The aim of this work is to incorporate inorganic compounds into the Nation matrix (composite membranes) for high temperature of a polymer electrolyte fuel cell (T(cell) > 100 degrees C). Three silicon oxides having a different morphology were synthesized starting with a tetraethyl orthosilicate as a precursor via sol-gel method: SBA15, SBA15-SH and SiO(2). Successively, composite Nation membranes were prepared using a 3% (w/w) of each powder through a standardized casting method. The influence of SiO(2) morphology on chemical-physical properties of the membranes was highlighted resulting in a reduction of the swelling parameters of the composite membranes if compared at T >= 80 degrees C to a recast bare Nation membrane, used as a reference. Good proton conductivity was also observed for all composite membranes with values of 0.144 S cm(-1), 0.136 S cm(-1), 0.090 S cm(-1) and 0.078 S cm(-1) recorded at 80 degrees C (100% RH) for Nrecast, NSBA15, NSBA15-SH and NSiO(2), respectively. The polarisation curves carried out at 120 degrees C (75% RH, 1.5 abs. bar) have revealed a higher stability for NSBA15 membrane after a short time-test, probably because the silica morphology is able to retain water within the polymer matrix and, in accordance to the swelling data. (C) 2011 Elsevier B.V. All rights reserved.