【作者】 刘凤志；

【导师】 蒋治良；

【作者基本信息】 广西师范大学 ， 无机化学， 2003， 硕士

【摘要】 第一部分： 在沸水加热及稳定剂聚乙烯醇存在下，用水合肼还原Se(IV)制备了橙红色的硒纳米粒子。其呈球形，平均粒径为12 nm。研究了硒纳米粒子的吸收光谱和共振散射光谱，它在580nm产生一个吸收峰；在470 nm和570nm处产生二个瑞利散射峰，其中570nm处的瑞利散射峰是由于硒纳米粒子量子呈色效应产生的特征瑞利散射峰即共振散射峰（或共振瑞利散射峰），470 nm峰主要由于光源在470 nm处有最强发射所致。探讨了溴酚蓝、甲基橙、溴甲酚紫等染料分子吸收对硒纳米粒子共振散射光谱影响。理论和实验表明, 溴酚蓝、甲基橙、溴甲酚紫等染料分子的非弹性吸收是产生瑞利散射峰和瑞利散射谷的一个重要原因。第二部分： 水浴加热氯金酸-荧光素类染料-柠檬酸三钠体系20 min后，体系发生荧光猝灭，生成了以荧光素类染料为核，金为包裹层的[(FD)m]nucleus[(Au)n]shell复合纳米粒子。 研究了纳米反应体系的吸收光谱、荧光光谱、同步扫描光谱。实验结果表明，体系发生荧光猝灭后，生成的复合纳米粒子的吸收光谱和金纳米粒子的吸收光谱相似；其共振散射光谱和金纳米粒子的共振散射光谱相似，都在580nm出现特征共振散射峰，即二者具有相同的固相（金）-液相界面。高效液相色谱表明，荧光素(FR)在tR=3.8min处有一色谱峰；[(FD)m]nucleus[(Au)]shell复合纳米粒子和金纳米粒子一样没有荧光素色谱峰。在荧光素溶液中加入金纳米粒子后，荧光素在510nm处的荧光峰猝灭，但它在tR=4.2min处有一色谱峰，这进一步表明了复合纳米粒子的结构是核-壳型结构。[(FD)m]nucleus[(Au)]shell复合纳米粒子的形成是导致体系荧光猝灭和共振散射效应的根本原因。第三部分 采用吸收光谱、荧光光谱、共振散射光谱研究了金纳米粒子-氯化钾体系、金纳米粒子-荧光素-氯化钾体系、金纳米粒子-罗丹明6G -氯化钾体系的光谱特性。对于金纳米粒子-氯化钾体系，金胶所带负电荷能被钾离子所带正电荷<WP=5>中和，致使金纳米粒子发生聚集，生成较大粒径的金纳米微粒，故体系的共振散射增强。对于金纳米粒子-荧光染料-氯化钾体系，荧光染料分子可吸附在金纳米粒子表面，当加入氯化钾溶液后，钾离子所带正电荷中和金纳米粒子中未被荧光染料分子所占居表面所带的负电荷，使金纳米粒子发生聚集，生成较大粒径的金纳米微粒，使体系的共振散射强度增大，表现为共振增强；由于荧光分子被包裹在金纳米微粒中，无法与激发光作用，故表现为荧光猝灭。更多还原

【Abstract】 Part 1Selenium nanoparticle were prepared by heating, which used hydrazine hydrate as reducing agent and used polyvinyl alcohol as stabilizer. The results showed that the selenium colloids have better-dispersion and stability .The average diameter is 12 nm. The procedure has rapidity and convenience .The absorption spectrum and Rayleigh scattering spectrum of Selenium colloid were studied. The maximum absorption peak of selenium colloid is at 580 nm. There are two Rayleigh scattering peaks at 470nm and 570 nm. Owing to quanta colored effect, the Rayleigh scattering peak at 570nm is characteristic Rayleigh scattering peak,namely resonance scattering peak(or resonance Rayleigh scattering peak) . The peak at 470 nm is mainly due to that absorption of light resource at 470 nm is strongest The influence of the dyes on the Rayleigh scattering of Selenium nanoparticle has also been studied, such as bromophenol blue(BB), methyl orange(MO), bromcresol purple(BP) ect. It is found out that the absorption of dye molecules is one of important factors to result to Rayleigh scattering peak and valley.Part 2Composite gold nanoparticles were prepared by heating system of HAuCl4- fluorescence dye -Tri-sodium citrate (TSC). In this paper, the absorption spectra, fluorescence spectra and synchronous scanning spectra of the system were studied before and after fluorescence quenching. It has been found out that absorption spectra and Rayleigh scattering spectra of composite gold nanoparticles are similar to gold nanoparticle. There is a Rayleigh scattering peak at 580nm both the composite gold nanoparticles and gold nanoparticle. The reason is that composite gold nanoparticles<WP=7>and gold nanoparticle have same solid (gold)-liquid interface .The HPLC of the system has no peak like gold nanoparticle, if fluorescein was added before reacting. The HPLC of system has a peak like fluorescein, if fluorescein was added after reacting. Therefore, the core/shell structure of composite gold nanoparticles was proved once more. Fluorescent molecules are wrap up inside Composite gold nanoparticles and no more interact on excited light, So that there is fluorescence quenching.Part3The spectral properties of (Au)n-KCl, (Au)n-(FR)k-KCl and (Au)n-(RDG6G)k-KCl were studied by using absorption spectra, fluorescence spectra and Rayleigh scattering spectra. For the system of (Au)n-KCl, the negative charges on (Au)n surface are neutralized by K+, so (Au)n aggregate into bigger Au nanoparticle. The intensity of Rayleigh scattering of system enhances greatly. For the system of (Au)n-(FD)k-KCl, fluorescence dye molecules are firstly absorbed on the surface of Au nanoparticle. When KCl are added, the negative charges of (Au)n surface which are not occupied by dye molecules are neutralized by K+, the smaller Au nanoparticles turn into bigger nanoparticles. The intensity of Rayleigh scattering of system enhances. Fluorescence dye molecules are wrap up among gold nanoparticles, and no more interact with the excited light, So that there is fluorescence quenching.更多还原