Poly(arylene ether ketone) with an Ultrahigh-Selectivity Hydrophilic Phase Proton Transport Channel by Grafting Sulfonated Benzotriazole Groups onto Pendant Chains

Abstract

The practice of site control for functional groups to achieve better interactions has become popular in recent years. Capitalizing on such developments, sulfonated 5-carboxybenzotriazole (SCBTA), serving as a new monomer that combines multiple functional groups, is grafted onto pendant chains of poly­(arylene ether ketone) (PAEK) via an amidation reaction to fabricate a series of novel proton-exchange membranes (N m A n -SCBTA). The structure of the resulting membranes is confirmed by 1H NMR and Fourier transform infrared (FT-IR). Transmission electron microscopy (TEM) and small-angle X-ray spectroscopy (SAXS) analyses reveal well-defined microphase-separated structures. Among these samples, a membrane having an amino bisphenol monomer content of 70% (N7A3-SCBTA) exhibits high conductivity (0.089 S·cm–1, at 90 °C), oxidative stability (95.7%), and tensile strength (65.74 MPa), while its selectivity is as high as 91.9 × 104 S·s·cm–3 at 25 °C; this value is even more than 27 times that of recast Nafion (3.3 × 104 S·s·cm–3). These results indicate that there is great potential for these membranes to be used in direct methanol fuel cells (DMFCs).

Monolithic Macromolecule Membrane Based on Polybenzimidazole: Achieving High Proton Conductivity and Low Fuel Permeability through Multiple Cross-Linking

“…Figure a shows the curve of methanol permeability with temperature. The permeability was positively correlated with temperature due to the thermal motion of molecules . At 70 °C, the methanol permeability coefficients of mPBI-CMPEI(20)-TTPSA­(20, 30) were 6.92 × 10 –8 and 7.93 × 10 –8 cm 2 /s, respectively.…”

“…The permeability was positively correlated with temperature due to the thermal motion of molecules. 49 At 70 °C, the methanol permeability coefficients of mPBI-CMPEI(20)-TTPSA(20, 30) were 6.92 × 10 −8 and 7.93 × 10 −8 cm 2 /s, respectively. At a high hydration level, methanol permeability increased with an increase in the TTPSA content, which was consistent with the change of water uptake, indicating that the hydrophilic TTPSA forms continuous water channels in the membrane to promote the diffusion of methanol.…”

Sulfur-Doped Hierarchically Porous Open Cellular Polymer/Acid Complex Electrolyte Membranes for Efficient Water-Free Proton Transport

“…Fuel cells are an electrochemical devices that can instantly convert the chemical energy stored in fuel into electrical energy. Polymer exchange membrane fuel cells (PEMFCs) are promising power converters among fuel cells owing to their high power density, high fuel efficiency, and low-polluting byproducts. − A drawback of known polymer exchange membranes (PEMs) based on perfluorosulfonic acid is their strong dependence on the use of water owing to their operation under water-assisted proton transportation. This dependence some concerns regarding water and thermal management, slow electrode catalytic kinetics, low carbon monoxide tolerance, and water condensation, thereby limiting the operation of the PEM to temperatures up to the boiling point of water. − Thus, systems that do not require water and/or use other media with higher boiling point are required.…”

Sulfonated poly (arylene ether sulfone)-graft-sulfonated poly (vinyl alcohol) proton exchange membranes: Improved proton selectivity

“…Its proton selectivity is even more than 27 times than that of recast Nafion. 28 Li et al 29 prepares graft copolymer proton exchange membranes based on poly (arylene ether sulfone) and polystyrene using atom transfer radical polymerization. The membranes exhibit considerable high proton conductivity (0.151 S cm À1 , 85 C), owing to the graft polymer architecture and phase-separated morphology.…”