Highly efficient recovery of propane by mixed-matrix membrane via embedding functionalized graphene oxide nanosheets into polydimethylsiloxane

To construct rapid C₃H₈ transport pathways in polymer matrix, alkyl chain-functionalized graphene oxide (GO) was prepared via grafting octadecylamine (ODA) molecules and then embedded into polydimethylsiloxane (PDMS) matrix to obtain high-efficiency mixed matrix membranes (MMMs). The incorporation of alkyl chains contributes to lowering the surface energy of GO nanosheets and providing higher affinity with PDMS matrix. Additionally, the alkyl chains on the surface of ODA-functionalized GO nanosheets (ODA-GO) are in favor of C₃H₈ adsorption, thus conferring continuous and specific transport pathways for C₃H₈. The optimized membrane with ODA-GO loading of 0.3 wt% exhibits the C₃H₈ permeance of 1897 GPU and the C₃H₈/N₂ ideal selectivity of 67, which are 50.2 and 72.5% higher than those of bare PDMS membrane, respectively. The simultaneous enhancement of C₃H₈ permeance and C₃H₈/N₂ ideal selectivity indicates that ODA-GO is an effective filler applied in MMMs for C₃H₈ recovery.