Designing meso- and macropore architectures in hybrid organic-inorganic membranes by combining surfactant and breath figure templating (BFT)

Hybrid organic-inorganic'' membranes are synthesized by growing a functionalized mesoporous sol-gel''-derived SiO2 network into a hydrophobic fluorinated polymer. Processing guidelines are proposed to optimize the porosity at the macro-, meso- and micro-scales by templating the surface of the membrane through a modi. cation of the thermal processing at 30-80 degrees C in air. Such a hierarchical design exploits the benefits of the facile water retention of the breath figure to produce membranes with high proton conductivity (50 mS cm(-1) at 70 degrees C) under 100% relative humidity and develops the surface area and the interfacial area between the hydrophobic and hydrophilic domains.