doi:10.1021/acsami.3c16093engMartínez-Izquierdo, LidiaGarcía-Comas, CristinaDai, ShanNavarro, MartaTissot, AntoineSerre, ChristianTéllez, CarlosCoronas, JoaquínUltrasmall Functionalized UiO-66 Nanoparticle/Polymer Pebax 1657 Thin-Film Nanocomposite Membranes for Optimal CO2 SeparationART-2024-137347Ultrasmall 4 to 6 nm nanoparticles of the metal–organic framework (MOF) UiO-66 (University of Oslo-66) were successfully prepared and embedded into the polymer Pebax 1657 to fabricate thin-film nanocomposite (TFN) membranes for CO2/N2 and CO2/CH4 separations. Furthermore, it has been demonstrated that ligand functionalization with amino (−NH2) and nitro (−NO2) groups significantly enhances the gas separation performance of the membranes. For CO2/N2 separation, 7.5 wt % UiO-66-NH2 nanoparticles provided a 53% improvement in CO2 permeance over the pristine membrane (from 181 to 277 GPU). Regarding the CO2/N2 selectivity, the membranes prepared with 5 wt % UiO-66-NO2 nanoparticles provided an increment of 17% over the membrane without the MOF (from 43.5 to 51.0). However, the CO2 permeance of this membrane dropped to 155 GPU. The addition of 10 wt % ZIF-94 particles with an average particle size of ∼45 nm into the 5 wt % UiO-66-NO2 membrane allowed to increase the CO2 permeance to 192 GPU while maintaining the CO2/N2 selectivity at ca. 51 due to the synergistic interaction between the MOFs and the polymer matrix provided by the hydrophilic nature of ZIF-94. In the case of CO2/CH4 separation, the 7.5 wt % UiO-66-NH2 membrane exhibited the best performance with an increase of the CO2 permeance from 201 to 245 GPU.2024http://zaguan.unizar.es/record/13220010.1021/acsami.3c16093http://zaguan.unizar.es/record/132200oai:zaguan.unizar.es:132200info:eu-repo/grantAgreement/ES/DGA/T68-23Rinfo:eu-repo/grantAgreement/ES/MCIN-AEI/PID2019-104009RB-I00-AEI-10.13039-501100011033info:eu-repo/grantAgreement/EUR/MICINN/TED2021-130621B-C41ACS applied materials & interfaces 16, 3 (2024), 4024-4034byhttps://creativecommons.org/licenses/by/4.0/deed.esinfo:eu-repo/semantics/openAccess