Combined Surface and Volume Templating of Highly Porous Nanocast Carbon Monoliths
Combined Surface and Volume Templating of Highly Porous Nanocast Carbon Monoliths
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DOI：
10.1002/adfm.200305183
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发表时间：
2005-05
影响因子：
19
通讯作者：
A. Lu;J. Smått;M. Lindén
中科院分区：
文献类型：
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作者：
A. Lu;J. Smått;M. Lindén
以含双峰孔隙率的硅胶为骨架，采用一步浸渍法制备了具有三或四峰孔隙率的纳米碳块。结合体积和表面模板，以及用作支架的起始二氧化硅整体的受控合成，可以同时在几个长度尺度上灵活地控制孔径大小。用氮气吸附、扫描电子显微镜、透射电子显微镜和压汞测孔仪对其进行了表征。结果表明，碳整体在微米尺度上代表了起始二氧化硅整体的正复制品，而体积模板化的中孔是二氧化硅支架的负复制品。除了中孔和大孔外，炭块还表现出微孔率。不同的孔隙率模式以分层的结构中结构的方式排列，这被认为是要求高表面积和材料上的低压降相结合的应用的最佳选择。
Nanocast carbon monoliths exhibiting a three‐ or four‐modal porosity have been prepared by one‐step impregnation, using silica monoliths containing a bimodal porosity as the scaffold. Combined volume and surface templating, together with the controlled synthesis of the starting silica monoliths used as the scaffold, enables a flexible means of pore‐size control on several length scales simultaneously. The monoliths were characterized by nitrogen sorption, scanning electron microscopy, transmission electron microscopy, and mercury porosimetry. It is shown that the carbon monoliths represent a positive replica of the starting silica monoliths on the micrometer length scale, whereas the volume‐templated mesopores are a negative replica of the silica scaffold. In addition to the meso‐ and macropores, the carbon monoliths also exhibit microporosity. The different modes of porosity are arranged in a hierarchical structure‐within‐structure fashion, which is thought to be optimal for applications requiring a high surface area in combination with a low pressure drop over the material.