由粗氧化锌制备纳米活性氧化锌的研究

采用碳酸氢铵法由粗氧化锌制备纳米活性氧化锌。研究了用碳酸氢铵法由粗氧化锌制备活性氧化锌的热力学、中间体碱式碳酸锌的主要组成和碱式碳酸锌热分解的温度对形貌的影响;考察了中间体碱式碳酸锌的热分解温度和时间对纳米活性氧化锌的纯度、白度、比表面积和表观密度的影响。碱式碳酸锌焙解生成纳米活性氧化锌适宜的温度和时间分别为600℃和1h时,产品中氧化锌的质量分数为97.6%,粒度<100nm,比表面积50m2/g,表观密度0.21g/cm3。     

货架喷塑前处理工艺的选择与应用

介绍了CZ99-03(7)常温锌系磷化剂在货架上的应用,根据货架构件的特点,优化货架喷塑前处理工艺,讨论了影响磷化质量的工艺因素,提出了提高磷化效果的措施以及进一步改进磷化工艺的工艺设计。     

Electrochemical Behaviour of Al, Al—In and Al–Ga–In Alloys in Chloride Solutions Containing Zinc Ions

The electrochemical behaviour of Al, Al—In and Al–Ga–In alloys in 0.6 m NaCl solutions with and without Zn²⁺ was investigated. The study was performed by means of open circuit potential, potentiodynamic polarization, potentiostatic current-time and electrochemical impedance spectroscopy measurements as well as by SEM-EDAX examination. It was found that the Al—In alloy exhibits the highest negative open circuit potential in 0.6 m NaCl and the corrosion resistance of the tested electrodes decreases in the following order: Al > Al–Ga–In > Al—In. The greater activity of the Al—In alloy was interpreted on the basis of the autocatalytic attack by indium. The potentiostatic current–time measurements in Zn²⁺ containing electrolyte at potentials above the pitting potential revealed that Zn²⁺ has an insignificant influence on the Al electrode, while it enhances the corrosion of the Al–Ga–In alloy and improves the attack morphology of the Al—In alloy. Furthermore, the impedance spectra recorded under open circuit conditions showed a decrease in the polarization resistance of Al—In and Al–Ga–In alloys in presence of Zn²⁺ indicating the activating effect of Zn²⁺ ions.     

含磷的锌基合金的研究现状

简要评述了含磷的锌基合金的研究现状。介绍了Ｚｎ－Ｐ合金镀液中配体和光亮剂的选择、Ｚｎ－Ｐ合金度层中引入第二种金属可以提高镀层中磷含量，同时讨论了Ｚｎ－Ｐ镀层、ＺＺｎ－Ｆｅ－Ｐ镀层的耐蚀性。     

4—（2—吡啶偶氮）间苯二酚分光光度法测定奶粉中微量锌的含量的研究

研究了在溴化十六烷基三甲基铵（ＣＴＭＡＢ）存在下，４－（２－吡啶偶氮）间苯二酚（ＰＡＲ）与Ｚｎ（Ⅱ）显色反应的适宜条件，结果表明，在ｐＨ值为８．０～１０．５的范围内，锌与ＰＡＲ形成稳定的１：２的橙红色络合物，其最大吸收波长为５０５ｎｍ试剂的最大吸收波长为４２５ｎｍ配合物的摩尔吸光系数在５０５ｎｍ，处为８６２×１０＾４ｌ．ｍｏｌ＾－１．ｃｍ＾－１。Ｚｎ（Ⅱ）浓度在０～２５μｇ／２５ｍｌ范围内符合比耳     

Zinc hydroxystannate and zinc stannate as flame‐retardant agents for flexible poly(vinyl chloride)

The flame‐retardant and smoke‐suppressant properties of inorganic tin compounds such as zinc hydroxystannate (ZHS) and zinc stannate (ZS) were investigated in a comparison with alumina trihydrate, magnesium hydroxide, and Sb₂O₃ through the limiting oxygen index test and smoke density test. The flame‐retardant mechanisms were studied through the char yield test, SEM, quantitative analysis, thermogravimetry and differential thermal analysis. The thermal degradation in air of flexible PVC treated with the above compounds was studied by thermal analysis from ambient temperature to 800°C. The results showed that tin compounds such as ZHS and ZS could be used as a highly effective flame retardant for flexible PVC, and it appears that the tin compound may exert its action in both the condensed and vapor phases, but mainly in condensed phases as a Lewis acid. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1469–1475, 2005     

火焰原子吸收分光光度法测定锌精矿中的锌

采用原子吸收分光光度法对测定锌精矿中的锌含量进行了研究。通过实验,证明该方法干扰少,操作简便,结果准确可靠,适用于高含量锌分析。     

重铬酸钾滴定法测定甲基磺酸锡中Sn~(2+)和Sn~(4+)的含量

研究了以重铬酸钾间接滴定甲基磺酸锡中Sn2+和Sn4+含量的方法。在6mol/L盐酸中用锌粉把Sn4+还原为Sn2+,加入硫酸铁铵快速氧化Sn2+,硫酸铁铵中的Fe3+被还原为Fe2+。用重铬酸钾滴定Fe2+来间接测定Sn2+和Sn4+含量。方法相对标准偏差为1.65‰,回收率99.98%。该方法简便,快速,结果准确可靠。     

液相合成纳米氧化锌及其光催化性能探讨

以硝酸锌和氢氧化钠为原料,分别以水和醇作为溶剂,采用液相直接沉淀法合成纳米氧化锌。在以水为反应溶剂条件下,研究了反应时间、反应温度、反应物浓度和反应物配比对纳米氧化锌中位径和形貌的影响,得到制备较小中位径及合适长径比纳米氧化锌的最优反应条件,即:反应时间为3 h、反应温度为70 ℃、锌离子浓度为0.5 mol/L、锌离子与氢氧根浓度比为1:2。在上述最优反应条件下,研究了不同醇溶剂对纳米氧化锌中位径、形貌及其光催化性能的影响。研究发现,随着溶剂碳链长度的增长,纳米氧化锌中位径呈现上下波动,无明显变化规律,形貌由球状向柱状发展,光催化性能总体不断减弱。     

SiO2/Zn2SnO4/环氧丙烯酸酯涂层的阻燃性能

为了探究复合纳米颗粒对环氧丙烯酸酯（EA）涂层阻燃性能的影响，以十六烷基三甲基溴化铵（CTAB）和正硅酸乙酯（TEOS）为原料合成了介孔二氧化硅纳米颗粒，以ZnCl₂和SnCl₄·5H₂O为原料合成了锡酸锌（Zn₂SnO₄）纳米颗粒，将它们复合制成了介孔二氧化硅/锡酸锌复合纳米颗粒（SiO₂/Zn₂SnO₄），并用X射线粉末衍射仪（XRD）、透射电镜（TEM）对其表征。将所制的纳米颗粒（介孔SiO₂、Zn₂SnO₄、SiO₂/Zn₂SnO₄）与丙烯酸、丙烯酰胺、EA复合，经UV光固化制备出3种涂层（SiO₂/EA、Zn₂SnO₄/EA、SiO₂/Zn₂SnO₄/EA），通过紫外-可见光谱仪、差示扫描量热仪（DSC）及氧指数测定仪等对涂层的透光率、热稳定性、阻燃性能进行测试。结果表明：SiO₂/Zn₂SnO₄/EA涂层的综合性能较佳，当SiO₂/Zn₂SnO₄质量分数为4.85%时，该涂层的热稳定性及阻燃性能最佳，其极限氧指数、燃烧级别、残炭率（500℃下马弗炉煅烧）和硬度分别为31、V-0、17.32 % 及6H。