Ultrathin self-assembled anionic polymer membranes for superfast size-selective separation.

Area of Science:

• Materials Science
• Nanotechnology
• Separation Science

Background:

• Growing demand for functional nanomaterials necessitates advanced separation technologies.
• Existing nanoporous membranes often face limitations in permeability and fouling resistance.

Purpose of the Study:

• To fabricate ultrahigh permeable nanoporous membranes with tunable thickness.
• To evaluate the separation performance and fouling resistance of the novel membranes.

Main Methods:

• Fabrication of membranes via self-assembly of anionic polymer on copper hydroxide nanostrand templates.
• Characterization of membrane pore size (5-12 nm) and thickness (down to 85 nm).
• Assessment of water flux and size-selective separation of gold nanoparticles.

Main Results:

• Achieved ultrahigh water flux (3306 L m⁻² h⁻¹ bar⁻¹) with 85 nm thick membranes, significantly exceeding commercial standards.
• Demonstrated excellent size-selective separation of 5 nm and 15 nm gold nanoparticles.
• Exhibited good fouling resistance towards negatively-charged solutes.

Conclusions:

• The facile self-assembly approach provides a general method for producing ultrathin anionic polymer membranes.
• These novel nanoporous membranes show significant potential for efficient separation and purification of nanoparticles and biomacromolecules.