Amine functionalized 3D porous organic polymer as an effective adsorbent for removing organic dyes and solvents

Organic dyes and solvents are emerging pollutants; the development of new materials for their efficient adsorption and removal is thus of great significance. In this work, we report the application of an amine functionalized triptycene-based 3D polymer (TPP-NH2) as a novel adsorbent for the fast removal of organic dyes in aqueous solution and organic solvents with a view to understanding its adsorption kinetics, adsorption isotherms, desorption and adsorbent regeneration. The adsorption of organic dyes (cationic methylene blue, MEB, and anionic methyl orange, MO) on TPP-NH2 was fast, and most of the dyes were adsorbed in 60 min. The adsorption of MEB and MO follows pseudo-second-order kinetics and fits the Langmuir model, where the maximum adsorption capacity increased from 204.9 mg g(-1) to 560.6 mg g(-1) and 213.2 mg g (-1) to 803.2 mg g(-1) for MEB and MO, respectively, as the temperature increased, suggesting that the adsorption of MEB and MO on TPP-NH2 is favorable at high temperatures via an endothermic process. The pH has no obvious effect on the adsorption of MEB and MO. The used TPP-NH2 could be regenerated effectively and recycled at least five times without a significant loss of adsorption capacity. In addition, the TPP-NH2 can adsorb up to 33 times its own weight in organic solvents while wiping off the water. The high surface area, hierarchical porosity and pi-pi stacking interactions between the aromatic rings of MEB and MO and the aromatic rings of 3D TPP-NH2 were responsible for the efficient adsorption. Therefore, the TPP-NH2 that was synthesized using the facile strategy possesses significant potential in the treatment of wastewater.