CO₂-philic moderate selective layer mixed matrix membranes containing surface functionalized NaX towards...

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Mixed matrix membranes (MMMs) are crucial for industrial gas separation.
• Functionalized nano-zeolites offer potential for enhanced membrane performance.
• Pebax and PES are common polymers used in membrane technology.

Purpose of the Study:

• To investigate the impact of -COOH surface functionalization on NaX nano-zeolites within MMMs.
• To develop highly permeable and selective functional moderate selective layer mixed matrix membranes (F-MSL-MMMs).
• To evaluate the separation efficiency of CO2/N2, CO2/CH4, and CH4/N2 gas mixtures.

Main Methods:

• Preparation of F-MSL-MMMs using functionalized NaX nano-zeolites and a Pebax matrix on a PES support.
• Characterization of membrane morphology and dispersion of nano-zeolites.
• Gas permeation experiments to measure permeability and selectivity at various filler loadings and feed pressures.

Main Results:

• Surface functionalization (-COOH) of NaX nano-zeolites significantly improved their dispersion and interaction within the polymeric matrix.
• The F-MSL-MMMs exhibited superior separation performance compared to membranes with unmodified zeolites.
• Optimal performance was achieved with 1.5% NaX incorporation, yielding high CO2 permeability and selectivity for CO2/N2, CO2/CH4, and N2/CH4 mixtures at 6 bar.

Conclusions:

• -COOH surface functionalization of NaX nano-zeolites is an effective strategy to enhance MMMs for gas separation.
• The developed F-MSL-MMMs demonstrate excellent potential for efficient industrial gas separation applications.
• Further research can explore varying functionalization strategies and zeolite loadings for tailored separation performance.