Unit-cell wide SBA-15 type mesoporous silica nanoparticles

Abstract

With large and 2D hexagonally ordered mesopores, SBA-15 is the superstar among mesoporous silicas reported so far and has found many applications. To prepare SBA-15 nanoparticles is of particular interest for biomedical application yet remains challenging. In this work, rod-shaped SBA-15 nanoparticles (SBA-15NPs), with 2–3 mesopore channels in width (called unit-cell wide) and averaged length of 94.8 nm, are for the first time prepared in a boric acid catalyzed P123 templating system based on the partitioned cooperative self-assembly principle in a one-pot preparation. The BET surface area and total pore volume of typical SBA-15NPs reach 553 m2g-1 and 1.52 cm3g-1, respectively. The preparation of SBA-15NPs relies on PCSA process that bestows long and thin tubular SBA-15 pre-structures with many defects in low-temperature synthesis step, which are then cut into SBA-15NPs by a sulfuric acid enhanced Ostwald ripening process in hydrothermal treatment step. In enzyme adsorption tests, SBA-15NPs demonstrate higher capacity and faster adsorption compared with conventional rod-shaped SBA-15.