ABSTRACT
Microporous ETS-4 particles were synthesized by the hydrothermal method and characterized by XRD and FESEM/EDX. Nafion/ETS-4 composite membranes were prepared by mixing 5 wt% Nafion solution with microporous titanosilicate ETS-4. The water uptake increased with an increase in the ETS-4 content. However, the IEC decreased with an increase in the ETS-4 content due to the addition of ETS-4 with no reactive sites (–SO3H). From the FE-SEM/EDX images, it was confirmed that Nafion/ETS-4 composite membranes had homogenous distribution over the surface. The methanol permeability of composite membranes decreased with an increase in ETS-4 content up to 15 wt% of ETS-4 and increased with further addition. The proton conductivity decreased with an increase in the ETS-4 content. From methanol permeability and proton conductivity results, it was confirmed that the selectivity parameter of the NE10 composite membrane containing 10 wt% ETS-4 was the highest value.
