Preparation of Porous, Hierarchically Organized Glass Monoliths via Combination of Sintering and Phase Separation

摘要

Hierarchically structured, porous materials have been successfully prepared via a combination of sintering and phase separation of a sodium borosilicate glass. The materials were characterized using N2-adsorption, Hg-intrusion, and scanning electron microscopy. Some hardness measurements were performed to investigate the mechanical stability. Secondary pore sizes were adjusted by the use of different grain fractions of the filler, different primary pore sizes could be obtained by a variation of the annealing conditions. Thus, both pore systems can be adjusted independently. The resulting monoliths consist of a system of secondary pores between 20 and 150 um and primary pores within the walls of the open-pored sintered material between 1 and 70 nm. The hierarchical porous materials exhibit surface areas up to 420 m~2/g and total porosities up to 74%.