Melamine-functionalization of the carbonyl-rich polymers for iodine vapor and Hg2+ capture

The solvent and catalyst in the Friedel-Crafts acylation play an important role in the chemical structure and porosity of the polymers. Herein, the mixture of carbon disulfide (CS2) and nitrobenzene (PhNO2) was employed as the solvent and (CF3SO3)2Sn was applied as the catalyst, and the carbonyl-rich polymers were successfully prepared based on the Friedel-Crafts acylation. The prepared polymers possessed moderate Brunauer-Emmet-Teller (BET) surface area (SBET, 446 m2/g), pore volume (Vtotal, 0.21 cm3/g) and unique microporosity. The abundant carbonyl groups on the polymers afforded its further chemical modification. The subsequent melamine (MA) functionalization according to the Schiff base reaction offered the resulting polymers high SBET (up to 680 m2/g), Vtotal (up to 1.01 cm3/g) and nitrogen (N) content (up to 50.04 %). The adsorption experiments revealed that TPA-TPC-10MA with the largest Vtotal (1.01 cm3/g) adsorbed iodine (I2) vapor efficiently, with the maximum capacity of 505 wt%, whereas TPA-TPC-8MA containing the highest N content (50.04 %) removed Hg2+ efficiently, with the maximum capacity of 781 mg/g, and different adsorption mechanism was clarified in detail.