Effect of membrane hydrophilization on ultrafiltration performance for biomolecules separation

Area of Science:

• Materials Science
• Chemical Engineering
• Membrane Technology

Background:

• Ultrafiltration (UF) membranes are susceptible to fouling, reducing performance.
• Hydrophilization is crucial for developing low-fouling UF membranes.
• Various modification strategies exist, each with potential drawbacks.

Purpose of the Study:

• To compare the effectiveness and stability of different hydrophilization techniques for UF membranes.
• To evaluate post-modification, polymer blending, and reactive phase separation methods.
• To assess the impact of hydrophilization on membrane characteristics and performance.

Main Methods:

• Photograft copolymerization of poly(ethylene glycol) methacrylate (PEGMA) for post-modification.
• Non-solvent induced phase separation (NIPS) with hydrophilic additives for polymer blending.
• Reactive phase separation involving UV irradiation before coagulation.
• Characterization using contact angle, FTIR, and SEM.
• Performance evaluation through fouling tests with proteins, polysaccharides, and humic acid.

Main Results:

• All methods enhanced membrane hydrophilicity and reduced fouling.
• Post-modification and polymer blending decreased contact angle but also reduced hydraulic permeability.
• Conventional phase separation methods showed leaching of modifiers.
• Reactive phase separation demonstrated improved stability of the modifier agent within the membrane matrix.

Conclusions:

• Hydrophilization is effective in reducing UF membrane fouling.
• Reactive phase separation presents a more stable approach for incorporating hydrophilic agents compared to conventional methods.
• Trade-offs between hydrophilicity, permeability, and long-term stability must be considered in membrane design.