Novel aminated F-Ce nanosheet mixed matrix membranes with controllable channels for CO2 capture

Abstract

Membrane separation is a novel technology that has been widely studied for efficient CO2 capture. This study aims to synthesize novel porous amino-functionalized nanosheets using PEI (polyethyleneimine) (PEI-F-Ce) and PEI-F-Ce/polyethylene oxide (PEO) mixed matrix membranes (MMMs). PEI-F-Ce nanosheets were prepared via the electrostatic self-assembly method, allowing for the adjustment of both lateral and pore sizes of the nanosheets by varying the PEI concentration. The MMMs loaded with 2 % PEI-F-Ce-2.5 nanosheets exhibit excellent CO2 permeability (641 Barrer) and outstanding CO2/N2 selectivity (70.1). These values surpassed those of pure PEO membranes by 62 % and 53 %, respectively, exceeding the 2019 upper bound. PEI-F-Ce-2.5 nanosheets with a stable pore channel 3.406 nm improved CO2 transport and showed a large CO2 adsorption capacity of 1.32 mmol g−1, leading to enhanced the CO2/N2 reaction selectivity. Moreover, the reversible reaction of CO2 with –NH2 enhanced the CO2/N2 selectivity by 5.1 times at −20 °C, thereby highlighting its potential for cryogenic gas separation applications.