Antifouling PTFE Hollow Fiber Microfiltration Membrane with a Double-Defense Mechanism

Area of Science:

• Materials Science
• Environmental Engineering
• Surface Chemistry

Background:

• Polytetrafluoroethylene (PTFE) membranes are crucial for treating highly polluted wastewater.
• Enhancing PTFE membrane performance requires robust hydrophilic modification, which remains a significant challenge.
• Existing methods struggle to create durable hydrophilic coatings on PTFE surfaces.

Purpose of the Study:

• To develop a novel surface engineering strategy for robust hydrophilic modification of PTFE hollow fiber membranes.
• To create a durable double-layer hydrogel coating on PTFE for improved wastewater treatment.
• To investigate the filtration and antifouling performance of the modified PTFE membranes.

Main Methods:

• Surface grafting of PTFE hollow fiber membranes with N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane (AEAPTS).
• In situ coating of a poly(vinyl alcohol) (PVA) hydrogel layer via Schiff base reaction and aldol condensation.
• Anchoring a second polyion complex (PIC) hydrogel layer onto the PVA layer through hydrogen bonding and topological entanglements.

Main Results:

• A robust poly(vinyl alcohol) (PVA) and polyion complex (PIC) double-layer (DL) hydrogel coating was successfully constructed on PTFE membranes.
• The PVA/PIC DL hydrogel coating demonstrated excellent strength and chemical resistance.
• The modified membranes exhibited durable microfiltration and antifouling properties due to a hydration layer and polyzwitterionic brushes.

Conclusions:

• The developed surface engineering strategy provides a robust method for hydrophilic modification of PTFE membranes.
• The PVA/PIC DL hydrogel coating significantly enhances the filtration performance and durability of PTFE membranes for wastewater treatment.
• The double-defense mechanism effectively repels pollutants, leading to superior antifouling capabilities.