Imidazolium ionic liquid incorporation on sulfonated poly(styrene‐isobutylene‐styrene) proton exchange membranes

Abstract

Ionic liquids (ILs) with different anions and cations were incorporated in sulfonated poly(styrene‐isobutylene‐styrene) (SIBS) to modify its chemical, morphological, and transport properties for direct methanol fuel cell (DMFC) applications. Different loadings of IL and different solvents were studied to have a better understanding of the incorporation process and the ability of the solvent to affect the interaction of the IL with the sulfonated polymer. Morphological characterization with SAXS and AFM suggested changes caused by the incorporation of the IL and by the solvent used. FT‐IR spectra showed small variations in energy related to interactions of the IL with the sulfonic groups which caused thermogravimetric stabilization of the ionic domains. Other results suggest that water has a very significant effect on the morphology, interaction with the IL, and transport properties of the membranes. Optimal concentration of IL (∼10 mol %) provides enough water to produce efficient proton conductivity (0.15 S/cm) and minimal methanol permeability (0.8 × 10−6 cm2/s). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44900.

Chemical and morphological effects of blended sulfonated poly(styrene‐isobutylene‐styrene) and isopentylamine for direct methanol fuel cell applications

“…Except for SIBS 57 blend membranes, the IPA incorporation greatly increased the amount of bound water to the ionic domain in each sulfonation level. This confirms the hydrophilic nature of the amine groups which, when incorporated in the membrane, causes a greater solvation of water molecules around the ionic domain 28 that could favor the proton transport through membrane.…”

A Bibliometric Analysis of Research on Supported Ionic Liquid Membranes during the 1995–2015 Period: Study of the Main Applications and Trending Topics

“…Imidazolium ILs with different anions, cations, in different concentrations and incorporated using different solvents have been analysed to determine the effects of all these variables in the chemical, thermal, morphological and transport properties of membranes made of sulfonated poly(styrene-isobutylene-styrene). The results demonstrated that there is an optimum amount of IL that simultaneously allows enough water for efficient proton conductivity and minimum methanol permeability in a DMFC [ 161 ].…”

High‐performance blended membranes based on poly(arylene ether sulfone) and sulfonated poly(styrene‐isobutylene‐styrene) for direct methanol fuel cell applications

“…Iron (II) sulfate heptahydrate (>99%) and hydrogen peroxide (35 wt% in H 2 O) were obtained from Sigma-Aldrich. Poly (styrene-isobutylene-styrene) sulfonated at 88% (SIBS 88) was obtained from previous work in our laboratory (Ortiz-Negr on et al, 2017) and employed after 48 h of drying at 60 C. 34…”

“…However, despite the sulfonic groups added to the blend by incorporating SIBS 88, the copolymers could not exchange protons (i.e., ethers and sulfones), which are not accounted for in this measurement. 34,35…”