LTA/Poly(1-trimethylsilyl-1-propyne) Mixed-Matrix Membranes for High-Temperature CO2/N2 Separation

Mixed‐matrix membranes (MMM) consisting of poly(1‐trimethylsilyl‐1‐propyne) (PTMSP) as continuous matrix and small‐pore LTA‐framework zeolites with Si/Al ratios from 1 (commercial zeolite A) to ∞ (ITQ‐29) as dispersed phase were prepared by solution casting. The thermal stability of the MMM is as high as that of glassy PTMSP polymer, whose high permeability is maintained even at increasing temperature. The effect of the Si/Al ratio in the zeolite fillers on the membrane performance is observed by the increasing CO2/N2 permselectivity of low‐Si/Al ratio zeolite A‐based membranes, in comparison with pure silica ITQ‐29. The performance of the LTA‐type zeolite‐PTMSP MMM was adjusted to the modified Maxwell model by estimating the chain immobilization factor and the interphase thickness as a function of temperature, Si/Al ratio, and zeolite loading. Membrane gas separation is a simple and energy‐conservative technology for post‐combustion carbon capture. Here, mixed‐matrix membranes were prepared using the highly permeable poly(1‐trimethylsilyl‐1‐propyne) polymer and small‐pore LTA‐type zeolites by the solution casting method and the performance of the mixed‐matrix membranes was adjusted to the modified Maxwell model.