Barium sulfate aggregates with an average size of 0.5μm were synthesized at pH 7, directed by ethylenediaminetetraacetic acid （EDTA） anions. The particle morphology, chemical composition, and size distribution of t...Barium sulfate aggregates with an average size of 0.5μm were synthesized at pH 7, directed by ethylenediaminetetraacetic acid （EDTA） anions. The particle morphology, chemical composition, and size distribution of the BaSO4 aggregates were characterized. The as-synthesized BaSO4 particles were spherical and comprised many interconnected nanoballs, of which the surface properties were affected by the EDTA anions. The adsorption of EDTA anions reversed the charge and weakened the surface polarity of BaSO4, instigating the formation of aggregates by a self-assembly and transformation process. The resulting BaSO4 particles at pH 9-10 were ellipsoidal and featured smooth surfaces. Based on the zeta potential of BaSO4, variations in the morphology induced by changes in pH were closely related to the adsorption of mono- and multi-valent anions onto the electrical double layer of BaSO4.展开更多
Fluoride is an impurity in nickel sulfate production,which is required for electric vehicle batteries.Hydrous zirconium oxide(HZO)was evaluated for removing fl uoride from nickel sulfate solution.Maximum fluoride remo...Fluoride is an impurity in nickel sulfate production,which is required for electric vehicle batteries.Hydrous zirconium oxide(HZO)was evaluated for removing fl uoride from nickel sulfate solution.Maximum fluoride removal occurred at pH value 4 and optimal pH value is 4–5,considering Zr solubility.Fluoride availability decreases with pH due to hydrogen fluoride and zirconium fluoride aqueous species.Fluoride removal is initially rapid,with 50 wt.%removal in 7 min,followed by slow removal up to 68 wt.%after 72 h and follows second order rate kinetics.Fluoride removal was dominated by an ion exchange mechanism and resulting Zr–F bonds were observed using Fourier-transform infrared spectroscopy.The presence of nickel sulfate decreased loading capacity compared to a salt-free solution.HZO maintained adsorption capacity through five cycles of loading and regeneration.展开更多
A novel bis(guanidiniums) receptor for the catalytic cleavage of phosphosdiester was prepared and self-assembly architecture through hydrogen bonds and electrostatic interactions among the bis(guanidiniums) receptor, ...A novel bis(guanidiniums) receptor for the catalytic cleavage of phosphosdiester was prepared and self-assembly architecture through hydrogen bonds and electrostatic interactions among the bis(guanidiniums) receptor, the sulfate anion and water molecule was revealed by X-ray crystallographic analysis.展开更多
The tris（2-aminoethyl）amine （tren）-based tris（4-pyridylurea） receptor L has been synthesized and its anion binding properties were studied. The ligand forms a 2 ： 1 （host/guest） complex with MgSO4, [SO4^2 L2]...The tris（2-aminoethyl）amine （tren）-based tris（4-pyridylurea） receptor L has been synthesized and its anion binding properties were studied. The ligand forms a 2 ： 1 （host/guest） complex with MgSO4, [SO4^2 L2], in which a sulfate ion is encapsulated by six urea groups from the two ligands through multiple hydrogen bonds. The metal ions do not coordinate to the pyridyl groups but exist as the hydrate [Mg（H2O）6]2＋ and interact with the [SO4 L2] capsules in the outer coordination sphere to form a three dimensional extended structure. The anion binding behav- ior of ligand L in solution was studied.展开更多
Sulfate mass transfer coefficient(MTC) is a sensitive parameter to evaluate the kinetic leakage of anion exchange resin used in condensate polishing system of thermal and nuclear power plant.However,a sufficiently pre...Sulfate mass transfer coefficient(MTC) is a sensitive parameter to evaluate the kinetic leakage of anion exchange resin used in condensate polishing system of thermal and nuclear power plant.However,a sufficiently precise determination method has not been well established.In this paper,the final expression of sulfate MTC derived based on plug flow reactor model is the same as Harries' model,which is widely acknowledged in this field.In the determining system we constructed,in-situ calibration of the concentration of sulfate and its cation conductivity was conducted and sulfate MTCs of four typical strongly basic anion exchange resin samples were determined.The systematic error is 8.26% and the calibrated curve used for quantifying sulfate is obtained.The repeatability and reproducibility standard deviation are 0.05×10^(-4) m·s^(-1) and 0.07×10^(-4) m·s^(-1) respectively,which are lower than previous works.By controlling test condition accurately,this study has developed a more precise sulfate MTC determining method.This method provides a basis for further research.展开更多
基金supported by the Natural Science Foundation of Hebei Province(B2012202106)
文摘Barium sulfate aggregates with an average size of 0.5μm were synthesized at pH 7, directed by ethylenediaminetetraacetic acid （EDTA） anions. The particle morphology, chemical composition, and size distribution of the BaSO4 aggregates were characterized. The as-synthesized BaSO4 particles were spherical and comprised many interconnected nanoballs, of which the surface properties were affected by the EDTA anions. The adsorption of EDTA anions reversed the charge and weakened the surface polarity of BaSO4, instigating the formation of aggregates by a self-assembly and transformation process. The resulting BaSO4 particles at pH 9-10 were ellipsoidal and featured smooth surfaces. Based on the zeta potential of BaSO4, variations in the morphology induced by changes in pH were closely related to the adsorption of mono- and multi-valent anions onto the electrical double layer of BaSO4.
基金the financial support from the Brazilian research funding agencies Coordination for the Improvement of Higher Education Personnel(CAPES)for the postdoctoral scholarshipresearch fellow National Council for Scientific and Technological Development(CNPq-Process 308044/20185)+1 种基金Minas Gerais State Agency for Research and Development(FAPEMIG)the financial support from the University of Queensland Research Stimulus Allocation 2(Fellowships)scheme for the year of 2021 for awarding a post-doctoral fellowship。
文摘Fluoride is an impurity in nickel sulfate production,which is required for electric vehicle batteries.Hydrous zirconium oxide(HZO)was evaluated for removing fl uoride from nickel sulfate solution.Maximum fluoride removal occurred at pH value 4 and optimal pH value is 4–5,considering Zr solubility.Fluoride availability decreases with pH due to hydrogen fluoride and zirconium fluoride aqueous species.Fluoride removal is initially rapid,with 50 wt.%removal in 7 min,followed by slow removal up to 68 wt.%after 72 h and follows second order rate kinetics.Fluoride removal was dominated by an ion exchange mechanism and resulting Zr–F bonds were observed using Fourier-transform infrared spectroscopy.The presence of nickel sulfate decreased loading capacity compared to a salt-free solution.HZO maintained adsorption capacity through five cycles of loading and regeneration.
基金Project supported by the National Science Foundation of China (No. 29872014)
文摘A novel bis(guanidiniums) receptor for the catalytic cleavage of phosphosdiester was prepared and self-assembly architecture through hydrogen bonds and electrostatic interactions among the bis(guanidiniums) receptor, the sulfate anion and water molecule was revealed by X-ray crystallographic analysis.
基金the National Natural Science Foundation of China
文摘The tris（2-aminoethyl）amine （tren）-based tris（4-pyridylurea） receptor L has been synthesized and its anion binding properties were studied. The ligand forms a 2 ： 1 （host/guest） complex with MgSO4, [SO4^2 L2], in which a sulfate ion is encapsulated by six urea groups from the two ligands through multiple hydrogen bonds. The metal ions do not coordinate to the pyridyl groups but exist as the hydrate [Mg（H2O）6]2＋ and interact with the [SO4 L2] capsules in the outer coordination sphere to form a three dimensional extended structure. The anion binding behav- ior of ligand L in solution was studied.
文摘Sulfate mass transfer coefficient(MTC) is a sensitive parameter to evaluate the kinetic leakage of anion exchange resin used in condensate polishing system of thermal and nuclear power plant.However,a sufficiently precise determination method has not been well established.In this paper,the final expression of sulfate MTC derived based on plug flow reactor model is the same as Harries' model,which is widely acknowledged in this field.In the determining system we constructed,in-situ calibration of the concentration of sulfate and its cation conductivity was conducted and sulfate MTCs of four typical strongly basic anion exchange resin samples were determined.The systematic error is 8.26% and the calibrated curve used for quantifying sulfate is obtained.The repeatability and reproducibility standard deviation are 0.05×10^(-4) m·s^(-1) and 0.07×10^(-4) m·s^(-1) respectively,which are lower than previous works.By controlling test condition accurately,this study has developed a more precise sulfate MTC determining method.This method provides a basis for further research.
