Recent advances in polymer blend membranes for gas separation and pervaporation

Recent interest in developing high performance polymeric membranes has evolved the molecular transport performance in gas separation and pervaporation. The synthesis of polymer with novel structures may improve the separation performance of a membrane. However, it always accompanies undeterminable risk such as economic costs and development duration. Polymer blends have gained interdisciplinary interest as promising modification strategy owing to the advantages of being versatile, straightforward and least expensive besides having cost- and time-effective routes in developing membranes with desirable separation performance. Despite these advantages, polymer blends have encountered the main challenges of compatibility at the molecular level, resulting in unsatisfactory membrane separation performance. The thermodynamic properties of polymer blends lead to different phase behaviors of the end products such as being miscible, immiscible and partially miscible. Due to the significant importance of compatibility in polymer blends, this review summarizes the fundamental understanding of phase behaviors, molecular interactions, separation properties and prediction models from the polymer blend membranes. Moreover, the recent progress on state-of-the-art polymer blend membranes in various energy-related applications, especially for gas separation and pervaporation will be reviewed. Lastly, the perspectives on the current challenges and future opportunities to facilitate polymer blend membranes will be discussed.