Pillararene polymers have been widely used as excellent adsorbents for water treatment, but pillararene polymers with ultra-high specific surface area and versatility are still rarely reported. Herein, a quaternary ammonium salt modified pillar [5] arene polymer, QPBP [5], with specific surface area of 1844 m2 g-1 was successfully synthesized. Since QPBP [5] has abundant different adsorption sites, it exhibits excellent performance for the simultaneously removal of organic pollutants with different charges from water. The selected three model pollutants, Rhodamine B (RhB, positively charged), Sulfamethazine (SMT, electrically neutral) and Fulvic acid (FA, negatively charged), could be rapidly and efficiently removed from water by QPBP [5] within 10 min, which are much faster than them by most of the reported adsorbents. RhB and SMT are mainly adsorbed through hydrophobic interactions with the QPBP [5] surface, while FA is mainly removed through ion exchange. In addition, QPBP [5] also showed excellent reusability and adsorption performance for the environmentally relevant concentration of pollutants. Furthermore, the quaternary ammonium groups on QPBP [5] makes it a solid disinfectant with excellent antibacterial properties. In conclusion, QPBP [5] is a promising multifunctional adsorbent for the treatment of complex pollutants in water.

Organic micropollutant in the aquatic environment has become a worldwide problem. In this study, a new DMpillar[5]arene-based porous organic polymer (DMPBP[5]) with the highest surface area of 1347.4 & PLUSMN; 39.3 m(2) g(-1) is developed through Friedel-Crafts alkylation reaction between DMpillar[5]arene (DMP5) and 4,4 & PRIME;-bis (chloromethyl)-1,1 & PRIME;-biphenyl (BCMBP) to remove a wide range of organic micropollutants with fast removal rate and large uptake amounts. The synthesized DMPBP[5] can capture many types of organic pollutants in water including positively charged, negatively charged and neutral ones and those with different hydrophilicity, through host-guest interaction, hydrophobic interaction, electrostatic interaction and 7C-7C interaction. For some pollutants, the adsorption kinetic constants of DMPBP[5] are thousands of times larger than that of activated carbon (AC) and even 104-105 times larger than that of resin (XAD-4), and the adsorption capacities of DMPBP[5] are about 3 and 4 times higher than that of AC and XAD-4, respectively. The superior adsorption performance of DMPBP[5] is attributed to permanent porosity and accessible binding sites because of the introduction of rigid structure. Even at environmentally relevant concentrations, DMPBP[5] can quickly remove the pollutants simultaneously and can be easily regenerated with methanol under ambient conditions. In short, due to the wide adsorption range, excellent adsorption performance, and easy recyclability, DMPBP[5] is an excellent adsorbent for wastewater treatment with great application potential.

Keeping water clean is of vital significance for human health and environmental protection. In order to remove organic micro-pollutants and natural organic substances in water bodies and kill pathogenic microorganisms simultaneously, this study synthesized a multifunctional porous β-cyclodextrin polymer with a high specific surface area by introducing quaternary ammonium groups and rigid benzene rings, respectively, which was then polymerized with crosslinking agent-4,4'-bis (chloromethyl)-1,1'-biphenyl (BCMBP) in an ionic liquid system. The grafting of quaternary ammonium groups was beneficial for the removal of negative-charged humic acid (HA) and sterilization. The introduction of numerous rigid structures during benzylation and Friedel-Crafts alkylation reaction could significantly improve the porosity and specific surface area of the polymer, conducive to the exposure of cyclodextrin binding sites and contaminant adsorption. By changing the proportions of quaternization and benzylation, the structure and surface properties of the polymer could be adjusted, thus further regulating the adsorption performance. Compared with activated carbon, the polymer named BQCD-BP with a huge surface area of 1133 m2 g-1 prepared under optimized conditions showed outstanding adsorption performance and sterilization ability. The pseudo-second-order kinetic constant of BQCD-BP reached 1.2058 g·mg-1·min-1, which was approximately 50 times greater than that of activated carbon (0.0256 g·mg-1·min-1) under the same experimental condition. The adsorption capacity of BQCD-BP to HA was twice as high as that to AC, and the antibacterial ability of BQCD-BP was significant, achieving 90% at the dosage of 1g L-1. Moreover, the adsorption process was hardly affected by the hydrochemical conditions, and the polymer was easy to regenerate. In addition, the excellent adsorption and antibacterial performance of the polymer were also identified by natural water treatment. COD was almost completely removed, and the removal efficiency of TP reached 92% after contact with BQCD-BP. The sterilization rate of BQCD-BP to viable bacteria in complex water bodies reached 82%. Undoubtedly, BQCD-BP is a potential multifunctional water treatment material with reasonable design in the actual water purification.

Porous thienyl cyclodextrin polymer was synthesized in a green recyclable ionic liquid system for the first time to remove PPCPs.