The urgent demand of CO2 capture in energy relevant fields largely boosts the development of novel membranes with superior separation performance. Polymers of intrinsic microporosity (PIMs), representing the next-generation membrane materials, exhibit high intrinsic permeability but low selectivity originating from their twisted ladder-like backbone structure. Introduction of a CO2-selective secondary filler phase leads to the formation of mixed matrix membranes (MMMs), providing a facile approach to improve CO2 separation performance of PIM-based membranes. Here we report simultaneous enhancements in CO2 permeability and selectivity within high-permeability PIM-1 membranes by incorporating porous two-dimensional metal organic framework (named NUS-8, NUS stands for National University of Singapore) nanosheets. The large lateral size of NUS-8 nanosheets not only promotes filler dispersion within the polymer matrix, but also improves the crystallinity of the polymer phase, generating extra CO2-selective paths in resultant membranes. The PIM-1/NUS-8 MMM with 2 wt% NUS-8 nanosheets exhibited the optimum separation performance, of which the CO2 permeability exceeded 6400 Barrer and the CO2/CH4, CO2/N2 selectivity reached 30 and 26, respectively, surpassing the 2008 Robeson upper bound. The as-prepared PIM-1/NUS-8 MMMs possess great potential for CO2 capture.

Enhancing polymer crystallinity in mixed matrix membranes using metal organic framework nanosheets for efficient CO2 capture

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.