Sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene/sulfonated poly(ether sulfone) and...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Proton exchange membranes (PEMs) are crucial for fuel cell performance.
• Developing PEMs with improved ion-exchange capacity, thermal stability, and conductivity is essential.

Purpose of the Study:

• To fabricate novel proton exchange membranes using sulfonated polystyrene ethylene butylene polystyrene (sPSEBPS), sulfonated poly ether sulfone (SPES), and hexagonal boron nitride (hBN).
• To evaluate the physicochemical and structural properties of these composite membranes for fuel cell applications.

Main Methods:

• Solution casting technique for membrane fabrication.
• Functionalization of PSEBPS using chlorosulfonic acid.
• Polymerization to yield SPES from specific monomers.
• Blending of sPSEBPS and SPES followed by incorporation of hBN.
• Characterization using X-Ray photoelectron spectroscopy, water absorption, ion-exchange capacity, and ionic conductivity measurements.

Main Results:

• Successful incorporation of hBN into the sPSEBPS/SPES polymer matrix was confirmed.
• Water absorption ranged from 19.5 to 29.8%.
• The membrane with 4.0 wt% hBN exhibited a maximum ion-exchange capacity of 1.21 meq g^-1, significantly higher than the control (0.48 meq g^-1).
• Composite membranes showed enhanced thermal stability compared to the control.
• The sPSEBPS/SPES/hBN-4 composite membrane achieved an ionic conductivity of 0.0329 S cm^-1 at 30 °C.

Conclusions:

• The fabricated sPSEBPS/SPES/hBN composite membranes possess desirable properties for fuel cell applications.
• The addition of hBN significantly enhances ion-exchange capacity and thermal stability.
• These materials represent a promising advancement in PEM technology for efficient energy conversion.