Enhanced Swelling and Barrier Properties Stability of SPEEKbased Polymer Electrolytes Nanocomposite Membran

Abstract

The objective of this study is to prepare SPEEK/Cloisite15A®/TAP nanocomposite membranes and to characterize their physicochemical properties as polymeric electrolyte nanocomposites. SPEEK membranes with various degrees of sulfonation (DS) were first prepared. Subsequently, 1 wt. % of Cloisite15A® and 2,4, 6–triaminopyrimidine (TAP), respectively, were introduced into the SPEEK matrices via solution intercalation method. The Cloisite15A® and TAP additives were used as reinforcing material for the SPEEK/Cloisite15A®/TAP (SP/CL/TAP) nanocomposite membranes in terms of the barrier properties, swelling and morphological structure. The effect of DS on the SP/CL/ TAP nanocomposite membranes was studied in terms of their swelling behavior, proton conductivity and methanol permeability. Field emission scanning electron micrographs (FESEM) and X–Ray diffraction (XRD) patterns confirmed that the Cloisite15A® particles were completely distributed to allow the nanosize dispersion in the polymer matrix. The swelling behavior of SPEEK membrane at DS of 88% was improved in the presence of Cloisite15A® and TAP. All SPEEK nanocomposite membranes studied exhibited improved methanol barrier properties compared with the parent SPEEK membranes. Owing to significant conductivity, remarkable barrier properties, high swelling stability and outperformed DMFC performance, SP63/CL/TAP nanocomposite membranes can be considered as a polymer electrolyte membrane for DMFC applications.