Diffusion-Regulated Interfacial Polymerization of Hierarchically Microporous Polyamide Membranes for Permselective...

Area of Science:

• Materials Science
• Chemical Engineering
• Polymer Chemistry

Background:

• Interfacial polymerization is key for task-specific polyamide (PA) membranes.
• Highly cross-linked PA membranes often have limited microporosity, hindering gas separation efficacy.

Purpose of the Study:

• To develop an ionic liquid (IL)-regulated interfacial polymerization process.
• To fabricate PA nanofilms with kinked tetrakis (4-aminophenyl) methane monomers for enhanced gas separation.

Main Methods:

• Utilized IL-regulated interfacial polymerization with varying IL/H2O ratios.
• Employed in situ UV-Vis spectroscopy to monitor monomer diffusion.
• Fabricated and tested PA-TAM7/3-60 min membranes for CO2/CH4 separation.

Main Results:

• IL presence increased TMC diffusion, leading to denser, more cross-linked membranes.
• Achieved CO2 permeance of 29.8 GPU and CO2/CH4 selectivity of 109, surpassing the Robeson upper bound.
• Demonstrated excellent plasticization resistance with minimal performance loss at high CO2 pressures.

Conclusions:

• The IL-regulated process effectively tunes PA membrane structure and gas separation performance.
• The developed membranes show significant potential for demanding, task-specific gas separation applications.
• High cross-linking density contributes to superior plasticization resistance, crucial for industrial gas separations.