SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2017
·
IF 4.784
Jun-wei Wang,Hong-xia Zhou,Cui-zhen Zhang,Wen-ning Liu,Bai-yao Zhao
As a thermal energy storage medium (TESM) at moderate-high temperature of concentrating solar power (CSP), the molten NaCl-MgCl 2 has sharp corrosive action on a metal container. The influence of MgCl 2 content on a metal corrosion behavior is not clear. The corrosion behavior of a Fe based alloy (GH1140) in molten NaCl-MgCl 2 (at 1123 K) with different content of MgCl 2 (wt%：0.0，48.9，61.0，93.6) were studied by the submergence corrosion experience. Results show that: after corrosion for 5 h, there is a negative correlation between the weight loss of samples and the content of MgCl 2 . In the molten salt without MgCl 2 , the sample was corroded according to the mechanism of “dissolution as anode- oxidizing- peeling off of oxide film”. After adding a little MgCl 2 in the molten salt , an unprotected MgO shell was formed on the sample surface. The samples weight decreased and obeyed a line law. The elements of Fe and Cr deplete in the corrosion layer. Corrosion mechanism is “dissolution as anode- oxidizing- reduction- chlorination”. When the content of MgCl 2 is very high in the molten salt, partial pressure of Cl 2 increases. The corrosion mechanism is similar to what in the molten salt with a little MgCl 2 , but the chlorination reaction is more severe.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2015
·
IF 2.037
Haijun Han,Dongdong Li,Lijiang Guo,Yan Yao,Haitang Yang,Dewen Zeng
Water activity for binary KCl–H2O, NaCl–H2O and MgCl2–H2O, as well as two ternary NaCl–MgCl2–H2O and KCl–MgCl2–H2O, systems has been measured by using an isopiestic method at 323.15 K. The isopiestic results obtained show that the isopiestic composition lines of the NaCl–MgCl2–H2O system was found to obey the Zdanovskii rule, whereas the KCl–MgCl2–H2O system was observed to deviate slightly. The experimental water activities determined were applied to regress the parameters of the Pitzer model with a good agreement. The model with new parameters is validated by comparing water activity predictions with those given in the literature and not used in the parametrization process and calculating the solubility of the NaCl–MgCl2–H2O and KCl–MgCl2–H2O systems at various temperatures with the comparison of literature values.
研究领域:
化学
·
热力学
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Fengli Yang,Qing Xia,Guangpin Lin,Yi Su,Wei Lin,Huabing Zhang,Guobin Liang
Saccharide is the main product of biomass hydrolysis, which can be converted into high-value-added chemicals and fuels, and the isomerization of glucose to fructose is a decisive step in biomass conversion technology. In this research, the isomerization reaction of glucose catalyzed by MgCl 2 -700 in water has been studied, and the fructose yield and selectivity reached 36.4 % and 79.3 %, respectively in an aqueous system at 120 °C for 60 min. The results of electrospray ionization tandem mass spectrometry (ESI-MS) and density functional theory (DFT) show that [MgCl(aq)] + formed in an aqueous system coordinated with glucose for isomerization reaction, and the binding of C1/C2 sites of the β-glucopyranose and [MgCl(aq)] + promoted the 1,2-intramolecular hydride shift of glucose, thus rapidly converting glucose into fructose.
研究领域:
生物化学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS
·
2020
·
IF 1.529
Bin Wang,Chong Lu,Jing Hu,Weixin Lu
Ethylene vinyl alcohol (EVOH) with excellent barrier properties has insufficient thermomechanical properties. The introduction of magnesium chloride (MgCl2) as an initiator in EVOH blends improved its properties by cross-linking. Torque behavior and gel experiment analysis indicated that a cross-linking in EVOH was formed. The cross-linking mechanism was confirmed through 13C nuclear magnetic resonance spectroscopy (13C NMR) and Fourier-transform infrared (FTIR) spectrometry. In 13C NMR spectra, the splitting peaks of CH carbon and CH2 carbon tended to disappear, and the stretching vibration peak of –C=C– was observed in the FTIR spectra. The formation of hydrogen bond between MgCl2 and EVOH destroyed the intramolecular and intermolecular hydrogen bonds of EVOH, which contributed to the dehydration of –OH to form –C=C–, and –C=C– was the basis for a cross-linking reaction. The thermal analysis of blends demonstrated that the melting temperature and crystallization temperature decreased, and the crystallinity gradually disappeared when the MgCl2 content increased. Glass transition temperature significantly increased as the intermolecular force enhanced. Thermogravimetric analysis showed that a cross-linked structure could improve the thermostability of EVOH with an increase in the MgCl2 content. Mechanical test results revealed a remarkable increase in the tensile strength of EVOH as the MgCl2 content increased.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2024
·
IF 4.7
Li-guo ZHU,Chong-lin BAI,Ling-xin KONG,Bin YANG,Bao-qiang XU
To reduce the production cost of titanium, a new method for direct preparation of low-oxygen titanium powder by the magnesiothermic reduction of TiO 2 with the assistance of a MgCl 2 -HoCl 3 molten salt was proposed. Thermodynamic calculations showed that the magnesiothermic reduction of TiO 2 was feasible. However, hindrance of the reduction reaction by the reduction by-product of MgO resulted in a considerably high O concentration in the titanium powder. The addition of HoCl 3 to the system significantly reduces the activity of MgO to produce low-oxygen titanium powder. Thermochemical deoxidation and reduction experiments were conducted with MgCl 2 -HoCl 3 molten salt in the temperature range of 1023-1273 K. The results showed that titanium powder with oxygen concentration (mass fraction) below 5.00×10 -4 can be prepared at the Mg-MgCl 2 -HoOCl-HoCl 3 equilibrium.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLUTION CHEMISTRY
·
2018
·Vol. 48
·期 3
·367-378
·
IF 1.401
Li Hongxia,Guo Lijiang,Li Jianqiang
The water activities of the MgCl 2 –RbCl–H 2 O ternary system and its sub-binary systems have been measured with the isopiestic method at 323.15 K. The measured water activities for the MgCl 2 –H 2 O and RbCl–H 2 O sub-binary systems agree well with the results reported in literature. The measured equal water activity lines of the MgCl 2 –RbCl–H 2 O ternary system are not straight lines, which means the mixing behavior of the solutions do not obey Zdanovskii’s rule. The solubility of the MgCl 2 –RbCl–H 2 O ternary system has been determined with the Flow-Cloud-Point method at 323.15 K, and the measured results are roughly consistent with values reported in the literature. The Pitzer model was selected to correlate the water activity and solubility data measured in this work. The predicted water activities and solubility isotherm for the MgCl 2 –RbCl–H 2 O ternary system at 323.15 K, with binary solution parameters only, both deviated from the experiment values. The ternary solution Pitzer model parameters were obtained by fitting the measured water activities in the ternary system. The water activities and solubility isotherms of the MgCl 2 –RbCl–H 2 O ternary system at 323.15 K were calculated including both binary and ternary solution parameters. The calculated water activities are consistent with the experimental values. The calculated solubility isotherms are roughly consistent with experiment values, except they deviate somewhat in the RbCl crystallization region.
研究领域:
化学
·
物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2017
·
IF 2.323
Lijiang Guo,Yaxiao Wang,Lanying Tu,Jianqiang Li
Water activities of the CsCl–MgCl2–H2O ternary system and its sub-binary systems were elaborately measured by an isopiestic method at 298.15 K. The solubility of this ternary system at 298.15 K was also measured by two different methods, namely isothermal method and Flow-Cloud-Point method. The solubilities measured by the two different methods were consistent with each other. A Pitzer model was used to represent the thermodynamic properties and calculate the solubility isotherms for the CsCl–MgCl2–H2O ternary system at 298.15 K. Both the equal water activity lines and the solubility isotherms are calculated with parameters reported in literature. It was found that only the calculated equal water activity lines with the parameters reported by Scharge et al. are consistent with the experimental values of this work. However, all the calculated solubility isotherms deviated from the experimental data in this work. New set of ternary parameters were obtained by fitting the water activities and solubility data of this work. Using the new parameters, the calculated equal water activity lines and solubility isotherms agreed with experimental values measured in this work.
研究领域:
物理化学
·
无机化学
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2022
·Vol. 24
·期 38
·23490-23496
·
IF 3.945
Yuyue Yan,Jiaqi Zhang,Guanhua Ren,Lu Zhou,Liyuan Liu,Xueqian Zhang,Ligang Chen,Chunmei Ouyang,Jiaguang Han
The interaction of MgCl2 with H2O is heavily involved in biological and chemical processes. In this work, freezing-induced hydrate formation from MgCl2 aqueous solution was monitored using terahertz time-domain spectroscopy. At low temperatures, two phase transitions from brine to hydrate formation could be clearly observed, and the formation of hydrate was accompanied by the emergence of new THz fingerprint peaks at 1.02, 1.56, and 1.84 THz, respectively. Integrating XRD and quantum chemical calculations, we attributed the absorption peaks to the vibrational modes of the formed MgCl2·12H2O. This demonstrates the potential of THz spectroscopy for application in the detection of biological processes in low-temperature environments, such as cell freezing.
研究领域:
化学
·
生物物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOLUTION CHEMISTRY
·
2017
·Vol. 46
·期 9
·1767-1777
·
IF 1.342
Guo Lijiang,Wang Yaxiao,Tu Lanying,Li Jianqiang
Water activities for the MgCl 2 –RbCl–H 2 O ternary system and its sub-binary MgCl 2 –H 2 O and RbCl–H 2 O systems at 298.15 K have been measured using the isopiestic method. The measured results for the binary systems agree well with literature data. The measured equal water activity lines for the MgCl 2 –RbCl–H 2 O ternary system deviate from Zdanovskii’s rule. The solubilities for the MgCl 2 –RbCl–H 2 O ternary system also have been measured using a isothermal visual first/last crystal method, and the results are consistent with one reported set of solubility data. Pitzer’s model was selected to correlate the measured water activity and solubility data and the parameters reported in the literature are re-examined by comparing the model-calculated equal water activity lines and solubilities with experimental values measured in this work. New and reasonable parameters are obtained by fitting the water activity and solubility data measured in this work and those reported in the literature. The water activities and solubilities were simulated with the new parameters and the results show that the Pitzer model can successfully represent the thermodynamic properties and be used to calculate the solubility isotherms.
研究领域:
化学热力学
·
物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2018
·
IF 2.196
Lijiang Guo,Lanying Tu,Yaxiao Wang,Jianqiang Li
Water activities in the ternary system CsCl–MgCl2–H2O and its sub-binary systems at 323.15 K were elaborately measured by an isopiestic method. Moreover, the solubility of the CsCl–MgCl2–H2O system at 323.15 K was also measured by the flow-cloud-point method. A Pitzer model was used to predict the measured water activity and solubility data. The binary parameters for the CsCl–H2O system at 323.15 K were obtained by fitting the measured water activities for this binary system. The calculated water activity and solubility isotherms for the CsCl–MgCl2–H2O system at 323.15 K, with binary parameters only, deviated from the experimental values. This means that it is insufficient with binary parameters only to predict the water activity and calculate the solubility isotherms of the CsCl–MgCl2–H2O system at 323.15 K. The calculated solubility isotherms with both binary and mixing parameters, obtained by fitting the measured water activity, also deviated from experimental values. A new set of reasonable ternary parameters for the CsCl–MgCl2–H2O system was obtained by fitting the measured water activity and solubility data of this work. The calculated solubility isotherms with these parameters agreed with experimental results.
研究领域:
化学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2024
·
IF 6.9
Qiang Wang,Chun-guang Song,Hai-qing Hao,Meng Wang,Zong-yu Feng,Yong-qi Zhang,Xiang-xin Xue,Xiao-wei Huang
Wastewater recycling is the desired goal of the rare earth separation plants for current ecological requirements and economic benefit. The MgCl 2 wastewater generated during rare earth extraction and separation process was treated by spray pyrolysis for the first time to achieve full recycling. The kinetic of spray pyrolysis process and the mechanism affecting the activity of MgO powder were investigated. The results showed that the rate determining step of MgCl 2 solution spray pyrolysis was transformed from a chemical reaction control to a diffusion process control after the temperature exceeded 1073 K. The MgO powder prepared by spray pyrolysis was rough and porous, the embedding of Cl made MgO grains severely distorted, producing more defects. Meanwhile, polycrystalline basic magnesium chloride likewise had more defects. These two points resulted a higher density of defects of MgO powders, and causing higher activity. Moreover, at a temperature of 1173 K, MgCl 2 concentration of 300 g/L and N 2 flow rate of 40 L/min, the thermal decomposition rate of MgCl 2 reached 99.54%, the alkalinity of the powder reached 0.045 mol/g, and the iodine absorption value reached 102.72 mg I 2 /g MgO. Meanwhile, the high purity hydrochloric acid with a concentration of 6.70 mol/L was obtained.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Ling Yu,Xiubin Sun,Chao Liu,Lulu Xiao,Dapeng Tan,Guoliang Zhang
Construction of tight acid-resistant nanofiltration membranes (ARNFMs) with high performance is attracting more and more attention due to the high demand for resourceful treatment of acidic wastewater. In this work, we designed and prepared high-performance polyamine composite ARNFMs with low molecular weight cutoff (MWCO) for MgCl2 rejection based on the differences in diffusion rates between low molecular weight amine molecules (LA-molecules) and polyethylenimine (PEI, Mw = 1800 Da). The LA-molecules reacted with cyanuric chloride (CC) before PEI and the formed primary layer hindered the contact between PEI and CC to some extent. As a result, a thinner separation layer of the polyamine composite ARNFM was constructed due to the introduction of LA-molecules, which endowed the membrane with a much higher water permeability (up to 4.1 times) compared with the pristine polyamine ARNFM. Moreover, the effects of the primary layer structure on the polyamine composited performance and structure were further investigated by utilizing the different reactivity of four LA-molecules (piperazine (PIP), m-phenylenediamine (MPD), diethylene triamine (DETA), and PEI (Mw = 600 Da)) with CC. The triamine structure and short molecular chain of DETA helped to form a just right primary layer with appropriate defects and hence assisted the fabrication of a tight polyamine composite ARNFM. The optimized PEI/DETA2:8-CC composite ARNFM exhibited a quite high MgCl2 rejection rate of 99.1% due to the nondefective separation layer, low MWCO (∼144 Da), and the narrow pore size distribution. In addition, all the polyamine composite ARNFMs showed good acid stabilities in 3 wt % HCl for 72 h at a high temperature of 50 °C.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
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