Fabrication of pebax-1657-based mixed-matrix membranes incorporating N-doped few-layer graphene for carbon dioxide capture enhancement
Journal
Journal of Membrane Science
Journal Volume
602
Date Issued
2020
Author(s)
Abstract
In this study, an environmentally friendly method was developed to fabricate N-doped few-layer graphene (N-FLG)/Pebax mixed-matrix membranes (MMMs) for CO2 capture. A supermixer was introduced to ensure homogeneity of the N-FLG in the Pebax solution, and a highly efficient method of N-FLG/Pebax MMM preparation was achieved. The membrane structures were analyzed by SEM, while the N-FLG morphology was examined by SEM, AFM, XPS and EDX. A detailed molecular simulation was applied to mimic and predict the behavior of and interaction between membranes and gas molecules. Through the simulation, an independent analysis of transport-related characteristics, such as diffusivity, solubility and permeability, was achieved. In addition, the simulation indicated that the affinity of N-FLG for CO2 molecules improves the CO2 capture performance, that the membranes are solubility-dependent when prepared with low contents of N-FLG and that the effect of diffusivity increases as the addition of N-GO increases above 5 wt%. The simulation results were highly correlated with the experimental results, while the experimental gas permeability results showed that the optimal performance of N-FLG/Pebax MMM was obtained with the addition of 4 wt% N-FLG, providing CO2 permeability and CO2/N2 selectivity of 239.8 Barrer and 95.5, respectively. Pebax-1657-based MMMs incorporating N-FLG nanosheets fabricated by an environmentally friendly method can therefore be considered a promising material for CO2 capture applications.
Type
journal article