Construction of antifouling zwitterionic membranes by facile multi-step integration method

Area of Science:

• Materials Science
• Chemical Engineering
• Polymer Science

Background:

• Membrane fouling significantly degrades separation membrane performance, necessitating efficient solutions.
• Traditional methods for mitigating fouling are often complex and inefficient.
• Poly(aryl ether sulfone) (PAES) membranes are widely used but susceptible to fouling.

Purpose of the Study:

• To develop an efficient multi-step integration method for preparing antifouling zwitterionic PAES ultrafiltration (UF) membranes.
• To investigate the impact of zwitterion content on membrane morphology, hydrophilicity, water flux, and rejection.
• To enhance the antifouling properties of PAES UF membranes through zwitterionic modification.

Main Methods:

• Synthesis of a bisphenol precursor with tertiary amine groups for zwitterionic grafting.
• Preparation of zwitterionic modified UF membranes via graft copolymerization and non-solvent-induced phase separation (NIPS).
• Characterization of membrane properties including morphology, hydrophilicity, pure water flux, and protein rejection.

Main Results:

• Optimized morphology, hydrophilicity, water flux, and rejection were achieved by tuning zwitterion content.
• The zwitterionic modification formed a hydration layer, effectively reducing protein adsorption.
• The resulting PAES-Z-x membrane exhibited increased pure water flux (up to 311 L m⁻²h⁻¹ bar⁻¹), high BSA rejection (97%), and good FRR (82.8%).

Conclusions:

• The developed multi-step integration method is simple and effective for preparing antifouling zwitterionic PAES UF membranes.
• Zwitterionic modification significantly improves the antifouling performance of PAES UF membranes.
• This approach offers a new direction for enhancing the performance and longevity of PAES UF membranes in separation processes.