Solvent‐free fabrication of proton‐conducting membranes based on commercial elastomers

Abstract

Five different types of elastomers were examined as the matrix materials in the preparation of non-fluorinated proton exchange membranes utilizing a solvent-free route via the in situ reaction of sodium 4-styrenesulfonate (NaSS). The morphology of the elastomer/NaSS vulcanizates was studied to evaluate the effect of polarity, viscosity and saturation degree of the elastomer matrixes. Much better dispersion of NaSS was found in chlorosulfonated polyethylene rubber (CSM) and hydrogenated nitrile butadiene rubber (HNBR) matrixes than in the other three types of elastomer matrixes. For CSM/NaSS and HNBR/NaSS proton exchange membranes, distinctive membrane properties were observed and correlated with their different structure and morphologies. The CSM/NaSS membranes exhibited the proton conductivity as high as~0.03 S cm À1 and the selectivity (the ratio of proton conductivity to methanol permeability) higher than that of Nafion.

Enhanced Proton Conductivity in Sulfonated Poly(ether ether ketone) Membranes by Incorporating Sodium Dodecyl Benzene Sulfonate

“…The IECs of the membranes were determined by an acid–base titration method according to the literature [ 21 , 22 ]. After immersing the dried membrane (~0.2 g) in 5.0 M NaCl solution (15 mL) for 24 h to release all H + , the amount of H + was titrated with 0.01 M NaOH standard solution using phenolphthalein as an indicator.…”

Anchoring Water Soluble Phosphotungstic Acid by Hybrid Fillers to Construct Three-Dimensional Proton Transport Networks

“…To determine the proton conductivity, membrane samples were placed in a custom built four-probe conductivity cell in liquid water (or in a humidity cabinet), and AC impedance measurement was performed on an electrochemical workstation (Zennium Pro., Zahner, Kronach, Germany). The proton conductivity (σ) of the membranes was determined according to the following Equation [ 38 ]: where L is the distance between the two electrodes, R is the membrane resistance, and S is the cross-sectional area of the membrane.…”

Sulfonated poly(ether ether ketone) composite membranes based on amino‐modified halloysite nanotubes that effectively immobilize phosphotungstic acid

“…Membrane ion exchange capacity (IEC) was determined by an acid–base titration method according to the literature. [ 29 ] Membrane water uptake was calculated by equation Water uptake = ( w w − w d )/ w d × 100%, where w d and w w are the masses of the dry and wet membranes, respectively. The membrane samples were cut into the rectangular shape to measure the area swelling.…”