doi:10.1016/j.seppur.2022.121447engMohsenpour, S.Ameen, A. W.Leaper, S.Skuse, C.Almansour, F.Budd, P. M.Gorgojo Alonso, P.PIM-1 membranes containing POSS - graphene oxide for CO2 separationART-2022-129999PIM-1 mixed matrix membranes (MMMs) were fabricated with polyhedral oligomeric silsesquioxane (POSS) and graphene oxide (GO) functionalized with POSS (GO-POSS), and tested for CO2/N2 (single gas) and CO2/CH4 (1:1, v:v gas mixture). The CO2 permeability of the best performing fresh MMM (containing 0.05 wt% GO-POSS) was ~ 12000 Barrer, which is 69% higher than that of the neat PIM-1 membrane, with about the same selectivity (CO2/CH4 selectivity ~ 12 and CO2/N2 selectivity ~ 20). In both cases, the gas separation data surpass the 2008 Robeson upper bound. In addition to the initial CO2 permeability enhancement, the use of GO-POSS is an efficient strategy to slow down physical aging. The MMM at a filler loading of 0.75 wt% showed less than half of the reduction in CO2 permeability than the neat PIM-1 membrane 160 days after preparation (26% for the MMM vs 58% for the purely polymeric one). © 2022 The Author(s)2022http://zaguan.unizar.es/record/11880610.1016/j.seppur.2022.121447http://zaguan.unizar.es/record/118806oai:zaguan.unizar.es:118806info:eu-repo/grantAgreement/ES/MICINN/RYC2019-027060-ISeparation and Purification Technology 298 (2022), 490703 [12 pp]byhttp://creativecommons.org/licenses/by/3.0/es/info:eu-repo/semantics/openAccess