Facile Morphology Control during Rapid Fabrication of Nanosized Organosilica Particles

Nanosized organosilica particles with tunable morphology are of great interest for versatile applications because of their enhanced properties. However, it is still a great challenge to control the morphology during fabrication of organosilica nanoparticles (NPs). In this study, a facile approach based on flash nano-precipitation (FNP) technique is presented, which achieves an efficient fabrication of organosilica NPs with controllable morphology by utilizing an amphiphilic block copolymer poly(2-(dimethylamino) ethylmethylacrylate-b-poly(epsilon-caprolactone) (PDMAEMA-b-PCL) as the stabilizer. Such a preparation process is performed in a multi-inlet vortex mixer that enables an intense mixing of the silicon precursor with the aqueous solution of a catalyst at an ultrashort time scale, leading to the formation of numerous tiny reaction droplets stabilized by PDMAEMA-b-PCL, followed by the basic-catalyzed hydrolytic condensation. Interestingly, by controlling the composition and mixing parameter of feeding streams involved in the FNP process, golf ball-like, cubic, bowl-like, and hollow organosilica NPs can be easily obtained. The resultant NPs show a narrow size distribution and are expected to find potential applications in various fields, such as nanomedicine, nanocatalysts, and adsorption separation.