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本文通过锡酸四丁酯［Sn(OBun)4］Sol-Gel过程中溶胶稳定性、acacH稳定剂作用、催化剂、pH影响及溶胶体系流变学测量，提出acacH的螯合中间体Sn(OBun)2(acac)2稳定机理、催化作用机理。流变学测量发现溶胶特性粘度［η］很好地符合近似线性模型，单体官能度f≈2.0，SnO2胶粒为近似线性分子链，分型维度D≈1.80，分形结构介于SAW链和无规高斯链之间，为螯合中间体Sn(OBun)2(acac)2的存在提供了实验证据。

In this paper,it was investigated experimentally that the SnO2 sol solution stability in teh sol-gel process derived by the precursor Tetrabutyiorthostannate (Sn(OBun)4:TBOS) was dramatically influenced by stability agent Acetylacetone (acacH),catalyst species,solution pH values.Based on the experimental observations, the sol stability role of agent acacH correlated to the chelate intermediate Sn(OBun)2(acac)2 as well as catalysis mechanismi were suggested through convincing discussion.It is revealed from rheological measurements of SnO2 sol systems that the relationship between the intrinsic viscosity ［η］ and the sol solution concentration of SnO2 sol particles is in good agreement with Quasi-Linear model of macromolecules,the functionality of modified monomer f is approximately equal to 2。0,and SnO2 sol particles show themselves as quasi-linear chain.On the other hand,its fractal dimension D≈1.80,and fractal structure stands between self-avoiding walk (SAW) chain and random Gussian chain.The evidence that the chelate intermediate Sn(OBun)2(acac)2 exists in the sol-gel process is presented by this study.