MgAl_2O_4陶瓷复合膜的制备与表征

Preparation and characterization of MgAl_2O_4 ceramic composite membrane

用溶胶 -凝胶法制备MgAl2 O4陶瓷复合膜 ,该膜材在其熔点温度 (2 1 3 5℃ )前无任何相变 ,具有很高的热稳定性 .在制膜过程中 ,先合成铝镁双醇盐 ,然后走颗粒溶胶 -凝胶路线 ,以α -Al2 O3陶瓷膜为载体 ,制备尖晶石复合陶瓷膜 ,膜的最终烧结温度为 1 1 73 .1 5K .通过实验 ,优化了过程参数 ,如 pH值 ,温度 ,溶胶的组成 .膜平均孔径为 1 2nm ,BSA(牛血清白蛋白 )的截留率达 96%以上 ,纯水的渗透率为 5～ 1 3 g/ (cm2 ·min·MPa) .

A crack-free MgAl_2O_4 ceramic composite membrane has been prepared using sol-gel process,which has higher thermal stability due to its no phase transition up to the melting point of 2*!135*!℃.To prepare the membrane,a mixed Mg-Al alkoxide (MgAl_2( i PrO)_8·2 i PrOH was first synthesized ,then hydrolyzed and peptized in aqueous solution. The gel layer was coated from the colloid on a porous substrate ( α -Al_2O_3) and then thermally treated at 900*!℃.The parameters such as pH,temperature,sol composition during the sol preparation have been optimized in the view of controlling particle size.The pore size of the resulted top layer is between 12 nm,and its retention to BSA is above 96%.