Controlled synthesis of monodispersed mesoporous silica nanoparticles: Particle size tuning and formation mechanism investigation

Abstract In this work, systematic studies were performed to investigate the effects of experimental parameters ( e . g . reaction temperature, stirring rate and concentration of triethanolamine (TEA)) on the particle sizes of mesoporous silica nanoparticles (MSNs). Results revealed that the stirring rate played a key role in the size-controlling of MSNs. Additionally, both the reaction temperature and the concentration of TEA showed relatively obvious influence on the sizes of MSNs. We supposed that the MSNs particles were formed by the aggregation and condensing of silica-surfactant micelles and the diameters of MSNs were dependent on the concentration of silica-surfactant micelles. In order to obtain MSNs with small sizes, low reaction temperature and rapid stirring rate were adopted to reduce the concentration of silica-surfactant micelles and suppress the growth of MSNs. As a surface capping ligand, TEA could suppress the particle growth and prevent the particle aggregation of MSNs. By simply controlling the synthetic parameters, MSNs with adjustable size from 20 to 110 nm were obtained. Moreover, the obtained MSNs displayed narrow size distribution and well dispersity in water, which made them highly promising in biomedical applications.