4.6 Article

Proton exchange membranes from sulfonated polyetheretherketone and sulfonated polyethersulfone-cardo blends: Conductivity, water sorption and permeation properties

Journal

ELECTROCHIMICA ACTA
Volume 111, Issue -, Pages 419-433

Publisher

PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.electacta.2013.07.158

Keywords

Fuel cell; Proton exchange membrane; Ionic conductivity; Water diffusion; Sorption

Funding

  1. network Materiaux Polymeres-Plasturgie (MPP)
  2. Regional Council of Basse-Normandie

Ask authors/readers for more resources

Five blend membranes were prepared by solvent evaporation from solutions of the synthesized sulfonated polyetheretherketone (SPEEK) and sulfonated polyethersulfone-cardo (SPESc). Their ion exchange capacity and degree of sulfonation determined by acid-base titration and by thermogravimetric analysis were consistent. The blends glass transition behavior obtained by differential scanning calorimetry suggests that the two sulfonated polymers are compatible in the whole composition range. The values of the activation energy for proton transport determined by conductivity measurements on the SPEEK-based blend membranes were in the range of 13-34 kJ mol(-1), which suggest a mixed transport mechanism that involves both proton jumps on ionic sites and water of hydration and diffusion of proton-water complex in hydrophilic domains. The water vapor sorption in the membranes exhibits sigmoid-shape isotherms which were well fitted by the new dual mode sorption model, and the fitted parameters values were successfully used to model the change in the water permeation flux with the upstream water activity using the first Fick's diffusion equation. The fast increase in the permeation flux beyond a critical value of activity (0.5) was owing to the exponential concentration-dependent diffusion coefficient. These modelings allowed us to show a strong increase in the limit diffusion coefficient of water and a decrease in the water-diffusion plasticization coefficient with the SPEEK content in the polymer blends. (C) 2013 Elsevier Ltd. All rights reserved.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.6
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available