Polymer membranes are known as one of the most energy efficient methods in gas separation, and are widely used in natural gas purification, water purification and desalination, hydrogen separation, and carbon capture. The “solution-diffusion” mechanism of polymer membranes for gas separation indicates that an effective way to improve the gas separation is to increase the “free volume” of polymer membranes. This increase in free volume is typically achieved through synthesizing new polymers with rigid backbones and bulky side groups. However, these rigid and bulky polymers typically suffer severe physical aging, significantly shortening the lifespan of the membranes. Our approach is to design novel polymer membranes based on polymer nanocomposites that have a slow aging rate, good mechanical properties, and a built-in mechanism to tune “free volume” at the interfacial layer. Different from previous strategies that use polymer nanocomposites with repulsive polymer-nanoparticle interactions (dewetted interface), the current proposal is inspired by a recent work (Cheng, S.; et al. Phys. Rev. Lett. 2016, 116 (3), 038302.), and relies on attractive polymer-nanoparticle interactions (wetted interface). This new strategy can also overcome the problem in previous strategies of poor control of the performance of final products due to aggregation of nanoparticles, making the polymer nanocomposite an ideal candidate to address the existing challenges in the field.
Publications:
Bilchak, C. R.; Buenning, E.; Asai, M.; Zhang, K.; Durning, C. J.; Kumar, S. K.; Huang, Y.; Benicewicz, B. C.; Gidley, D. W.; Cheng, S.; Sokolov, A. P.; Minelli, M.; Doghieri, F. Polymer-grafted nanoparticle membranes with controllable free volume Macromolecules 2017, 50 (18), 7111-7120.
Hong, T.; Niu, Z.; Hu, X.; Gmernicki, K.; Cheng, S.; Fan, F.; Johnson, J. C.; Hong, E.; Mahurin, S.; Jiang, D.-e.; Long, B.; Mays, J.; Sokolov, A.; Saito, T. Effect of cross-link density on carbon dioxide separation in polydimethylsiloxane-norbornene membranes ChemSusChem 2015, 8 (21), 3595-3604.
Cao, P.-F.; Li, B.; Hong, T.; Xing, K.; Voylov, D. N.; Cheng, S.; Yin, P.; Kisliuk, A.; Mahurin, S. M.; Sokolov, A. P.; Saito, T. Robust and elastic polymer membranes with tunable properties for gas separation ACS Appl. Mater. Interfaces 2017, 9 (31), 26483-26491.