MOF-Modified High Permeability Polyimide Membrane for Gas Separation

Abstract

This study explored the application of MOF-modified membrane for gas separation. Microporous aluminum fumarate (A520) was used to modify polyimide (PI) membrane using N-methylpyrrolidone (NMP) as solvent. The MOF-modified mixed matrix membrane (MMM) was subjected to gas permeability tests, using gas permeability apparatus (GPA). GPA results showed that adding 10wt% MOF to the membrane increased permeabilities of N2 and CO2 gases by up to 34%, and by 19% for O2 gas, without compromising selectivity. Further increasing MOF loading beyond 10wt% considerably decreased selectivities despite significantly increased permeabilities. Cahn adsorption experiment confirmed and supported this GPA data. These results indicate that MOF were successfully intercalated with the polymer as revealed by scanning electron microscope (SEM) images. Other characterizations like dynamic mechanical analysis (DMA), x-ray diffraction (XRD), and positron annihilation lifetime spectroscopy (PALS) showed that the interface and mechanical properties of the MMM also improved. MOF loading beyond 10wt% revealed aggregations forming non-selective voids that probably caused lowered selectivity.

Preparation of High‐Strength and High‐Permeability EC/PI/MOF Mixed Matrix Membrane**

“…The H 2 permeability of ZIF-8 membranes achieved 2.87 × 10 À 5 mol m À 2 s À 1 Pa À 1 . Bernabe et al [30] selected microporous aluminum fumarate (A520) to modify polyimide for CO 2 gas separation. The MOF-modified polyimide membranes showed that CO 2 permeability was 16.95 Barrer, while the CO 2 /N 2 mixture gas selectivity was 3.5, which improved by 38.6 % of permeability compared to pure polyimide membrane.…”

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%.…”