Hierarchical meso-mesoporous and macro-mesoporous silica templated by mixtures of polyoxyethylene ­fluoroalkyl ether and triblock copolymer

Abstract

We report here the synthesis of different kinds of hierarchical porous silica materials by using mixtures of an amphiphilic block copolymer (Pluronic P123) and a nonionic fluorinated surfactant. In particular, we have taken advantage of the difference in polarities between the two compounds to design dual-mesoporous materials through the cooperative templating mechanism (CTM). We have undertaken a complete study of this system by varying the composition of the mixed micelles and the synthesis conditions. We have shown that both the dual-mesoporosity and the mesopore ordering are favored when materials are prepared with fluorine-rich and P123-rich micelles. However, when the P123-rich micelles predominate, the mesostructure is less organized and the dual-porosity depends on the P123 content. In addition, concentrated emulsions were formed by incorporating perfluorodecalin (PFD) in the surfactant mixture, and hierarchical macro-mesoporous materials were prepared by combining the CTM and the emulsion templating mechanism.