Microporous Aluminum Fumarate (A520) Metal-Organic Framework as Modifier to Free-Standing Mixed Matrix Membrane

Abstract

Microporous aluminum fumarate (A520) is one of the very few metal-organic frameworks (MOFs) that have been promoted to the level of commercial applications and has recently been proven to exhibit a rigid character with an accessible permanent porosity. This study explored the maximum loading amount of A520 for mixed matrix membrane (MMM) preparation by blending it with polyimide (PI) using N-methylpyrrolidone (NMP) as solvent, without compromising the membrane integrity. Scanning electron microscope (SEM) images revealed that MOFs were able to infiltrate the pores and structures of the polymer, improving the interface and mechanical properties of the polymer, as supported by different characterizations like dynamic mechanical analysis (DMA), x-ray diffraction (XRD), and positron annihilation lifetime spectroscopy (PALS). Results showed that MOF loading beyond 10wt% revealed aggregations that compromised the integrity of the membrane.

MOF-Modified High Permeability Polyimide Membrane for Gas Separation

“…This could be due to MOF aggregations creating nonselective voids [20]. These aggregations were also reported in the previous work [17]. Cahn adsorption experiment (Fig.…”

“…As the MOF loading increases, the selective free volume void around the intercalated MOF particles also increases. This could be due to the rigid structure of A520 creating possible molecular sieving property for the membrane [17], as demonstrated by the increase in permeation (Fig. 1).…”

“…SEM and XRD data confirmed the intercalation of MOF in the membrane causing an improvement in the free volume diameter and distribution, as confirmed by PALS, without compromising the integrity of the membrane, as proven by DMA results. Characterization data was reported in detail in the author's previous work [17].…”

Optimization of a MOF Blended with Modified Polyimide Membrane for High-Performance Gas Separation

“…However, with industrially produced tunable separation membranes with excellent properties of metal-organic skeletal materials, it is necessary to focus on how to simultaneously produce separation membranes with high selectivity; high permeability; high mechanical strength; and stability. Bernabe et al [24,25] presented a modified polyimide membrane using microporous aluminum fumarate (A520) as the filler to improve permselectivity for CO 2 /N 2 and O 2 /N 2 . When compared to the pure PI membrane, these membranes have improved CO 2 permeability of 38.5% and O 2 permeability of 357.8%.…”

Fabrication and Characterization of PVDF/UiO-66(Zr) Mixed Matrix Membrane on Non-Woven PET Support

“…Modification with metal-organic framework (MOF) is an emerging discipline in the field of mixed matrix membrane (MMM) technology, that combines the superior gas separation properties of inorganic membrane and the economic processability of polymeric membrane [1]. MOFs have been increasingly gaining popularity and credibility as a membrane modifier because they generally enhance the membrane and synergize with the strengths of membrane technology that includes small footprint, high energy efficiency, low capital cost, easy operation, and flexible size [1]. MOF-based MMM easily surpasses the Robeson's Upper Bound or the trade-off between selectivity and permeability [2].…”