The synthesis of adsorbents that meet the need for large-scale production at relatively low cost and are capable of removing anionic and cationic toxic dyes from aqueous solutions, with high sorption capacity and reusability, is urgently needed from an environmental and industrial viewpoint. In this context the identification of hydrogels that remove dyes efficiently under ambient conditions and at near-neutral pH without the necessity of pre-treatment is an imperative. In this study we report the preparation of two hydrogels using the redox polymerisation of acrylamide, hydroxyethylmethacrylate (HEMA) and N-isopropylacrylamide (H1) and acrylamide, HEMA, N-isopropylacrylamide and perylene-5-ylpent-3-yne-2-methylprop-2-enoate-co-2-methyl-2-(prop-2-enoylamino)propane-1-sulfonic acid (PePnUMA-co-AMPS) (H2). These hydrogels proved to be effective for the removal of methylene blue (MB), fuchsin acid (FA) and Congo Red (CR) from aqueous solution at near-neutral pH where their adsorption behaviour was in keeping with the Langmuir model having q_max values of 769.2 mg g⁻¹ (MB), 1666.7 mg g⁻¹ (FA) and 2358.2 mg g⁻¹ (CR). The adsorption of MB and FA by these hydrogels follows pseudo-first-order kinetics, whilst the adsorption of CR follows pseudo-second-order kinetics. Detailed thermodynamic analysis indicated that the dye–adsorbent interaction is primarily one of physisorption in nature. Finally, desorption studies carried out in 1.0 mol L^–1 NaClO₄ indicated that these adsorbents could be recycled at least four times using a variety of dyes while maintaining their mechanical properties. © 2021 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

中文翻译：

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一种有效的可重复使用的苝水凝胶，用于去除污染水中的一些有毒染料

从环境和工业的角度来看，迫切需要合成能够以相对较低的成本满足大规模生产需求、能够从水溶液中去除阴离子和阳离子有毒染料、具有高吸附能力和可重复使用性的吸附剂。在这种情况下，确定在环境条件下和接近中性 pH 值下无需预处理即可有效去除染料的水凝胶势在必行。在这项研究中，我们报告了使用丙烯酰胺、甲基丙烯酸羟乙酯 (HEMA) 和N-异丙基丙烯酰胺( H1 ) 和丙烯酰胺、HEMA、N-异丙基丙烯酰胺和 perylene-5-ylpent-3-yne-2-methylprop的氧化还原聚合制备两种水凝胶-2- enoate-合作-2-甲基-2-(丙-2-烯酰氨基)丙烷-1-磺酸(PePnUMA- co- AMPS) ( H2 )。这些水凝胶被证明是有效除去亚甲蓝（MB）中，从在接近中性pH值的水溶液品红酸（FA）和刚果红（CR），其中它们的吸附的行为与Langmuir模型保持具有q_最大值769.2 mg g ^-1 (MB)、1666.7 mg g ^-1 (FA) 和 2358.2 mg g ^-1(CR)。这些水凝胶对 MB 和 FA 的吸附遵循伪一级动力学，而 CR 的吸附遵循伪二级动力学。详细的热力学分析表明，染料-吸附剂相互作用主要是自然界中的一种物理吸附。最后，在 1.0 mol L ^–1 NaClO _{4 中}进行的解吸研究表明，这些吸附剂可以使用各种染料至少回收四次，同时保持其机械性能。© 2021 作者。由 John Wiley & Sons Ltd 代表化学工业协会出版的Polymer International。