Particle size and pore adjustment of dendritic mesoporous silica using different long alkyl-chain imidazolium ionic liquids as templates

Abstract

The fine-tuning of the pore structure on the mesoscopic scale of dendritic mesoporous silica nanoparticles (DMSNs) is a challenge but very important. In this work, a series of imidazolium ionic liquids (ILs) with different alkyl chain lengths (named CxMImBr: x = 12, 14, 16, 18, 20, and 22, respectively) were synthesized as structure-directing agents based on the highly designable structural advantages of ILs, and the particle size and pore adjustment of DMSNs was investigated. Through the reasonable regulation of alkyl chain length, molar mass, and ratio, it can realize the fine control of monodisperse DMSNs pore size (2–21 nm) and particle size (200–500 nm). On this basis, the pore size and particle size can be further controlled independently by reasonable design of reaction condition. This study provides a controlled way to construct multi-scale and multi-level DMSNs materials.