Crystalline ZrO2 Monoliths with Well-Defined Macropores and Mesostructured Skeletons Prepared by Combining the Alkoxy-Derived Sol–Gel Process Accompanied by Phase Separation and the

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• 作者：Junko Konishi ; Koji Fujita ; Satoshi Oiwa ; Kazuki Nakanishi ; Kazuyuki Hirao
• 刊名：Chemistry of Materials
• 出版年：2008
• 出版时间：March 25, 2008
• 年：2008
• 卷：20
• 期：6
• 页码：2165 - 2173
• 全文大小：1331K
• 年卷期：v.20,no.6(March 25, 2008)
• ISSN：1520-5002

文摘

We have successfully prepared multiscale porous crystalline zirconia (ZrO₂) monoliths by combining the alkoxy-derived sol–gel process accompanied by phase-separation and the solvothermal process. The gelation can be controlled by the addition of N-methylformamide to the starting solution, while the phase separation is induced by the incorporation of poly(ethylene oxide). Amorphous ZrO₂ monolithic gels with well-defined bicontinuous macropores and microstructured skeletons are obtained when the transient structure of polymerization-induced phase separation is fixed by the gelation. The size of the macropores is controlled in the range of 300 nm to 2 µm by adjusting the amount of poly(ethylene oxide). The solvent exchange of the mother liquor in the as-gelled wet specimens with absolute ethanol, followed by the solvothermal treatment at temperatures above 210 °C, brings about the formation of mesopores and stabilizes tetragonal ZrO₂ nanocrystals without disturbing the macroporous morphology. The resultant macro-mesoporous crystalline ZrO₂ gels possess the surface area over 200 m² g⁻¹.