【作者】 周红霞；

【导师】 张丽君；

【作者基本信息】 苏州科技学院 ， 环境工程， 2009， 硕士

【摘要】 聚萘二胺是继聚苯胺,聚吡咯,聚噻吩之后的又一类新型芳香族大π共轭结构的导电高聚物,因含有大量的氨基、亚氨基活性集团而具有许多新的功能,尤其对某些重金属离子具有高效的络合吸附作用。通过电化学聚合将其修饰于电极可以和某些重金属离子形成络合物,从而实现对重金属离子的富集与测定。本文就聚萘二胺修饰电极的制备、应用及国内外的研究进展做了介绍,并利用聚萘二胺对汞、银、铜离子的高效络合吸附作用,建立了分别测定环境中痕量汞、银、铜离子的新方法以及同时测定环境水样中痕量铜和汞的方法。实验采用循环伏安扫描的方法,制备了聚1,8-萘二胺修饰玻碳电极,讨论了聚萘二胺的电聚合条件(如反应介质、循环扫描电位、扫描速率、扫描时间等)及其电化学行为;研究了Hg2+、Ag+、Cu2+在聚1,8-萘二胺修饰电极上的伏安特性,通过“预富集-阳极溶出”建立了测定溶液中痕量Hg2+、Ag+、Cu2+的新方法。选择了最佳的富集底液和溶出底液,优化了各种实验参数(如富集底液的pH和浓度,富集时间,阳极溶出时的扫描范围,静止电位,静止时间,扫描速率等),并考察了其它离子的干扰影响。另外,对金属离子在修饰玻碳电极表面的电化学反应机理进行了初步探讨。实验发现,在最佳实验条件下阳极溶出时,汞在+0.07V获得一灵敏的溶出峰,在0.001~0.1mgL-1及0.1~5mgL-1浓度范围内与峰电流成良好的分段线性关系,检出限达0.0005mgL-1;银在0.0V获得一灵敏的溶出峰,在0.0008~0.1mgL-1浓度范围内与峰电流成良好的线性关系,检出限达0.0005mgL-1;铜在-0.25V及+0.40V处分别获得灵敏的溶出峰,在0.0008~0.1mgL-1及0.1~2mgL-1浓度范围内与峰电流成良好的分段线性关系,检出限达0.0005mgL-1;当同时测定环境水样中痕量的铜和汞时,在选定的实验条件下,Cu2+和Hg2+分别在0.001~0.2mgL-1及0.002~1mgL-1浓度范围内与峰电流呈良好的线性关系,检出限分别为0.0008mgL-1和0.001mgL-1。该电极制备简单快速,可重复使用,该法操作简便,灵敏度高,选择性好,抗干扰能力强,用于实际水样中痕量汞、银、铜的测定,效果良好,是传统测定方法的另一种选择。相信其在痕量物质的检测及传感器方面会有长足发展,有望发展成为性能优异的检测电极和传感器。更多还原

【Abstract】 Polydiaminonaphthalene is a new type of conducting polymer withπ-bond following polyaniline, polypyrrole and polythiophene, which has many more new functions due to a large number of amino groups and imido groups, and it can form complexes with several heavy metal ions. This characteristic makes it possible for the electrodes to concentrate and detect the heavy metal ions in dilute solutions when polydiaminonaphthalene is modified on electrodes. This paper introduced the prepararation and application of polydiaminonaphthalene modified electrode according to the latest literature. Based on the highly adsorption charicteristic of poly(1,8-diaminonaphthalene), methods for the separate determination of trace Hg2+, Ag+, Cu2+ and the simultaneous determination of trace Cu2+ and Hg2+ in water sample were established.In this paper, poly(1,8-diaminonaphthalene) modified glassy carbon electrode was prepared by cyclic voltammetry. It discussed parameters of electropolymerization, such as reaction medium, scan potential, scan rate, scan time and so on, the electrochemical behavior of the polymer was also researched. Hg2+, Ag+, Cu2+ were firstly accumulated on the modified electrode, then the accumulated mercury, silver and copper were anodically stripped by differential pulse voltammetry separately. The volt-ampere characteristics of Hg2+, Ag+, Cu2+ were studied. Different parameters, such as the pH and concentration of the accumulating solution, preconcentration time were studied, the scan potential, rest potential, rest time, scan rate and so on were optimized when it was anodic stripping. It also studied the interference of other ions. In addition, the electrochemical reaction mechanism of the metal ions on the modified glassy carbon electrode were discussed preliminary.The conclusions of the experiment were as follows: at the optimum experiment condition, when anodically stripped by differential pulse voltammetry, a well-defined anodic peak of mercury was at +0.07V, the linear ranges were 0.001~0.1 mgL-1 and 0.1~5mgL-1 with a detection limit of 0.0005mgL-1; a well-defined anodic peak of silver was at 0.0V, the linear range was 0.0008~0.1mgL-1 with a detection limit of 0.0005 mgL-1; two anodic peaks of copper could be observed at -0.25V and +0.40V, the linear ranges were 0.0008~0.1 mgL-1 and 0.1~2 mgL-1 with a detection limit of 0.0005 mgL-1. When it was used for the simultaneous determination of trace Cu2+ and Hg2+, the linear range of copper was 0.001~0.2mgL-1, the detection limit was 0.0008mgL-1; the linear range of mercury was 0.002~1mgL-1, the detection limit was 0.001mgL-1.This method is easy, fast, anti-interference, the detector is having good selectivity, high sensitivity as well as low detection limit, the results were satisfied when it was used to detect trace Hg2+, Ag+ and Cu2+ in water sample, it can be regarded as an new alternative to the conventional method, the future high perfermance of these electrodes as potential detecting electrodes and sensors are foresee.更多还原