Synthesis of Bimodal Nanostructured Silicas with Independently Controlled Small and Large Mesopore Sizes
Synthesis of Bimodal Nanostructured Silicas with Independently Controlled Small and Large Mesopore Sizes
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DOI：
10.1021/la0351156
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发表时间：
2003-08
期刊：
影响因子：
3.9
通讯作者：
Jihong Sun;Zhiping Shan;T. Maschmeyer;M. Coppens
中科院分区：
文献类型：
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作者：
Jihong Sun;Zhiping Shan;T. Maschmeyer;M. Coppens
我们报告了通过完全化学的模板-支架路线合成双峰结构二氧化硅，该路线能够独立控制小和大的中孔尺寸。在第一步中合成的介孔MCM-41纳米颗粒在第二步中交联，得到双峰多孔材料。在第二合成步骤期间添加的三嵌段共聚物表面活性剂形成组装体，纳米颗粒在组装体周围聚集并交联，显著影响次级孔径分布的平均值和宽度，而不影响初级孔径。通过改变第二步的条件，可以容易地合成具有受控的双峰纳米孔径分布的多种二氧化硅。通过X射线衍射、高分辨透射电子显微镜、扫描电子显微镜、29 Si固体核磁共振谱、N2吸附和脱附以及热重分析表征了其织构和结构性能。
We report on the synthesis of bimodal, structured silicas by a fully chemical, templating−scaffolding route that enables independent control over small and large mesopore sizes. Mesoporous MCM-41 nanoparticles, synthesized in a first step, are cross-linked in a second step, leading to a bimodal porous material. Triblock copolymer surfactants added during the second synthesis step form assemblies, around which the nanoparticles aggregate and cross-link, considerably influencing both the average and the width of the secondary pore size distribution, without affecting the primary pore size. By changing the conditions of the second step, one can easily synthesize a broad variety of silicas with a controlled bimodal nanopore size distribution. Textural and structural properties were characterized by X-ray diffraction, high-resolution transmission electron microscopy, scanning electron microscopy, 29Si solid-state NMR spectroscopy, N2 adsorption and desorption, and thermogravimetric analysis.