【作者】 席君兰；

【导师】 董文举；

【作者基本信息】 河南师范大学 ， 分析化学， 2010， 硕士

【摘要】 有机/无机纳米复合材料已经引起了学术和技术方面的广泛关注和研究,其中聚合物和无机纳米粒子复合材料是当前十分活跃的研究领域,已经涉及到化学、物理学、生物学及材料学等领域。聚合物和无机纳米粒子复合材料因具有良好的光化学性质、导电性、电催化性和生物相容性等优点而得到广泛的应用。化学修饰电极是当前电化学和电分析化学十分活跃的研究领域,聚合物和无机纳米粒子复合材料作为电极材料已经广泛地用于制作生物传感器、电致变色器件等,它在生物电分析、生物传感器研制等方面有重要的理论研究意义和广阔的应用前景。本文围绕聚合物和无机纳米粒子复合材料的制备、表征、性质、及其在光催化、电催化和传感器领域的应用进行了一些研究工作。一、核壳结构聚多巴胺/银纳米导电复合材料的制备、性质和应用以多巴胺为还原剂,硝酸银为氧化剂,利用氧化还原反应,生成银纳米粒子,同时多巴胺发生聚合反应,在银纳米粒子上原位形成一层聚多巴胺膜,最终形成了核壳结构的聚多巴胺/银纳米复合材料。该材料具有好的生物相容性,分散性,导电性和催化性,对中性红氧化有很好的光催化和电催化能力。利用扫描电子显微镜,透射电子显微镜考察了纳米复合材料的形貌,从电镜图上可以观察到纳米复合物粒子的粒径大小以及材料的核壳结构,聚多巴胺膜包裹在银纳米粒子的表面,形成聚多巴胺/银纳米复合材料。此外,利用紫外可见光谱考察该材料,在425 nm处出现了银的特征吸收峰,表明了银纳米粒子的产生。形成的聚多巴胺膜对银纳米粒子有保护作用,可以防止银纳米粒子氧化失去活性。另外,研究了该材料对中性红的光催化氧化及其修饰电极对中性红的电催化氧化。结果表明复合材料显著地加大和加快了中性红的降解,同时,该材料修饰电极对中性红有较灵敏的电化学响应,在优化的实验条件下,用差分脉冲伏安法测定其还原峰电流与中性红的浓度在1.0×10^-6～1.1×10^-5 mol/L的范围内呈良好的线性关系,检测限为2.1×10^-7 mol/L。二、核壳结构聚苯胺纳米导电复合材料的制备、表征、应用以碳酸钙为核,利用静电相互作用,采用层层组装的方法将壳聚糖,聚苯乙烯磺酸钠依次包裹在碳酸钙核上。包裹的聚电解质对碳酸钙核具有保护作用,它防止了核的形貌发生变化而失去作用。苯胺单体以碳酸钙/聚电解质微球为核,在K2S2O8的氧化作用下发生聚合,形成具有核壳结构的碳酸钙/聚电解质/聚苯胺微球。1.利用扫描电子显微镜考察了材料的形貌,可以看到聚电解质对碳酸钙核具有保护作用,并且可以观察到聚苯胺在核上发生了聚合。从该材料的紫外可见光谱、红外光谱和循环伏安图上也可以观察到聚苯胺的峰,表明了聚苯胺层的形成。2.将该材料滴涂在玻碳电极上制备出的修饰电极,对多巴胺有较好的电化学响应。测定同浓度的多巴胺,复合材料修饰电极的峰电流约是单纯碳酸钙修饰电极的2倍,表明了该电极材料有较好的电催化能力。三、聚苯胺膜/金纳米导电复合材料制备及其对多巴胺的电催化先通过原位电聚合苯胺单体在玻碳电极上修饰一层聚苯胺膜,再直接电还原吸附在聚苯胺膜上的氯金酸根离子（AuCl4-）,制备了聚苯胺/金纳米粒子复合物。利用聚苯胺/金纳米粒子复合物制备的传感器对多巴胺的氧化显示出了很好的催化能力,催化电流和多巴胺溶液在3.0×10^-6 mol/L～1.15×10^-4 mol/L浓度范围内呈线性关系,检测限是8.0×10^-7 mol/L （S/N = 3）更多还原

【Abstract】 Organic/inorganic nanocomposites have induced extensive attention and research in the fields of science and nanotechnology. The study of polymer and inorganic nanoparticles composite materials is an active field,involves chemistry, physics, biology, material science and so on. Polymer and inorganic nanoparticles composite materials are widely utilized duing to its good optical property, conductivity, electrocatalysis and biocompatible. The research of chemically modified electrode is an active field of electrochemistry and electroanalytical chemistry presently. Polymer and inorganic nanoparticles composite materials act as electrode materials have been applied to prepare biosensors, electrochromic device and so on, nanocomposite materials modified electrode has an important theorial significance and extensive application prospect in biological electroanalysis and preparation of biosensor.In this thesis, we developed our work focusing on preparation, characterization, properties of polymer and inorganic nanoparticles composite materials and its application in photocatalysis, electrocatalysis and sensor field。1. Polydopamine/Silver Conducting Nanoparticle Composite with Core-Shell Structure: Fabrication, Characterization and Application in Electrocatalysis, Photocatalysis toward Neutral RedDopamine hydrochloride （DA） （dissolved in 1.0×10-2 mol/L carbonate/bicarbonate buffer with pH 8.5） as a reductant and the source of polymer, silver nitrate （ AgNO3 ） as an oxidant and the source of silver nanoparticles （AgNPs）, are mixed to yield polydopamine/silver nanoparticle composite （PDA/AgNPs） with core-shell structure. Composite material has good biocompatibility, highly uniform dispersion of the nanoparticles with a narrow size distribution, conductivity and high good catalysis and optics. It has formidable electro catalysis and photochemical catalysis to oxidize neutral red （NR）.The morphology of the resulting products were characterized by scanning electron microscopy （SEM）and transmission electron microscope（TEM）, we can see the particle size and core-shell construction of the PDA/AgNPs composites, the PDA film wrap the Ag nanopaticles. Moreover, optical properties were characterized using UV-Vis spectra, the characteristic peak of AgNPs was observed at 425 nm on the spectra, indicated that AgNPs was produceed. PDA film can protect AgNPs, avoiding of oxidation. photocatalysis and electrocatalysis of composite material to oxidize NR are investigated in this thesis. The resuilt demonstrated that the PDA/AgNPs expedited the degradation of NR, and the PDA/AgNPs possessed the cataytic ability to degrade the NR. Minewhile, PDA/AgNPs modified electrodes possess sensitive response to neutral red, under optimum conditions and using differential pulse mode, the reduction peak current was linearly related to the concentration of NR over the range of 1.0×10^-6～1.1×10^-5 mol/L with a correlation coefficient of 0.998, the detection limit was 2.1×10^-7 mol/L （S/N=3）. 2. Polyaniline Conducting Composite Material with Core-Shell Structure: Fabrication, Characterization and Applicationcalcium carbonate （CaCO3） microparticles act as template, adopt the technique of layer-by-layer assembly utilizing electrostatic interaction to orderly coating polyelectrolyte chitosan and sodium poly（styrene sulfonate）. polyelectrolyte layers （PEs） can stabilize CaCO3 microparticles. Using CaCO3 microparticles stabilized with PEs as parent core, polyaniline （PAN） was in-situ formed around the microparticles, and formed PAN/（PEs）6/CaCO3 microparticles with core-shell structure.The morphology of the resulting products were characterized by scanning electron microscopy （ SEM ）, result indicated PEs can stabilize CaCO3 microparticles, and PAN was in-situ formed around microparticles. UV-Vis spectroscopy displayed characteristic peak of PAN, demonstrated PAN layer formed.PAN/（PEs）6/CaCO3 microparticles modified electrodes possess sensitive response to DA, peak current of modified electrodes to oxidize DA is about two times than pure CaCO3 microparticles modified electrodes, demonstrated composite materials possess good conductivity.3. Polyaniline/Au Conducting Nanocomposite:Fabrication and Electrocatalysis to Dopaminepolyaniline/Au nanoparticles nanocomposite （PANI/AuNPs） was prepared via direct electroreduction of AuCl4- ions adsorbed onto glassy carbon electrode （GCE）, which was previously coated with PANI via in-situ electropolymerization. The PANI/AuNPs based biosensor displayed good catalysis ability for the oxidation of dopamine （DA）, and the calatytic current exhibited linear response to DA in the range of 3.0×10^-6 mol/L～1.1×10^-4 mol/L, with a low detection limit of 8.0×10^-7 mol/L （S/N = 3）.更多还原