3D printed MOF-based mixed matrix thin-film composite membranes

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Technology

Background:

• Metal-organic framework (MOF)-based mixed-matrix membranes (MMMs) offer excellent separation performance and processability.
• High gas permeance is crucial for large-scale CO2 separation from flue gas, typically achieved with thin membranes.
• Few MOF MMMs are fabricated as thin-film composite (TFC) membranes, limiting their application.

Purpose of the Study:

• To fabricate robust TFC MMMs using a 3D printing technique for CO2 separation.
• To investigate the impact of casting concentration and electrospray cycles on membrane properties and performance.
• To develop TFC MMMs with improved CO2 permeance and selectivity.

Main Methods:

• Fabrication of TFC MMMs using a 3D printing technique, specifically electrospray printing.
• Systematic study of casting solution concentration (0.1 wt% vs. 0.5 wt%) and electrospray cycles.
• Characterization of membrane thickness and evaluation of CO2/N2 separation performance.

Main Results:

• Low concentration (0.1 wt%) resulted in thin membranes (<500 nm) with poor CO2/N2 selectivity due to defects.
• Increased concentration (0.5 wt%) yielded TFC MMMs with a thickness of 2-3 μm.
• The 2-3 μm thick TFC MMMs demonstrated three times higher CO2 permeance compared to neat PIM-1 membranes.

Conclusions:

• The study successfully fabricated the first 3D printed TFC MMMs using electrospray printing.
• Optimizing casting concentration is critical for achieving defect-free membranes with enhanced separation performance.
• These robust TFC MMMs show significant potential for efficient CO2 separation in industrial applications.