99Mo是重要的医用放射性核素,溶剂萃取法是反应堆辐照~(235)U靶生产裂变99Mo的分离方法之一。为探讨离子液体Cyphos IL 101用于裂变99Mo分离的可能性,本研究评价了离子液体Cyphos IL 101在硝酸体系中对Mo(Ⅵ)的萃取行为,重点考察了稀释...99Mo是重要的医用放射性核素,溶剂萃取法是反应堆辐照~(235)U靶生产裂变99Mo的分离方法之一。为探讨离子液体Cyphos IL 101用于裂变99Mo分离的可能性,本研究评价了离子液体Cyphos IL 101在硝酸体系中对Mo(Ⅵ)的萃取行为,重点考察了稀释剂、水相初始pH、萃取时间、温度、离子液体浓度等对萃取Mo(Ⅵ)的影响。结果表明,选用甲苯作为稀释剂时,Cyphos IL 101对Mo(Ⅵ)的萃取效果最好,在pH=3条件下,萃取率高达98.87%;萃取为自发进行的过程,且可在5 min达到平衡;选用1 mol/L Na_2CO_3作为反萃剂,一次反萃可将负载有机相中96.56%的Mo反萃到水相中。构建的离子液体Cyphos IL 101萃取体系对Mo与主要杂质Sr、Cs、Te等有很好的分离效果,体现了其对Mo(Ⅵ)的高选择性萃取能力。以上结果可为将离子液体Cyphos IL 101引入裂变99Mo的分离工艺流程提供参考。展开更多
The interaction of nitrilotriacetic acid （NTA） and iminodiacetic acid （IDA） with tungsten（VI） （pH 7.5） and molybdenum（VI） （pH 6.00） has been studied in aqueous solutions at 25℃, and different ionic streng...The interaction of nitrilotriacetic acid （NTA） and iminodiacetic acid （IDA） with tungsten（VI） （pH 7.5） and molybdenum（VI） （pH 6.00） has been studied in aqueous solutions at 25℃, and different ionic strengths （0.1 〈 1 （mol dm^-3） 〈 1.0 for NaClO4） by a combination of potentiometric and UV spectroscopic（260-270 nm） measurements. Dependence on ionic strength was taken into account by using the Bronsted-Guggenheim-Scatchard specific ion interaction theory （SIT） and parabolic model. The data included in this work, together with some previously published data, make it possible to calculate parameters for dependence on ionic strength by using the aforementioned models.展开更多
Complexation of two ligands, iminodiacetic acid and ethylenediamine-N,N′-diacetic acid, with molybdenum（Ⅵ） was studied in aqueous solutions. Molybdenum（Ⅵ） forms a mononuclear complex with the aforementioned lig...Complexation of two ligands, iminodiacetic acid and ethylenediamine-N,N′-diacetic acid, with molybdenum（Ⅵ） was studied in aqueous solutions. Molybdenum（Ⅵ） forms a mononuclear complex with the aforementioned ligands of the type MoO3L^2-. All measurements have been carried out at 25 ℃ and different ionic strengths ranging from 0.1 to 1.0 mol·L^-1 of NaClO4, with the pH justified to 6.0. Equilibrium concentration products and stoichiometry of the complexes have been determined from a combination of potentiometric and UV spectroscopic measurements. Comparison of the ionic strength effect on these complex formation reactions has been made using a Debye-Hückel type equation and Bronsted-Guggenheim-Scatchard specific ion interaction theory （SIT）. Debye-Hückel theory predicted the first order effects on simple electrolyte solutions. Interactions between the reacting species and the ionic medium were taken into account in the SIT model. All of the calculations have been done by the computer program Excel 2000.展开更多
By using spectrophotometric and potentiometric techniques the formation constants of the species formed in the systems H^＋＋ Mo（Ⅵ）＋nitrilotriacetic acid and H^＋ ＋ nitrilotriacetic acid have been determined in ...By using spectrophotometric and potentiometric techniques the formation constants of the species formed in the systems H^＋＋ Mo（Ⅵ）＋nitrilotriacetic acid and H^＋ ＋ nitrilotriacetic acid have been determined in aqueous solutions of propanol at 25 ℃ and constant ionic strength 0.1 molodm^-3 sodium perchlorate. The composition of the complex was determined by the continuous variation method. It was shown that molybdenum（Ⅵ） forms a mononuclear 1 ： 1 complex with nitrilotriacetic acid of the type MoO3L^-3 at -lg[H^＋] =5.8. The formation constants in various media were analyzed in terms of Kamlet and Taft＇s parameters. Linear relationships were observed when lg Ks was plotted versusp. Finally, the results were discussed in terms of the effect of solvent on complexation.展开更多
文摘99Mo是重要的医用放射性核素,溶剂萃取法是反应堆辐照~(235)U靶生产裂变99Mo的分离方法之一。为探讨离子液体Cyphos IL 101用于裂变99Mo分离的可能性,本研究评价了离子液体Cyphos IL 101在硝酸体系中对Mo(Ⅵ)的萃取行为,重点考察了稀释剂、水相初始pH、萃取时间、温度、离子液体浓度等对萃取Mo(Ⅵ)的影响。结果表明,选用甲苯作为稀释剂时,Cyphos IL 101对Mo(Ⅵ)的萃取效果最好,在pH=3条件下,萃取率高达98.87%;萃取为自发进行的过程,且可在5 min达到平衡;选用1 mol/L Na_2CO_3作为反萃剂,一次反萃可将负载有机相中96.56%的Mo反萃到水相中。构建的离子液体Cyphos IL 101萃取体系对Mo与主要杂质Sr、Cs、Te等有很好的分离效果,体现了其对Mo(Ⅵ)的高选择性萃取能力。以上结果可为将离子液体Cyphos IL 101引入裂变99Mo的分离工艺流程提供参考。
文摘The interaction of nitrilotriacetic acid （NTA） and iminodiacetic acid （IDA） with tungsten（VI） （pH 7.5） and molybdenum（VI） （pH 6.00） has been studied in aqueous solutions at 25℃, and different ionic strengths （0.1 〈 1 （mol dm^-3） 〈 1.0 for NaClO4） by a combination of potentiometric and UV spectroscopic（260-270 nm） measurements. Dependence on ionic strength was taken into account by using the Bronsted-Guggenheim-Scatchard specific ion interaction theory （SIT） and parabolic model. The data included in this work, together with some previously published data, make it possible to calculate parameters for dependence on ionic strength by using the aforementioned models.
文摘Complexation of two ligands, iminodiacetic acid and ethylenediamine-N,N′-diacetic acid, with molybdenum（Ⅵ） was studied in aqueous solutions. Molybdenum（Ⅵ） forms a mononuclear complex with the aforementioned ligands of the type MoO3L^2-. All measurements have been carried out at 25 ℃ and different ionic strengths ranging from 0.1 to 1.0 mol·L^-1 of NaClO4, with the pH justified to 6.0. Equilibrium concentration products and stoichiometry of the complexes have been determined from a combination of potentiometric and UV spectroscopic measurements. Comparison of the ionic strength effect on these complex formation reactions has been made using a Debye-Hückel type equation and Bronsted-Guggenheim-Scatchard specific ion interaction theory （SIT）. Debye-Hückel theory predicted the first order effects on simple electrolyte solutions. Interactions between the reacting species and the ionic medium were taken into account in the SIT model. All of the calculations have been done by the computer program Excel 2000.
文摘By using spectrophotometric and potentiometric techniques the formation constants of the species formed in the systems H^＋＋ Mo（Ⅵ）＋nitrilotriacetic acid and H^＋ ＋ nitrilotriacetic acid have been determined in aqueous solutions of propanol at 25 ℃ and constant ionic strength 0.1 molodm^-3 sodium perchlorate. The composition of the complex was determined by the continuous variation method. It was shown that molybdenum（Ⅵ） forms a mononuclear 1 ： 1 complex with nitrilotriacetic acid of the type MoO3L^-3 at -lg[H^＋] =5.8. The formation constants in various media were analyzed in terms of Kamlet and Taft＇s parameters. Linear relationships were observed when lg Ks was plotted versusp. Finally, the results were discussed in terms of the effect of solvent on complexation.
