Results 131 to 140 of about 373 (157)

X-ray photoelectron spectroscopic study of hydrated aluminas and aluminas

Journal of Materials Research, 1994
X-ray photoelectron spectra of hydrated aluminas (boehmite, diaspore, bayerite, and gibbsite), transition aluminas (y, δ, η, θ, X, and k –Al2O3) and corundum (α-Al2O3) have been studied for spectral characterization of each compound. The O1s spectra are shifted 0.2–1.2 eV to higher binding energy (Eb) in the order of α-Al2O3 < boehmite, diaspore <
Takeshi Tsuchida, Hideaki Takahashi
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Rate of surface hydration on alumina

Kolloid-Zeitschrift & Zeitschrift für Polymere, 1968
The measurement of water adsorption on crystalline α-alumina having low surface area has been carried out in order to investigate the surface hydration rate. The surface was exposed to the saturated water vapor for a given time at a constant temperature, and then the chemisorbed amount was determined.
Tetsuo Morimoto, Mahiko Nagao
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Controlling hydration of hydratable alumina via co‐grinding with Mg–Al hydrotalcite

Journal of the American Ceramic Society, 2023
Abstract The on‐site industrial application of hydratable alumina (HA)‐bonded castables is inhibited by the high hydration rate of HA. In this study, the hydration behavior of HA co‐ground with sheetlike Mg–Al hydrotalcite (MAT) is investigated. The properties of castables bonded with MAT‐bearing HA are systematically assessed.
Liugang Chen, Liu Guo, Hongrui Zhang, Ye Li   +3 more
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Thermoanalytical study on the chlorination of hydrated aluminas and transition aluminas

Thermochimica Acta, 1979
Abstract The chlorination processes of four hydrated aluminas (bayerite, gibbsite, pseudoboehmite, boehmite) and four transition aluminas (η-,γ-,δ-,θ-Al2O3) were studied in the presence of active carbon by means of a gas-flow DTA apparatus. In the case of hydrated alumina systems three exothermic peaks appeared at about 230, 460 and 500°C or above ...
T. Tsuchida, T. Ishii, R. Furuichi, H. Haga   +3 more
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Stability and dehydration of alumina hydrates with the β-alumina structure

Journal of Solid State Chemistry, 1978
Abstract The stability of alumina hydrates with the β-alumina structure was determined over a wide range of temperature and water pressures by high temperature X-ray diffraction and thermal gravimetric analysis. There are two isomorphs, distinguished by different concentrations of intracrystalline water, which reversibly interconvert by absorption ...
W.L. Roth, M.W. Breiter, G.C. Farrington
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Hydration mechanism and sintering characteristics of hydratable alumina with microsilica addition

Ceramics International, 2019
Abstract Hydratable alumina is potential for the application in refractory industry as one of Ca-free binders, but it is greatly limited because of the excess hydration of rho-alumina (ρ-Al2O3). In this study, hydration mechanism and sintering characteristics of hydratable alumina with different microsilica addition are researched, via the ...
Nana Xu, Yuanbing Li, Shujing Li, Hailu Wang, Ruofei Xiang, Si Ouyang   +5 more
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Hydration and Carbonation of Beta Alumina Powders

Journal of The Electrochemical Society, 1985
Etudes, par thermogravimetrie, calorimetrie de balayage differentiel et diffractometrie RX, de l'adsorption de l'eau par des poudres d'alumine β lithiee, potassique et sodee. On note, de plus, que les echantillons d'alumine β reagissent avec CO 2 en presence d'eau pour former des carbonates hydrates ...
A. Marini, G. Flor, V. Massarotti, A. R. McGhie, G. C. Farrington   +4 more
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Hydration of Sodium β‐ and β′′‐Aluminas

Journal of the American Ceramic Society, 1987
The enthalpy and entropy for the hydration of sodium β ‐ and β ′′‐aluminas have been determined by measuring the infrared absorbance of single‐crystal samples following equilibration at elevated temperatures in water vapor pressures ranging from 3 to 70
NANCY J. DUDNEY, J. B. BATES
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Controlled morphologies and hydration process of hydratable alumina by using citric acid

Journal of the Australian Ceramic Society, 2020
Hydration mechanisms of hydratable alumina (HA) in citric acid at different pH are investigated in this study, aiming to improve rapid hydration process and massive hydration heat. By adding citric acid to adjust solution pHs to 2, 3, and 4, the crystal phase, morphologies, and microstructure of the HA hydrates are characterized by X-ray powder ...
Nana Xu, Yuanbing Li, Shujing Li, Hailu Wang, Ruofei Xiang, Si Ouyang   +5 more
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Hydration of Alumina Cluster Anions in the Gas Phase

Journal of the American Chemical Society, 2004
Hydration reactions of anionic aluminum oxide clusters were measured using a quadrupole ion trap secondary ion mass spectrometer, wherein the number of Lewis acid sites were determined. The extent of hydration varied irregularly as cluster size increased and indicated that the clusters possessed condensed structures where the majority of the Al atoms ...
Anita K, Gianotto, Jennifer W, Rawlinson, Kevin C, Cossel, John E, Olson, Anthony D, Appelhans, Gary S, Groenewold   +5 more
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