Ammonium-Functionalized Hollow Polymer Particles As a pH-Responsive Adsorbent for Selective Removal of Acid Dye
Ammonium-Functionalized Hollow Polymer Particles As a pH-Responsive Adsorbent for Selective Removal of Acid Dye
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铵官能化中空聚合物颗粒作为 pH 响应型吸附剂用于选择性去除酸性染料
DOI：
10.1021/acsami.6b04199
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发表时间：
2016-07-06
影响因子：
9.5
通讯作者：
Yang, Wantai
中科院分区：
文献类型：
--
作者：
Qin, Yan;Wang, Li;Yang, Wantai
在这项工作中，专门设计并合成了一种壳内具有高密度铵基团的新型铵功能化空心聚合物颗粒（HPP-NH3+）。得益于高表面积和高密度的带正电荷的铵基团，所制备的 HPP-NH3+ 可以作为选择性吸附剂来去除带负电荷的酸性染料（例如甲基蓝 a-MB）。使用Freundlich和Langmuir等温线模型评估a-MB在HPP-NH3+上的平衡吸附数据，Langmuir等温线表现出更好的拟合，最大吸附容量为406 mg/g。最重要的是，由于双官能团（铵基和羧基）的存在，HPP-NH3+表现出显着的pH依赖性平衡吸附能力，当溶液pH值从9降至2时，平衡吸附能力从59 mg/g急剧增加到449 mg/g。这种独特性使得吸附的染料HPP-NH3+可以在温和条件下（弱碱性溶液，pH 10）轻松再生，以回收a-MB和HPP-NH3+，而传统吸附剂的回收通常在特别恶劣的条件下进行。再生后的HPP-NH3+可重复用于染料去除，即使经过5次吸附脱附循环后，去除效率仍保持在98%以上。 HPP-NH3具有高吸附容量、pH敏感性、易于再生和良好的重复使用性，在水处理、药物控制释放和pH响应递送领域具有巨大的应用潜力。
In this work, a novel type of ammonium-functionalized hollow polymer particles (HPP-NH3+) with a high density of ammonium groups in the shell has been specially designed and synthesized. Benefiting from both the high surface area and from the high density of positively charged ammonium groups, the as-prepared HPP-NH3+ can serve as a selective adsorbent for the removal of negatively charged acid dye (e.g., methyl blue a-MB). The equilibrium adsorption data of a-MB on the HPP-NH3+ were evaluated using Freundlich and Langmuir isotherm models, and Langmuir isotherm exhibited a better fit with a maximum adsorption capacity of 406 mg/g. Most importantly, because of the presence of dual functional groups (ammonium and carboxyl groups), the HPP-NH3+ showed a significant pH-dependent equilibrium adsorption capacity, which increased dramatically from 59 mg/g to 449 mg/g as the solution pH decreased from 9 to 2. This uniqueness makes the dye adsorbed HPP-NH3+ can be facilely regenerated under mild condition (in weak alkaline solution, pH 10) to recover both a-MB and the HPP-NH3+, whereas the recovery of conventional adsorbents is commonly performed under particularly severe conditions. The regenerated HPP-NH3+ can be reused for dye removal and the dye removal efficiency remained above 98% even after five adsorption desorption cycles. Because of its high adsorption capacity, pH-sensitivity, easy regeneration, and good reusability, the HPP-NH3 has great potential for the application in the field of water treatment, controlled drug release, and pH responsive delivery.