Shen Haoyu, Sun Meina, Hu Meiqin, Cheng Jinjin
Ningbo Institute of Technology, Zhejiang University Ningbo 315100 China
Greentown Agricultural Testing Technology Co., Ltd Hangzhou 310052 China.
RSC Adv. 2018 Aug 23;8(52):29928-29938. doi: 10.1039/c8ra06085a. eCollection 2018 Aug 20.
A series of ethylenediamine-grafted ion imprinted magnetic polymers (FeO@IIPs) were synthesized ultrasonic assisted suspension polymerization with perchlorate (ClO ) as an ion imprinting template. They were characterized by XRD, EA, VSM, FTIR and XPS and applied as adsorbents for ClO removal from aqueous solutions. The effects of the usage amount of crosslinking agent divinylbenzene (DVB) used for preparation on the structure and the adsorptive performance of FeO@IIPs were investigated. The results show that the FeO@IIPs have an average size of 200-800 nm, which increases with the increase of the amount of DVB from 0 to 2 g during the preparation process. The saturation magnetization intensities are at 35.6-42.8 emu g, which decrease with the increase of the usage amount of DVB. The addition of DVB is beneficial to the formation and stability of the ion imprinted cavity of FeO@IIPs. The effects of the solution pH value, initial concentration of ClO , and adsorption time on the adsorption properties of ClO in aqueous solutions were investigated. The results show that the adsorption capability is affected significantly by solution pH value and reaches the maximum adsorption capacity at pH 3.0. The best adsorption capacity and selectivity of FeO@IIPs to ClO can be obtained when the usage amount of DVB is at 0.5 g for synthesis. The adsorption mechanisms might include both ion exchange and electrostatic interaction. The isothermal adsorption curves mainly obey the Langmuir model with the theoretical maximum adsorption capacities ( ) at 76.92-111.1 mg g and the experimental maximum adsorption capacities ( ) at 75.7-108.9 mg g, respectively, which are much higher than those of the non-ion imprinted material (FeO@NIP, : at 60.61 mg g and at 59.0 mg g). The adsorption kinetic studies show that the adsorption processes reach equilibrium within 10 min and the kinetic data are well fitted to the pseudo-second-order model. There is almost no interference by the coexisting anions for the selective adsorption of ClO , with a imprinting factor () at 1.8, and selectivity factor () larger than 5.9 for several kinds of common co-existing anions, respectively. The FeO@IIPs are ideal candidates for removal of ClO from aqueous solution.
通过超声辅助悬浮聚合法，以高氯酸盐（ClO₄⁻）为离子印迹模板，合成了一系列乙二胺接枝的离子印迹磁性聚合物（Fe₃O₄@IIPs）。采用X射线衍射（XRD）、元素分析（EA）、振动样品磁强计（VSM）、傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）对其进行了表征，并将其用作从水溶液中去除ClO₄⁻的吸附剂。研究了制备过程中交联剂二乙烯基苯（DVB）用量对Fe₃O₄@IIPs结构和吸附性能的影响。结果表明，Fe₃O₄@IIPs的平均粒径为200 - 800 nm，在制备过程中，随着DVB用量从0增加到2 g，粒径增大。饱和磁化强度为35.6 - 42.8 emu/g，随DVB用量的增加而降低。DVB的加入有利于Fe₃O₄@IIPs离子印迹空腔的形成和稳定性。考察了溶液pH值、ClO₄⁻初始浓度和吸附时间对水溶液中ClO₄⁻吸附性能的影响。结果表明，吸附能力受溶液pH值影响显著，在pH 3.0时达到最大吸附容量。当合成时DVB用量为0.5 g时，Fe₃O₄@IIPs对ClO₄⁻具有最佳的吸附容量和选择性。吸附机制可能包括离子交换和静电相互作用。等温吸附曲线主要符合Langmuir模型，理论最大吸附容量（qₘ）为76.92 - 111.1 mg/g，实验最大吸附容量（qₑ）为75.7 - 108.9 mg/g，均远高于非离子印迹材料（Fe₃O₄@NIP，qₘ：60.61 mg/g，qₑ：59.0 mg/g）。吸附动力学研究表明，吸附过程在10 min内达到平衡，动力学数据与准二级模型拟合良好。共存阴离子对ClO₄⁻的选择性吸附几乎没有干扰，印迹因子（IF）为1.8，对几种常见共存阴离子的选择性因子（SF）均大于5.9。Fe₃O₄@IIPs是从水溶液中去除ClO₄⁻的理想材料。
