Preparation of hierarchically structured porous aluminas by a dual soft template method

A general and potentially easy method of synthesizing aluminas possessing hierarchical pore structure is presented in this paper. This method is based on the integration of the sol–gel process with micelles of poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) block copolymer and oil droplets of decahydronaftalen (DHN) as dual pore templates. With the addition of n-pentanol as co-surfactant, DHN droplets diameter could be controlled within the range of ca. 2–12 μm. Mercury intrusion porosimetry shows that the produced alumina ceramics possess hierarchical structure composed of two families of pores, namely, the macro- (from 0.1 to 6 μm) and mesopores (from 8 to 10 nm). The relative population of each family and the average size of macropores could be easily controlled by adjusting the DHN quantity.