Hybrid mesoporous silica membranes, in short HMSMs, are a kind of novel membrane materials with unique structure of pores-in-pores synthesized by sol-gel, evaporation-induced self-assembly, aspiration-induced infiltration, counter diffusion self-assembly, vapor-phase synthesis and microwave-assisted synthesis methods. Such hybrid mesoporous silica membranes are composed of mesoporous silica materials inside the confined channels of porous membranes including organic porous membranes and inorganic porous membranes employed as the hard templates. In addition, various surfactants are used as the structure directing agents (SDA). Due to the different structure of HMSMs with pores-in-pores from those conventional mesoporous silica membranes and their attractively potential applications in the membrane-based adsorption, filtration and catalysis etc., those hybrid mesoporous silica membranes have attracted great attention during the past decade. This review focuses on the recent developments of this kind of novel hybrid membranes including the synthesis methods and the applications in the membrane-based nanofiltration, templated-syntheses of nanomaterials, enzyme immobilization, artificial biomembrane, sensor, reactor and drug delivery etc. Additionally, some problems found in the syntheses and the applications of such hybrid mesoporous silica membranes are analyzed and concluded in this review. Moreover, the development prospect of this kind of hybrid mesoporous silica membranes is discussed.

Contents
1 Introduction
2 Syntheses of hybrid mesoporous silica membrane
2.1 Sol-gel method
2.2 Evaporation-induced self-assembly method
2.3 Aspiration-induced infiltration method
2.4 Counter diffusion self-assembly method
2.5 Vapor-phase synthesis method
2.6 Microwave-assisted synthesis method
3 Applications of hybrid mesoporous silica membranes
3.1 Membrane-based nanofiltration
3.2 Templated-syntheses of nanomaterials
3.3 Enzyme immobilization, artificial biomembrane, sensor and drug delivery
3.4 Catalysis and membrane reactor
4 Conclusion and outlook