| Abstract
| - We report on the synthesis of bimodal, structured silicas by a fully chemical, templating−scaffoldingroute that enables independent control over small and large mesopore sizes. Mesoporous MCM-41nanoparticles, synthesized in a first step, are cross-linked in a second step, leading to a bimodal porousmaterial. Triblock copolymer surfactants added during the second synthesis step form assemblies, aroundwhich the nanoparticles aggregate and cross-link, considerably influencing both the average and the widthof the secondary pore size distribution, without affecting the primary pore size. By changing the conditionsof the second step, one can easily synthesize a broad variety of silicas with a controlled bimodal nanoporesize distribution. Textural and structural properties were characterized by X-ray diffraction, high-resolutiontransmission electron microscopy, scanning electron microscopy, 29Si solid-state NMR spectroscopy, N2adsorption and desorption, and thermogravimetric analysis.
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