Article

Interfacial Behavior of Acidic Organophosphorus Extractant Monolayer at Air-Water Interface: Subphase pH and Spreading Solvent Effect

  • Gao Zhen ,
  • Huang Kun ,
  • Du Lin ,
  • Liu Huizhou
Expand
  • a Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190;
    b School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083;
    c Environment Research Institute, Shandong University, Qingdao 266237;
    d School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049

Received date: 2019-01-02

  Online published: 2019-03-18

Supported by

Project supported by the National Natural Science Foundation of China (Nos. 51574213, 51074150).

Abstract

The interfacial properties of extractant molecules have a significant impact on their complexation reaction activity with rare earth ions at liquid-liquid interface during solvent extraction. Although it is known that acidic organophosphorus extractant exists mainly in the form of dimers in nonpolar organic solvent, the research on solvent extraction kinetics has pointed out that the extractant molecules should react with rare earth ions in the form of monomers at the interface. Therefore, understanding the existing forms of acidic organophosphorus extractant at the interface will help comprehend the interfacial reaction process in solvent extraction. Traditionally, the interfacial properties of the extractant molecules were investigated by measuring interfacial tension isotherms and calculating interfacial adsorption parameters. However, this method can not provide the information of interfacial active species and the aggregation behavior of them. In order to clarify the characteristics of the interfacial behavior of organic extractant molecules at the interface, the effect of subphase pH and the polarity of spreading organic solvent on the adsorption and aggregation behavior of P507 molecules at the air-water interface were investigated by surface pressure-area isotherms and infrared reflectance absorption spectroscopy (IRRAS) based on Langmuir monolayer technique. It was found that P507 monolayers spread by n-hexane at the air-water interface had a certain solubility in the subphase water due to the ionization of the polar groups of P507 molecules. And the solubility decreased as the subphase pH decreased. Thus, the surface pressure-area isotherms changed significantly due to the total amount of P507 molecules remaining on the surface of water changed with the subphase pH. When the subphase pH decreased below 2.0, the influence of the solubility of P507 molecules became inapparent and the amount of P507 molecules remaining on the surface water was almost unchanged. The intermolecular hydrogen bonds formed between the polar groups due to the protonation degree of P507 monolayers improved and the hydration ability of P507 polar groups was weakened. The aggregates formed in the monolayer were confirmed by the red shift of P-O-H groups in IRRAS spectra. However, when the P507 monolayers were spread by polar organic solvent (dichloromethane and chloroform), the existing forms of P507 molecules in the monolayers were changed with the polarity of spreading solvent. And the π-A isotherms of P507 monolayers didn't exhibit the shrinkage of molecular area which existed in the monolayers spread by n-hexane when subphase pH decreased. It meant that the existing forms and aggregation behavior of P507 molecules in monolayers could be altered by the spreading solvent and more P507 monomers existed in the monolayer as the polarity of spreading solvent increased. The conclusion was confirmed by the shift of the peak positions of P-O-H with the spreading solvent in IRRAS spectra. The present work highlights the significant influence of the existing forms of P507 molecules on the interfacial properties of P507 monolayer at the air-water interface and the aggregation behavior in the monolayers can be changed by subphase pH and the spreading solvent.

Cite this article

Gao Zhen , Huang Kun , Du Lin , Liu Huizhou . Interfacial Behavior of Acidic Organophosphorus Extractant Monolayer at Air-Water Interface: Subphase pH and Spreading Solvent Effect[J]. Acta Chimica Sinica, 2019 , 77(6) : 506 -514 . DOI: 10.6023/A19010006

References

[1] Jha, M. K.; Kumari, A.; Panda, R.; Kumar, J. R.; Yoo, K.; Lee, J. Y. Hydrometallurgy 2016, 165, 2.
[2] He, Y.; Chen, K.; Srinivasakannan, C.; Li, S.; Yin, S.; Peng, J.; Guo, S.; Zhang, L. Chem. Eng. J. 2018, 354, 1068.
[3] Qiao, B. F.; Muntean, J. V.; de la Cruz, M. O.; Ellis, R. J. Langmuir 2017, 33, 6135.
[4] Chen, K.; He, Y.; Srinivasakannan, C.; Li, S.; Yin, S.; Peng, J.; Guo, S.; Zhang, L. Chem. Eng. J. 2019, 356, 453.
[5] Miyake, Y.; Matsuyama, H.; Nishida, M.; Nakai, M.; Nagase, N.; Teramoto, M Hydrometallurgy 1990, 23, 19.
[6] Vandegrift, G. F.; Horwitz, E. P. J. Inorg. Nuck. Chem. 1980, 42, 119.
[7] Kanki, T.; Kim, H.; Tomita, A.; Asano, T.; Sano, N. Sep. Purif. Technol. 2000, 19, 93.
[8] Shen, J. L.; Xi, Z. K.; Gao, Z. L.; Sun, S. X.; Song, Q. S.; Guo, L. Q. Chin. J. Appl. Chem. 1984, 4, 57. (沈静兰, 奚正楷, 高自立, 孙思修, 宋其胜, 郭梁芹, 应用化学, 1984, 4, 57.)
[9] Su, W. R.; Chen, J. Ind. Eng. Chem. Res. 2016, 55, 8424.
[10] Wang, W. T.; Ye, S. J. Phys. Chem. Chem. Phys. 2017, 19, 4488.
[11] Zhang, T.; Cathcart, M. G.; Vidalis, A. S.; Allen, H. C. Chem. Phys. Lipids 2016, 200, 24.
[12] Chen, Y. Y.; Sun, R. G.; Wang, F. Y.; Pan, Q. Acta Chim. Sinica 2011, 69, 2299. (陈莹莹, 孙润广, 王夫雨, 潘勤, 化学学报, 2011, 69, 2299.)
[13] Zhang, B. B.; Ma, C.; Wang, X. G.; Hu, M. B.; Wang, X. L.; Wang, W. Acta Chim. Sinica 2015, 73, 441. (张贝贝, 马驰, 王小刚, 胡敏标, 王晓乐, 王维, 化学学报, 2015, 73, 441.)
[14] Zhang, T.; Brantley, S. L.; Verreault, D.; Dhankani, R.; Corcelli, S. A.; Allen, H. C. Langmuir 2018, 34, 530.
[15] Adams, E. M.; Wellen, B. A.; Thiraux, R.; Reddy, S. K.; Vidalis, A. S.; Paesani, F.; Allen, H. C. Phys. Chem. Chem. Phys. 2017, 19, 10481.
[16] Song, C. S.; Ye, R. Q.; Mu, B. Z. Acta Chim. Sinica 2009, 67, 2038. (宋昌盛, 叶汝强, 牟伯中, 化学学报, 2009, 67, 2038.)
[17] Fang, L. M. M.S. Thesis, Harbin University of Science and Technology, Harbin, 2013. (方丽明, 硕士论文, 哈尔滨理工大学, 哈尔滨, 2013.)
[18] Li, S. Y.; Du, L.; Tsona, N. T.; Wang, W. X. Chemosphere 2018, 196, 323.
[19] Adams, E. M.; Verreault, D.; Jayarathne, T.; Cochran, R. E.; Stone, E. A.; Allen, H. C. Phys. Chem. Chem. Phys. 2016, 18, 32345.
[20] Yang, H. W.; Zhu, P. X.; Feng, Y. J.; Chen, Z.; Zhou, D. L.; Wu, D. C. Acta Chim. Sinica 2007, 65, 2081. (杨红伟, 朱谱新, 冯玉军, 陈志, 周栋梁, 吴大诚, 化学学报, 2007, 65, 2081.)
[21] Uphaus, R. A.; Vandegrift, G. F.; Horwitz, E. P. J. Colloid Interface Sci. 1982, 90, 380.
[22] Gershfeld, N. L.; Pak, C. Y. J. Colloid Interface Sci. 1967, 23, 215.
[23] Zhang, L. R.; Chen, S. M.; Jin, D. S.; Motoko, U.; Tisato, K. Acta Chim. Sinica 1992, 50, 868. (张亮仁, 陈珊妹, 金道森, 内田茂登子, 梶山千里, 化学学报, 1992, 50, 868.)
[24] Zeng, Z. X.; Chen, Q.; Xue, W. L.; Nie, F. Chin. J. Chem. Eng. 2004, 12, 263.
[25] Yao, Y. L.; Zeng, Z. X.; Xue, W. L.; Huang, S. D. Acta Chim. Sinica 2005, 63, 1939. (姚亚丽, 曾作祥, 薛为岚, 黄顺德, 化学学报, 2005, 63, 1939.)
[26] Cratin, P. D. J. Dispersion Sci. Technol. 1993, 14, 559.
[27] Binghua, Y.; Nagaosa, Y.; Satake, M.; Nomura, A.; Horita, K. Solvent Extr. Ion Exch. 1996, 14, 849.
[28] Petty, M. C. Langmuir-Blodgett films:An introduction, Cambridge University Press, Cambridge, 1996, pp. 55~57.
[29] Guennouni, Z.; Cousin, F.; Faure, M. C.; Perrin, P.; Limagne, D.; Konovalov, O.; Goldmann, M. Langmuir 2016, 32, 1971.
[30] Ibrahim, T. H. Sep. Sci. Technol. 2011, 46, 2157.
[31] Sun, G. X.; Yang, Y. H.; Bao, M.; Cui, Y.; Sun, S. X. J. Inorg. Chem. 1996, 2, 212. (孙国新, 杨永会, 鲍猛, 崔玉, 孙思修, 无机化学学报, 1996, 2, 212.)
[32] Kusaka, R.; Watanabe, M. Phys. Chem. Chem. Phys. 2018, 20, 29588.
[33] Nukada, K.; Naito, K.; Maeda, U. Bull. Chem. Soc. Jpn. 1960, 33, 894.
[34] Wu, J. G.; Shi, N.; Gao, H. C.; Chen, D.; Guo, H.; Weng, S. F.; Xu, G. X. Sci. China, Ser. B 1983, 12, 1071. (吴瑾光, 施鼐, 高宏成, 陈滇, 郭海, 翁诗甫, 徐光宪, 中国科学(B辑), 1983, 12, 1071.)
[35] Xu, Z. H.; Wong, S. F.; Guo, H.; Wu, J. G.; Xu, G. X. Acta Sci. Nat. Univ. Pekin. 1983, 6, 45. (许振华, 翁诗甫, 郭海, 吴瑾光, 徐光宪, 北京大学学报(自然科学版), 1983, 6, 45.)
[36] Zhang, C.; Wang, L.; Huang, X.; Dong, J.; Long, Z.; Zhang, Y. Hydrometallurgy 2014, 147, 7.
[37] Ta, A. T.; Hegde, G. A.; Etz, B. D.; Baldwin, A. G.; Yang, Y.; Shafer, J. C.; Jensen, M. P.; Maupin, C. M.; Vyas, S. J. Phys. Chem. B 2018, 122, 5999.

Outlines

/