Preparation of mixed matrix membranes by layered double hydroxides of amino acid intercalation and Pebax for ameliorated CO2 separation

Abstract

CO2 capture, storage and utilization has been acknowledged as an important strategy for climate change mitigation. 2D materials have great advantages in gas separation due to their high aspect ratio and nano-sized thickness, such as LDH with tunable interlayer ions. In this work, 12-Aminododecanoic acid was incorporated as an intercalator between MgAl LDH layers and used as filler for the preparation of mixed matrix membranes (MMMs). Amino and carboxyl groups in amino acids could be used to enhance the performance of CO2 gas separation by quadrupole moment effect and increasing the layer spacing. The XRD pattern showed an increase in the layer spacing, while the characteristic peaks of amino and carboxyl groups were observed in the FTIR pattern and the initial characteristic peaks did not disappear, indicating that the amino acids were successfully intercalated into the LDH layer. The experimental results indicated that MMMs with 5 wt% 12AA-LDH achieved CO2 permeability of 92.57 Barrer and CO2/N2 selectivity of 50.8, which increasing by 125 % and 17 %, compared to pristine Pebax membranes. It could be observed that 2D materials can be used in gas separation by cross-linking and intercalation to preparing high performance separation membranes.