多孔氧化锆块体材料的水热处理

Hydrothermal Treatment of Macroporous ZrO_2 Monoliths

以无机锆盐氧氯化锆(ZrOCl2·8H2O)为前驱体,聚氧乙烯(PEO,Mv=106)为相分离诱导剂,环氧丙烷(PO)为凝胶促进剂,采用溶胶-凝胶伴随相分离制备孔径尺寸可控、骨架连续的多孔氧化锆块体材料,并对所制备的多孔块体材料进行水热处理,考察了水热溶剂体系、氨水浓度、水热温度和时间对多孔氧化锆块体结晶特性和孔结构特征的影响。结果表明,在氨水/乙醇溶液中进行水热处理时,形成了四方相的氧化锆晶粒,同时块体骨架变得光滑均匀,内部构造出了发达的介孔结构,其比表面积从172m2/g增加至584m2/g,平均孔径从27.7nm增加至58.3nm;增大氨水的浓度、延长水热处理时间、增加水热温度都能提高块体骨架的修饰效果和结晶性。

With ZrOCl2·8H2O as precursor,propylene oxide(PO)as gelation acceleration agent and poly(ethylene oxide)(PEO)as phase separation inducer,ZrO2 monoliths with controllable continuous macropores were prepared via the sol-gel process accompanied by phase separation.The prepared ZrO2 gels were hydrothermally treated,and the effects of the solvent system,ammonia concentration,hydrothermal duration and temperature on the crystallization and pore structures of the monoliths were investigated.The results showed that after hydrothermal treatment with the ethanol solution of ammonia,tetragonal ZrO2 monoliths with smooth skeletons and well-defined mesopores were obtained,the BET surface area was enhanced from 172 to 584m2/g and the average pore size increased from 27.7to 58.3nm.The modification and crystallization of skeletons of monoliths by hydrothermal treatment could be improved through increasing ammonia concentration,extending treatment duration or raising temperature.