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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且骨架连续的多孔氧化锆块体材料,利用扫描电镜、X射线衍射、差热分析等测试手段对所制得块体材料进行了表征。结果表明:PO借助不可逆的开环反应提高体系的pH值,从而促进溶胶体系的凝胶化;PEO则诱导体系发生相分离,并获得共连续多孔块体;ZrO2干凝胶在热处理前呈无定形态,400℃热处理后有四方相晶体出现,800℃热处理后四方相基本都转变为单斜相;热处理所产生的晶型转变基本不影响块体材料的微观形貌。
Polyoxyethylene (PEO, MV = 106) as phase separation inducer and propylene oxide (PO) as gel accelerator were prepared by sol-gel method using zirconium oxychloride zirconium oxide (ZrOCl2.8H2O) as precursor. The porous zirconia material with controlled pore size and continuous skeleton was prepared by phase separation. The prepared bulk material was characterized by scanning electron microscopy, X-ray diffraction and differential thermal analysis. The results showed that PO could increase the pH value of the system by means of irreversible ring-opening reaction to promote the gelation of the sol system; PEO induced the phase separation of the system and obtain the co-continuous porous block; ZrO2 xerogel was After annealing at 400 ℃, tetragonal crystals appeared. After 800 ℃ heat treatment, the tetragonal phase basically changed into monoclinic phase. The crystal transformation produced by heat treatment did not affect the microstructure of the bulk material.