SiO_2对Al_2O_3凝胶纤维相变的影响  

Effects of silica on phase transformation of alumina gel fiber

作　　者：何静[1] 林志君[1] 张力[1] 丁马太[1] 陈立富[1] 

机构地区：[1]厦门大学材料学院特种先进材料实验室高性能陶瓷纤维教育部重点实验室,福建厦门361005

出　　处：《功能材料》2013年第7期926-931,共6页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51072169)

摘　　要：以尿素催化硅酸乙酯水解制得SiO2溶胶。采用29Si NMR、27 Al NMR、FT-IR、TEM、DTA、XRD和SEM等对SiO2溶胶、Al2O3凝胶纤维化学结构和微观结构研究结果表明,该SiO2溶胶稳定性好,含有大量的单硅酸Si(OH)4,能和Al2O3表面的Al—OH反应生成Al—O—Si键而有效地将其包裹,从而阻止了过渡态Al2O3微晶的相互接触,抑制了α-Al2O3的成核和生长。Silica sol was prepared by the hydrolysis of tetraethyl orthosilicate（TEOS）,using urea as the catalyst.It was used to suppress the α-Al2O3 phase formation during the heating of alumina gel fibers.29Si NMR,27Al NMR,FT-IR,DTA,XRD,SEM and TEM were used to characterize the silica sol and the alumina-silica fibers.It has been found that the silica sol is nearly neutral and highly stable.It contains silicic acid Si（OH）4 as the major silicon species.The silica sol can coat the alumina sol particles efficiently and interact chemically with the Al—OH groups of alumina sol to form the Al—O—Si linkages.The Al—O—Si film separates the transitional alumina crystallites from coarsening,suppressing the nucleation and crystal growth of α-Al2O3.

关 键 词：AL2O3纤维 SIO2 相变 溶胶-凝胶 

分 类 号：TQ343.5[化学工程—化纤工业]