Room-Temperature Ionic Liquids as Template to Monolithic Mesoporous Silica with Wormlike Pores via a Sol−Gel Nanocasting Technique

Abstract

This paper reports a novel room-temperature ionic liquid (RTIL), [C 4 mim] + BF 4 -, as template to monolithic mesoporous silica with wormhole framework via a convenient nanocasting technique. In contrast with the applied liquid crystal self-assembly of long-chain surfactants on the preparation of mesoporous nanostructures, a new so-called hydrogen bond- co -π−π stack mechanism was proposed to be responsible for the present self-assembly of the RTIL in the reaction system for the formation of the wormlike mesopore, in which both the hydrogen bonds formed between the [BF 4 ] - and silano group of silica gel and the π−π stack interaction of the neighboring imidazolium rings play crucial roles in the formation of the wormhole framework of mesporous silica. The proposed hydrogen bond- co -π−π stack mechanism with the RTIL as template may open a new pathway to prepare mesoporous materials.