Optimization of Polyelectrolyte Coacervate Membranes via Aqueous Phase Separation

Area of Science:

• Materials Science
• Polymer Chemistry
• Environmental Engineering

Background:

• Conventional polymeric membranes rely on toxic organic solvents like NMP for fabrication.
• There is a critical need for sustainable membrane fabrication processes for water purification.

Purpose of the Study:

• To investigate the potential of polyelectrolyte complexes (PECs) for sustainable membrane fabrication.
• To explore the use of aqueous phase separation for creating next-generation water purification membranes.

Main Methods:

• Fabrication of membranes using poly(sodium 4-styrenesulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDADMAC) in potassium bromide (KBr) solution.
• Systematic evaluation of dope solution and coagulation bath effects on membrane formation, morphology, and pure water permeance (PWP).
• Analysis using scanning electron microscopy and dead-end filtration tests; assessment of salt annealing post-treatment.

Main Results:

• Treated PEC membranes achieved a PWP of 6.2 L m⁻² h⁻¹ bar⁻¹.
• High dye removal efficiency: 91.7% for methyl orange and 80.5% for methylene blue.
• Demonstrated ability to repel *Escherichia coli* bacteria under static conditions.

Conclusions:

• PEC membranes fabricated via aqueous phase separation offer a sustainable and effective alternative to conventional membranes.
• The study provides fundamental insights into PEC membrane pore formation and separation mechanisms.
• Findings support the development of advanced, eco-friendly materials for membrane-based separations.