Sulfonated laponite particles were used to prepare polysulfone and sulfonated polysulfone composite membranes for fuel cell application. The styrene sulfonic acid groups of laponite were obtained by polymerizing the monomer after laponite activation with a He cold plasma. Membranes with different contents in modified laponite were prepared. The water retention properties of these membranes were investigated by using water pervaporation and water vapour sorption measurements. The incorporation of hydrophilic laponite increased the tortuosity path in diffusion and the quantity of water sorbed in the membranes. A study of the dynamic aspect of these measurements was carried out and the diffusion coefficients were calculated at different characteristic times. Sulfonated polysulfone membrane gave a proton conductivity of 0.09 S cm(-1). After the addition of modified laponite the conductivity was significantly increased to 25% leading to membrane of correct conductivity for fuel cell use. (C) 2010 Elsevier B.V. All rights reserved.