MEMBRANES WITH A LOW LOADING OF METAL–ORGANIC FRAMEWORK-SUPPORTED IONIC LIQUIDS FOR CO2/N2 SEPARATION IN CO2 CAPTURE
Answering the societal challenge “Secure, clean and efficient energy”, we studied Mixed Matrix Membranes (MMM) comprising a very low upload of IL@MOF with an improved CO2/N2 separation with applicability as CO2 adsorber for the development of fuel cells. Preparation of the MMMs starts by the immobilization of the ionic liquids (ILs), 1,1,3,3-tetramethylguanidinium azide (TMGA) and 1-ethyl 3-methylimidazolium tricyanomethane ([EMIM][C(CN)3])) into 3D metal–organic frameworks (MOFs, MOF-5 and Mg-MOF-74). The incorporation of these composites in a polyimide-based matrix (Matrimid® 5218) to yield [IL@MOF]@Matrimid®5218 proved to be an efficient strategy to improve the permeability and selectivity toward CO2/N2 mixtures, presenting also a remarkable improvement in membrane flexibility and mechanical resistance. Using MOF-5, a crystalline phase different from its original phase is obtained after the incorporation of hydrated IL without loss of adsorptive properties (Cover Picture - Energy Technol. 2017, 5, 2158-2162).