Immobilizing imidazolium ionic liquid in flexible proton exchange membranes to modify microstructure fracture

Construction of Successive Proton Conduction Channels to Accelerate the Proton Conduction Process in Flexible Proton Exchange Membranes

“…39 Notably, the sharp increase at the beginning stage was primarily derived from the strong stiffness of Kevlar nanofibers that withstand the external force. As discussed in flexible membranes, 25,40,41 the structure rearrangement of polymer molecular chains in SEBS guaranteed the toughness of SEBS-based composite membranes. However, the degradation of polymer molecular chains due to the breakdown of van der Waals force caused the E decrease of PAdoped membranes, such as (5.05 ± 0.61) MPa for (K/PA/ S) 3 /PA, (4.09 ± 0.35) MPa for (K/PA/S) 3 -f/PA, (3.91 ± 0.40)−(6.15 ± 0.43) MPa for (K/PA/S) 3 -x/PA, and (3.47 ± 0.48)−(4.92 ± 0.40) MPa for (K/PA/S) 3 /PA-x.…”

“…The (K/PA/S) 3 membrane was constructed with the spin coating technique. 25 The multilayer microstructure can be easily constructed by optimizing the concentration of the solution and adjusting the duration with revolutions per minute (rpm) of spin coating. Typically, the primary procedures included spin coating of 2 mL Kevlar/DMSO solution at 200 rpm for 10 s, covering 2 mL of 100 wt % PA on the Kevlar nanofiber layer at 60 °C for 10 min, and spin coating of 10 mL SEBS/ heptane solution at 100 rpm for 10 s (Figure 1).…”

“…Additionally, a complex stage ranging from 170 to 350 °C in the (K/PA/S) 3 /PA membrane was primarily caused by the coverage of PA dehydration with the degradation of Kevlar nanofibers. 25 Figure 3B exhibits the weight variation of the membranes immersed in Fenton reagent at 68 °C for 120 h. The pristine membrane and folded and stretched membranes respectively presented the residual weight percentages of 40.1, 35.7, and 43.9%. According to the images (Figure S3), (K/PA/S) 3 , (K/ PA/S) 3 -f, and (K/PA/S) 3 -50 membranes kept structural integrity without visible cracks at 68 °C for 72 h. However, some crinkles were observed, with the test lasting 120 h. Li and co-workers prepared the N-PBI membrane with a residual weight percentage of 40.1% in Fenton reagent at 80 °C for 120 h. 31 Zhao and co-workers reported a facile strategy to reinforce the oxidative stability by introducing free radical scavengers.…”

“…The flexible high-temperature PEMs have ever been prepared by our group through alternate deposition of Kevlar nanofibers and SEBS polymer. , Kevlar nanofibers are used since they can combine PA molecules and conduct protons through successive proton conduction channels composed of ammonium groups in composite membranes. Additionally, the flexible polymer of SEBS guarantees enough flexibility and mechanical strength.…”

Temperature‐dependent mechanical performance of Nafion® 212 proton exchange membrane under uniaxial and biaxial loading

“…These multilayered membranes exhibited excellent performance as membrane electrolytes at elevated temperatures under anhydrous conditions. Song et al 9 provided a facile strategy in addressing the challenges associated with sacrificing charge transport mobility and tensile stress due to microstructure modification from the imidazolium ionic liquid. It is worth noting that the mechanical degradation of the proton exchange membrane (PEM) can significantly affect the structural integrity and service life of the fuel cell 10–15 .…”