇ量级硅的测定结果表明，该法能满足微量硅的分析要求     

Ceramic Coatings on Ceramic Substrates by Liquid Metal Transfer

A variety of ceramic coatings have been put on ceramic substrates by the molten metal transfer technique. In the diffision coating process a reactant metal dissolved in a molten "transfer agent" metal reacts with a substrate to form the coating. Titanium dissolved in molten tin has been reacted with silicon carbide, aluminum nitride, and silicon nitride substrates to produce titanium carbide and titanium nitride coatings, respectively. Similarly tantalum metal has been reacted to form carbide or nitride coatings. The unreacted tin is finally removed by decantation followed by acid leaching.     

Simultaneous preparation of TiO2 and ammonium alum,and microporous SiO2 during the mineral carbonation of titanium-bearing blast furnace slag

In this study, a route for simultaneous mineralization of CO₂ and production of titanium dioxide and ammonium alum, and microporous silicon dioxide from titanium-bearing blast furnace slag (TBBF slag) was proposed, which is comprised of (NH₄)₂SO₄ roasting, acid leaching, ammonium alum crystallization, silicic acid flocculation and Ti hydrolysis. The effects of relevant process parameters were systematically investigated. The results showed that under the optimal roasting and leaching conditions about 85% of titanium and 84.6% of aluminum could be extracted while only 30% of silicon entered the leachate. 84% of Al³⁺ was crystallized from the leachate in the form of ammonium aluminum sulfate dodecahydrate with a purity up to 99.5 wt%. About 85% of the soluble silicic acid was flocculated with the aid of secondary alcohol polyoxyethylene ether 9 (AEO-9) to yield a microporous SiO₂ material (97.4 wt%) from the crystallized mother liquor. The Al- and Si-depleted solution was then hydrolyzed to generate a titanium dioxide (99.1 wt%) with uniform particle size distribution. It was figured out that approximately 146 kg TiO₂ could be produced from 1000 kg of TBBF slag. Therefore, the improved process is a promising method for industrial application.     

浮选萃取分光光度法测定钛酸钡中痕量硅的研究

研究了应用浮选萃取光度法的原理测定钛酸钡中痕量硅的方法。在pH为1.2时,硅与钼酸铵生成硅钼杂多酸(硅钼黄),用抗血酸将其还原为硅钼蓝,当通入空气时,生成的硅钼蓝吸附在气泡上,随气泡上升到有机相,最终浮选分离进入异戊醇。络合物最大吸收波长位于803 nm,硅含量在0～1.4 mg/L范围内符合比尔定律,摩尔吸光系数为3×104 L/(mol.cm),相关系数为0.996 7,加标回收率在96%～102.5%。该方法集分离与测定于一体,具有灵敏度高、选择性好、方便、快速的特点,可用于钛酸钡中硅的测定。     

提高硅钼黄比色溶液稳定性的研究

试验、分析和总结了影响β硅钼黄稳定性的显色条件、溶液组成及稳定剂的选用等诸多因素。发现丙酮的稳定效果比乙醇好,且没有光化学还原干扰。试验表明,在pH,0.6～1、钼酸铵含量为0.8%～1.2%、丙酮含量为5%～10%、大体积显色所形成的β硅钼黄在30,℃以下能稳定4,h以上,且重现性好,能较好地满足分析要求。用氟化钾和硼酸进行解聚处理后的试液,若在玻璃容量瓶中显色并放置,氟仍会侵蚀玻璃,引起干扰。研究改进后的硅钼黄法,其准确度和精密度与抗坏血酸还原-硅钼蓝法相似,分析微量二氧化硅S≤0.014%、RSD≤1.5%,但比硅钼蓝法快速、简便、节省试剂。     

Simultaneous preparation of TiO2 and ammonium alum,and microporous SiO2 during the mineral carbonation of titanium-bearing blast furnace slag

In this study, a route for simultaneous mineralization of CO₂ and production of titanium dioxide and ammonium alum, and microporous silicon dioxide from titanium-bearing blast furnace slag (TBBF slag) was proposed, which is comprised of (NH₄)₂SO₄ roasting, acid leaching, ammonium alum crystallization, silicic acid flocculation and Ti hydrolysis. The effects of relevant process parameters were systematically investigated. The results showed that under the optimal roasting and leaching conditions about 85% of titanium and 84.6% of aluminum could be extracted while only 30% of silicon entered the leachate. 84% of Al³⁺ was crystallized from the leachate in the form of ammonium aluminum sulfate dodecahydrate with a purity up to 99.5 wt%. About 85% of the soluble silicic acid was flocculated with the aid of secondary alcohol polyoxyethylene ether 9 (AEO-9) to yield a microporous SiO₂ material (97.4 wt%) from the crystallized mother liquor. The Al- and Si-depleted solution was then hydrolyzed to generate a titanium dioxide (99.1 wt%) with uniform particle size distribution. It was figured out that approximately 146 kg TiO₂ could be produced from 1000 kg of TBBF slag. Therefore, the improved process is a promising method for industrial application.     

Silicon sputtering as a surface treatment to titanium alloy for bonding with PEKEKK

Thermoplastics, having strong polar or hydrogen bonding groups, are potential candidates for thin film bonding. In this investigation, a thermoplastic polymer poly(ether ketone ether ketone ketone) (PEKEKK) is used as an adhesive to bond the titanium alloy (Ti-6Al-4V). The titanium alloy is silicon-sputtered to improve the bond strength to PEKEKK. The bond strengths of butt-joined specimens prepared using silicon-sputtered, silane-coated, sodium hydroxide-anodized round bars of titanium alloy as adherends are determined and compared with that of untreated titanium alloy round bars. Of the various thicknesses of silicon layers studied, layers that are 200 Å thick proved to have a more durable bond, as demonstrated by soak test results in Ringer's solution. It is observed that silicon sputtering enhances the bond strength of titanium alloy/PEKEKK butt joints and provides a more resistant interface to intruding water. The combination of anodization followed by silicon sputtering further improves the durability of the bond. It is confirmed by XPS analysis that fracture does not take place between the silicon and the titanium substrate. Wetting studies by contact angle method using water as test liquid, indicate significantly better wetting after silicon sputtering for Ti-6AL-4V adherends.     

溶胶凝胶水热法制备TiO2及其光催化性能

以8 mL钛酸四丁酯为前驱体,十六烷基三甲基溴化铵为模板剂,采用溶胶-凝胶水热法制备二氧化钛,亚甲基蓝溶液为降解对象进行光催化研究,考察了水量、乙醇量、冰醋酸量、凝胶温度和pH值对光催化性能的影响。结果表明,水2.5 mL、乙醇28 mL、冰醋酸2 mL、凝胶温度40℃、pH值为2条件下制得的0.5 g二氧化钛对100 mL10 mg/L亚甲基蓝溶液降解率可以达到98.7%。     

Titanium dioxide grafted with silane coupling agents and its use in blue light curing ink

To improve the properties of titanium dioxide particles and realise their firm anchorage in blue light curing film, three modified titanium dioxide particles were prepared by grafting 3‐(trimethoxysilyl)propyl methacrylate, 3‐aminopropyltriethoxysilane and hexadecyltrimethoxysilane. The surface changes of titanium dioxide particles after modification were characterised. The dispersion stability, photo‐polymerisation, rheological and mechanical properties of modified titanium dioxide blue light curing inks were investigated. Results showed that compared with native titanium dioxide, modified titanium dioxide particles were more appropriate for blue light curing ink. The particle sizes of the three modified titanium dioxide particles became smaller, their surfaces exhibited hydrophobicity, and the viscosity of the modified titanium dioxide inks decreased slightly. Of the three modified titanium dioxide particles, 3‐(trimethoxysilyl)propyl methacrylate‐ and hexadecyltrimethoxysilane‐modified titanium dioxide particles exhibited better dispersion stability in blue light curing ink. In particular, 3‐(trimethoxysilyl)propyl methacrylate‐modified titanium dioxide blue light curing ink showed the best photo‐polymerisation and mechanical properties, which indicated the participation of the pigment grafted by double bonds in the blue light curable polymerisation. Using modified titanium dioxide in blue light curing ink, the dry/wet rubbing fastness of the printed fabrics improved.