Synthesis and characterization of new membranes based on sulfonated polysulfone/Zn,Al-heptamolibdate LDH

Abstract

New proton conducting organic/inorganic nano-hybrid polymer electrolyte membranes were synthesized by solving casting method. Inorganic nanopowders were a layered double hydroxides (LDH) with Zn,Al cations in which heptamolybdate were inserted. These nanopowders were prepared by anion exchange method from hydrotalcite (LDH) with interlayer anions (NO₃). The sulfonated polymers were prepared by an electrophilic aromatic substitution reaction between the polymer and trimethylsylil cholorosulfonate (TMSCS). The composites membranes were characterized by FTIR and TGA and water uptake was determined. Electrochemical impedance spectroscopy (EIS) was used to study the proton conductivity of the membranes. EIS measurements were performed facing the membrane to different HCl concentrations (103 ≤ c ≤101 M). It was concluded that these new composite membranes present good thermal properties and proton conductivity slightly higher than SPSU.