The thermodynamics of micella formation,interfacial characteristics,synergistic effects and interfacial kinetics for synergistic extraction system D_2 EHPA-MPA-Fe^(3+) have been studied.It was found that D_2EHPA in th...The thermodynamics of micella formation,interfacial characteristics,synergistic effects and interfacial kinetics for synergistic extraction system D_2 EHPA-MPA-Fe^(3+) have been studied.It was found that D_2EHPA in the mixed system strongly exhibits the effect on the micella formation thermodynamics and interracial characteristics of MPA.Some ther- modynamic parameters for constants of micelles formation(K_m).free energies of micelles formation(ΔG_m)and critical micella concentrations(CMC)were obtained.The inter- facial adsorption behaviour of D_2EHPA is opposite to that of MPA.The emulsification for single MPA and the mixed system was discussed.The synergistic effects were found in this mixed extraction system.It is proved that the process of the Fe^(3+) extraction for non-mixed extraction system is controlled by chemical reaction and the controlling reaction occurs at the interface.展开更多
The extraction of Nd^3＋ and Sm^3＋, including the extraction and stripping capability as well as the separation effect of Nd^3＋ or Sm^3＋, from a sulfuric acid medium, by mixtures of di-（2-ethylhexyl） phosphoric a...The extraction of Nd^3＋ and Sm^3＋, including the extraction and stripping capability as well as the separation effect of Nd^3＋ or Sm^3＋, from a sulfuric acid medium, by mixtures of di-（2-ethylhexyl） phosphoric acid （HDEHP, H2A2（0）） and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester （HEH/EHP, H2L2（0）） were studied. The distribution ratios and synergistic coefficients of Nd^3＋ and Sm^3＋ in different acidities were also determined. A synergistic extractive effect was found when HDEHP and HEH/EHP were used as mixed extractants for Sm^3＋ or Nd^3＋. The chemical compositions of the extracted complex were determined as Nd.（HA2）2-HL2 and Sm.（HA2）2-HL2. The extraction equilibrium constants, enthalpy change, and entropy change of the extraction reaction were also determined.展开更多
The gadolinium extraction by the mixtures of p-phosphorylated calixarene and 1-phenyl-3-methyl-4-benzoylpyrazalone-5 from nitrate medium was studied,which indicated an obvious synergistic effect between these two extr...The gadolinium extraction by the mixtures of p-phosphorylated calixarene and 1-phenyl-3-methyl-4-benzoylpyrazalone-5 from nitrate medium was studied,which indicated an obvious synergistic effect between these two extractants.The extractants exhibit no interaction with each other before the metal extraction.Gadolinium(Ⅲ)was extracted by the species of Ln(PMBP)_(2)L_(2)(NO_(3))instead of Ln(PMBP)_(3)•(HPMBP)or Ln(NO_(3))_(3)•2L which are extracted by HPMBP or L alone.Thermodynamic functions(ΔG,ΔH,ΔS)were calculated.The extraction of other rare earths was also investigated and compared.Possible single rare earth separation was discussed.展开更多
文摘The thermodynamics of micella formation,interfacial characteristics,synergistic effects and interfacial kinetics for synergistic extraction system D_2 EHPA-MPA-Fe^(3+) have been studied.It was found that D_2EHPA in the mixed system strongly exhibits the effect on the micella formation thermodynamics and interracial characteristics of MPA.Some ther- modynamic parameters for constants of micelles formation(K_m).free energies of micelles formation(ΔG_m)and critical micella concentrations(CMC)were obtained.The inter- facial adsorption behaviour of D_2EHPA is opposite to that of MPA.The emulsification for single MPA and the mixed system was discussed.The synergistic effects were found in this mixed extraction system.It is proved that the process of the Fe^(3+) extraction for non-mixed extraction system is controlled by chemical reaction and the controlling reaction occurs at the interface.
基金the National Natural Science Foundation of China (50674016)the National High Technology Research and Develop-ment Program of China (863 Program) ( 2006AA06Z123)
文摘The extraction of Nd^3＋ and Sm^3＋, including the extraction and stripping capability as well as the separation effect of Nd^3＋ or Sm^3＋, from a sulfuric acid medium, by mixtures of di-（2-ethylhexyl） phosphoric acid （HDEHP, H2A2（0）） and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester （HEH/EHP, H2L2（0）） were studied. The distribution ratios and synergistic coefficients of Nd^3＋ and Sm^3＋ in different acidities were also determined. A synergistic extractive effect was found when HDEHP and HEH/EHP were used as mixed extractants for Sm^3＋ or Nd^3＋. The chemical compositions of the extracted complex were determined as Nd.（HA2）2-HL2 and Sm.（HA2）2-HL2. The extraction equilibrium constants, enthalpy change, and entropy change of the extraction reaction were also determined.
基金This work was supported by 973 Program(No.2012CBA01206)the National Natural Science Foundation of China(Nos.21221061,21301170 and 51222404).
文摘The gadolinium extraction by the mixtures of p-phosphorylated calixarene and 1-phenyl-3-methyl-4-benzoylpyrazalone-5 from nitrate medium was studied,which indicated an obvious synergistic effect between these two extractants.The extractants exhibit no interaction with each other before the metal extraction.Gadolinium(Ⅲ)was extracted by the species of Ln(PMBP)_(2)L_(2)(NO_(3))instead of Ln(PMBP)_(3)•(HPMBP)or Ln(NO_(3))_(3)•2L which are extracted by HPMBP or L alone.Thermodynamic functions(ΔG,ΔH,ΔS)were calculated.The extraction of other rare earths was also investigated and compared.Possible single rare earth separation was discussed.
