层接层自组装无机—有机纳米功能复合膜

【作者】 王永慧；

【导师】 胡长文；

【作者基本信息】 东北师范大学 ， 无机化学， 2003， 博士

【摘要】 构筑具有光、电、磁等性质的无机-有机纳米复合膜材料是当今材料科学中的一个研究热点。本论文工作以制备具有光电功能特性的多金属氧酸盐无机-有机纳米复合膜材料为主要研究方向，利用层接层自组装技术，使用含铕镧系多金属氧酸盐(包括[Eu(P₂W₁₇O₆₁)₂]^17-、[Eu(SiW₁₁O₃₉)₂]^13-和[Eu(W₅O₁₈)₂]^9-与聚电解质、Keggin型多金属氧酸盐[α-SiW₁₂O₄₀]^4-与部分掺杂的导电聚合物聚苯胺、以及Keggin型多金属氧酸盐[α-SiW₁₂O₄₀]^4-与两种有机染料分子（罗丹明B和罗丹明6G），制备出有序且稳定的无机-有机纳米复合膜。另外，利用层接层自组装技术与原位化学反应相结合的方法，制备出含有半导体ZnS纳米粒子的多层复合膜。采用UV-vis光谱、FTIR光谱、X-射线光电子能谱、椭圆光度法、扫描电子显微镜、原子力显微镜、透射电子显微镜、荧光光谱和标准四探针技术对所制备的纳米复合膜进行了组成、结构和性能表征。 研究结果说明，上述各种无机和有机组分均被掺杂到复合膜中，且保持原来的结构和性能。复合膜的特征吸光度和膜厚度随着双层数的增加而线性增长，而且也随所使用的沉积浓度的增加而增加。复合膜在广泛的沉积浓度范围内均表现出线性（或近似线性）的层接层均匀规则的生长，膜表面在很大面积内比较均匀平坦。复合膜具有良好的热稳定性和环境稳定性。ZnS纳米粒子在多层膜中是相当单分散的，直径为30-40nm左右。含铕多金属氧酸盐-聚电解质无机-有机复合膜在室温下均显示出Eu³⁺离子的特征红光发射，而且发射峰强度随双层数的增加而增长。Keggin型多金属氧酸盐-聚苯胺复合膜的电导率数量级约为10^-3Scm^-1。Keggin型多金属氧酸盐-染料复合膜均显示出染料分子的特征发光，发射峰强度随双层数增加而几乎线性增长，而且从极低浓度的染料溶液制备的超薄复合膜即可达到极高的发光强度。另外，含有ZnS纳米粒子的多层复合膜显示出ZnS纳米粒子的特征蓝光发射。更多还原

【Abstract】 Inorganic-organic nanocomposite film materials with optical, electrical, and magnetic properties are one of the research focuses in contemporary materials science. My doctoral dissertation places emphasis on the preparation of polyoxometalate-based inorganic-organic nanocomposite films with interesting luminescent or electrically conductive properties. By means of the layer-by-layer self-assembly technique, ordered and stable inorganic-organic nanocomposite films consisting of europium-containing lanthanide polyoxometalates (including [Eu(P2W17O61)2]17-, [Eu(SiW11O39)2]13-, and [Eu(W5O18)2]9-) andpolyelectrolytes, a Keggin-type polyoxometalate [a-SiW12O40]4- and partially doped polyaniline, [a-SiW12O40]4- and two organic dyes (Rhodamine B and Rhodamine 6G), respectively, have been fabricated. In addition, ZnS nanoparticle-containing multilayer films have been prepared by combination of the layer-by-layer self-assembly technique with in situ chemical reaction. The composition, structure, and properties of the as prepared composite films have been characterized in detail by UV-vis, FTIR, and X-ray photoelectron spectra, ellipsometry, scanning electron microscopy, atomic force microscopy, transmission electron microscopy, fluorescence spectroscopy, and standard four-probe technique.The experimental results show that the above inorganic and organic components were incorporated into the composite films and their identities were preserved. The characteristic absorbances and film thicknesses of the films increased with the number of bilayers and also with the deposition solution concentrations. The composite films exhibited linear (or nearly linear), uniform, and regular layer-by-layer growth in a wide range of deposition solution concentrations. The films showed a uniform and smooth surface in a large area and good environmental and thermal stabilities. The ZnS nanoparticles were well-dispersed in the multilayerfilms with sizes of ca. 30-40nm. The composite films comprising europium-containing lanthanide polyoxometalates all exhibited the characteristic red light emissions of Eu3+ ion and the emission intensity increased with the number of bilayers. The films made up of Keggin-type [a-SiW12O40]4- polyanion and polyaniline had conductivities with a magnitude of 10-3 S cm-1. The composite films assembled from [a-SiW12O40]4- and dye molecules showed characteristic luminescence of the dyes and the emission intensity increased almost linearly with the number of bilayers. Moreover, extremely high luminescent intensity of the composite films can be obtained by using dye solutions with very low concentrations. Further, the multilayer films containing ZnS nanoparticles exhibited blue light emission resulting from ZnS nanoparticles.更多还原