Royal Society Open Science
·
2018
·Vol. 5
·期 8
·
IF 2.504
Liuyi Ren,Hang Qiu,Wenqing Qin,Ming Zhang,Yubiao Li,Penggang Wei
The existence of metal ions should not be ignored in both hydrometallurgy and flotation. In this study, the effects of Ca2+, Mg2+ and Fe3+ on the flotation performance of cassiterite using octanohydroxamic acid (OHA) as the collector were investigated by micro-flotation tests, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, contact angle, zeta (ζ) potential measurements and atomic force microscopy (AFM) imaging. The results of the flotation and contact angle experiments showed that the addition of Ca2+, Mg2+ and Fe3+ significantly decreased both the recovery and contact angle of cassiterite with pH ranged from 6.0 to 12.0 in the presence of OHA collector. ζ-Potential measurements, solution chemistry analysis and FTIR measurements indicated that the flotation recovery of the cassiterite declined due to the CaOH+, MgOH+ and Fe(OH)3 sites on the cassiterite surface. XPS results indicated that the chemisorption of OHA and calcium ions on the cassiterite surface finally changed its chemical properties. The AFM images also revealed that new species Fe(OH)3 of Fe3+ formed and adsorbed on the cassiterite surface at pH 9.0. The adsorption of Fe(OH)3 reduced the adsorption of OHA on the cassiterite surface, thus the hydrophobicity of cassiterite was deteriorated.
研究领域:
矿物加工工程
·
表面化学
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产品关联
DOI
PubMed
高影响因子
DESALINATION
·
2018
·
IF 6.603
Ping Xu,Wei Wang,Xiaoming Qian,Haibo Wang,Changsheng Guo,Nan Li,Zhiwei Xu,Kunyue Teng,Zhen Wang
To effectively separate Mg 2+ and Li + from salt lake brine with high Mg 2+ /Li + mass ratio, a positive charged nanofiltration membrane with abundant -NH 3 + and -NH 2 + was designed and fabricated via interfacial polymerization between polyethyleneimine (PEI) and trimesoyl chloride (TMC) on the polyethersulfone ultrafiltration membrane. Zeta potential test revealed that at pH below 9.3, the resulting membrane exhibited a high positive charge due to a large amount of unreacted amine groups on the PEI branch. In the separation process, Donnan exclusion effect dominated the separation performance of resulting membranes for Mg 2+ and Li + . The results showed that the Mg 2+ /Li + mass ratio declined from initial 20 to 1.3 and the separation factor S Mg , Li was as low as 0.05 with a pure water permeation of 5.02 L/(m 2 hbar) after filtration with resulting NF membrane. The difference between the rejection for Mg 2+ and Li + reached up to 76%. Compared with membrane in previous studies, the separation performance for Mg 2+ and Li + of positive charged NF membrane prepared in this work increased more than one time. This research demonstrated the potential of positive charged PEI-TMC composite NF membrane for the separation of Mg 2+ and Li + from salt lake brine with high Mg 2+ /Li + mass ratio.
研究领域:
材料科学
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环境科学
·
化学工程
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DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2023
·
IF 4.4
Xianfa Zhang,Shuaibing Yu,Xuliang Pang,Xiaochen Ren,Bo Zhang,Jinming Kong,Lianzhi Li
A solvent-directed, new Schiff base multiple correspondence fluorescent probe, (E)-2-(2-hydroxybenzylidene) hydrazine-1-carboxamid (L), was synthesized for selective sensing of Cu 2+ and Mg 2+ ions. L showed excellent selectivity and high sensitivity toward Cu 2+ in “turn off” mode with a detection limit of 40.5 nM in 10 mM, pH = 7.0 PBS buffer. Contrary to that, when acetonitrile was used as the solvent, L exhibited highly selective and sensitive fluorescence sensing ability for Mg 2+ in “turn on” mode with a detection limit of 9.5 nM. L can coordinate to Cu 2+ and Mg 2+ in a 1:1 molar ratio, respectively, evidenced by Job’s plot analysis. Their binding modes were investigated by NMR, IR and XPS spectroscopies. Moreover, the satisfied results were obtained when L was used to detect Cu 2+ and Mg 2+ in real water samples.
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RARE METALS
·
2024
·
IF 9.6
Zeng Jin-Quan,Qi Jun-Lei,Yang Yue-Yang,Zhang Min-Hao,Lin Yuan-Hua
The practical application of CaSmAlO 4 microwave dielectric ceramics is limited by its low quality factor ( Q × f ) value and non-zero temperature coefficient resonant frequency ( τ f ) value. In this study, we introduced Mg 2+ –Ti 4+ ionic pairs into CaSmAlO 4 , along with an excess of 9% Sm 2 O 3 . The Mg 2+ –Ti 4+ ionic pairs substituted Al 3+ , and two phases simultaneously coexisted in the ceramics: CaSmAlO 4 and Sm 2 O 3 . As the doping concentration of Mg 2+ –Ti 4+ ionic pairs increased, the relative permittivity exhibited an upward trend, while the quality factor and resonant frequency temperature coefficient first rose and then descended. Remarkably, 0.09Sm 2 O 3 –0.91CaSmAl 0.7 Mg 0.15 –Ti 0.15 O 4 sintered at 1450 °C yielded excellent dielectric properties: ε r = 19.72, Q × f = 72,936 GHz, and τ f = –0.044 ppm·°C − 1 . The factors influencing the microwave dielectric properties of 0.09Sm 2 O 3 –0.91CaSmAlO 4 ceramics were further examined by considering the crystal structure, grain size, Lichtenecker logarithmic rule, tolerance factor and packing fraction. Graphic abstract
研究领域:
材料科学
·
电子工程
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2017
·
IF 3.133
Y.J. Niu,M.T. Liu,M.F. Li,J.X. Bi,H.T. Wu
Wolframite-structured Zn 1-x Mg x ZrNb 2 O 8 (0 ≤ x ≤ 0.1) ceramics were synthesized by the conventional solid-state method. The effects of Mg 2+ substitution on the sinter ability, crystal structures and microwave dielectric properties were systematically investigated. The Q·f values increased from 46,800 GHz to 53,400 GHz when the x value increased from 0 to 0.1. Based on the complex chemical bond theory, the intrinsic parameters were calculated to analyze the mechanism of dielectric loss in Zn 0.9 Mg 0.1 ZrNb 2 O 8 . The total lattice energy and bond energy of the Zn 0.9 Mg 0.1 ZrNb 2 O 8 were higher than that of ZnZrNb 2 O 8 , which was corresponding with the decrease of dielectric loss in the wolframite-structured compounds. The dielectric constant ( ε r ) and temperature coefficient of resonant frequency ( τ f ) of Zn 1-x Mg x ZrNb 2 O 8 ceramics were also heavily influenced by the addition of Mg 2+ . Typically, the dense Zn 0.9 Mg 0.1 ZrNb 2 O 8 ceramics sintered at 1200 °C exhibited excellent microwave dielectric properties with ε r = 27.82, Q·f = 53,400 GHz and τ f = −45.82 ppm/°C.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Yanfei Chen,Yuanlin Chen,Xueyi Guo,Zhenhong Liao,Jihong Huang
As a common gangue in many mineral flotation processes, the activation of quart by inevitable cations will worsen the flotation separation of valuable minerals from quartz. In this work, phosphate was selected to inhibit the activation of quartz flotation by Mg 2+ , and the role of PO 4 3− during flotation was deeply studied by density functional theory (DFT) calculation and a series of research methods. Micro-flotation experiments demonstrated the strong activation effect of Mg 2+ on quartz at pH 10, and the activation effect was significantly inhibited upon adding PO 4 3− to the flotation solution. DFT calculation predicted that Mg hydroxyl compounds (MgOH + and Mg(OH) 2 ) were easily adsorbed onto quartz surface, while Mg 3 (PO 4 ) 2 generated from the reaction between PO 4 3− and Mg 2+ would not be adsorbed onto the quartz surface, which was supported by zeta potential measurement, X-ray photoelectron spectroscopy (XPS) detection, and, scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS) test. Fourier transform infrared spectroscopy (FTIR) tests indicated that the Mg hydroxyl compounds adsorbed onto quartz surface would induce the adsorption of NaOL, which was responsible for the activation of quartz flotation. The addition of PO 4 3− to flotation solution containing Mg 2+ could effectively inhibit the generation of Mg hydroxyl compounds and the subsequent adsorption of NaOL, thereby achieving the depression of quartz flotation. This work provided an effective way for the depression of quartz flotation in complicated flotation systems.
研究领域:
矿物加工工程
·
表面化学
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产品关联
DOI
高影响因子
DESALINATION
·
2020
·
IF 7.098
Chengyi Zhang,Yingxin Mu,Song Zhao,Wen Zhang,Yuxin Wang
Lithium extraction from brines with the high Mg 2+ /Li + ratio is crucial for sustainable lithium resource and environmental protection. This study incorporated the classic tributylphosphate (TBP)/FeCl 3 system into the polyvinyl chloride (PVC) based polymer inclusion membrane (PIM) to extract Li + from the solution which is rich of Mg 2+ (The initial Mg 2+ /Li + molar ratio is 15). The morphology and composition of PIMs were characterized systematically, and the content of TBP/FeCl 3 carrier in the PIM was optimized. Compared to liquid-liquid extraction, the extraction ratio of Li + for PIM extraction increases by 20% and the separation factor of Li + over Mg 2+ increases by 5%. Besides, the loss ratio of Fe 3+ after one loop of liquid-liquid extraction is 17.79%, which is close to that of PIM extraction after three loops (18.30%), demonstrating that the PIM showed a good stability. Furthermore, the separation factor of Li + over Mg 2+ for the PIM with 50 wt% TBP/FeCl 3 is as high as 176 and the initial flux for Li + is 8.12 × 10 −4 mol m −2 h −1 . This study displays a TBP/FeCl 3 based PIM with high selectivity for Li + , providing a possible membrane technology for lithium extraction from brines.
研究领域:
材料科学
·
环境科学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Ziqian Meng,Jiadong Hou,Chufei Cheng,Bei Ren,Yang Miao,Weihua Ji
To create thermal barrier coatings (TBCs) with superior thermal characteristics and high-temperature stability, understanding the microscopic process of heat transfer in high-entropy solid solutions is crucial. In this study, novel (Zr 0.2(1-x) Ce 0.2(1-x) Pr 0.2(1-x) Y 0.2(1-x) Ho 0.2(1-x) Mg x )O 2-δ single-phase high-entropy fluorite-structured oxides with varying Mg elemental contents were successfully synthesized at 1600 °C. Given the unique ionic radius and valence nature of Mg 2+ , the effects of varying the Mg doping amount on the thermophysical properties and microstructures were explored. Furthermore, the mechanism influencing high-temperature thermal conductivity was studied at the microscopic scale using first-principles calculations to clarify the nature of the thermal conductivity behavior. On one hand, an increase in oxygen vacancies leads to an enhancement of the lattice distortion degree and phonon scattering level. On the other hand, divalent Mg 2+ activates the lattice via unequal substitutions, thereby reducing the thermal conductivity. The experimental and simulation results revealed that as Mg doping increases, the content of oxygen vacancies significantly increases, the degree of lattice distortion increases, phonon scattering is enhanced (19.54–21.37 THz), high-temperature thermal conductivity progressively decreases (1.91-1.20 w·m −1 ·K −1 ), and the coefficient of thermal expansion progressively increases (11.70 × 10 −6 -12.31 × 10 −6 K −1 ). These results offer a novel approach for designing doped high-entropy strategies that can satisfy the performance requirements of TBCs.
研究领域:
材料科学
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热力学工程
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产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2020
·
IF 2.726
Hao Tang,Ying Xu,Xianhua Cheng
In this study, Cr 3+ and Mg 2+ co-doped β-NaYF 4 :Yb 3+ /Er 3+ (NYFYE) microcrystals were synthesized for the first time by the facile hydrothermal method . Cr 3+ and Mg 2+ co-doping was confirmed to influence the structure, morphology and UCL property of NYFYE microcrystals. The growth mechanism of NYFYE microcrystals doped with different Cr 3+ and Mg 2+ was discussed in detail. With 16 mol% Cr 3+ and 4 mol% Mg 2+ co-doping into NYFYE, the UC emissions were enhanced to 7 times (green) and 4 times (red) higher than those of the undoped counterpart, and the mechanism was explored by considering the different roles of Cr 3+ and Mg 2+ , the surface quenching and concentration quenching effects. This finding suggests the co-doping of two different impurity ions may be a better approach than corresponding single impurity ion doping for morphology control and UCL intensity enhancement, which is instructive for high performance UC crystals design.
研究领域:
材料科学
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光学
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DOI
高影响因子
MATERIALS LETTERS
·
2021
·
IF 3.423
Heming Ji,Jiale Tang,Xunze Tang,Zhe Yang,Haiyan Zhang,Yannan Qian
The rod-like NaNbO 3 :Er 3+ /Yb 3+ nanocrystals codoped with Mg 2+ ions were firstly synthesized by hydrothermal method. The effect of Mg 2+ ions on the phase structure and morphology of NaNbO 3 :Er 3+ /Yb 3+ was investigated by XRD and SEM spectra. Addition of Mg 2+ ions enhanced the intensities of green and red UC emissions by about 3 times and prolonged the lifetime of the 4 S 3/2 → 4 I 15/2 transition of Er 3+ ions. The pump power dependences were measured to understand the upconversion mechanism under 980 nm excitation. The tailored local environment of Er 3+ ions by codoping Mg 2+ ions was responsible for the improved optical characteristics of NaNbO 3 :Er 3+ /Yb 3+ /Mg 2+ nanocrystals.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2016
·
IF 2.183
Renping Cao,Wenjie Luo,Haidong Xu,Zhiyang Luo,Qianglin Hu,Ting Fu,Dedong Peng
YbAlO 3 :Mn 4+ , YbAlO 3 :Mn 4+ , Li + , and YbAlO 3 :Mn 4+ , Mg 2+ phosphors are synthesized by high temperature solid-state reaction method in air. Their crystal structures and luminescence properties are investigated. Photoluminescence excitation (PLE) spectrum monitored at 677 nm contains broad PLE band with three PLE peaks located at ∼318, 395, and 470 nm within the range 220–600 nm. Emission spectra with excitation 318 and 470 nm exhibit three emission band peaks located at ∼645, 677, and 700 nm in the range of 610–800 nm and their corresponding chromaticity coordinates are about ( x = 0.6942, y = 0.3057). The possible luminous mechanism of Mn 4+ ion is analyzed by the simple energy level diagram of Mn 4+ ion. The optimum Mn 4+ -doped concentration in YbAlO 3 :Mn 4+ phosphor is about 0.4 mol% and the luminescence lifetime of YbAlO 3 :0.4%Mn 4+ phosphor is ∼0.59 ms. Emission intensity of YbAlO 3 :0.4%Mn 4+ phosphor can be enhanced ∼6 times after Mg 2+ ion is co-doped and it is ∼2 times when Li + ion is co-doped. The content in the paper is useful to research new Mn 4+ -doped luminescence materials and improve luminescence property of other Mn 4+ -doped phosphors.
研究领域:
材料科学
·
光学
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产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·Vol. 107
·期 10
·6833-6843
·
IF 3.5
Hailan Qin,Jianwei Zhao,Xiaoxin Chen,Hongtian Li,Shenghao Wang,Yuxiao Du,Ahmad Azmin Mohamad,Huanfu Zhou,Dawei Wang
The investigation of lead-free ceramics with exceptional piezoelectric properties holds great importance in the substitution of lead-based materials, hence promoting the development of green technology and fostering an environmentally sustainable society. This study successfully synthesized two series of Bi(Mg 2/3 Nb 1/3 )O 3 (BMN)-modified BiFeO 3 –BaTiO 3 (BF–BT) lead-free piezoelectric ceramics using the conventional solid-state reaction approach. The phase structure, microstructure, dielectric, and piezoelectric properties of these ceramics were comprehensively investigated. A typical perovskite structure is observed in all probed compositions, and the associated phase structure undergoes a gradual transition from a rhombohedral-cubic phase mixture to a cubic-dominant phase structure as increases the content of BMN and BT. All compositions exhibit obvious core–shell microstructures with inhomogeneous element distributions. Most importantly, the BF–0.30BT–0.005BMN and BF–0.34BT–0.03BMN piezoelectric ceramics presented remarkable values for the piezoelectric coefficient (225 pC/N) and converse piezoelectric coefficient (396 pm/V), respectively. These findings highlight the potential of BMN-modified BF–BT ceramics for use in high-performance piezoelectric applications.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）