Composite Membranes Based on Functionalized Mesostructured Cellular Foam Particles and Sulfonated Poly(Ether Ether...

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Development of advanced composite membranes is crucial for energy applications.
• Sulfonated polymers and functionalized silica nanoparticles offer tunable properties.
• Optimizing membrane performance requires understanding structure-property relationships.

Purpose of the Study:

• To design and characterize composite polymeric membranes based on sPEES and MCF silica.
• To investigate the influence of polymer molecular weight, silica functionalization, and silica content on membrane properties.
• To evaluate proton conductivity and compare performance against commercial standards.

Main Methods:

• Synthesis of composite membranes incorporating sulfonated poly(ether ether sulfone) (sPEES) and functionalized mesostructured cellular foam (MCF) silica nanoparticles.
• Systematic variation of polymer molecular weight, silica functional group, and silica loading.
• Characterization of membrane properties including water retention, ion exchange capacity (IEC), and proton conductivity.

Main Results:

• Water retention varied between 20-46% for high MW and 20-60% for low MW polymers.
• Ion exchange capacity (IEC) ranged from 0.02-0.07 mmol/g (high MW) and 0.03-0.09 mmol/g (low MW).
• Proton conductivity reached 15-70 mS/cm (high MW) and 0.1-150 mS/cm (low MW).
• A membrane with low MW polymer and 3% wt. functionalized silica showed performance comparable to Nafion® 117.

Conclusions:

• Composite membranes based on sPEES and functionalized MCF silica demonstrate tunable properties.
• Low molecular weight sPEES combined with silica functionalized with sulfonic groups yields high proton conductivity.
• These novel composite membranes present a viable alternative to conventional materials like Nafion® 117 for potential applications.