Putz Florian, Ludescher Lukas, Elsaesser Michael S, Paris Oskar, Hüsing Nicola
Materials Chemistry, Paris Lodron University Salzburg, Jakob-Haringer Str. 2a, Salzburg 5020, Austria.
Institute of Physics, Montanuniversitaet Leoben, Franz-Josef-Str. 18, Leoben 8700, Austria.
Chem Mater. 2020 May 12;32(9):3944-3951. doi: 10.1021/acs.chemmater.0c00302. Epub 2020 Apr 20.
Anisotropy is a key factor regarding mechanical or transport properties and thus the functionality of porous materials. However, the ability to deliberately design the pore structure of hierarchically organized porous networks toward anisotropic features is limited. Here, we report two straightforward routes toward hierarchically structured porous carbon monoliths with an anisotropic alignment of the microstructure on the level of macro- and mesopores. One approach is based on nanocasting (NC) of carbon precursors into hierarchical and anisotropic silica hard templates. The second route, a direct synthesis approach based on soft templating (ST), makes use of the flexibility of hierarchically structured resorcinol-formaldehyde gels, which are compressed and simultaneously carbonized in the deformed state. We present structural data of both types of carbon monoliths obtained by electron microscopy, nitrogen adsorption analysis, and SAXS measurements. In addition, we demonstrate how the degree of anisotropy can easily be controlled via the ST route.
各向异性是关乎多孔材料机械性能或传输性能以及功能的关键因素。然而，朝着各向异性特征有意设计分级组织多孔网络孔隙结构的能力是有限的。在此，我们报告了两种直接的方法，可制备具有宏观和介孔水平微观结构各向异性排列的分级结构多孔碳块体。一种方法是基于将碳前驱体纳米铸型（NC）到分级且各向异性的二氧化硅硬模板中。第二条路线是基于软模板法（ST）的直接合成方法，利用了分级结构间苯二酚 - 甲醛凝胶的柔韧性，该凝胶在变形状态下被压缩并同时碳化。我们展示了通过电子显微镜、氮气吸附分析和小角X射线散射（SAXS）测量获得的两种类型碳块体的结构数据。此外，我们还展示了如何通过ST路线轻松控制各向异性程度。
