To investigate the electrochemical reduction mechanism of Ta(Ⅴ)in ethylene carbonate and aluminum chloride(EC-AlCl3)solvate ionic liquid,cyclic voltammetry experiments were conducted on a tungsten working electrode.F...To investigate the electrochemical reduction mechanism of Ta(Ⅴ)in ethylene carbonate and aluminum chloride(EC-AlCl3)solvate ionic liquid,cyclic voltammetry experiments were conducted on a tungsten working electrode.Four reduction peaks were observed in the cyclic voltammogram of the EC-AlCl3-TaCl5 ionic liquid.The reduction peaks at-0.55,-0.72,and-1.12 V(vs Al)were related to the reduction of Ta(Ⅴ)to tantalum metal by three stages including the formation of Ta(Ⅳ)and Ta(Ⅲ)complex ions.The reduction of Ta(Ⅲ)to tantalum metal was an irreversible diffusion-controlled reaction with a diffusion coefficient of 3.7×10^-7 cm^2/s at 323 K,and the diffusion activation energy was 77 k J/mol.Moreover,the cathode products at 323 K were characterized by scanning electron microscopy,energy-dispersive spectroscopy,and X-ray photoelectron spectroscopy.The results showed that tantalum metal and tantalum oxides were obtained by potentiostatic electrodeposition at-0.8 V for 2 h.展开更多
Chemical modification of cassava starch by transesterification of a vegetable oil(palm kernel oil)using aluminum chloride as a Lewis acid catalyst was achieved under relatively mild conditions(temperature 60–110°...Chemical modification of cassava starch by transesterification of a vegetable oil(palm kernel oil)using aluminum chloride as a Lewis acid catalyst was achieved under relatively mild conditions(temperature 60–110°C;atmospheric pressure).The reaction was carried out without any additional solvent.The modified starch was characterized by degree of substitution(DS),FTIR,X-ray diffraction and thermal analysis.DS of 0.09 to 0.53 were obtained.The cassava starch presented an X-ray diffraction pattern of a type A starch.X-ray analyses showed that the reaction did not significantly affect the crystallinity of starch.The modified starch films(MStF)adsorbed less water than the reference native starch film(NStF)at all the relative humidities investigated.The MStF were also less soluble in water.The tensile tests showed an increase of the strength and a decrease of the flexibility of MStF compared to the reference NStF.The results showed that this chemical route could be used to increase the water resistance of starch-based materials.展开更多
The effects of pyrolysis mode and pyrolysis parameters on Cl content in alumina were investigated, and the alumina products were characterized by XRD, SEM and ASAP. The experimental results indicate that the spray pyr...The effects of pyrolysis mode and pyrolysis parameters on Cl content in alumina were investigated, and the alumina products were characterized by XRD, SEM and ASAP. The experimental results indicate that the spray pyrolysis efficiency is higher than that of static pyrolysis process, and the reaction and evaporation process lead to a multi-plot state of the alumina products by spray pyrolysis. Aluminum phase starts to transform into γ-Al2O3 at spray pyrolysis temperature of 600 °C, which is about 200 °C lower than that of static pyrolysis process. The primary particle size of γ-Al2O3 product is 27.62 nm, and Cl content in alumina products is 0.38% at 800 °C for 20 min.展开更多
Electrochemical deposition and nucleation of aluminum on tungsten electrode from AlCl3-NaCl melts were studied by cyclic voltammetry, chronopotentiometry and chronoamperometry. Cyclic voltammetry and chronopotentiomet...Electrochemical deposition and nucleation of aluminum on tungsten electrode from AlCl3-NaCl melts were studied by cyclic voltammetry, chronopotentiometry and chronoamperometry. Cyclic voltammetry and chronopotentiometry analyses showed that Al (Ⅲ) was reduced at 200℃ in two consecutive steps in an electrolyte of molten AlCl3-NaCl system with a composition 52:48 molar ratio. The current-time characteristics of nucleation aluminum on tungsten showed a strong dependence on overpotentials. Chronoamperometry showed that the deposition process of aluminum on tungsten was controlled by an instantaneous nucleation with a hemispherical diffusion-controlled growth mechanism. The results could lead to a better understanding of the AlCl3-NaCl melt system that has technological importance in electrodeposition of metals as well as in rechargeable batteries.展开更多
This research involved attempting to improve water quality at the Abu-Rawash WWTP by using aluminum chloride (AlCl3) as a coagulant combined with injection of carbon dioxide (CO2). The Abu-Rawash WWTP is the main sour...This research involved attempting to improve water quality at the Abu-Rawash WWTP by using aluminum chloride (AlCl3) as a coagulant combined with injection of carbon dioxide (CO2). The Abu-Rawash WWTP is the main source of water quality degradation at the Rosetta branch, Egypt. Sewage samples were collected from the effluent of the grit removal chamber. Jar tests were performed to estimate the optimum pH value and the coagulant dosage required to obtain acceptable treatment. Eleven samples were prepared with equal dosages of aluminum chloride (10.0 mg/L) and different pH values. The optimal pH values for the elimination of the biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), and turbidity ranged from 6.10 to 6.20 for the aluminum chloride. Results indicated that the appropriate AlCl3 dosage was 2.0 mg/L, especially at pH between 6.1 and 6.2. The results also showed that the AlCl3 was cost effective, especially after reducing pH value. It is also more cost effective than the other proposed solutions such as changing the effluent path of the Abu-Rawash WWTP to the desert.展开更多
Aluminum chloride (AlCl3) efficiently catalyzes one-pot multicomponent condensation of enolizable ketones or alkyl acetoacetates with aldehydes, acetonitrile and acetyl chloride to afford β-acetamido ketone or este...Aluminum chloride (AlCl3) efficiently catalyzes one-pot multicomponent condensation of enolizable ketones or alkyl acetoacetates with aldehydes, acetonitrile and acetyl chloride to afford β-acetamido ketone or ester derivatives in high to excellent yields and in relatively short reaction times. Moreover, by this synthetic method, some novel β-acetamido ketones and esters (i.e. one complex structure) are prepared.展开更多
A catalytic addition of amine N H bonds to carbodiimides using aluminum chloride as a Lewis acid catalyst is developed.The reaction proceeds under mild conditions without solvent to afford a series of substituted guan...A catalytic addition of amine N H bonds to carbodiimides using aluminum chloride as a Lewis acid catalyst is developed.The reaction proceeds under mild conditions without solvent to afford a series of substituted guanidines in good to excellent yields using a wide range of amines as substrates.Evidence of the proposed mechanism is provided by in situ infrared spectroscopy.展开更多
Flow-induced corrosion consists electrochemical and mechanical components. The present paper has to assessed the role of chloride ion and dissolved oxygen in the electrochemical component of flow induced corrosion for...Flow-induced corrosion consists electrochemical and mechanical components. The present paper has to assessed the role of chloride ion and dissolved oxygen in the electrochemical component of flow induced corrosion for AA5083-H321 aluminum-magnesium alloy which is extensively used in the construction of high-speed boats, submarines, hovercrafts, and desalination systems, in NaCI solutions. Electrochemical tests were carried out at flow velocities of 0, :2, 5, 7 and 10 m/s, in aerated and deaerated NaCI solutions with different sodium chloride concentrations. The results showed that the high rate of oxygen reduction under hydrodynamic conditions causes an increase in the density of pits on the surface. The increase of chloride ions concentration under flow conditions accelerates the rate of anodic reactions, but have no influence on the cathodic reactions. Thus, in the current work, it was found that under flow conditions, due to the elimination of corrosion products inside the pits, corrosion resistance of the alloy is increased.展开更多
Al-doped ZnO(AZO) powders were prepared by using metal chloride precursors and the sol-gel technique. IR peaks observed at 1590 cm-1 and 1620 cm-1indicated the formation of metal chelate as a consequence of the additi...Al-doped ZnO(AZO) powders were prepared by using metal chloride precursors and the sol-gel technique. IR peaks observed at 1590 cm-1 and 1620 cm-1indicated the formation of metal chelate as a consequence of the addition of acetylacetone to the metal chloride solution. TG-DSC analysis of the AZO gels confirmed the formation of metal chelate as evidenced by the development of several weight loss peaks accompanied by the introduction of new endothermic peaks. The resulting AZO gels were annealed at 500, 600, and 800 ℃ to study the effect of annealing temperature. XRD and SEM results showed that crystallization of AZO gels takes place around 600 ℃. Hexagonal wurtzite structure was identified as the main phase for all the samples. In addition, small shift of the XRD(002) peak coupled with XPS results from the AZO powders confirmed the successful doping of the ZnO powders. Micron sized rod-like AZO powders were uniform in dimension and morphology and remained stable even at 800 ℃.展开更多
The use of Crocin, derived from the flowers of Crocus sativus, is investigated as corrosion inhibitor for the AA1050, AA5083, AA5754 and AA6082 aluminum alloys in chloride ions environment. Aluminum and aluminum alloy...The use of Crocin, derived from the flowers of Crocus sativus, is investigated as corrosion inhibitor for the AA1050, AA5083, AA5754 and AA6082 aluminum alloys in chloride ions environment. Aluminum and aluminum alloys are subjected to corrosion in the aggressive environment of chlorides, so several green corrosion inhibitors, mostly of plant origin, with minimum impact on health and the environment have been examined. In this study, the inhibition efficiency of 1.25 mM Crocin in a 0.01 M NaCl corrosive solution was assessed via electrochemical corrosion techniques and gravimetric mass loss measurements of the aluminum alloys. The surface of the specimens was examined using Scanning Electron Microscopy, Energy Dispersive Spectroscopy, Stereomicroscopy and Glossiness measurements. Experimental results reveal the protective anticorrosive action of Crocin for all aluminum alloys in the sodium chloride medium.展开更多
Studies have suggested that aluminum, a neurotoxic metal, is involved in the progression of neurodegenerative diseases. Previous studies have confirmed that aluminum influences intracellular Ca^2+ homeostasis. Howeve...Studies have suggested that aluminum, a neurotoxic metal, is involved in the progression of neurodegenerative diseases. Previous studies have confirmed that aluminum influences intracellular Ca^2+ homeostasis. However, it remains unclear whether aluminum increases or decreases intracellular Ca^2+ concentrations. The present study demonstrated that Al^3+ competitively binds to calmodulin (CAM), together with Ca^2+, which resulted in loss of capacity of CaM to bind to Ca^2+, leading to increased [Ca^2+]i. Al^3+ stimulated voltage-gated calcium channels on cell membranes, which allowed a small quantity of Ca^2+ into the cells. Al^3+ also promoted calcium release from organelles by stimulating L-Ca^2+αlc to trigger calcium-induced calcium release. Although Al^3+ upregulated expression of Na+/Ca^2+exchanger mRNA, increased levels of Ca^2+ and Na+/Ca^2+ exchanger did not maintain a normal Ca^2+ balance. Al^3+ resulted in disordered intracellular calcium homeostasis by affecting calcium channels, calcium buffering, and calcium expulsion.展开更多
Objective: To examine the protective effect of Ginkgo biloba leaf extract (GbE) on learning and memory deficit induced by aluminum chloride (AlCl3), and explore its mechanisms. Methods: The rat models with learn...Objective: To examine the protective effect of Ginkgo biloba leaf extract (GbE) on learning and memory deficit induced by aluminum chloride (AlCl3), and explore its mechanisms. Methods: The rat models with learning and memory deficit were induced by administering via gastrogavage and drinking of AlCl3 solution. And the model rats were treated with GbE at the dose of 50, 100, 200 mg/kg every day for 2 months accompanied with drinking of AlCl3 solution, respectively. Their abilities of spatial learning and memory were tested by Morris water maze, and the acetylcholinesterase (ACHE) activity in serum was assayed with chemical method, the AChE expression in hippocampus was observed by immunohistochemistry assay, and then quantitative analysis was done by BI 2000 image analysis system. Results: Learning and memory deficit of rats could be induced by AlCl3 solution (P〈0.01), and AChE expressions in rats hippocampus were increased (P〈0.01); GbE ameliorated learning and memory deficit and reduced AChE expression in rats hippocampus in a dose-dependent manner, while GbE significantly increased serum AChE activity at the dose of 200 mg/kg each day (P〈0.05). Conclusion: GbE can ameliorate learning and memory deficit induced by AlCl3, which may be due to its inhibition of the AChE expression in hippocampus.展开更多
基金Projects(N182503033N172502003)supported by the Fundamental Research Funds for the Central Universities,China+1 种基金Project(2018M640258)supported by Postdoctoral Research Foundation of ChinaProject(GUIKE AA18118030)supported by Guangxi Innovation-driven Development Program,China。
文摘To investigate the electrochemical reduction mechanism of Ta(Ⅴ)in ethylene carbonate and aluminum chloride(EC-AlCl3)solvate ionic liquid,cyclic voltammetry experiments were conducted on a tungsten working electrode.Four reduction peaks were observed in the cyclic voltammogram of the EC-AlCl3-TaCl5 ionic liquid.The reduction peaks at-0.55,-0.72,and-1.12 V(vs Al)were related to the reduction of Ta(Ⅴ)to tantalum metal by three stages including the formation of Ta(Ⅳ)and Ta(Ⅲ)complex ions.The reduction of Ta(Ⅲ)to tantalum metal was an irreversible diffusion-controlled reaction with a diffusion coefficient of 3.7×10^-7 cm^2/s at 323 K,and the diffusion activation energy was 77 k J/mol.Moreover,the cathode products at 323 K were characterized by scanning electron microscopy,energy-dispersive spectroscopy,and X-ray photoelectron spectroscopy.The results showed that tantalum metal and tantalum oxides were obtained by potentiostatic electrodeposition at-0.8 V for 2 h.
文摘Chemical modification of cassava starch by transesterification of a vegetable oil(palm kernel oil)using aluminum chloride as a Lewis acid catalyst was achieved under relatively mild conditions(temperature 60–110°C;atmospheric pressure).The reaction was carried out without any additional solvent.The modified starch was characterized by degree of substitution(DS),FTIR,X-ray diffraction and thermal analysis.DS of 0.09 to 0.53 were obtained.The cassava starch presented an X-ray diffraction pattern of a type A starch.X-ray analyses showed that the reaction did not significantly affect the crystallinity of starch.The modified starch films(MStF)adsorbed less water than the reference native starch film(NStF)at all the relative humidities investigated.The MStF were also less soluble in water.The tensile tests showed an increase of the strength and a decrease of the flexibility of MStF compared to the reference NStF.The results showed that this chemical route could be used to increase the water resistance of starch-based materials.
基金Projects(U1202274,51004033,51204040)supported by the National Natural Science Foundation of ChinaProject(2012AA062303)supported by the National High Technology Research and Development Program of China+2 种基金Project(2012BAE01B02)supported by the National Science and Technology Support Program of ChinaProject(L2014096)supported by the Education Department of Liaoning Province,ChinaProject(N130702001)supported by the Fundamental Research Funds for the Central Universities,China
文摘The effects of pyrolysis mode and pyrolysis parameters on Cl content in alumina were investigated, and the alumina products were characterized by XRD, SEM and ASAP. The experimental results indicate that the spray pyrolysis efficiency is higher than that of static pyrolysis process, and the reaction and evaporation process lead to a multi-plot state of the alumina products by spray pyrolysis. Aluminum phase starts to transform into γ-Al2O3 at spray pyrolysis temperature of 600 °C, which is about 200 °C lower than that of static pyrolysis process. The primary particle size of γ-Al2O3 product is 27.62 nm, and Cl content in alumina products is 0.38% at 800 °C for 20 min.
基金supported by the National Basic Research Program of China (No.2007CB210305)the National Natural Science Foundation of China (Grant No.50674031).
文摘Electrochemical deposition and nucleation of aluminum on tungsten electrode from AlCl3-NaCl melts were studied by cyclic voltammetry, chronopotentiometry and chronoamperometry. Cyclic voltammetry and chronopotentiometry analyses showed that Al (Ⅲ) was reduced at 200℃ in two consecutive steps in an electrolyte of molten AlCl3-NaCl system with a composition 52:48 molar ratio. The current-time characteristics of nucleation aluminum on tungsten showed a strong dependence on overpotentials. Chronoamperometry showed that the deposition process of aluminum on tungsten was controlled by an instantaneous nucleation with a hemispherical diffusion-controlled growth mechanism. The results could lead to a better understanding of the AlCl3-NaCl melt system that has technological importance in electrodeposition of metals as well as in rechargeable batteries.
文摘This research involved attempting to improve water quality at the Abu-Rawash WWTP by using aluminum chloride (AlCl3) as a coagulant combined with injection of carbon dioxide (CO2). The Abu-Rawash WWTP is the main source of water quality degradation at the Rosetta branch, Egypt. Sewage samples were collected from the effluent of the grit removal chamber. Jar tests were performed to estimate the optimum pH value and the coagulant dosage required to obtain acceptable treatment. Eleven samples were prepared with equal dosages of aluminum chloride (10.0 mg/L) and different pH values. The optimal pH values for the elimination of the biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), and turbidity ranged from 6.10 to 6.20 for the aluminum chloride. Results indicated that the appropriate AlCl3 dosage was 2.0 mg/L, especially at pH between 6.1 and 6.2. The results also showed that the AlCl3 was cost effective, especially after reducing pH value. It is also more cost effective than the other proposed solutions such as changing the effluent path of the Abu-Rawash WWTP to the desert.
文摘Aluminum chloride (AlCl3) efficiently catalyzes one-pot multicomponent condensation of enolizable ketones or alkyl acetoacetates with aldehydes, acetonitrile and acetyl chloride to afford β-acetamido ketone or ester derivatives in high to excellent yields and in relatively short reaction times. Moreover, by this synthetic method, some novel β-acetamido ketones and esters (i.e. one complex structure) are prepared.
基金supported by the National Natural Science Foundation of China (20972107,20872106)the Department of National Education PhD Foundationthe Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘A catalytic addition of amine N H bonds to carbodiimides using aluminum chloride as a Lewis acid catalyst is developed.The reaction proceeds under mild conditions without solvent to afford a series of substituted guanidines in good to excellent yields using a wide range of amines as substrates.Evidence of the proposed mechanism is provided by in situ infrared spectroscopy.
文摘Flow-induced corrosion consists electrochemical and mechanical components. The present paper has to assessed the role of chloride ion and dissolved oxygen in the electrochemical component of flow induced corrosion for AA5083-H321 aluminum-magnesium alloy which is extensively used in the construction of high-speed boats, submarines, hovercrafts, and desalination systems, in NaCI solutions. Electrochemical tests were carried out at flow velocities of 0, :2, 5, 7 and 10 m/s, in aerated and deaerated NaCI solutions with different sodium chloride concentrations. The results showed that the high rate of oxygen reduction under hydrodynamic conditions causes an increase in the density of pits on the surface. The increase of chloride ions concentration under flow conditions accelerates the rate of anodic reactions, but have no influence on the cathodic reactions. Thus, in the current work, it was found that under flow conditions, due to the elimination of corrosion products inside the pits, corrosion resistance of the alloy is increased.
基金Funded by the Project of Instituto Politecnico Nacional(SIPIPN-20182176)
文摘Al-doped ZnO(AZO) powders were prepared by using metal chloride precursors and the sol-gel technique. IR peaks observed at 1590 cm-1 and 1620 cm-1indicated the formation of metal chelate as a consequence of the addition of acetylacetone to the metal chloride solution. TG-DSC analysis of the AZO gels confirmed the formation of metal chelate as evidenced by the development of several weight loss peaks accompanied by the introduction of new endothermic peaks. The resulting AZO gels were annealed at 500, 600, and 800 ℃ to study the effect of annealing temperature. XRD and SEM results showed that crystallization of AZO gels takes place around 600 ℃. Hexagonal wurtzite structure was identified as the main phase for all the samples. In addition, small shift of the XRD(002) peak coupled with XPS results from the AZO powders confirmed the successful doping of the ZnO powders. Micron sized rod-like AZO powders were uniform in dimension and morphology and remained stable even at 800 ℃.
文摘The use of Crocin, derived from the flowers of Crocus sativus, is investigated as corrosion inhibitor for the AA1050, AA5083, AA5754 and AA6082 aluminum alloys in chloride ions environment. Aluminum and aluminum alloys are subjected to corrosion in the aggressive environment of chlorides, so several green corrosion inhibitors, mostly of plant origin, with minimum impact on health and the environment have been examined. In this study, the inhibition efficiency of 1.25 mM Crocin in a 0.01 M NaCl corrosive solution was assessed via electrochemical corrosion techniques and gravimetric mass loss measurements of the aluminum alloys. The surface of the specimens was examined using Scanning Electron Microscopy, Energy Dispersive Spectroscopy, Stereomicroscopy and Glossiness measurements. Experimental results reveal the protective anticorrosive action of Crocin for all aluminum alloys in the sodium chloride medium.
基金supported by the Department of Hygienic Toxicology,Public Health College,Harbin Medical University,China
文摘Studies have suggested that aluminum, a neurotoxic metal, is involved in the progression of neurodegenerative diseases. Previous studies have confirmed that aluminum influences intracellular Ca^2+ homeostasis. However, it remains unclear whether aluminum increases or decreases intracellular Ca^2+ concentrations. The present study demonstrated that Al^3+ competitively binds to calmodulin (CAM), together with Ca^2+, which resulted in loss of capacity of CaM to bind to Ca^2+, leading to increased [Ca^2+]i. Al^3+ stimulated voltage-gated calcium channels on cell membranes, which allowed a small quantity of Ca^2+ into the cells. Al^3+ also promoted calcium release from organelles by stimulating L-Ca^2+αlc to trigger calcium-induced calcium release. Although Al^3+ upregulated expression of Na+/Ca^2+exchanger mRNA, increased levels of Ca^2+ and Na+/Ca^2+ exchanger did not maintain a normal Ca^2+ balance. Al^3+ resulted in disordered intracellular calcium homeostasis by affecting calcium channels, calcium buffering, and calcium expulsion.
基金Supported by the Project of Governor Talent Foundation ofGuizhou Province (No .2001016)
文摘Objective: To examine the protective effect of Ginkgo biloba leaf extract (GbE) on learning and memory deficit induced by aluminum chloride (AlCl3), and explore its mechanisms. Methods: The rat models with learning and memory deficit were induced by administering via gastrogavage and drinking of AlCl3 solution. And the model rats were treated with GbE at the dose of 50, 100, 200 mg/kg every day for 2 months accompanied with drinking of AlCl3 solution, respectively. Their abilities of spatial learning and memory were tested by Morris water maze, and the acetylcholinesterase (ACHE) activity in serum was assayed with chemical method, the AChE expression in hippocampus was observed by immunohistochemistry assay, and then quantitative analysis was done by BI 2000 image analysis system. Results: Learning and memory deficit of rats could be induced by AlCl3 solution (P〈0.01), and AChE expressions in rats hippocampus were increased (P〈0.01); GbE ameliorated learning and memory deficit and reduced AChE expression in rats hippocampus in a dose-dependent manner, while GbE significantly increased serum AChE activity at the dose of 200 mg/kg each day (P〈0.05). Conclusion: GbE can ameliorate learning and memory deficit induced by AlCl3, which may be due to its inhibition of the AChE expression in hippocampus.