Controlled synthesis of mesoporous carbons with tailored morphologies via a “silica-assisted” strategy

The controlled synthesis of mesoporous carbons (MCs) was achieved via a “silica-assisted” strategy under acid catalytic condition. The silica not only participates in co-assembly with resorcinol–formaldehyde (RF) to produce MCs, but also contributes to the increased porosity and controlled morphology of the resultant products. Interestingly, the morphology of the as-synthesized MCs can be controlled from bulk, spheres to apple-like morphology and the pore shape from ink-bottle-like to slitlike pores by varying the usage amount of SiO₂. A possible “silica-assisted” mechanism of the formation of MCs is proposed. The protonated RF resin could get facilitative access to the gap of SiO₂ nanospheres, due to the H-bonding interaction, capillary force, and Coulombic interactions analogized to the “S⁺X⁻I⁺” mechanism under acid condition. After carbonization and silica removal, the MCs with different morphologies are obtained. Nifedipine (NIP), as a model drug, was converted from a crystalline form to an amorphous state after being loaded into the MCs. The dissolution release rate of NIP was obviously improved, and the drug release results were fitted by the exponential function.