Amino-functionalized two-dimensional lamellar double metal hydroxide-based MMMs with interlayer CO2-philic transport channels for efficient CO2 capture

Due to its benefits of low energy consumption, minimal environmental pollution, and simple operation, membrane technology is considered a carbon capture technology with extensive application possibilities. In this study, the ultraviolet cross-linking method is used to inhibit crystallization of polymers with a molecular weight of less than 1500 and enable polyethylene oxide (PEO) to form a rubbery polymer matrix. This approach avoids membrane separation defects and low CO 2 solubility caused by high crystallinity. The hydroxyl-rich surface of layered double hydroxide (LDH) is used to provide the CO 2 -philic site in the form of “docking station-like” by introducing amino groups with a strong affinity for CO 2 , and forming a dual facilitated transport channel through the nanosheet interlayer channel and the presence of bound water to strengthen the reaction mechanism of the membrane. Based on the coupling of solubility-diffusion and facilitated transport mechanisms, the optimal separation performance is achieved when the NH 2 -PDA-LDH doping is 0.4 wt%, with a CO 2 permeability of 572.4 Barrer and a selectivity of up to 60.5. The interlayer fast transport channels result in a maximum permeability of 3982 Barrer in the wet state. Graphical