Metal-organic framework membranes with scale-like structure for efficient propylene/propane separation.

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Fabricating metal-organic framework (MOF) membranes for efficient propylene/propane separation faces challenges in selectivity, mechanical strength, and scalability.
• Existing MOF membranes often suffer from defects and poor durability, limiting their industrial applicability.

Purpose of the Study:

• To design and fabricate a novel ZIF-67 membrane with enhanced mechanical properties and separation performance for industrial propylene purification.
• To address the limitations of current MOF membranes by incorporating a bio-inspired, wear-resistant structure.

Main Methods:

• Fabrication of ZIF-67 membranes with a tangential-normal interlaced structure (TN-ZIF-67).
• Characterization of membrane structure, separation performance (propylene/propane selectivity), and mechanical stability.
• Evaluation of long-term stability through storage and abrasion tests.

Main Results:

• The TN-ZIF-67 membrane demonstrated a high propylene/propane separation factor of 221.
• The membrane exhibited excellent mechanical endurance, with performance unaffected by 1.5 years of storage or repeated abrasion.
• The fabrication process was successfully scaled up to tubular substrates with a 4 mm diameter.

Conclusions:

• The TN-ZIF-67 membrane offers a promising solution for defect-free, anti-wear MOF membranes with superior separation performance and stability.
• This bio-inspired design strategy paves the way for advanced MOF membranes in industrial gas separation applications.