Co-reporter:Zhipeng Wang, Songdong Ding, Xiaoyang Hu, Shimeng Li, Dongping Su, Lirong Zhang, Ying Liu, Yongdong Jin
Separation and Purification Technology 2017 Volume 181(Volume 181) pp:
Publication Date(Web):30 June 2017
DOI:10.1016/j.seppur.2017.02.043
•For the first time, a novel water-soluble ligand TEE-BisDGA was synthesized.•TEE-BisDGA had better separation efficiency for Am(III) over Eu(III) than TEDGA.•The extraction mechanisms were given.•The stability constants for Nd(III) complexes were determined.A novel water-soluble ligand of N,N,N‴,N‴-tetraethyl-N′,N″-ethidene bisdiglycolamide (TEE-BisDGA) was synthesized and used as a masking agent for selective extraction of Am(III) over Eu(III) from HNO3 solution by N,N,N′,N′,N″,N″-hexaoctylnitrilotriacetamide (NTAamide(C8)) in kerosene. Influences of acidity, concentration of water-soluble ligands and extractant as well as nitrate ions on the distribution ratios (D) and separation factors (SF) of Am(III) and Eu(III) were investigated. In the range of examined acidity from 0.001 to 0.2 mol/L, DAm and DEu decreased with the increase of HNO3 concentration. Using 0.1 mol/L NTAamide(C8) as an extractant, the maximum SFAm/Eu of 26 can be obtained in the presence of 0.01 mol/L TEE-BisDGA in aqueous phase with pH of 3.0, which was significantly higher than that case with no TEE-BisDGA. Job's method and mole ratio method were employed for extraction mechanism research. It has been shown that Am(III) and Eu(III) formed di-solvated species with TEE-BisDGA and mono-solvated species with NTAamide(C8), respectively. Moreover, the stability constants logβ values were obtained from UV–vis adsorption spectroscopic titration for Nd(III) complexes with TEE-BisDGA and N,N,N′,N′-tetraethyldiglycolamide (TEDGA), which indicated that TEDGA had a stronger complex ability than TEE-BisDGA.Download high-res image (219KB)Download full-size image
Co-reporter:Jieru Wang; Dongping Su; Dongqi Wang; Songdong Ding; Chao Huang; Huang Huang; Xiaoyang Hu; Zhipeng Wang;Shimeng Li
Inorganic Chemistry 2015 Volume 54(Issue 22) pp:10648-10655
Publication Date(Web):October 30, 2015
DOI:10.1021/acs.inorgchem.5b01452
1,3-Bis[3-(2-pyridyl)pyrazol-1-yl]propane (Bippp) and 1,2-bis[3-(2-pyridyl)pyrazyl-1-methyl]benzene (Dbnpp), the pyridylpyrazole based tetradentate ligands, were synthesized and characterized by MS, NMR, and FT-IR. The solvent extraction and complexation behaviors of Am(III) and Eu(III) with the ligands were investigated experimentally and theoretically. In the presence of 2-bromohexanoic acid, the two ligands can effectively extract Am(III) over Eu(III) and other rare earth(III) metals (RE(III)) in HNO3 solution with the separation factors (SFAm/RE) ranging from 15 to 60. Slope analyses showed that both Am(III) and Eu(III) were extracted as monosolvated species, which agrees well with the results observed from X-ray crystallography and MS analyses. The stability constants (log K) obtained from UV–vis titration for Eu(III) complexes with Bippp and Dbnpp are 4.75 ± 0.03 and 4.45 ± 0.04, respectively. Both UV–vis titration and solvent extraction studies indicated that Bippp had stronger affinity for Eu(III) than Dbnpp, which is confirmed by density functional theory (DFT) calculations. DFT calculations revealed that the AmL(NO3)3 (L = Bippp and Dbnpp) complexes are thermodynamically more stable in water than their Eu(III) analogues, which is caused by greater covalency of the Am–N than Eu–N bonds. Theoretical studies gave an insight into the nature of the M(III)–ligand bonding interactions.
Co-reporter:Mengling Tan, Chao Huang, Songdong Ding, Fang Li, Qingnuan Li, Lan Zhang, Chunxia Liu, Shimeng Li
Separation and Purification Technology 2015 Volume 146() pp:192-198
Publication Date(Web):26 May 2015
DOI:10.1016/j.seppur.2015.03.027
•Extraction power and selectivity of DMHMP are much higher than those of TBP.•There is no third phase in the extraction of sat. Th(NO3)4 with 30 vol.% DMHMP/kerosene.•For the first time, the solubility of DMHMP in various nitric acid was determined.•The extraction mechanism and the thermodynamic parameters were presented.The extraction behaviors of U(VI) and Th(IV), as well as the extraction of HNO3 were investigated by using di(1-methyl-heptyl) methyl phosphonate (DMHMP) as an extractant and kerosene as a diluent. Effects of contact time, acidity, concentration of extractant and temperature on the distribution ratios of U(VI) and Th(IV) were evaluated. HNO3 was extracted as mono-solvated species. In the investigation of acidity range from 0.01 to 6.0 mol/L, the distribution ratios of U(VI) and Th(IV) increased at first with the rise of HNO3 concentration up to 3.0 mol/L and then decreased. DMHMP exhibited higher selectivity for U(VI) than for Th(IV) with the separation factor SFU/Th values of 25–120, whereas under the same conditions, tri-n-butyl-phosphate (TBP) only had SFU/Th values of 1.4–26. Slope analyses showed that U(VI) and Th(IV) were extracted as di-solvated and tri-solvated species respectively. The thermodynamic parameters (ΔH, ΔS and ΔG) were presented and revealed that the extraction was exothermic. For the extraction of Th(VI) from various HNO3 by 30 vol.% DMHMP or TBP, the limiting organic concentration (LOC) was also given. FT-IR spectra indicated that it was PO bond, not PO bond that took part in the coordination with U(VI) and Th(IV). In addition, the solubility of DMHMP and TBP in various concentration HNO3 was determined using ICP-AES, and their thermal stability in air was also examined through TGA. DMHMP has much lower water solubility and higher thermal stability than TBP.
Co-reporter:Huang Huang, Songdong Ding, Dongping Su, Ning Liu, Jieru Wang, Mengling Tan, Jianen Fei
Separation and Purification Technology 2014 Volume 138() pp:65-70
Publication Date(Web):10 December 2014
DOI:10.1016/j.seppur.2014.10.008
•The selective solvent extraction of Th(IV) with NTAamide was investigated for the first time.•NTAamide exhibits high separation factors of Th(IV) over U(VI) and lanthanides(III) in the range between 2.5 × 102 and 10 × 103.•The detailed extraction mechanism for Th(IV) was discussed and the thermodynamic parameters were presented.•The crystal structure of Th(IV) complex with NTAamide was obtained.N,N,N′,N′,N″,N″-hexaoctylnitrilotriacetamide (NTAamide(C8)) and N,N,N′,N′,N″,N″-hexabutylnitrilotriacetamide (NTAamide(C4)) were synthesized for selective solvent extraction of Th(IV) from U(VI) and lanthanides(III) (Lns(III)) and for coordination between Th(IV) and NTAamide, respectively. NTAamide(C8) exhibits excellent extraction power and selectivity toward Th(IV) over U(VI) and Lns(III) in a wide range of acidity from 0.1 to 10.0 M HNO3. Very high SFTh/M in the range between 2.5 × 102 and 10 × 103 was observed. Slope analysis shows that Th(IV), U(VI) and Lns(III) were all extracted as mono-solvated species at 3.0 M HNO3. The thermodynamic parameters describing the extraction of Th(IV) indicate that the process is endothermic and spontaneous at 298 K. The single-crystal X-ray diffraction observations also establish that 1:1 complex is formed between NTAamide and thorium nitrate, which are in good accordance with the solvent extraction results, and NTAamide is coordinated with Th(IV) in a tetradentate coordination mode.
Co-reporter:Huang Huang, Songdong Ding, Ning Liu, Yuxuan Wu, Dongping Su, Song Huang
Separation and Purification Technology 2014 Volume 123() pp:235-240
Publication Date(Web):26 February 2014
DOI:10.1016/j.seppur.2013.12.039
•A new calixarene derivative with diglycolamide units (calix[4]arene-BDGA) was synthesized for treatment of HLLW.•The extraction behaviors of calix[4]arene-BDGA for Am(III) and Eu(III) in nitric acid solution were investigated in detail.•Calix[4]arene-BDGA has not only high distribution ratio, but also good separation factor for Eu(III) and Am(III).•Solvent extraction thermodynamics parameters were presented for the first time.A ligand derived from calix[4]arene functionalized at the lower rim with four diglycolamide (DGA) binding units containing n-butyl groups, which is denoted as calix[4]arene-BDGA, was synthesized and characterized by MS, 1H NMR and 13C NMR. The extraction behaviors of Am(III) and Eu(III) from nitric acid solution were investigated with calix[4]arene-BDGA in 95% kerosene/5% n-octanol (v/v). Effects of acidity, concentration of extractant and temperature on the distribution ratio of Am(III) and Eu(III) were evaluated. The results indicated the distribution ratio values of Am(III) and Eu(III) increase with the increase of nitric acid concentration in the examination of acidity range from 0.5 to 5.0 mol/L. The ligand has a higher selectivity for Eu(III) than for Am(III) with the separation factor SFEu(III)/Am(III) values of 4.5–7.3. Slope analysis from nitric acid medium indicated that Am(III) and Eu(III) were extracted as di-solvated species by calix[4]arene-BDGA. The extraction mechanism was described and the thermodynamic parameters (ΔH, ΔS and ΔG) were also presented.
Co-reporter:Yin-Qiao Zhao;Song-Dong Ding;You Yuan ;Yu-Zhong Wang
Journal of Applied Polymer Science 2014 Volume 131( Issue 6) pp:
Publication Date(Web):
DOI:10.1002/app.40026
ABSTRACT
The influences on the degradation of poly(p-dioxanone) (PPDO) under different temperature and relatively humidity is initially investigated by adding bis-(2,6-diisopropylphenyl) carbodiimide (commercial name: stabaxol®-1). The changes of intrinsic viscosity, mechanical properties, crystallinity, surface morphologies, and microstructure of PPDO and PPDO containing stabaxol®-1 for 6 weeks are monitored. With increasing the degradation time, the intrinsic viscosity and mechanical properties of PPDO decrease much faster than those of PPDO containing 0.6 wt % stabaxol®-1. During the degradation, PPDO containing 0.6 wt % stabaxol®-1 shows a better physical integrity than PPDO. It has been shown that stabaxol®-1 can retard the hydrolysis degradation of PPDO and enhance its hydrolytic stability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 40026.
Co-reporter:You Yuan;Song-dong Ding 丁颂东;Yin-qiao Zhao
Chinese Journal of Polymer Science 2014 Volume 32( Issue 12) pp:1678-1689
Publication Date(Web):2014 December
DOI:10.1007/s10118-014-1545-3
The effects of temperature and relative humidity on the hydrolytic degradation of poly(p-dioxanone) (PPDO) were investigated. The hydrolytic degradation behaviors were monitored by tracing the changes of water absorption, mechanical and crystalline properties, molecular weight and its distribution, surface morphologies, as well as infrared absorption peaks and hydrogen chemical shifts during the degradation. It is found that the water absorption increases whilst the intrinsic viscosity, tensile strength and elongation at break decrease as the temperature or relative humidity increases. With degradation time growing, the molecular weight drops and its distribution broadens. The crystallinity of PPDO has a tendency to increase at first and then to decrease, while the crystalline structure is not significantly changed. At the same time, some cracks are observed on the surface and keep growing and deepening. All results show that temperature plays more significant roles than relative humidity during the degradation. The analyses of Fourier transform infrared spectroscopy and hydrogen nuclear magnetic resonance spectroscopy reveal that the degradation of PPDO is a predominant hydrolysis of ester linkages.
Co-reporter:Song-Dong Ding;Zhong-Ping Liu;Tang Yang;Guang-Can Zheng
Journal of Polymer Research 2010 Volume 17( Issue 1) pp:
Publication Date(Web):2010 January
DOI:10.1007/s10965-009-9290-y
A kind of polycarbodiimide (PCD) as a thermal stabilizer was added into poly(p-dixoanone) (PPDO). The effect of PCD on the thermal stability and crystallization of PPDO was investigated by using non-isothermal thermalgravimetry (TG), differential scanning calorimetry (DSC), polarized optical microscopy (POM) and wide angle X-ray diffractometry (WAXD). It has been shown that the addition of PCD can enhance significantly the thermal stability of PPDO. The thermal decomposition temperature of PPDO increases with the increase of the amount of PCD added. The activation energies for non-isothermal thermal degradation estimated by Kissinger method are 160 and 106 kJ mol−1 for PPDO added with 5 wt% PCD and neat PPDO respectively. The results obtained from DSC and POM indicate that PCD plays a role of nucleating agent in the process of crystallization of PPDO. WAXD analyses reveal that the addition of PCD has no effect on the crystal structure of PPDO.
Co-reporter:S.-D. Ding;T. Yang;N. Liu;L. Zhang
Journal of the Iranian Chemical Society 2010 Volume 7( Issue 3) pp:545-553
Publication Date(Web):2010 September
DOI:10.1007/BF03246042
The extraction behaviors of strontium from nitric acid solution were investigated with N,N,N′,N′-tetraisobutyl diglycolamide (TiBDGA). Effects of acidity, diluents, concentration of extractant and temperature on the distribution ratio of strontium (DSr) were examined. The stoichiometry of the extracted molecule was Sr2+:TiBDGA of 1:3. The apparent extraction equilibrium concentration constant logKex was 3.25. The enthalpy change ΔH and entropy change ΔS were −55.6 kJ mol-1 and −124 J mol-1 K-1, respectively. The extraction is an exothermic process. Through two strip stages, strontium could be stripped effectively by 0.01 M nitric acid solution.
Co-reporter:Song-Dong Ding, Guang-Can Zheng, Jian-Bing Zeng, Li Zhang, Yi-Dong Li, Yu-Zhong Wang
European Polymer Journal 2009 Volume 45(Issue 11) pp:3043-3057
Publication Date(Web):November 2009
DOI:10.1016/j.eurpolymj.2009.08.019
A series of poly[p-dioxanone-(butylene succinate)] (PPDOBS) copolymers were prepared from p-dioxanone (PDO), 1,4-butanediol and succinate acids through a two-step process including the initial prepolymer preparation of poly(p-dioxanone)diol (PPDO-OH) and poly(butylene succinate)diol (PBS-OH) and the following copolymerization of the two kinds of prepolymers by coupling with hexamethylene diisocyanate (HDI). The molecular structures of the prepared PPDO-OH, PBS-OH and PPDOBS were characterized by hydrogen nuclear magnetic resonance spectroscopy (1H NMR). The crystallization of the copolymers was investigated by using differential scanning calorimetry (DSC), polarized optical microscopy (POM) and wide angle X-ray diffraction (WAXD). It has been shown that the crystallization rate and the degree of crystallization increases with the increase of the weight fraction of poly(butylene succinate) (PBS) blocks in the copolymers. In phosphate buffer solution with pH 7.4 at 37 °C for 18 weeks, the hydrolytic degradation behaviors of the copolymers were studied. The changes of retention weight, water absorption, pH value, and surface morphologies with the degradation time showed that the hydrolytic degradation rate of PPDOBS could be controlled by adjusting the weight fraction of poly(p-dioxanone) (PPDO) and PBS blocks in the copolymers. The changes of the thermal properties of PPDOBS during the degradation were also investigated by DSC.
Co-reporter:Zhong-Ping Liu;Song-Dong Ding;Ying-Jia Sui ;Yu-Zhong Wang
Journal of Applied Polymer Science 2009 Volume 112( Issue 5) pp:3079-3086
Publication Date(Web):
DOI:10.1002/app.29310
Abstract
The effect of polycarbodiimide (PCD) on hydrolytic stability of poly(p-dioxanone) (PPDO) was investigated by hydrolytic degradation of PPDO and PPDO added with PCD (PPDOCD) in phosphate buffer solution (pH = 7.4) at 37°C. The variation of weight, water absorption, pH, molecular weight, tensile properties, surface morphologies, and thermal properties with degradation time were evaluated. After 11 weeks, the weight loss and water absorption of PPDO was 24 and 30%, respectively, but the corresponding values were only 3 and 5% for PPDOCD5, where 5 represents the weight percentage of PCD added; the molecular weight of PPDO decreased much faster than that of PPDOCD. The pH of the solution was monitored for 15 weeks and a final pH value of the solution involving PPDOCD5 was 6.81 whereas that of PPDO solution was 3.77, indicating that more acid fragments from PPDO samples migrate into the buffer solution. Surface morphological changes showed a better physical integrity for PPDOCD samples and they also kept their mechanical properties for a longer time than PPDO samples. These results revealed that PCD can retard the hydrolysis degradation of PPDO and enhance its hydrolytic stability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
