Synthesis of dendritic mesoporous silica nanoparticles by ultrasonic assisted microchannel continuous flow reaction†

Dendritic mesoporous silica nanoparticle (DMSN) possess advantages such as high specific surface area, excellent chemical stability, and good biocompatibility, which make it is a research hotspot in the field of nanomaterials. The microemulsion templating method (MET) is one of the common methods for synthesizing DMSN, but it typically requires a long reaction time. In this paper, we propose an ultrasonic-assisted microchannel continuous flow reaction to shorten the reaction time. The ultrasonic-assisted microchannel continuous flow reaction system consists of an injection system, dispersion chip, ultrasonic-assisted mixing chip, reaction coil, and condensation coil. By optimizing factors including total flow rate, material ratio, reaction temperature, reaction coil inner diameter, reaction coil length, and the concentration of NaOH and HCl in the microemulsion, the optimal synthesis conditions were determined. Under the best conditions, the reaction time for synthesizing DMSN was 33.6 min; compared to the 24 h required for synthesis in the three-neck flask, it had been shortened by 42 times. The findings of this study provide a new method for the preparation of DMSN.