Molecular-Level Pore Engineering for Precise Separation via Active Solvent-Mediated Interfacial Polymerization

Area of Science:

• Materials Science
• Chemical Engineering
• Polymer Science

Background:

• Polymer membranes require precise pore size control for effective separations.
• Current methods struggle with homogeneous sub-nanometer pore tuning in polymer matrices.
• Traditional solvents lead to uncontrolled polymerization, hindering pore engineering.

Purpose of the Study:

• To develop a novel strategy for molecular-level pore engineering in polymer membranes.
• To enable precise tuning of sub-nanometer pores for enhanced separation performance.
• To overcome limitations of traditional solvents in controlling polymerization.

Main Methods:

• Utilized a microemulsion as an active solvent for interfacial polymerization.
• Employed localized quasi-homogeneous polymerization templated by ~1 nm microemulsions.
• Investigated pore structure and performance using techniques like positron annihilation spectroscopy and small-angle X-ray scattering.

Main Results:

• Achieved molecular-level pore engineering in polyamide membranes.
• Resulting membranes showed high water permeance (58.7 L m⁻² h⁻¹ bar⁻¹) with excellent NaCl-Na₂SO₄ selectivity.
• Demonstrated scalability to 1-inch hollow fiber modules without performance loss.

Conclusions:

• The active solvent-mediated strategy offers a versatile and scalable method for membrane pore engineering.
• This approach significantly enhances membrane performance for water treatment and chemical separations.
• The method enables precise control over pore size and distribution, surpassing current limitations.