Bifunctional Porous Organic Polymers Based on Postfunctionalization of the Ketone-Based Polymers

Two novel nitrogen-rich metal-organic nanotubes: syntheses, structures and selective adsorption toward rare earth ions

The construction and development of metal-organic nanotubes (MONTs) with nanoscale interior channel diameters for potential applications is of great interest. An angular nitrogen-rich ligand, 3,6-bis(2-ethylimidazole)-2-methylpyrimidine (beim-CH3), was designed to construct MONTs by coupling with the V-shaped carboxylate ligands of benzophenone 4,4'-dicarboxylic acid (H2bpndc) and 4,4'-oxybisbenzoic acid (H2obba). Two new MONTs were synthesized and named NCD-166 ([Zn(bpndc)(beim-CH3)]·H2O) and NCD-167 ([Zn(obba)(beim-CH3)]·H2O), and they were isostructural and have almost identical tube inner diameters of approximately 1.76 nm. Benefiting from the abundantly exposed nitrogen and oxygen atoms in their tube walls and open nanoporous channels, they display superior adsorption capacities for Eu3+ (150.90 mg g-1) and high adsorption selectivity (>96%) in the low-concentration solutions. Additionally, it was revealed that the adsorption effect of ether oxygen on rare earth elements was significantly better than that of carbonyl oxygen. The adsorption isotherm conformed to the Langmuir model and the adsorption kinetics obeyed the pseudo-second-order model. These results clearly indicate that such novel MONTs are favorable sorbents for REEs.

Preparation of hypercrosslinked porous polymer with manifold functional groups for sensitive determination of phenylurea herbicides in beverages and celtuce samples

Wide use of phenylurea herbicide has caused serious residue problem and threaten human health. It is important to develop viable method for their sensitive determination. Herein, a multi-functionalized porous polymer was prepared by crosslinking hexafluorobisphenol A with pyromellitic dianhydride. Using the multi-functionalized porous polymer as solid phase extraction sorbent, combined with high performance liquid chromatography, a sensitive method was established for determining phenylurea herbicides in beverages and celtuces. High sensitivity was achieved, with method detection limit (S/N = 3) of 0.01---0.025 ng mL-1 for beverages, 1.70 ng g-1 for celtuce, and quantitation limits of 0.03---0.10 ng mL-1 for beverages, 5.00 ng g-1 for celtuce. The method recoveries were 80.5---120.0 % with relative standard deviations lower than 6.1%. Adsorption mechanism mainly involved F-π, F-O, π-π, polar interactions and hydrogen-bonding interactions. This study offers a simple protocol to develop multi-functional sorbents for extraction of organic pollutants.

Carboxyl functionalized sorbent based solid-phase extraction for sensitive determination of endocrine disrupting chemicals in bottled water, juice and milk

Endocrine disrupting chemicals (EDCs) pose a serious threat to human health even at extremely low concentration. Three carboxyl functionalized porous polymers (PDA-DPBP, PTCDA-DPBP and ODPA-DPBP) were synthesized for the first time and employed as solid-phase extraction sorbent to enrich phenolic EDCs at trace level. Compared with PTCDA-DPBP, ODPA-DPBP and corresponding carboxyl-free counterpart (PC-DPBP), PDA-DPBP delivered superior enrichment efficiency for the phenolic EDCs, which can be ascribed to the strong hydrogen bonding, pore filling, hydrophobic interaction and π-π interaction between PDA-DPBP and phenolic EDCs. Coupled with high performance liquid chromatography, phenolic EDC residues in bottled water, juice and milk samples were enriched and determined. At the optimum conditions, the PDA-DPBP based method provided a good linear response in the range of 0.04-100ng mL-1 for bottled water, 0.07-100ng mL-1 for juice and 0.15-500ng mL-1 for milk samples. The detection limits (S/N=3) were 0.01-0.04, 0.02-0.06 and 0.05-0.10ng mL-1 for bottled water, juice and milk, respectively. The method recoveries were in the range from 81.6% to 116%, with RSDs ≤ 7.7%. This work provides an attractive and reliable alternative method for sensitive determination of phenolic EDCs.

Novel Carbazole-Based Porous Organic Polymer for Efficient Iodine Capture and Rhodamine B Adsorption

A new porous organic polymer (CTF-CAR), which takes carbazole as the electron-rich center unit and thiophenes as the auxiliary group, has been synthesized through catalyst-free Schiff-base polymerization. At the same time, the structure, thermal stability, morphology, and other basic properties of the polymer were analyzed by IR, NMR, TGA, and SEM. Then, CTF-CAR was applied to iodine capture and rhodamine B adsorption. Due to its strong electron donor ability and abundant heteroatom binding sites, which have a positive effect on the interaction between the polymer network and adsorbates, CTF-CAR exhibits high uptake capacities for iodine vapor and rhodamine B as 2.86 g g-1 and 199.7 mg g-1, respectively. The recyclability test also confirmed that it has good reusability. We found that this low-cost and catalyst-free synthetic porous organic polymer has great potential for the treatment of polluted water and iodine capture.