Bifunctional Porous Organic Polymers Based on Postfunctionalization of the Ketone-Based Polymers
Lizhi Wang, Gui Chen, Qin Xiao, Du Zhang, Yafei Sang, Jianhan Huang
Abstract
Multifunctional porous organic polymers (POPs) are excellent porous materials for CO2 capture and Hg2+ adsorption. Especially, plentiful ultramicropores (d < 0.7 nm) and a high nitrogen (N) content are beneficial for CO2 capture, and the micropores and the specific functional groups are helpful for Hg2+ adsorption, while the facile construction of the multifunctional POPs still remains a challenge. Herein, a series of bifunctional POPs was simply fabricated from the ketone-based polymers on the basis of the postfunctionalization. Because of their low Brunauer–Emmett–Teller (BET) surface area (SBET) and pore volume (Vtotal), the polymers were further carried out the Schiff-based reaction using melamine (MA) as the postmodifier. As the rigid external cross-linker, MA embedded in the pores of the polymers and supported the skeleton of the polymers. The resulting polymers showed a sharp increase of the SBET (up to 703 m2/g) and Vtotal (up to 0.657 cm3/g), high N content (up to 36.95 wt %), and three-dimensional hierarchical porosity. In particular, the high ultramicropore volume (up to 0.199 cm3/g) of the resulting polymers made them effective for CO2 capture (193 mg/g; 273 K and 1 bar). The high micropore volume (up to 0.272 cm3/g) and abundant N (up to 36.95 wt %) offered them high Hg2+ capacity (425 mg/g at 298 K). This facile postfunctionalization strategy is potentially useful for the fabrication of some other multifunctional POPs.