Recent Applications of Polymer Blends in Gas Separation Membranes

Polymeric membranes are extensively used for gas separations but their performance is limited by the upper bound trade‐off discovered by Robeson in 1991. Among the attractive modifications available to increase the performance of polymeric membranes, polymer blending is a unique technique because it offers a time‐ and cost‐effective method of tuning the properties of membranes. A variety of polymer blends has been explored in recent years. The application of polymer blends in gas separation membranes is described by critically analyzing the performance of polymer blend membranes. Polymer blend membranes of different polymer pairs are reviewed and evaluated in terms of phase behavior, permeability, and selectivity. Polymer blending is an effective technique to enhance the so far limited performance of polymeric membranes in gas separation applications. Recently developed polymer blend membranes are critically reviewed in terms of permeability, selectivity, and phase behavior. Future directions of research and innovations for such membranes are highlighted.