催化剂对SiO2凝胶结构及复合体系发光性能的影响

用溶胶—凝胶的方法制备了染料掺杂的SiO2凝胶复合体系。无机基质制备过程中的各种条件对无机基质的微结构有很大影响，从而对复合材料的性能有很大影响。大量的研究表明，凝胶制备过程的诸多因素如催化剂、水的加入量及凝胶的后处理等因素影响最大，这些因素对凝胶结构的影响已有系统的研究，但其对有机—无机复合体系发光影响的研究还未多见。详细研究了在其他条件不变的情况下酸碱催化条件对复合体系结构及染料发光性能的影响。香豆素102(C102)在不同状态下的荧光分析表明，无论是碱还是酸催化所得薄膜复合材料，C102分子在其中基本都以单体的形式存在，与在溶液中相比发光移向短波。碱催化的样品其结构更有利于染料以单体的形式存在，但碱催化的膜表面粗糙，结构疏松，而酸催化的膜表面平整，结构致密。所以以HCl为催化条件的样品适合更进一步的应用。

Effect of the Catalyst on the Structure and Optical Properties of Organic Dyes Doped Silica Gels

Silica gels have lots of unique capabilities. In this paper organic dyes doped silica gels were prepared by sol-gel method in order to find the effect of the catalysts on structure and optical properties of the composite. From the emission spectra of coumarin 102(C102) in different conditions, the emission peak of PL shifted to short wavelength in both the composite material films compared with solution. Most of dye molecules were being monomers in ethanol, and few of them were being dimmer. As water joined it was found that a red-shift of emission peak appears. This showed that the gather degree became higher. When in sol catalyzed by acid the dye molecules were wrapped in the hole together with water and ethanol, so the concentration in hole was higher than average. On the other hand, hydrolysis product began to polymerize after aging two days, and the product was water. So the proportion of water added in composite. These two aspects resulted in red shift. The pH degree was very high in sol catalyzed by alkali, this restrain dye molecules polymerize. Doped in silica gels, the C102 molecules were isolated and adsorbed in the tiny pores of the inorganic network steadily. Almost all of them existed in the form of monomer, so the spectra were similar to that of a single molecule. In structure, the sample catalyzed by acid had flat surface and dense structure, but it had hackly surface and open structure catalyzed by the alkali. All the results showed that the sample catalyzed by acid can be better used as a solid laser material.