Electrospun Hybrid Perfluorosulfonic Acid/Sulfonated Silica Composite Membranes

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Developing advanced membranes is crucial for efficient fuel cell performance.
• Perfluorosulfonic acid (PFSA) ionomers are key components in proton exchange membranes (PEMs).
• Incorporating reinforcing materials and functional networks can improve membrane properties.

Purpose of the Study:

• To fabricate and evaluate composite membranes using electrospinning for fuel cell applications.
• To investigate the impact of sulfonated silica network placement on membrane performance.
• To compare the properties of the developed composite membranes with existing materials.

Main Methods:

• Electrospinning was used to create composite membranes with PFSA, PVDF, and sulfonated silica.
• Sulfonated silica was incorporated either within the PFSA matrix or PVDF fibers.
• Proton conductivity, swelling, and mechanical strength were measured under various conditions.

Main Results:

• Type-A membranes (silica in PFSA fibers) showed significantly higher proton conductivity (25-35% increase) and reduced swelling (68% reduction) compared to pristine PFSA membranes.
• Type-B membranes (silica in PVDF fibers) exhibited lower proton conductivity.
• The optimized Type-A membrane demonstrated superior swelling and mechanical strength compared to neat perfluoroimide acid (PFIA) films with similar proton conductivity profiles.

Conclusions:

• Electrospun nanofiber composite membranes with sulfonated silica in PFSA fibers are a viable alternative to ultra-low EW fluorinated ionomer PEMs.
• The placement of the sulfonated silica network critically influences membrane properties.
• These composite membranes show potential for improving fuel cell technology.