%0 Journal Article %T Matrimid®5218/AO-PIM-1 Blend Membranes for Gas Separation %J Journal of Membrane Science and Research %I FIMTEC & MPRL %Z 2476-5406 %A Longo, Mariagiulia %A Comesaña-Gándara, Bibiana %A Monteleone, Marcello %A Esposito, Elisa %A Fuoco, Alessio %A Giorno, Lidietta %A McKeown, Neil Bruce %A Jansen, Johannes Carolus %D 2022 %\ 07/01/2022 %V 8 %N 3 %P - %! Matrimid®5218/AO-PIM-1 Blend Membranes for Gas Separation %K polymer blend %K polymer of intrinsic microporosity %K polyimide %K Gas separation membrane %K Maxwell model %R 10.22079/jmsr.2021.540493.1504 %X In the search for more efficient gas separation membranes, blends offer a compromise between costly high-performance  polymers and low-cost commercial polymers. Here, blends of the polymer of intrinsic microporosity, AO-PIM-1, and  commercial Matrimid® 5218 polyimide are used to prepare dense films by solution casting. The morphology of the pure polymers and their blends with 20, 40, 60 and 80 wt% of AO-PIM-1 in Matrimid® are studied by scanning electron  microscopy (SEM), and their pure gas permeability is studied as a function of the blend composition with H2, He, O2, N2,  CH4 and CO2. The polymers were found only partially miscible and a two-phase structure was formed with large  domains of each polymer. When necessary, the films were coated with a thin silicone layer to heal possible pinhole  defects. Even small amounts of Matrimid® in AO-PIM-1 resulted in an unexpectedly strong decrease in the permeability  of the PIM, whereas a small amount of the PIM led to a modest increase in permeability of Matrimid®. Due to the two-hase structure, the Maxwell model was more suitable to describe the gas permeability as a function of the blend  composition than the model for miscible blends. At low Matrimid® concentrations in AO-PIM-1, all models fail to describe the experimental data due to an unexpectedly strong depression of the permeability of the PIM by Matrimid®.  Time lag measurements reveal that the changes in permeability as a function of the blend composition are mostly due to  changes in the diffusion coefficient.  %U https://www.msrjournal.com/article_247090_90911239af38d4968d5bed09c778da84.pdf