Nanoporous Functional Materials
Solids with ordered mesopore arrangement can be synthesized either via soft- or hard-templating methods. Typical materials that are obtained via soft-templating are MCM-41 or SBA-15 silicas. Amorphous silica walls are condensed around hexagonally ordered arrays of soft micelles consisting of amphiphilic molecules. Removal of the organics results in silica with ordered mesopores (2-50 nm). Carbon deposition in the pores of such silica and removal of the solid silica is hard-templating. As the results either carbon rods (complete pore filling) or carbon tubes (only deposition of carbon layer on silica wall) are obtained. The image shows a typical electron density distribution through a section of an array of hexagonally arranged carbon tubes (CMK-5). It has been calculated from a low-angle XRD pattern via inverse Fourier Transformation of reflection intensities.