Morphology control of phase-separation-induced alumina-silica macroporous gels for rare-earth-doped scattering media
Morphology control of phase-separation-induced alumina-silica macroporous gels for rare-earth-doped scattering media
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DOI：
10.1021/jp0481658
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发表时间：
2004-09
影响因子：
3.3
通讯作者：
S. Murai;K. Fujita;K. Nakanishi;K. Hirao
中科院分区：
文献类型：
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作者：
S. Murai;K. Fujita;K. Nakanishi;K. Hirao
研究了在聚环氧乙烷存在下，氧化铝-二氧化硅(−-SiO_2)溶胶-凝胶体系的相分离行为。通过诱导平行于Sol−凝胶转变的相分离，可以从含Al~(3+)高达10mol%的起始组合物中获得具有相互连接的大孔的无定形凝胶。在本体系中加入SmCl3·6H2O制备了掺Sm3+的大孔凝胶。掺Sm~(3+)的烧结Al_2O_3-−-SiO_2大孔玻璃由于Sm~(3+)的4f-−-4f跃迁而产生光致发光，且荧光强度随Al~(3+)含量的增加而增强。在Al_2O_3-−-SiO_2大孔玻璃中，Sm~(3+)还原为Sm~(2+)是在还原气氛下进行的。
Phase-separation behavior in the sol−gel system of alumina−silica (Al2O3−SiO2) in the presence of poly (ethylene oxide) has been investigated. Amorphous gels with interconnected macropores can be obtained from the starting composition containing up to 10 mol % Al3+ by inducing phase separation parallel to the sol−gel transition. SmCl3·6H2O is added to the present system to yield Sm3+-doped macroporous gels. The sintered Al2O3−SiO2 macroporous glasses doped with Sm3+ exhibit the photoluminescence due to the 4f−4f transition of Sm3+, and the intensity of fluorescence increases with increasing Al3+ content. The reduction of Sm3+ to Sm2+ is accomplished in Al2O3−SiO2 macroporous glasses by heat treatment in a reducing atmosphere.