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Design of experiments (DOE) was first adopted to analyze the process parameters of a cabinet type air conditioning panel including melt temperature, mold temperature, pressure holding pressure and pressure holding time, which influenced the warpage deformation of the injection-molded part significantly. Subsequently, the response surface methodology (RSM) was applied to construct the second-order response surface model by taking four process parameters as experimental variables and the warpage of the panelas a goal. The process parameters with minimum warpage were optimized, which led to a high accuracy for the model as well as alow prediction error rate of 2.486 %. Finally, the optimal of process parameters were obtained by particle swarm optimization (PSO) for the two-order response surface model. The verification results indicated that the optimization error of PSO was 4.882 %. Compared to the RSM optimization, the actual value of warpage was reduced by 38.367 % from 5. 217 mm to 3.459 mm, which was reduced, suggesting that this optimization effect was much better. [ABSTRACT FROM AUTHOR]

Strontium-90 (90Sr) is the most abundant radionuclide in radioactive wastes, and is typically isolated by treatment with an inorganic ion-exchange material. Most inorganic ion-exchange materials contain oxygen. The ion-exchange chemistry of layered metal sulfides is relatively poorly explored compared with that of oxide ion-exchange materials. Here, a layered metal sulfide (UCR-28), constructed from [ZnGe3S9(H2O)]4− supertetrahedral clusters, was prepared under hydrothermal conditions and used for the removal of Sr2+ ions from aqueous solution. Batch experiments showed that UCR-28 had affinity for Sr2+ ions at pH values ranging from 1 to 10 and the maximum ion-exchange capacity of UCR-28 (50.1 mg/g) was achieved at pH 7. Thermodynamic parameters for the ion-exchange process were evaluated, and the enthalpy and Gibbs free energy results suggested the Sr2+ ion-exchange process was endothermic and spontaneous. The ion-exchange data were a good fit to the Langmuir model. In addition, the metal sulfide reported here had a relatively high thermal stability. The results of this study provide insight into the largely unknown ion-exchange chemistry of metal sulfides, and could be used for design of new chalcogenide frameworks with improved ion-exchange properties. [ABSTRACT FROM AUTHOR]

Glutarimidedioxime is a cyclic amidoxime moiety formed during the synthesis of amidoxime-functionalized fibers and apparently facilitates the extraction of uranium from seawater. Herein, we comprehensively explore differences between molybdenum and vanadium coordinated by glutarimidedioxime. The high adsorption of vanadium is explained by the formation of rare nonoxido vanadium(V) complexes, where each bare V 5+ is coordinated with two tridentate glutarimidedioxime ligands. By contrast, molybdenum is coordinated by only one glutarimidedioxime ligand, and the oxido Mo═O bonds in molybdate cannot be displaced by the ligand. Under seawater conditions, vanadium is fully complexed. Meanwhile, approximately 25% of molybdenum ions are in the form of free molybdate even if the concentration of glutarimidedioxime is 100000 times that of molybdenum. Glutarimidedioxime was expected to be more stable in the presence of metal ions than without them. However, complexation with molybdenum accelerated the degradation of the glutarimidedioxime ligand to release hydroxylamine. Molybdenum(VI) was then reduced by hydroxylamine, which itself was oxidized into nitrosyl. Vanadium heavily outcompetes adsorption of uranium, while molybdenum causes the degradation of glutarimidedioxime; the latter issue has previously been neglected and was first reported here.

N -(2-Hydroxyethyl)ethylenediamine- N , N ', N '-triacetic acid (HEDTA, denoted as H 3 L) is a strong chelating ligand that is widely used in the separation of f elements as relevant to the nuclear fuel cycle. There is much to be known about the structure and composition of the coordination sphere of the complexes of HEDTA with lanthanides. The complexation of HEDTA with light lanthanides (La 3+ , Nd 3+ , and Eu 3+ ) was investigated thermodynamically and structurally in aqueous solutions. Potentiometry and microcalorimetry were performed to acquire the complexation constants (25-70 °C) and enthalpies (25 °C), respectively, at I = 1.0 mol·L -1 NaClO 4 . Coordination modes of the complexes were analyzed by luminescence spectroscopy and NMR spectroscopy. The results indicate that there are two successive Ln 3+ /HEDTA complexes, LnL aq and Ln 2 (H -1 L) 2 2- (Ln 3+ refers to La 3+ , Nd 3+ , and Eu 3+ ; H -1 L 4- refers to deprotonation of the hydroxyl group) during titration. The hydroxyl group of HEDTA is coordinated in the Ln 3+ /HEDTA complex. The dinuclear Ln 2 (H -1 L) 2 2- complex is present as a carboxyl-bridged centrosymmetric dimer, and two carboxyl groups in bridging positions are coordinated to two adjacent Ln 3+ cations. Complexation of NdL aq is exothermic, while formation of the hydrolytic complex Nd 2 (H -1 L) 2 2- is endothermic. Both NdL aq and Nd 2 (H -1 L) 2 2- complexes are driven by entropic force. These data will help to predict the behavior of lanthanides in the separation process, where HEDTA is used as the aqueous complexant.