Constructing Connected Paths between UiO-66 and PIM-1 to Improve Membrane CO₂ Separation with Crystal-Like Gas...

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Metal-organic-framework (MOF)-based hybrid membranes often exhibit limited gas permeability, hindering efficient CO2 separation.
• Interfacial defects and rigid polymer structures can impede fast CO2 transport in MOF-polymer composite membranes.

Purpose of the Study:

• To develop a new strategy for interweaving UiO-66 and PIM-1 to create enhanced CO2 transport pathways in hybrid membranes.
• To improve CO2 permeability and selectivity in MOF-based membranes by minimizing interfacial defects and utilizing intrinsic MOF pore chemistry.

Main Methods:

• Fabrication of UiO-66-CN@sPIM-1 hybrid membranes by interweaving UiO-66-CN crystals with thermally treated and cross-linked PIM-1 (sPIM-1).
• Rigidification of sPIM-1 via thermal treatment to ensure permanent polymer voids.
• Characterization of membrane structure and evaluation of CO2/N2 separation performance.

Main Results:

• UiO-66-CN@sPIM-1 membranes demonstrated exceptionally high CO2 permeability, reaching 15433.4-22665 Barrer.
• The CO2/N2 permeation selectivity of the membranes (23.9-28.6) approached that of single UiO-66 crystals.
• The pore chemistry of UiO-66-CN was preserved, enabling effective CO2 adsorption.

Conclusions:

• The developed UiO-66-CN@sPIM-1 membranes offer a promising solution for practical CO2 separation by creating efficient transport pathways.
• The strategy of interweaving MOFs with rigidified polymers effectively minimizes defects and enhances separation performance.
• These membranes show potential for industrial applications in carbon capture and gas separation technologies.