Nanofiltration Membrane with Enhanced Ion Selectivity Based on a Precision-Engineered Ultrathin Polyethylene...

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Nanofiltration (NF) is vital for water treatment and separation.
• Existing research primarily optimizes the selective layer of NF membranes.
• The supporting layer's role in NF membrane performance is often overlooked.

Purpose of the Study:

• To investigate improving NF membrane performance by controlling the ultrathin supporting layer.
• To develop an innovative NF membrane utilizing a submicrometer ultrathin polyethylene (PE) supporting layer.
• To explore the tunable interface properties of the ultrathin PE supporting layer for selective layer control.

Main Methods:

• Fabrication of a submicrometer ultrathin PE membrane via biaxial stretching.
• Precise control over the structure and surface properties of the PE supporting layer.
• Utilizing the ultrathin PE supporting layer as a tunable interface for interfacial polymerization.

Main Results:

• Developed the thinnest NF membrane to date with an overall thickness of approximately 630 nm.
• Achieved ultrahigh Cl-/SO42- selectivity of 338.03, surpassing current literature benchmarks.
• Demonstrated significant enhancements in overall NF membrane performance through supporting layer optimization.

Conclusions:

• The supporting layer plays a critical role in the preparation and performance of NF membranes.
• Precisely controlling the ultrathin supporting layer offers a novel pathway for NF membrane innovation.
• This approach holds potential for developing next-generation ultrathin, high-performance NF membranes.