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Sorption of aluminum and gallium in the form of hydroxo complexes on a weakly basic AN-31 anion exchanger at 298 K from model solutions is investigated. Based on the experimental data, the forms of ions sorbed by the solid phase o...
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Sorption of aluminum and gallium in the form of hydroxo complexes on a weakly basic AN-31 anion exchanger at 298 K from model solutions is investigated. Based on the experimental data, the forms of ions sorbed by the solid phase of the anion exchanger are determined. Sorption of pentahydroxy aluminate and pentahydroxy gallate ions occurs in the Stern-Helmholtz layer. Apparent constants and Gibbs energies of ion-exchange reactions are calculated. The values of the total exchange capacity of gallate ions of 55-58 g/kg in static conditions determine the use of an AN-31 anion ex change resin during the concentration of gallium ions from alkali aluminate solutions.
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For materials design of the accelerator, it is important to analyze the hydration reaction of the accelerator. Accordingly, the effect of sodium aluminate, which is a typical component substance of the accelerator, on the initial ...
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For materials design of the accelerator, it is important to analyze the hydration reaction of the accelerator. Accordingly, the effect of sodium aluminate, which is a typical component substance of the accelerator, on the initial hydration was investigated. The hydration reaction of amorphous calcium aluminate, which is a kind of calcium aluminate compounds, significantly depends on the addition of sodium aluminate. Sodium aluminate inhibited the hydration of amorphous calcium aluminate. This phenomenon was supposed that the sodium aluminate provide on the surface of amorphous calcium aluminate particles with aluminum hydroxide ion, which create gel hydration products. In addition, it was proven that increasing the calcium ion concentration could prevent hydration inhibition.
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С помощью электрофореза показано, как алюминий передвигается в почвах в форме аниона к положительному электроду, что опровер...
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С помощью электрофореза показано, как алюминий передвигается в почвах в форме аниона к положительному электроду, что опровергает представление о его участии в обменных процессах как катиона.
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С помощью электрофореза показано, как алюминий передвигается в почвах в форме аниона к положительному электроду, что опровер...
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С помощью электрофореза показано, как алюминий передвигается в почвах в форме аниона к положительному электроду, что опровергает представление о его участии в обменных процессах как катиона.
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This paper aims to assess the effect of the transition metals (TM) loading procedure on the incorporation of Go~(2+) and Cu~(2+) in zeolite Y, and their relevance to stability of the zeolite, particularly with respect to the therm...
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This paper aims to assess the effect of the transition metals (TM) loading procedure on the incorporation of Go~(2+) and Cu~(2+) in zeolite Y, and their relevance to stability of the zeolite, particularly with respect to the thermal transformation to the spinel phases. In this work, zeolite Y prepared from Egyptian kaolin was used. XRF, XRD, TEM, UV/visible absorption measurements, and atomic absorption analyses in addition to the visual observations are recorded. XRF has been used to investigate the materials composition. TEM and XRD indicate the presence of nanoparticle spinel upon the calcination of the TM-zeolites at 1000 °C. In addition to spinel particles, XRD shows the formation of metal oxides, SiO_2 and alumino-silicate phases. According to the transition metal and the cation loading process, different phases were detected. UV/visible absorption measurements and the visual observations are used to determine the experimental condition of the highest spinel content. It has been noticed that the experimental conditions of the metal sorption processes greatly affect the phase transformation. Stability and thermal transformation of zeolite depend on the initial concentration of the transition cation solutions and the number of loading cycles.
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? 2022 Elsevier B.V.Graphite intercalation compounds are the main reason behind the successful Li-ion battery technology. However, the alternative chemistries in the energy storage sector are up surging to achieve high energy and ...
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? 2022 Elsevier B.V.Graphite intercalation compounds are the main reason behind the successful Li-ion battery technology. However, the alternative chemistries in the energy storage sector are up surging to achieve high energy and power densities with enhanced safety measures using the cost-effective materials. Dual-ion batteries fall into such category, typically designed with the graphite electrodes. The major challenge is the design of the electrodes that are capable of allowing bulky ions upon intercalation without causing any structural disintegration. To surpass this challenge, bipolar organic electrodes are of preferable choice due to the ease of processability and tunability. Here, we report organic electrode as prospective battery material for the dual-ion batteries application. Polythiophene composite with carbon nanotubes achieved through a single pot chemical oxidative synthetic procedure and the successful composite is comprehensively evaluated using FTIR, FESEM, and HRTEM analyses. The synergetic impact of forming the composite is thoroughly studied with the electrochemical analysis, where the composite shown ～200 mAh/g, retained at the current density of 50 mA/g. The composite sustains for > 900 cycles, maintaining > 99% Coulombic efficiency. The charge holding mechanism is studied for the composites using the XPS, FTIR and XRD patterns recorded on the cycled electrodes, delineating the efficiency of the electrodes for practical applications. Post electrochemical analysis on the electrodes reveal the stable morphology of the composite with better porosity and no passivation formed, leaving positive note on the composite formation over the pristine electrodes.
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12CaO center dot 7Al(2)O(3) (C12A7) with a unique nano-porous structure and free O2- ions entrapped in sub-nanometer-sized cages is a fast oxygen-ion-conducting material. These free O2- may be replaced by various oxygen-related sp...
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12CaO center dot 7Al(2)O(3) (C12A7) with a unique nano-porous structure and free O2- ions entrapped in sub-nanometer-sized cages is a fast oxygen-ion-conducting material. These free O2- may be replaced by various oxygen-related species, OH-, O2- and O-, by tuning the atmosphere during the heat treatment. We examined the conduction mechanism for stoichiometric C12A7 (C12A7: O2-). in which O2- ions exist as counter anions in sub-nanometer-sized cages, by Raman measurement of C12A7:O2- annealed in a dry O-18(2) atmosphere. It was revealed that the primary ion conducting species is an O2- ion which diffuses via exchange with O2- in the cage wall. An experimental result on the sample containing O- ions implied that O- is more mobile than O2- in C12A7. Ab initio calculations on the diffusion paths of O2- and O- ions in C112A7 supported the above experimental results.
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Ion-photon emission (IPE) was investigated under Ar~+ ion bombardment of magnesium aluminate spinel crystals of different compositions MgO·nAl_2O_3 (n = 1.0; 2.5) and, for comparison Al-metal target. For all targets the only emis...
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Ion-photon emission (IPE) was investigated under Ar~+ ion bombardment of magnesium aluminate spinel crystals of different compositions MgO·nAl_2O_3 (n = 1.0; 2.5) and, for comparison Al-metal target. For all targets the only emission of metal excited particles was observed, which leads to lines of Al Ⅰ, Al Ⅱ, Al Ⅲ, Mg Ⅰ and Mg Ⅱ spectra. It was revealed that quantum yield of the IPE of different lines were equal in the range of values 10~(-4)-10~(-7) photon/ion and increases in 5-7 times of that originated from decay of atomic excited states with E_(ex) ≤ 4.83 eV for oxides to compare with metal. The main criteria, which determines the conservation of excitation in flying-off atoms or ions is relation between the band structure of target and energy level of corresponding exited state of emitting particles. Analysis of obtained data allows us to estimate the width of conduction band (μ) in spinel: 0.995 eV ≤ μ ≤ 1.16 eV. There was suggested the new approach for description of energy distribution of emission of knocked out excited particles. The best agreement of calculated data with experimental ones was obtained when the contribution of both the cascade collisions and surface recoil processes of primary ions in solids are included to generate flying-off excited particles.
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The early hydration of calcium aluminate cement (CAC) with different kinds of zinc (II), such as ZnSO4 center dot 7H(2)O, ZnO, Zn(NO3)(2)center dot 6H(2)O and ZnCl2, was analyzed. Changes in consistency, setting time, hydration he...
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The early hydration of calcium aluminate cement (CAC) with different kinds of zinc (II), such as ZnSO4 center dot 7H(2)O, ZnO, Zn(NO3)(2)center dot 6H(2)O and ZnCl2, was analyzed. Changes in consistency, setting time, hydration heat flow, hydration heat amount, ion concentration in solution, and hydration products were found upon the addition of different Zn2+. The water consumption of standard consistency of CAC is decreased with different Zn2+. Zn(2+)can delay the initial hydration of CAC. The induction period of cement with Zn(2+)is longer than that of CAC, especially the reaction time of the acceleration period is extended. Zn(2+)can promote hydration hydrate of CAC at 24 h. The characteristic diffraction peaks of CA and CA(2)in CAC with different Zn(2+)are significantly reduced. It can inhibit the formation of CAH(10)and promote the formation C(3)AH(6)and AH(3)in hydration products at 24 h.
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De-alumination often occurs during the ion-exchange of zeolite from Na to H form. This should be one reason of controversy among researchers. Humid atmosphere causes the de-alumination of H-mordenite unless at least a few percent ...
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De-alumination often occurs during the ion-exchange of zeolite from Na to H form. This should be one reason of controversy among researchers. Humid atmosphere causes the de-alumination of H-mordenite unless at least a few percent of NH_4~+ is remained. On the other hand, simple H-Y zeolite readily decomposes with humidity. In this case, the de-alumination uniformly on the external surface and inside the hulk is needed to keep the zeolite structure. Such a de-alumination was observed by a heat treatment of partially exchanged NH_4Na-Y (NH_4:Na=ca. 6:4) under the presence of ammonia and water vapor.
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