Mixed matrix membranes with fast and selective transport pathways for efficient CO₂ separation.

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Mixed matrix membranes (MMMs) are crucial for gas separation.
• Pebax MH 1657 (Pebax) is a common polymer matrix.
• Enhancing CO2 separation performance is a key challenge.

Purpose of the Study:

• To fabricate and characterize Pebax-based MMMs incorporating porous carbon nanosheets (PCNs).
• To investigate the effect of PCNs on CO2 transport and selectivity.
• To optimize PCNs loading for improved gas separation.

Main Methods:

• Fabrication of MMMs with varying PCNs content within a Pebax matrix.
• Characterization of PCN orientation and pore structure within the polymer matrix.
• Gas permeation testing using CO2/CH4 and CO2/N2 mixed gases.

Main Results:

• PCNs exhibited preferential horizontal orientation in the Pebax matrix.
• PCNs created fast CO2 transport pathways, increasing permeability.
• Reduced PCN pore size enhanced CO2/gas selectivity.
• Pebax-PCNs-10 membranes achieved 520 barrer permeability and 51 selectivity for CO2/CH4.
• Pebax-PCNs-10 membranes achieved 614 barrer permeability and 61 selectivity for CO2/N2.

Conclusions:

• PCNs significantly improve CO2 separation performance in Pebax MMMs.
• The orientation and pore structure of PCNs are critical for enhanced gas transport and selectivity.
• Optimized PCNs loading leads to superior CO2 permeability and selectivity for industrial gas separations.