Magnetically induced orientation of mesochannels in 2D-hexagonal mesoporous silica films
Magnetically induced orientation of mesochannels in 2D-hexagonal mesoporous silica films
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DOI：
10.1039/b608780a
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发表时间：
2006-09
影响因子：
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通讯作者：
Y. Yamauchi;M. Sawada;A. Sugiyama;T. Osaka;Y. Sakka;K. Kuroda
中科院分区：
文献类型：
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作者：
Y. Yamauchi;M. Sawada;A. Sugiyama;T. Osaka;Y. Sakka;K. Kuroda
在平行于衬底的稳定均匀磁场下，采用浸渍法制备了具有单轴定向介孔通道的介孔二氧化硅薄膜。采用两种模板系统地研究了强磁场（12特斯拉）对制备介孔二氧化硅薄膜的影响。以离子CTAB（十六烷基三甲基溴化铵）为前驱体溶液制备二维六方介孔二氧化硅薄膜时，膜的面内XRD结果表明，介孔通道呈平行于磁场方向的微取向。采用非离子型P123（聚氧聚乙烯-聚氧聚丙烯-聚氧聚乙烯三嵌段共聚物）前驱体溶液制备介孔硅膜时，介孔通道的定向分布变窄（FWHM约为20°）。使用大分子，如三嵌段共聚物，可以成功地实现磁诱导取向。通过θ-2θ x射线衍射（XRD）、面内x射线衍射（XRD）、透射电镜（TEM）和高分辨率扫描电镜（HR-SEM）表征了磁排列介孔的空间取向。
Mesoporous silica films with uniaxially oriented mesochannels were prepared by dip coating under a steady-homogeneous magnetic field parallel to a substrate. The effect of a strong magnetic field (12 Tesla) on the preparation of mesoporous silica films was systematically investigated by using two kinds of templates. When mesoporous silica films with a 2D-hexagonal structure were prepared by using an ionic CTAB (hexadecyltrimethylammonium bromide)-based precursor solution, the in-plane XRD results of the films proved that the mesochannels were slightly oriented parallel to the magnetic field. When mesoporous silica films were prepared by using a non-ionic P123 (polyethylene oxide–polypropylene oxide–polyethylene oxide triblock copolymer)-based precursor solution, the directional distribution of the mesochannels became narrow (FWHM was about 20°). The use of large molecules such as triblock copolymers leads to successful magnetically induced orientation. The spatial orientations of the magnetically aligned mesochannels are elucidated by θ–2θ XRD, in-plane XRD, cross-sectional transmission electron microscopy (TEM), and high resolution scanning electron microscopy (HR-SEM).