Mixed matrix membranes based on ionic liquids and porous organic polymers for selective CO2 separation
Ana R. Nabais, S. Ansar Ahmed, Muhammad Younis, Jin‐Xiu Zhou, João R. Pereira, Filomena Freitas, David Mecerreyes, João G. Crespo, Mu‐Hua Huang, Luísa A. Neves, Liliana C. Tomé
Abstract
The development of more efficient materials is a crucial step in the development of gas separation membranes. In this work, we combine ionic liquids (ILs) and porous organic polymers (POPs) for the first time to fabricate a new type of mixed matrix iongel membranes, which are entirely composed of organic materials. The new azo-POPs reported in this work were specifically designed due to their “CO2-philic” feature to be incorporated in iongel materials. The membranes, comprising 80 wt% of [C2mim][TFSI] IL and 20 wt% of poly(ethylene glycol) diacrylate (PEGDA) network, were prepared using a solvent-free UV curing method. The unique properties of azo-POPs within the iongel material resulted in the fabrication of dense and defect-free membranes with improved gas separation performances, in terms of both CO2 permeability (62.3–90.6 barrer) and, CO2/CH4 (9.9–12.0), CO2/H2 (6.0–12.1) and CO2/N2 (16.8–53.1) ideal selectivities, with the latter revealing to be highly dependent on the morphological properties of the azo-POPs. Furthermore, iongel characterization in terms of morphology, chemical structure and thermal properties, confirmed the potential of the novel mixed matrix iongels for CO2 separation processes.