CO2-selective mixed matrix membranes (MMMs) containing graphene oxide (GO) for enhancing sustainable CO2 capture

- GO was firstly incorporated into PEO-based cross-linked membranes for CO2 capture.
- The incorporation of GO can enhance gas transport performance of PEO membranes.
- GO incorporation restrains molecular chain entanglement to increase FFV of MMMs.
- The immersion of PEGDME into MMMs can further increase the CO2 capture ability.

In this study, GO was deliberately incorporated into cross-linked poly (ethylene oxide) (PEO) matrix to obtain novel CO2-selective mixed matrix membranes (MMMs) for sustainable CO2 capture. Various characterizations have been carried out to explore the physicochemical properties of cross-linked PEO membranes before and after GO incorporations. The cross-sectional morphologies of MMMs illustrated a favourable polymer-nanofiller interface between GO and PEO matrix. The mechanical tests indicated the enhanced mechanical properties of membranes after GO incorporation. The gas transport performance of MMMs was investigated in detail. Interestingly, the GO incorporation obviously enhanced the gas permeability of pristine cross-linked PEO membrane because GO restrains the molecular chain entanglement and expands the cross-linked network structures, resulting in the increased fractional free volume (FFV). The gas permeabilities of MMMs demonstrate the highest values at 1.0 wt% GO contents. Furthermore, the incorporation of poly(ethylene glycol) dimethyl ether (PEGDME) into MMMs significantly improved the gas transport properties. The improved mechanical properties and excellent CO2 capture performance of GO incorporated PEO network membrane disclosed in this study provide the new opportunity to tackle energy and environmental issues.

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