Mixed-Matrix Membranes Containing Carbon Nanotubes Composite with Hydrogel for Efficient CO₂ Separation

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Efficient carbon dioxide (CO2) separation is crucial for climate change mitigation and industrial processes.
• Developing advanced membrane materials with high permeability and selectivity remains a significant challenge.

Purpose of the Study:

• To synthesize and characterize a novel N-isopropylacrylamide hydrogel coated carbon nanotubes composite (NIPAM-CNTs).
• To fabricate mixed-matrix membranes (MMMs) using poly(ether-block-amide) (Pebax MH 1657) and NIPAM-CNTs for enhanced CO2 separation.
• To investigate the role of NIPAM-CNTs in improving CO2 transport pathways and membrane performance.

Main Methods:

• Synthesis of NIPAM-CNTs composite filler.
• Fabrication of MMMs by incorporating NIPAM-CNTs into a Pebax MH 1657 matrix.
• Characterization of membrane performance for CO2/CH4 and CO2/N2 separation.

Main Results:

• The NIPAM-CNTs composite filler facilitates CO2 transport via CNT nanochannels and enhances water content via NIPAM hydrogel.
• MMMs with 5 wt% NIPAM-CNTs achieved a CO2 permeability of 567 barrer and CO2/CH4 selectivity of 35, and CO2/N2 selectivity of 70.
• The performance of the MMMs surpassed the 2008 Robeson upper bound, indicating superior separation efficiency.

Conclusions:

• NIPAM-CNTs composite filler effectively enhances CO2 transport pathways in MMMs.
• The developed MMMs demonstrate excellent potential as advanced materials for efficient CO2 separation.
• This study offers a promising strategy for designing high-performance membranes for gas separation applications.