The development of new membranes cheaper than Nafion®, with similar conductivity and lower hydrogen/methanol cross-over, is crucial for widespread commercial applications of Polymer Electrolyte Membrane Water Electrolysers (PEMWEs) and Direct Methanol Fuel Cells (DMFCs) [1, 2]. This study reports on the synthesis and development of PEMs based on sulfonated polysulfone (sPSf) for application both in WEs and DMFCs at different operating temperatures. The sPSf was synthesized by using trimethyl silyl chlorosulfonate as sulfonating agent in a homogeneous phase of chloroform [3]. In order to try to reduce methanol crossover in DMFCs, functionalized silica was prepared (by reacting silica with neat chlorosulfonic acid at room temperature) and added as a filler in the sPSf membrane. The prepared membranes were physico-chemically characterized and used as electrolytes in PEMWEs and DMFCs [4, 5]. Besides, the transport properties of water and methanol through the electrolyte membranes as a function of methanol concentration (e.g. 1M - 5M CH3OH) and temperature (from room temperature up to 80°C) were analyzed by using Pulse Field Gradient (PFG) NMR technique. References [1] A. S. Aricò, S. Siracusano, N. Briguglio, V. Baglio, A. Di Blasi, V. Antonucci, J. Appl. Electrochem. 43 (2013) 107-118. [2] F. Lufrano, V. Baglio, P. Staiti, V. Antonucci, A.S. Aricò, J. Power Sources 243 (2013) 519-534. [3] F. Lufrano, V. Baglio, P. Staiti, A. Stassi, A.S. Aricò, V. Antonucci, J. Power Sources 195 (2010) 7727-7733. [4] S. Siracusano, V.Baglio, F.Lufrano, P.Staiti, A.S.Aricò, Journal of Membrane Science 448 (2013) 209-214. [5] F. Lufrano, V. Baglio, O. Di Blasi, P. Staiti, V. Antonucci, A. S. Aricò, Phys. Chem. Chem. Phys. 14 (2012) 2718-2726.