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A novel isoxazoline‐based porous adsorbent (PB‐TTNO) is prepared by click polymerization and freeze‐drying from a methyl‐containing bis(nitrile oxide) stable at room temperature. The introduction of four methyl groups around the nitrile oxide group reduces the activity of the bis(nitrile oxide) and make it react more mildly with polybutadiene, resulting in PB‐TTNO with a more uniform pore size. Meanwhile, the electron‐donating methyl groups further increase the π–π interaction between the polymer benzene ring and the TNT benzene ring. The π–π interaction enables one benzene ring in the polymer to interact with two TNT molecules to form a sandwich structure, which further improves the adsorption capacity. The synergistic effect of dual π–π interactions and dipole‐π interactions makes the maximum adsorption capacity of PB‐TTNO reach 235.3 mg g−1 within 12 h at 25°C. The factors such as pH value, adsorbent dosage, contact time, initial TNT concentration, and temperature are also discussed. The adsorption kinetics fit well with the pseudo‐second‐order model, and the Langmuir model exhibits better correlation for equilibrium data analysis. In addition, the adsorption data of PB‐TTNO in real water samples are similar to those in laboratory, and the maximum adsorption capacity decreases by only 15% after five adsorption–desorption cycles. [ABSTRACT FROM AUTHOR]

The efficient separation of low-concentration radionuclides by the eco-friendly adsorbent is a compelling requirement in the development of nuclear industry. Hence, a novel composite consisted of one-dimensional palygorskite (Pal) and three-dimensional pomelo peel (PP) is prepared by self-assembly approach (PP/Pal) and coupling agent approach (PP/KPal) for removing uranium (U(VI)) from aqueous solution. Moreover, the mass ratio (PP/Pal), adsorbent dosage, pH, contact time, temperature, and ionic strength are investigated. Two adsorption kinetic models and isotherm models are used to investigate the kinetic behaviors and adsorption capacity, respectively. The maximum adsorption capacities were 370.5 mg·g−1 on PP/Pal and 357.3 mg·g−1 on PP/KPal at pH 6.0, contact time 150 min and 25 °C. Meanwhile, the composite can be easily separated from water via a simple filtering. Furthermore, thermodynamic parameters indicate that adsorption is an endothermic and spontaneous process. And the surface complexation, ion exchange, and electrostatic attraction play a vital role. This work shows that the PP/Pal composite with high efficiency, low cost, and green has a further application in the treatment of wastewater containing U(VI). [ABSTRACT FROM AUTHOR]

This cover image by Yewei Xu and Hongyang Deng demonstrates the adsorption mechanism of TNT by the isoxazoline-based porous polymer. The polymer has an unprecedented adsorption capacity for TNT through the - and dipole- interactions. In addition, the polymer possesses recycling properties. [Extracted from the article]

• Click polymerization was used for efficient adsorption of TNT. • Synergistic effect of Lewis acid-base, dipole-π, and π-π interactions was applied. • The maximum adsorption capacity at 25°C was up to 90.7 mg/g within 3 h. • The porous polymer was reversible and could be reused. A series of hydrophobic porous polymer containing isoxazoline and siloxane groups were successfully prepared via catalyst-free click polymerization and freeze-drying technology. In addition to hydrophobicity, synergistic effect of three molecular aborption interactions, namely point-to-point Lewis acid-base, point-to-face dipole-π, and face-to-face π-π interactions, endowed the resulting porous polymer with good 2,4,6-trinitrotoluene (TNT) adsorption efficiency from wastewater. At the same time, the adsorption efficiency of the resulting porous polymer in different natural/polluted water samples was similar to those in laboratory, and about 80% of the initial adsorption capacity remained after five adsorption-desorption cycles. The results showed that hydrophobic porous polymer containing isoxazoline and siloxane groups is a promising adsorbent for the treatment of TNT wastewater. [ABSTRACT FROM AUTHOR]