In-situ confined polymerization constructing highly compatible MOFs TFN membranes for efficient CO2 separation

This study innovatively proposed an in-situ confined polymerization strategy of trimesoyl chloride (TMC) and piperazine (PIP) within MOFs nanosheets, successfully constructing a thin film nanocomposite (TFN) separation membrane with excellent interfacial compatibility. The method employed MOFs nanosheets as confined templates to achieve bottom-up in-situ construction of a continuous and dense polyamide matrix. By precisely controlling the number of polymerization cycles, the MOFs content in the functional layer was effectively regulated from 83.3 wt% to 42.6 wt%. Benefiting from the molecular-level interfacial compatibility between MOFs and the polymer phase, as well as the synergistic effect of efficient solution diffusion and fine molecular sieving mechanisms, the TFN membranes demonstrated significantly enhanced CO 2 separation performance, CO 2 permeance reached 1688.3 GPU with selectivities of 36.4 for CO 2 /N 2 and 38.9 for CO 2 /CH 4 , which surpassed the Upper bound (2008 and 2019). The TFN membranes exhibited outstanding long-term operational stability (selectivity fluctuation <3.6%) under rigorous conditions including prolonged 14-day continuous testing and variable temperature (35-75 °C) and pressure (0.1-0.5 MPa) conditions. This work provided a new paradigm for the precise design and scalable fabrication of gas separation membranes, opening new avenues for the development of high-performance separation membranes.