研究报告
孔岩,韩志勇,庄媛,郝昊天,韩昆,石宝友,于建伟.磁性高分子复合水凝胶的制备及其对水中铜离子的吸附性能[J].环境科学学报,2018,38(3):1001-1009
磁性高分子复合水凝胶的制备及其对水中铜离子的吸附性能
- Preparation of magnetic polymer hydrogel and their application in Cu(II) removal from water
- 基金项目:国家重点研发计划项目(No.2016YFA0203204)
- 孔岩
- 1. 兰州理工大学石油化工学院, 兰州 730050;2. 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085
- 韩志勇
- 兰州理工大学石油化工学院, 兰州 730050
- 庄媛
- 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085
- 郝昊天
- 1. 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085;2. 北京林业大学环境科学与工程学院, 北京 100083
- 韩昆
- 1. 兰州理工大学石油化工学院, 兰州 730050;2. 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085
- 石宝友
- 1. 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085;2. 中国科学院大学, 北京 100049
- 于建伟
- 1. 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085;2. 中国科学院大学, 北京 100049
- 摘要:以海藻酸钠和聚乙烯醇为骨架负载磁性纳米Fe3O4颗粒合成了两种磁性高分子复合水凝胶材料:一种是以Ca2+交联制备的磁性海藻酸钙单网络水凝胶(SAPFe),另一种是以海藻酸钙和聚乙烯醇经循环冷冻解冻制成的磁性双网络水凝胶(DAPFe).利用SEM、FTIR、BET对合成的材料进行表征,并研究了SAPFe和DAPFe对Cu2+的吸附性能.结果表明,DAPFe比表面积达89.01 m2·g-1,平均孔径为2.2 nm,DAPFe比SAPFe具有更低的含水率、更高的交联程度、更发达的孔隙结构和更高的比表面积.DAPFe对Cu2+的最大吸附量可达207.01 mg·g-1,远大于SAPFe(173.01 mg·g-1).SAPFe和DAPFe对Cu2+的吸附等温线均符合Langmuir模型,吸附动力学符合准二级吸附动力学模型.通过分析SAPFe和DAPFe吸附Cu2+前后官能团的变化,发现磁性高分子复合水凝胶具有丰富的羧基和羟基功能性官能团,并通过与Cu2+产生螯合作用实现去除.
- Abstract:Two kinds of magnetic polymer hydrogel materials were synthesized with sodium alginate, polyvinyl alcohol and Fe3O4 nanoparticles as novel magnetic adsorbents to remove copper ions from aqueous solution:One is the single network magnetic hydrogel (SAPFe) prepared by Ca2+ crosslinking, and the other is the double network magnetic hydrogel (DAPFe) made by the cyclic freezing and thawing of SAPFe. Magnetic Fe3O4 nanoparticles were mixed into the hydrogels to create magnetic response and effectively separated by using an external magnetic field. The hydrogels were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and BET surface area. The results show that the specific surface area of the DAPFe was 89.01 m2·g-1 which is higher than that of SAPFe. The DAPFe has average pore size of 2.2 nm. The Maximum adsorption capacity of Cu2+ on SAPFe reaches 207.01 mg·g-1, which is higher than SAPFe (173.01 mg·g-1). The results indicate that the adsorption process for Cu2+ could be well described by the Langmuir adsorption isotherm model, and the adsorption kinetics follow the pseudo-second order kinetics equation. FTIR spectra before and after adsorption of Cu2+ on the SAPFe and DAPFe implies that the chelation between -COOH-/-OH groups and Cu2+ is the main removal mechanism.