【作者】 刘蕊；

【导师】 王纪孝；

【作者基本信息】 天津大学 ， 膜科学与技术， 2008， 硕士

【摘要】 聚吡咯是一种物理化学性能优异的导电聚合物,在很多方面有着良好的应用前景。聚吡咯易形成不溶不熔的颗粒,限制了它的应用。定向生长的聚吡咯纳米线具有更高导电性和机械强度。聚吡咯纳米线修饰电极对许多化合物的氧化还原反应具有催化作用,它能够降低电化学反应的过电位、增大响应电流,因此可以用于组装电化学传感器。亚硝酸盐易与胺类化合物反应生成强致癌性物质亚硝胺。本文以亚硝酸根离子为模型化合物研究聚吡咯纳米线修饰电极的电催化性能,具有重要的理论和实际意义。使用可溶性淀粉为诱导剂在磷酸盐溶液中电化学合成了聚吡咯纳米线。研究了纳米线的生长过程及淀粉在其生长过程中的作用,考察了聚合电位、单体浓度、聚合时间、温度、酸度、高氯酸锂浓度以及淀粉浓度等对聚吡咯纳米形貌的影响。对聚吡咯纳米线进行了红外光谱分析。在硫酸溶液中,研究了可溶性淀粉诱导制备的聚吡咯纳米线修饰电极的电化学行为。研究了修饰电极对亚硝酸根离子的电催化还原作用,制备了性能优良的亚硝酸根离子传感器。循环伏安研究表明聚吡咯纳米线修饰电极可以有效降低亚硝酸根离子的还原过电位并且对亚硝酸根离子的电还原有显著的催化作用。双电位阶跃计时电流法研究发现聚吡咯纳米线修饰电极对亚硝酸根离子的电催化还原电流与亚硝酸根离子浓度成线性关系,能够在实验所测范围内(7.81×10^-5M～0.02M)准确测定离子浓度。亚硝酸根离子的催化还原电流随电解液温度、吡咯聚合电量和亚硝酸盐溶液酸度的增大而提高。聚吡咯纳米线修饰电极的后处理也对电极性能产生影响。所制备的传感器稳定性有待提高。更多还原

【Abstract】 Polypyrrole,one of the inherent conducting polymers, has promising applications in many fields. Because of its insoluble and infusible under normal conditions, polypyrrole’s application is restricted. Polypyrrole nanowires have advantage characters on conductivity and mechanical intensity over ordinary samples. Polypyrrole nanowire modified electrodes have obvious catalytic effect on many redox reactions. It can reduce the overpotential, increase response current and prevent analyte and products from absorbing on the surface of electrode. Nitrite is an essential precursor in formation of nitrosamines which have been shown to be potent carcinogens.Polypyrrole nanowires were synthesized by electrochemical method under the induce of souble starch. The growth process of polypyrrole nanowires and function of starch were investigated. Obviously, the morphology of polypyrrole is affected by polymerization potential, monomer concentration, polymerization charge, test temperature, acidity of electrolyte, concentration of LiClO₄ and souble starch. The FTIR spectra of polypyrrole nanowires was also analyzed.The electrochemical behavior of polypyrrole nanowire modified electrode was studied. The sensor performance namely electrocatalytic performance of polypyrrole nanowire modified electrode towards nitrite was studied. The experimental results show that the modified electrodes have obvious catalytic effect towards nitrite. The electroreduction current has a good linear relationship to the concentration of nitrite. The concentration of nitrite can be accurately tested in the range of 7.81×10^-5 and 0.02M. The experimental parameters such as testing temperature, polymerization charge, electrochemical extraction time and the pH of the test solution have effects on the reduction current. The post-treatment also has effect on the performance of modified electrode. The long term stability of nitrite sensor shoule be improved.更多还原