Hierarchically Structured Nanoparticle-Free Omniphobic Membrane for High-Performance Membrane Distillation.

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Membrane distillation (MD) faces challenges like pore wetting and scaling, limiting its application.
• Developing robust membranes is crucial for effective wastewater treatment and desalination.

Purpose of the Study:

• To create a novel omniphobic membrane with enhanced structural integrity and wetting resistance for MD.
• To demonstrate the membrane's efficacy in treating challenging hypersaline wastewater.

Main Methods:

• Fabrication of a hierarchical re-entrant architecture via spray-water-assisted non-solvent-induced phase separation (SWNIPS).
• Surface functionalization using "thiol-ene" click chemistry for fluorination.
• Performance evaluation through contact angle measurements, abrasion tests, and long-term MD operation.

Main Results:

• The fabricated membrane exhibited an ultrahigh water contact angle (166.8°) and ultralow sliding angle (3.6°).
• Demonstrated exceptional structural robustness and excellent wetting resistance against low-surface-tension liquids.
• Achieved stable long-term MD operation for brine wastewater treatment and high water recovery (∼60%) from shale gas wastewater.

Conclusions:

• The study presents a nanoparticle-free, scalable method for producing high-performance omniphobic MD membranes.
• The developed membranes offer superior structural robustness and wetting resistance for hypersaline wastewater treatment.
• This approach significantly advances the practical application of MD technology.