Characterization and structural investigation of fractal porous-silica over an extremely wide scale range of pore size

We have succeeded in creating Menger sponge-like fractal body, i.e., porous-silica samples with Menger sponge-like fractal geometries, by a novel template method utilizing template particles of alkylketene dimer (AKD) and a sol-gel synthesis of tetramethyl orthosilicate (TMOS). We report here the first experimental results on characterization and structural investigations of the fractal porous-silica samples prepared with various conditions such as calcination temperature and packing condition of the template particles. In order to characterize the fractal porous-silica samples, pore volume distribution, porosity and specific surface area were measured over an extremely wide scale from 1 nm to 100 μm by means of mercury porosimetry, 1H NMR cryoporometry, nitrogen gas adsorption experiments together with direct evaluations of cross-sectional fractal dimension Dcs, and size limits of Dcs. We have found that the pore volume distribution and specific surface area of the fractal porous-silica samples can be discussed in terms of different fractal porous structures at different scale regions.

Graphical abstractHierarchical porous structures of fractal porous-silica samples over an extremely wide scale range studied by mercury porosimetry,11H NMR cryoporometry and nitrogen gas adsorption experiments.Figure optionsDownload full-size imageDownload as PowerPoint slide