College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
College of Energy, Xiamen University, Xiamen, 361102, China.
Chemosphere. 2021 Jun;272:129640. doi: 10.1016/j.chemosphere.2021.129640. Epub 2021 Jan 13.
The mesoporous poly(N,N'-methylene-bis(1-(3-vinylimidazolium)) chloride), labeled as PDVIm-Cl, with double anions (Cl) and low monomer molecular weight was synthesized and applied in the adsorption of anionic dyes (acid orange 7 (AO7), sunset yellow (SY), reactive blue 19 (RB19), congo red (CR)). Due to the mesoporous structure, abundant Cl and positively charged imidazole rings, the poly(ionic liquid) (PIL) exhibited superior adsorption ability towards anionic dyes. What is more, the RB19 adsorption by PDVIm-Cl could achieve the highest capacity (2605 ± 254 mg g) which was nearly twice higher than the maximum adsorption capacity of the previously reported materials. All the adsorption kinetic data and isotherms fitted well with the pseudo second-order model and Langmuir-Freundlich model. To better explore the practical potential of the PIL for dye adsorption, the adsorption under different pH values and column adsorption performances were also evaluated. Results showed that PDVIm-Cl exhibited high removal efficiencies for anionic dyes over a wide pH range (2-10). Also, the great reusability could be well demonstrated by the achievable continuous column adsorption-desorption process. It is worth mentioning that the regeneration could be realized with very little desorbent which was far less than the adsorption volume flowing through the column and the desorption efficiency was well maintained after three consecutive cycles. At last, the adsorption mechanism was explored by experiments combined with quantum chemical calculations and showed anionic dyes adsorption by PDVIm-Cl was a joint process dominated by the ion exchange, electrostatic interaction, hydrogen bond and π-π stacking.
介孔聚（N，N'-亚甲基双（1-（3-乙烯基咪唑））氯化物），标记为 PDVIm-Cl，具有双阴离子（Cl）和低单体分子量，被合成并应用于阴离子染料（酸性橙 7（AO7）、日落黄（SY）、活性蓝 19（RB19）、刚果红（CR））的吸附。由于具有介孔结构、丰富的 Cl 和带正电荷的咪唑环，该聚（离子液体）（PIL）对阴离子染料表现出优异的吸附能力。此外，PDVIm-Cl 对 RB19 的吸附能力达到了最高容量（2605 ± 254 mg g），几乎是之前报道的材料最大吸附容量的两倍。所有吸附动力学数据和等温线都很好地符合伪二级模型和 Langmuir-Freundlich 模型。为了更好地探索 PIL 对染料吸附的实际潜力，还评估了不同 pH 值下的吸附和柱吸附性能。结果表明，PDVIm-Cl 在很宽的 pH 范围（2-10）内对阴离子染料表现出高去除效率。此外，通过实现连续的柱吸附-解吸过程，很好地证明了其良好的可重复使用性。值得一提的是，通过使用远远少于流过柱子的吸附体积的少量洗脱剂即可实现再生，并且在连续三个循环后解吸效率保持良好。最后，通过实验结合量子化学计算探索了吸附机制，表明 PDVIm-Cl 对阴离子染料的吸附是一个由离子交换、静电相互作用、氢键和π-π堆积共同主导的联合过程。
