化学学报 ›› 2015, Vol. 73 ›› Issue (2): 116-125.DOI: 10.6023/A14110779 上一篇    下一篇

研究论文

功能性离子液体萃取水溶液中Cu2+:实验与理论

刘梦莹a, 车佳宁a, 吴蔚闳a, 卢运祥a, 彭昌军a, 刘洪来a, 卢浩b, 杨强b, 汪华林b   

  1. a 华东理工大学结构可控先进功能材料及其制备教育部重点实验室和化学系 上海 200237;
    b 华东理工大学国家环境保护化工过程环境风险评价与控制重点实验室 上海 200237
  • 收稿日期:2014-11-12 出版日期:2015-02-14 发布日期:2015-01-29
  • 通讯作者: 彭昌军, cjpeng@ecust.edu.cn; Tel &Fax: 021-64252218;杨强, qyang@ecust.edu.cn, Tel &Fax: 021-64252748. E-mail:cjpeng@ecust.edu.cn;qyang@ecust.edu.cn
  • 基金资助:

    项目受国家自然科学基金(Nos. 21103047, 21136004)和中央高校基本科研业务费资助(No. 222201313001).

Extraction of Copper from Aqueous Solution with Functional Ionic Liquids: Experiment and Theoretical Calculation

Liu Mengyinga, Che Jianinga, Wu Weihonga, Lu Yunxianga, Peng Changjuna, Liu Honglaia, Lu Haob, Yang Qiangb, Wang Hualinb   

  1. a Key Laboratory for Advanced Materials and Department of Chemistry, East China University of Science and Technology, Shanghai 200237, China;
    b Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China
  • Received:2014-11-12 Online:2015-02-14 Published:2015-01-29
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21103047, 21136004) and the Fundamental Research Funds for the Central Universities of China (No. 222201313001).

本工作针对含硫脲基咪唑憎水功能离子液体在溶液中Cu2+萃取方面的应用及其机理进行研究. 考察了萃取两相体积比、金属离子浓度、时间、无机盐NaCl、溶液pH及离子液体烷基链长等因素的影响. 结果表明: 室温条件下, 0.1 mL离子液体[CnMPSM][PF6] (n=4、6、8)与5 mL 21.94 mg/L的氯化铜溶液室温条件下超声混合30 min, 溶液中Cu2+的去除率即超过95%; 且此类离子液体对金属离子的萃取效果顺序为: n=4≈n=6>n=8. 以[HMPSM][PF6]为研究对象, 发现溶液中无机盐NaCl的含量以及溶液pH 对金属离子的萃取效果影响不明显. 与传统离子液体[Cnbim][PF6] (n=6、8)相比, 硫脲基的引入使其萃取率由20%左右提高到99%, 且有效避免因阳离子交换而引起水中咪唑阳离子含量增加问题. 通过理论计算发现, 功能离子液体对金属离子的萃取依赖于官能团中的S元素与Cu2+之间较强的静电及路易斯酸碱作用, 与萃取实验中离子液体未和Cu2+发生阳离子交换作用相吻合.

关键词: 硫脲, 离子液体, 萃取, 金属铜离子, 计算

This work studied the extraction of copper (II) ions from aqueous solution with thiourea-appended imidazolium hydrophobic ionic liquids and the extraction mechanism by experiment and theory. The influence of parameters affecting the extraction of copper ion, such as the metal ion concentrations, volume ratio between aqueous solution and ionic liquid, contact time, sodium chloride and pH, as well as alkyl chain length was analyzed. In the case of room temperature, the volume ratio between aqueous/IL phases was 50, the extraction efficiencies >95% could be obtained for copper ion with all the ionic liquids [CnMPSM][PF6] (n=4, 6, 8). The results also suggest that n=4 did the same work on the extraction efficiency with n=6 but higher than n=8, while pH and the salt in the solution had little effect on the extraction efficiency for the extraction with [HMPSM][PF6]. The grafted functional group significantly enhanced the extraction efficiency for Cu2+ from 20% to over 99% compared with traditional ILs. To the IL [HMPSM][PF6], the content of imidazolium cation in the aqueous solution before and after extraction with functional IL reduces from 1.24% to 0.85% which means the coordination effect between functional group and the metal ion restrains the release of [HMPSM]+ cation from functional IL to the aqueous solution, while it increases from 0.63% to 0.87% for traditional IL, which is consistent with the results caused by the cation exchange mechanism. In the theory part, the lanl2dz-ECP basis set was employed for transition metal Cu, whereas for the remaining atoms 6-31G (d,p) was applied, cation-anion interaction energies of the ILs and the binding energies between Cu (II) ion and the ILs were calculated, also the surface properties most-negative-surface electrostatic potential (Vs,min) and the lowest surface average local ionization energy (īs,min), were determined by the Multiwfn 2.4 program. All the calculation results show that the sulfur atom from cation is easier to attract the metal ion electrostatically and covalently, thus leads to the high efficiency of extraction.

Key words: thiourea-appended, ionic liquids, extraction, copper, calculation