Mixed matrix membranes comprising PMP polymer with dispersed alumina nanoparticle fillers to separate CO2/N2

In regards to the evolution of desirable properties and chemical structure for high performance of gas separation by membranes, mixed matrix membranes (MMMs), need to be carefully designed and controlled to realize high efficiency. This research investigates the role of the main parameters in the fabrication and performance analysis of MMMs prepared through blending of alumina nano particles (Al2O3) and poly(4-methyl-1-pentyne) known as PMP with various weight percentages of alumina nano-particles in the PMP precursor. Precursor and resultant MMMs were characterized using thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) techniques. SEM images demonstrated the proper dispersion of Al2O3 particles in the precursor matrix. Results indicated that the microstructure of the precursor, blend composition, and the content of nano particles play an important role in gas transport properties of the resulting MMMs. The influence of the percentage of alumina nano particles used in the precursor matrix on the CO2 and N-2 permeability and CO2/N-2 illustrated a selective trend for the MMMs. Using higher alumina content resulted in membranes with higher permeability and ideal selectivity. The highest rate of CO2 and N-2 permeability could be obtained from PMP-alumina with a loading of 30 wt% alumina (PMP30) at 10 bar. Furthermore, these results suggest that PMP30 MMMs (at operating pressures of 8 bar) are exceptional candidates for the CO2/N-2 separation, offering enhanced gas pair selectivity in the range of 4.5-5 depending on the operating pressure. The results of this research revealed that high-performance gas separation by MMMs can be realized through adopting a judicious combination of blending and dispersing techniques.