Monodispersed large-mesopore mesoporous silica nanoparticles enabled by sulfuric acid assisted hydrothermal process

In this work, it is demonstrated that monodispersed large-pore mesoporous silica nanoparticles (ML-MSNs) can be prepared by a sulfuric acid assisted hydrothermal process (SAH). The strategy is based on a SAH process enabled transformation from conventionally prepared MSNs with small mesopores (~2.6 nm) into large-mesopore ML-MSNs (over 10 nm) and high surface area (exceeding 500 m2g-1) in a rather green and controllable manner. A synergistic effect of ethanol employed in the synthesis step and more importantly the hydrothermal treatment process step in ethanolic sulfuric acid solution at high temperature is newly acknowledged in such SAH process, as manifested by different techniques. Such process enables reliable control over porous structures by varying the SAH condition. Moreover, ML-MSNs with tuneable mesostructures are shown to allow rational control over loading and release performance of water-insoluble drug molecules of Indomethacin.