Inorganic–organic hybrid membranes with anhydrous proton conduction prepared from tetraethoxysilane, 3-glycidyloxypropyltrimethoxysilane, trimethyl phosphate and diethylethylammonium trifluoromethanesulfonate

New silicon source (3-glycidyloxypropyltrimethoxysilane (GPTMS)) was used to make non-glass inorganic–organic hybrid membranes with diethylethylammonium trifluoromethanesulfonate ([dema][TfO]) by the sol–gel method. The hybrid membranes were studied with respect to their structural, thermal, proton conductivity and pores properties. The Fourier transform infrared spectroscopy (FT-IR) results showed that there was intermolecular interaction between ionic liquid and Si–O–Si skeleton structure in the inorganic–organic hybrid membranes. The thermogravimetric (TG) and differential scanning calorimetry (DSC) analysis showed that the hybrid membranes displayed good chemical stability and were thermally stable up to more than 200 °C in air. The N2 adsorption test showed the hybrid membranes had good pore property and ionic liquid influenced the structure of hybrid membrane. Proton conductivity was measured from 20 °C to 220 °C and high conductivity of 1.2×10−2 S/cm was obtained for a 60 wt% [dema][TfO] doped hybrid membrane (ionogel) at 220 °C under anhydrous conditions. This method for the preparation of hybrid membranes is promising and may be used for the proton exchange membrane in fuel cells.