The novel unsymmetrical extractant N,N′-dimethyl-N,N′-dioctylmalonamide (DMDOMA) was prepared by reaction of diethyl malonate with N-methyl octanamine. The extraction mechanism and the behavior of uranyl nitrate wit...The novel unsymmetrical extractant N,N′-dimethyl-N,N′-dioctylmalonamide (DMDOMA) was prepared by reaction of diethyl malonate with N-methyl octanamine. The extraction mechanism and the behavior of uranyl nitrate with DMDOMA employed cyclohexane as diluent were studied. The effects of concentrations of nitric acid, sodium nitrate, extractant and also the temperature on the extraction were considered. The stoichiometry of the extracted species is and the coordination of extracted species was suggested based on the IR data. The value of ΔH of extraction is -26.9 ± 0.80 kJ·mol-1. The value of the apparent extraction constant is 133.88 ± 17.92, which shows that the optimization of extractant structure improves the extractability of malonamide for uranyl nitrate.展开更多
The extraction behavior of N,N-diethyl-N,N-dibenzenyl-urea（DEDBU）and N,N-dimethyl-N,N-dibenzenyl-urea（DMDBU）to uranium（VI）and thorium（IV）from nitric acid solution was studied by using xylene or chloroform as d...The extraction behavior of N,N-diethyl-N,N-dibenzenyl-urea（DEDBU）and N,N-dimethyl-N,N-dibenzenyl-urea（DMDBU）to uranium（VI）and thorium（IV）from nitric acid solution was studied by using xylene or chloroform as diluent.The effect of aqueous HNO3 concentration,extractant concentration,salting-out agent concentration and aqueous UO2+2/Th4+concentration on extraction distribution ratio of U（VI）and Th（IV）was determined.The results show that the extraction behavior of the extractants DEDBU and DMDBU to U（VI）is similar to that of TBP,the solvation numbers both are two.Under the experimental condition,the extractants DEDBU and DMDBU do not show the extraction behatvior to Th（IV）.This means that the estractants may have potential application to separate U（VI）and Th（IV）.展开更多
文摘The novel unsymmetrical extractant N,N′-dimethyl-N,N′-dioctylmalonamide (DMDOMA) was prepared by reaction of diethyl malonate with N-methyl octanamine. The extraction mechanism and the behavior of uranyl nitrate with DMDOMA employed cyclohexane as diluent were studied. The effects of concentrations of nitric acid, sodium nitrate, extractant and also the temperature on the extraction were considered. The stoichiometry of the extracted species is and the coordination of extracted species was suggested based on the IR data. The value of ΔH of extraction is -26.9 ± 0.80 kJ·mol-1. The value of the apparent extraction constant is 133.88 ± 17.92, which shows that the optimization of extractant structure improves the extractability of malonamide for uranyl nitrate.
文摘The extraction behavior of N,N-diethyl-N,N-dibenzenyl-urea（DEDBU）and N,N-dimethyl-N,N-dibenzenyl-urea（DMDBU）to uranium（VI）and thorium（IV）from nitric acid solution was studied by using xylene or chloroform as diluent.The effect of aqueous HNO3 concentration,extractant concentration,salting-out agent concentration and aqueous UO2+2/Th4+concentration on extraction distribution ratio of U（VI）and Th（IV）was determined.The results show that the extraction behavior of the extractants DEDBU and DMDBU to U（VI）is similar to that of TBP,the solvation numbers both are two.Under the experimental condition,the extractants DEDBU and DMDBU do not show the extraction behatvior to Th（IV）.This means that the estractants may have potential application to separate U（VI）and Th（IV）.
