Ormosil/Sulfonated Polyetheretherketone-Based Hybrid Composite Proton Conducting Membranes

Abstract

A modi?ed silane bearing a sulfonic acid function (?sulfonated diphenylsilanediole, SDPSD?)was prepared and characterized. The resulting ormosil was mixed with sulfonated polyetheretherketone ?SPEEK? with high degree of sulfonation (?0.9)? leading to homogeneous composite membranes. The formation of the composite substantially modi?ed the properties of SPEEK in terms of water uptake and solubility. The structural and electrochemical performance of the components and of the composite were investigated with thermogravimetric analysis, ?eld emission scanning electron microscopy,1H and 29Si nuclear magnetic resonance, both in solution and in the solid state, and electrochemical impedance spectroscopy. Both conductivity values, as high as 0.1 S cm?1, and 1H diffusion coef?cients of the composite SPEEK/SDPSD demonstrated that it possesses good proton transport characteristics up to 120�C, and it is then suitable for application as an electrolyte in polymer electrolyte fuel cells operating at intermediate temperature.