Preparation of organic-inorganic hybrid silica membranes using organoalkoxysilanes: The effect of pendant groups

► Pore sizes of hybrid silica membranes were obtained by normalized Knudsen-based permeance (NKP). ► The incorporation of pendant groups into the hybrid silica membranes decreased the H2 permeances. ► Methyltriethoxysilane (MTES)-derived silica membranes showed a CH4/C3H8 selectivity of 91. ► Pore-size tuning of hybrid silica membranes was simply realized by changing the types of pendant groups and varying firing conditions.