Asymmetric supported dense lanthanum tungstate membranes

Abstract

In this work, a colloidal processing route for dense asymmetric La28-xW4+xO54+3x/2 membranes for hydrogen gas separation applications was established. Dip coating process conditions were optimized to obtain ≈20 m thick dense layer supported on a porous substrate of the same composition. Surfactants based on electrostearic stabilization were evaluated to obtain stable suspensions in ethanol. The effect of the quantity and type (rice starch and carbon black) of sacrificial pore formers was evaluated for the porous substrates. Based on our results, samples made with 35- 45 vol.% carbon black are the best choice to obtain highly porous supports with the optimum characteristics for the fabrication of asymmetric membranes.