锡酸四丁酯[Sn(OBu^n)_4]水解缩合实验研究

Experimental Study on Hydrolysis and Condenation of Tetrabutylorthostannate[Sn(oBu^n)_4]

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 SnO\-2 sol solution stability in teh sol\|gel process derived by the precursor Tetrabutyiorthostannate (Sn(OBu\+n)\-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(OBu\+n)\-2(acac)\-2 as well as catalysis mechanismi were suggested through convincing discussion.It is revealed from rheological measurements of SnO\-2 sol systems that the relationship between the intrinsic viscosity [η] and the sol solution concentration of SnO\-2 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 SnO\-2 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(OBu\+n)\-2(acac)\-2 exists in the sol\|gel process is presented by this study.