Formation of W/O microemulsions in TBP-Pd(II)-HCl extraction system and spectroscopic research on the evolution of solution aggregation structure

doi:10.3964/j.issn.1000-0593(2008)09-2038-06

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	Formation of W/O microemulsions in TBP-Pd(II)-HCl extraction system and spectroscopic research on the evolution of solution aggregation structure
	Huang Kun 1; Qi Jian 1; Liu Xue-xin 2; Liu Yu-feng 1; Li Wei-hong 1; Yang Zhan-lan 1; Weng Shi-fu 1; Xu Yi-zhuang 1; Wu Jin-guang 1
刊名	SPECTROSCOPY AND SPECTRAL ANALYSIS
	2008-09-01
卷号	28 期号:9 页码:2038-2043
关键词	Spectral Analysis Solution Structure Microemulsion Palladium Solvent Extraction
ISSN号	1000-0593
DOI	10.3964/j.issn.1000-0593(2008)09-2038-06
英文摘要	The formation of W/O microemulsions in the extraction system TBP-Pd(II )-HCl was investigated. The solution structural evolution of the palladium. loaded organic phases, with the variation in the content of acid into the organic phases, was characterized by various spectroscopic techniques such as DLS, FTIR and (31) P-/(1) H NMR. The results indicated that (1) the extraction behaviors of palladium was related to the formation of W/O microemulsion structure in the loaded organic solutions. Because of the co-extraction of hydrochloric acid, there formed the microscopic aggregates in the loaded organic phases. (2) The variation in the HCl content in organic phase resulted in corresponding changes in solution structure. With the increase in the HCl content, the average radii of nanoscopic aggregates in the organic phases increased and then decreased. The extraction of HCl into the organic phase exhibited a distinct impact on the O-H stretching vibration and O-H-O bending vibration of water molecules in the microscopic W/O micelles. FTIR spectra of the organic phase saturated with acids show that the broad band of O-H stretching vibration of water extended to a very wide range and overlaped with the C-H stretching vibration bands. The higher the acid concentration in the organic phase was, the greater the overlapping. On the other hand, it was also observed that a remarkable change appeared in the O-H-O bending vibration of water and the stretching vibration of P=O in TBP molecules shifted to lower frequency. With the increase in acid content in the TBP organic phases the observed (31) P NMR chemical shifts decreased and varied to up-field; whereas the (1)H NMR chemical shift of H(+) increased and even became larger than that of deuterium chloride-d at a lower frequency field. The changes in delta(31)(P) to opposite direction of delta(H+) means that TBP molecules were associated with acid protons and water molecules in microemulsion pools to form RP=O center dot H(+) or RP=O center dot H(3)O(+), and then interacted with PdCl(4)(2-) complex ions, which finally led to the extraction of palladium into the organic phase. (3) When forming the W/O reversed micelles/micioemulsions, the concentration of acid within the microscopic micelles was even higher than that of saturated concentrated hydrochloric acid. It was the microscopic structural changes in organic phase microemulsion "water pool" that resulted in the corresponding variations in the palladium extraction behaviors.
语种	英语
出版者	OFFICE SPECTROSCOPY & SPECTRAL ANALYSIS
WOS记录号	WOS:000259688600019
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/63909]
专题	中国科学院化学研究所
通讯作者	Wu Jin-guang
作者单位	1.Peking Univ, Coll Chem & Mol Engn, Beijing 100871, Peoples R China 2.Chinese Acad Sci, Inst Chem, Beijing 100080, Peoples R China
推荐引用方式 GB/T 7714	Huang Kun,Qi Jian,Liu Xue-xin,et al. Formation of W/O microemulsions in TBP-Pd(II)-HCl extraction system and spectroscopic research on the evolution of solution aggregation structure[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS,2008,28(9):2038-2043.
APA	Huang Kun.,Qi Jian.,Liu Xue-xin.,Liu Yu-feng.,Li Wei-hong.,...&Wu Jin-guang.(2008).Formation of W/O microemulsions in TBP-Pd(II)-HCl extraction system and spectroscopic research on the evolution of solution aggregation structure.SPECTROSCOPY AND SPECTRAL ANALYSIS,28(9),2038-2043.
MLA	Huang Kun,et al."Formation of W/O microemulsions in TBP-Pd(II)-HCl extraction system and spectroscopic research on the evolution of solution aggregation structure".SPECTROSCOPY AND SPECTRAL ANALYSIS 28.9(2008):2038-2043.