Functionalization and fabrication of soluble polymers of intrinsic microporosity for CO2 transformation and uranium extraction

Abstract

Task-specific porous polymer PIM-1-based quaternary ammonium iodide (PIM-1-AI) with available catalytic site has been obtained by functionalization of the precursor polymer of intrinsic microporosity PIM-1 and used in the capture and fixation of CO2. PIM-1-AI not only have the ability to capture CO2 (4.6 wt%, 273 K), but also can act as metal-free catalyst for CO2 conversion reaction without any co-catalyst to prepare various cyclic carbonates. The yields of the corresponding reactions catalyzed by PIM-1-AI range from 87 % to 99 % at 2.5 MPa and 90 oC. Furthermore, post-functionalization of PIM-1 has also been performed for the synthesis soluble PIM-1-based amidoxime (PIM-1-AO) with adsorbent groups and high BET specific surface area (511 m2 g-1). Given that the inevitable mass loss of solid powder absorbents in the process of recycling and reutilization for practical use, herein, solid powder PIM-1-AO was fabricated into film and foam-supporting monolithic adsorbents to meet the need of practical application for uranium uptake. We found that PIM-1-AO film has the highest uranium uptake ability (180.3 mg g-1) tested in real seawater with evaluated uranium (7.98 ppm) at the pH of 8.2 and room temperature. Foam-supporting PIM-1-AO can shorten the balanced time from 10 to 4 h in compare with PIM-1-AO powder. Moreover, both PIM-1-AO film and foam-supporting PIM-1-AO as integrated adsorbents can be reused at least 5 times and retain their mass stability.