Molecular sieving metal-organic framework (MOF) membranes have great potential for energy-efficient chemical separations, but a major hurdle is the lack of a scalable and inexpensive membrane fabrication mechanism. We describe a route for processing MOF membranes in polymeric hollow fibers, combining a two-solvent interfacial approach for positional control over membrane formation (at inner and outer surfaces, or in the bulk, of the fibers), a microfluidic approach to replenishment or recycling of reactants, and an in situ module for membrane fabrication and permeation. We fabricated continuous molecular sieving ZIF-8 membranes in single and multiple poly(amide-imide) hollow fibers, with H2/C3H8 and C3H6/C3H8 separation factors as high as 370 and 12, respectively. We also demonstrate positional control of the ZIF-8 films and characterize the contributions of membrane defects and lumen bypass.

http://science.sciencemag.org/content/sci/345/6192/72.full.pdf

Interfacial microfluidic processing of metal-organic framework hollow fiber membranes

The latest developments in zeolite membranes are reviewed, with an emphasis on the synthesis techniques, including seed assembly and secondary growth methods. This review also discusses the current industrial applications of zeolite membranes, the feasibility of their use in membrane reactors and their hydrothermal stability. Finally, zeolite membranes are compared with metal–organic framework (MOF) membranes and the latest advancements in MOF and mixed matrix membranes are highlighted.

/pdf/zeolite-membranes-a-review-and-comparison-with-mofs-1732j0qjlu.pdf

Zeolite membranes – a review and comparison with MOFs

Recent developments in zeolite membranes for gas separation

In this work, the concept of zeolite (zeolitic) membrane is discussed from a practical perspective. We consider the limitations of the existing synthesis methods and speculate on new opportunities of zeolites and zeolite-type materials such as metal organic frameworks for the production of membranes. This paper focuses on the barriers that need to be eliminated before the commercialization of these membranes becomes attractive. Additional opportunities for commercialization may arise in the shape either of mixed matrix membranes, taking advantage of composites with polymers, or as zeolite coatings useful for a plethora of new applications.

W.V. Chiu

Papers

Post-synthesis defect abatement of inorganic membranes for gas separation

Rapid thermal processing of inorganic membranes

High-performance membrane supports: A colloidal approach to the consolidation of coarse particles