摘要
研究了催化剂对锡酸四丁酯Sn(OBun) 4 水解缩合反应、胶粒生长结构的影响 ,给出了切粘度 η、特性粘度〔η〕及pH随时间的变化曲线。结果表明 :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 ,分形锥度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。SnO2 溶胶粒的生长遵循三阶段模型和胶粒结构不变的规律 。
By the experimental effect of catalyst species on hydrolysis,condensation and grain growth structure of SnO_2 sol systems derived by the precursor Tetrabutylorthostannate Sn(OBu n)_4.It was reported that tear viscosity η,intrinsic viscosity 〔η〕 and pH values of the sol solution system varied dynamically with time.It is revealed from dynamical curve 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.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.In this paper,the growth character of SnO_2 sol grains and its structural evolution rule were discussed,and proton H + production phenomena associated with sol grain growth process were also explained.The growth process of SnO_2 sol grains is controlled by a three-stage growth model,and grain structure keeps invariant during the growth period before sol-gel transformation and sol solution acidity (pH) influences profoundly the sol grain growth rates.
出处
《中国陶瓷工业》
CAS
北大核心
2004年第1期10-14,28,共6页
China Ceramic Industry
基金
国家科委重点科技攻关项目 (编号 :96 - 1 1 9- 0 4 - 0 1 - 0 5)
