Controllable synthesis of mesoporous carbon nanospheres with uniform size by a facile one-pot aqueous strategy under highly acidic conditions

Abstract

Because of the uncontrollable cross-linking rate of carbon precursors and the serious macroscopic phase separation during the organic–organic self-assembly process, the synthesis of mesoporous carbon nanospheres (MCNs) with uniform diameter<200 nm remains a challenge. In this study, we developed a direct acid-assisted, aqueous self-assembly method to synthesize such uniform MCNs with particle and pore sizes of ∼100 and ∼3.5 nm, respectively, by fine-tuning the volume ratio of ethanol/water under a high concentration of triblock copolymer F127 (7.9 × 10−4 mol L−1). The formation of uniform spheres was affected by the polymerization rate of carbon precursors and macroscopic phase separation, which are closely related to the amount of ethanol and F127. The highly acidic conditions could partially protonate carbon precursors and template, quickly inducing the self-assembly process with resorcinol/formaldehyde as carbon precursors and F127 as a morphology-controlling and interface-stabilizing agent. Because of their high surface area, large pore size, and nanoscaled and uniform spherical characteristics, the obtained MCNs loaded with the poorly water-soluble model drug itraconazole (ITZ) apparently increased the dissolution and release rates of ITZ.