荧光素掺杂的TiO_2凝胶的制备及光谱研究

近些年来，溶胶－凝胶(Sol-Gel)方法作为一种软化学合成方法具有很多优点［1］，例如制作简单、烧结温度低，制得样品稳定、坚韧，制备灵活性高等。作为一种常用的染料，荧光素(FL)常用于研究非线性光学。利用Sol-Gel法可以很好地将染料分子固定在光…

Preparation and luminescent properties of inorganic polymer nano - Structured hybrid films doped with rare earth complexes

The inorganic/polymer hybrid films with good luminescent properties have been obtained by the sol - gel process via incorporating the polymer component doped with rare earth complexes. These films exhibit good toughness and transparency. Their fluorescence spectra and lifetimes indicate that they all have the characteristic luminescence of the central rare earth ions. The lifetimes of these films are longer than those of pure complexes. TEM have showed that the rare earth complexes are dispersed homogeneously in SiO2/PVB interpenetratiny networks, and the dispersed size is between 20 and 30 nn.

Isobutane/butene alkylation over supported heteropoly acid catalysts: I. Influence of the structure of silica

Catalysts consisting of heteropoly acids (HPAs) supported on different silica and mesoporous molecular sieves have been prepared by impregnation and the sol-gel method, respectively, and their catalytic behavior in fixed-bed alkylation of isobutane with butene has been investigated. The activity, selectivity and stability of the supported-HPA catalysts could be correlated with the surface acidity of the catalysts, the structure of supports as well as the time on stream (TOS). In the fixed-bed reactor, the acidity of the heteropoly acid is favorable to the formation of dimerization products (C-8(=)); especially, the pore size of supports was seen to have an important effect on activity and product distribution of the catalysts. Contrary to the traditional solid-acid catalysts, the supported-HPA catalysts own an excellent stability for alkylation, which makes it possible for these supported catalysts to replace the liquid-acid catalysts used in industry.

Luminescence properties of rare earth (Eu3+ and Tb3+) complexes with conjugated carboxylic acids and 1,10-phenanthroline incorporated in silica matrix

Binary and ternary complexes of europium and terbium with conjugated carboxylic acid (nicotinic acid and 3,4-furandicarboxylic acid) and 1,10-phenanthroline were introduced into silica gel by the sol-gel method. The luminescence behavior of the complexes in silica gels was studied compared with the corresponding solid state complexes by means of emission, excitation spectra and lifetimes. The result indicated that the rare earth ions (EU3+ and Tb3+) showed fewer emission lines and slightly lower emission intensities in the silica gel than those in pure rare earth complexes. The lifetimes of rare earth ions (EU3+ and Tb3+) in silica gel doped with rare earth complexes became longer than those in pure rare earth complexes. (C) 1998 Elsevier Science S.A.

溶胶—凝胶技术在功能材料制备中的应用

引言溶胶—凝胶(Sol-gel)技术作为在低温和温和条件下合成无机化合物或制备无机材料的重要方法,具有许多独特的优点:(1)由于在溶胶—凝胶法中所用的原料首先被分散在溶剂中而形成低粘度的溶液,因此就可以在很短的时间内获得分子水平上的均匀性。在形成凝胶时,反应物之间也是在分子水平上被均匀地