Preparation of Helical Mesoporous Silica and Hybrid Silica Nanofibers Using Hydrogelator
Preparation of Helical Mesoporous Silica and Hybrid Silica Nanofibers Using Hydrogelator
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DOI：
10.1021/cm0519030
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发表时间：
2006-02
影响因子：
8.6
通讯作者：
Yonggang Yang;Masahiro Suzuki;Hiroaki Fukui;and Hirofusa Shirai;K. Hanabusa
中科院分区：
文献类型：
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作者：
Yonggang Yang;Masahiro Suzuki;Hiroaki Fukui;and Hirofusa Shirai;K. Hanabusa
采用溶胶-凝胶法，在剪切流场中，以手性阳离子凝胶因子为引发剂，成功制备了螺旋状介孔二氧化硅、亚甲基二氧化硅、乙烷二氧化硅、乙烯二氧化硅、辛烷二氧化硅和亚苯基二氧化硅纳米纤维。这些螺旋纳米纤维由成束的超细纳米纤维构成，所述超细纳米纤维由成束的纳米管形成。最小单元的纳米管具有内径均匀的内部螺旋通道。二氧化硅纳米纤维的形貌对制备条件敏感。在酸性条件下，扫描电子显微镜图像显示右手螺旋纳米纤维。在碱性条件下，形成棒状介孔纳米纤维。亚苯基-二氧化硅的圆二色性光谱表明，凝胶因子的手性转移到杂化二氧化硅的亚苯基链段的排列中。热稳定性如此之高，以至于亚苯基-二氧化硅的形态即使在空气中在650 °C下煅烧5小时后也能保持。
Helical mesoporous silica, methylene−silica, ethane−silica, ethene−silica, octane−silica, and phenylene−silica nanofibers were successfully prepared by sol−gel polymerization using a chiral cationic gelator under a shear flow. These helical nanofibers were constructed by bundles of ultrafine nanofibers that were formed by bundles of nanotubes. The nanotubes of the smallest unit had inner helical channels with uniform inside diameters. The morphologies of the silica nanofibers were sensitive to preparation conditions. In acidic conditions, scanning electron microscopy images showed right-handed helical nanofibers. In basic conditions, rodlike mesoporous nanofibers were formed. The circular dichroism spectrum of the phenylene−silica indicated that the chirality of the gelator was transferred to the arrangement of the phenylene segment of the hybrid silica. The thermostability was so high that the morphologies of the phenylene−silica were maintained even after being calcined at 650 °C for 5 h in air.