Tian Bozhi, Liu Xiaoying, Solovyov Leonid A, Liu Zheng, Yang Haifeng, Zhang Zhendong, Xie Songhai, Zhang Fuqiang, Tu Bo, Yu Chengzhong, Terasaki Osamu, Zhao Dongyuan
Molecular Catalysis and Innovative Materials Lab, Department of Chemistry, Fudan University, Shanghai 200433, PR China.
J Am Chem Soc. 2004 Jan 28;126(3):865-75. doi: 10.1021/ja037877t.
In this paper, we bring forward an effective strategy, solvothermal postsynthesis, to prepare ordered mesoporous silica materials with highly branched channels. Structural characterizations indicate that the titled mesoporous materials basically have the cubic double gyroidal (space group Ia-3d) structure with small fraction of distortions. The mesopore sizes and surface areas can be up to 8.8 nm and 540 m2/g, respectively, when microwave digestion is employed to remove the organic templates. A phase transition model is proposed, and possible explanations for the successful phase transition are elucidated. The results show that the flexible inorganic framework, high content of organic matrix, and nonpenetration of poly(ethylene oxide) segments may facilitate the structural evolution. This new synthetic strategy can also be extended to the preparation of other double gyroidal silica-based mesoporous materials, such as metal and nonmetal ions doped silica and organo-functionalized silica materials. The prepared 3D mesoporous silica can be further utilized to fabricate various ordered crystalline gyroidal metal oxide "negatives". The mesorelief "negatives" (Co3O4 and In2O3 are detailed here) prepared by impregnation and thermolysis procedures exhibit undisplaced, displaced, and uncoupled enantiomeric gyroidal subframeworks. It has been found that the amount of metal oxide precursors (hydrated metal nitrates) greatly influence the (sub)framework structure and single crystallinity of the mesorelief metal oxide particles. The single crystalline gyroidal metal oxides are ordered both at mesoscale and atomic scale. However, these orders are not commensurate with each other.
在本文中，我们提出了一种有效的策略——溶剂热后合成法，用于制备具有高度分支通道的有序介孔二氧化硅材料。结构表征表明，所述介孔材料基本具有立方双螺旋结构（空间群Ia-3d），仅有少量畸变。当采用微波消解去除有机模板时，介孔尺寸和比表面积分别可达8.8 nm和540 m2/g。提出了一个相变模型，并阐明了成功相变的可能解释。结果表明，柔性无机骨架、高含量有机基质以及聚环氧乙烷链段的不穿透性可能促进了结构演化。这种新的合成策略还可扩展到制备其他基于双螺旋二氧化硅的介孔材料，如金属和非金属离子掺杂的二氧化硅以及有机功能化二氧化硅材料。所制备的三维介孔二氧化硅可进一步用于制造各种有序的结晶螺旋金属氧化物“负片”。通过浸渍和热解程序制备的介观浮雕“负片”（此处详细介绍了Co3O4和In2O3）呈现出未位移、位移和未耦合的对映体螺旋子框架。已发现金属氧化物前驱体（水合金属硝酸盐）的量对介观浮雕金属氧化物颗粒的（子）框架结构和单晶性有很大影响。单晶螺旋金属氧化物在介观尺度和原子尺度上都是有序的。然而，这些有序性彼此并不相称。
