Organic–Inorganic Hybrid Membranes Based on Sulfonated Poly(ether ether ketone) and Tetrabutylphosphonium Bromide Ionic Liquid for PEM Fuel Cell Applications

Abstract

Ionic liquids (ILs), with their inherent ionic conductivity and negligible vapor pressure, can be exploited in proton exchange membrane (PEM) fuel cells for which thermal management is a major problem and the cell operation temperature is limited by the boiling point of water. In this work, sulfonated poly(ether ether ketone) (SPEEK) membranes were modified by the incorporation of tetrabutylphosphonium bromide ([P 4 4 4 4 ]Br) by solvent-casting. Electrochemical impedance spectroscopy (EIS) was used to study the electrical properties of the modified membranes. Simultaneous TGA and FTIR studies were used to evaluate the thermal

Preparation and Comparative Stability of a Kaolinite-Tetrabutylphosphonium Bromide Intercalation Compound for Heat and Solvent Treatments

“…Since the reaction temperature was higher than the TBPBr melting point (ca. 104 °C), 29 Kaol-DMSO was dispersed in the TBPBr melt. After the reaction, the TBPBr melt was removed using a Pasteur pipette, and excess 1,4-dioxane was added to the solid.…”

“…The X-ray diffraction (XRD) patterns were recorded on a Rigaku RINT-2500 diffractometer operated at 20 mA and 40 kV with monochromatic Cu Kα radiation. The solid-state 13 C and 29 Si nuclear magnetic resonance (NMR) spectra were recorded on a JEOL ECX-400 spectrometer at 100.52 and 103.15 MHz, respectively. The solid-state 13 C NMR spectra were obtained using cross polarization (CP) and magic angle spinning (MAS) techniques with a contact time of 1.5 ms and a spinning rate of 8 kHz.…”

“…The solid-state 13 C NMR spectra were obtained using cross polarization (CP) and magic angle spinning (MAS) techniques with a contact time of 1.5 ms and a spinning rate of 8 kHz. The solidstate 29 Si NMR spectra were obtained using CP and MAS techniques with a contact time of 5 ms and a spinning rate of 10 kHz. The Fourier transform infrared spectra (KBr disk method) were recorded on a JASCO FT/IR-460 Plus spectrometer with a resolution of 2.0 cm −1 .…”

“…Thus, we consider quaternary phosphonium salts with phosphorus atom at the center of their structures as guest species for kaolinite. Among these, tetrabutylphosphonium bromide (TBPBr), whose melting point is 104 °C, 29 is a suitable candidate. We focus here on a new preparation of a kaolinite-TBPBr intercalation compound (Kaol-TBPBr) via the reaction between the TBPBr melt and an intermediate, Kaol-DMSO.…”

Porphyrin/sPEEK Membranes with Improved Conductivity and Durability for PEFC Technology

“…In order to improve the mechanical properties of the polymeric matrix, in particular at high temperature operative conditions, advanced composite membranes have been obtained by introducing inorganic or organic fillers into the pure polymer, thus achieving stabilization through the occurrence of strong covalent or weak supramolecular interactions . In particular, sPEEK hybrid membranes , have shown improved physicochemical properties such as oxidative stability, proton conductivity, water absorption, and so on. ,− The functionalization of sPEEK polymer with organic moieties such as benzimidazole, imidazole, or triazole , or also phthalocyanine dyes, , as well as polymeric blend with polyethylenimine or polyaniline, have also been reported to improve membrane microstructure, thermal properties, water uptake, and conductivity with respect to the pristine polymer. Recently, in order to improve proton conductivity under drastic humidity conditions (relative humidity, RH < 25%), we reported an investigation on composite membranes based on sPEEK and 5,10,15,20-tetra­(4-pyridyl)­porphyrin (TPyP), which retain the structural and morphological properties of the pure polymer .…”