摘要
本文借助X射线衍射物相分析和热分析对Mg或Li稳定的Naβ"-Al2O3粉体和陶瓷在不同温度条件下与水发生的作用进行了系统地研究.实验表明,在密闭的常温条件下水主要以分子形式进入Naβ"-Al2O3的传导层内,形成水合物Naβ"-Al2O3·H2O;随着温度的升高,在β"-Al2O3中将发生H3O+与Na+之间的离子交换,生成(Na+,H3O+)β"-Al2O3·H2O;当温度进一步提高至250℃时,β"-Al2O3结构明显地分解,产生一系列氢氧化物,通常离子交换和分解速度较慢,在短时间内仅局限于陶瓷的表面.研究认为,水合化的β"-Al2O3对泥浆中的游离Na+离子具有束缚作用.
The performances of Naβ〃-Al2O3(Mg) and Naβ〃-Al2O3(Li) ceramilcs and powders in water were investigated systematically by X-ray diffraction and thermal analysis. The experiments show that H2O molecules could eliter the conduction planes at room temperature to form the hydrated compound Naβ〃Al2O3.H2O. When the temperature is raised, the ion exchange between Na+ in β〃-Al2O3 takes place, leading to the formation of mired-ion Na+-H3O+β〃-Al2O3.H,O. While at temperatures over 250℃,Na+β〃Al2O3.H2O is decomposed markedly and converts to several hydrokides. The rate of ion exchange and decomposition are usually low and therefore are restricted over ceramic surfaCe. The experimental results suggest that hydrated Naβ〃-Al2O3.H2O grains are able to bind free sodium ions in the slumes resulted.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
1996年第2期297-302,共6页
Journal of Inorganic Materials
基金
863国家高科技项目资助