摘要
运用ＸＲＤ，ＦＴ－ＩＲ，（２７）￣Ａｌ－ＮＭＲ，（２９）￣Ｓｉ－ＮＭＲ等手段和化学滴定等方法研究了随ｐＨ值变化的铝改性硅溶胶胶粒结构。结果表明：当铝改性硅溶胶的ｐＨ高于４．０时，溶胶胶粒中的铝原子主要以在次级配位上与四个硅原子相连接的［ＡｌＯ＿４］四面体的形式存在；当溶胶的ｐＨ下降到４．０左右时，溶胶的胶粒结构被破坏，Ａｌ￣（３＋）离子被溶出，而胶粒中的Ｎａ￣＋离子则在ｐＨ小于６．０时就开始溶出。
The effect of pH values on the structure of Al-modified silica sol particles was investigated bymeans of FT-IR,XRD,27_Al-NMR,29_Si-NMR and chemical titration.The results show that the Al atoms inthe Al-modified silica sol particles exist mainly in the form of AlO_4 tetrahedra linked with 4 Si atoms in thesecond coordination sphere when pH value is higher than 4.0.As pH value decreases to around 4.0,the struc-ture of the sol particles begin to be broken and then Al￣(3+)and Na￣+ ions dlasolve in the solution.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
1995年第3期301-307,共7页
Journal of The Chinese Ceramic Society
关键词
铝改性硅溶胶
胶粒结构
PH值
红外光谱
aluminium-modified silica sol,structure change,Fourier-infra-red,NMR
