Microfluidic synthesis of silica nanoparticles using polyethylenimine polymers

A microfluidic reactor system for the synthesis of silica nanoparticles has been developed from commercially available ETFE tubing (0.17-1.0 mm diameter) connected in series to support the hydrolysis, nucleation and particle growth based on a sol-gel method in the presence of PEI polymer at room temperature. Two microfluidic reactor configurations, laminar flow and segmented flow, have been evaluated. Both microfluidic reactors produce particles with narrower size distributions and higher particle yields compared to batch based process. In addition, microfluidic methods offer the possibility to tune particle sizes and size distributions by varying the operation variables such as flow rate, reactor tube diameter and residence time.