Performance of PVDF Based Membranes with 2D Materials for Membrane Assisted-Crystallization Process

Area of Science:

• Materials Science
• Chemical Engineering
• Water Treatment Technologies

Background:

• Membrane crystallization (MCr) offers a novel approach for freshwater recovery and salt production from desalination brine.
• Developing efficient composite membranes is crucial for optimizing MCr performance.

Purpose of the Study:

• To fabricate and evaluate composite polymeric membranes incorporating graphene and bismuth telluride for membrane crystallization.
• To compare the performance of these novel membranes against pristine membranes.

Main Methods:

• Fabrication of composite membranes using graphene and bismuth telluride inks via wet-jet milling (WJM) technology.
• Incorporation of 2D materials into PVDF membranes.
• Performance evaluation in membrane crystallization experiments using 5 M NaCl solution.

Main Results:

• PVDF membranes with 7% bismuth telluride achieved the highest flux (3.9 L∙m⁻²h⁻¹).
• Composite membranes produced more uniform NaCl crystals compared to pristine membranes, particularly with few-layer graphene.
• All membranes demonstrated high salt rejection (>99.9%), with graphene membranes reaching 99.99%.

Conclusions:

• Composite membranes show significant potential for efficient freshwater recovery and salt production via MCr.
• The developed membranes exhibit excellent salt rejection and flux, without wetting phenomena during tests.
• Graphene and bismuth telluride integration enhances membrane performance for MCr applications.