Synthesis of Alumina Through Hydrothermal Oxidation of Aluminum Powder Conjugated with Surfactant-Directed Oriented Growth Review
Journal |
Materials Research Innovations
ISSN: 1432-8917 , E-ISSN: 1433-075X |
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Output data | Year: 2005, Volume: 9, Number: 3, Pages: 69-71 Pages count : 3 DOI: 10.1080/14328917.2005.11784899 | ||
Tags | C3 alcohols, Hydrothermal oxidation of aluminum, Structure and texture of alumina | ||
Authors |
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Affiliations |
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Funding (2)
1 | Russian Foundation for Basic Research | 99-03-32853 |
2 | International Association for the Promotion of Co-operation with Scientists from the New Independent States of the Former Soviet Union | YSF-00-199 |
Abstract:
The synthesis of Al2O3 by aluminum metal oxidation finds an increasingly wide application for preparation of catalysts and supports, sensor devices and filter elements despite high energy expenses for the synthesis of aluminum metal (high-temperature electrolysis, spraying during powder production, rolling during foil production, etc.) . This method yields aluminum oxide with novel textural, mechanical and chemical properties that cannot be obtained for samples prepared by precipitation. For example, oxidation of powder aluminum with In and Ga additives made it possible to
prepare aluminum oxide with different ratios of η- and γ- modifications in the final product. The aluminum conversion degree in this process was typically close to 100%. The slit-like pore structure of the oxide consisted of pores 30 Å wide, whereas its surface area reached 320m2/g. Anodic oxidation of aluminum foil yielded Al2O3 consisting of cylindrical pores with honeycomb structure having a narrow size distribution. Depending on the electrochemical oxidation conditions, the mean pore size varied from 90 to 300 Å, with the surface area varying from 28 to 73 m2/g. The aluminum conversion degree and the texture of the prepared oxide were controlled by such parameters as temperature, electrolyte composition, current, reaction time, etc. Slow oxidation of a micron aluminum wire by oxygen at temperatures above the aluminum melting point (up to 1400 °C) yielded aluminum oxide with the corundum structure formed into a mechanically sound device with 80–90% porosity and submicron size pores. Hydrothermal oxidation of aluminum powder placed in a special die providing access of water vapor from an autoclave at 120–250 °C produced highly porous granulated composites with varying Al2O3/Al ratios preserving the shape of the die. Partial oxidation of
aluminum with the formation of hydroxides accompanied by the growth of the solid phase volume resulted in consolidation of the product into a durable monolith with developed mesoporous structure. Aluminum oxide was formed after calcination due to thermal decomposition of the hydroxide. The formed alumina was characterized by a highly ordered microporous structure with slot-like pores and channels from 10 to 60 Å wide. The specific surface area of the prepared oxide could be varied from 120 to 340 m2/g. Its phase composition was analyzed in detail. During the experiments it was found that under the hydrothermal conditions, substances dissolved at high pressures and temperatures could transfer from the die to the autoclave and back. This phenomenon allowed for additional
modification of the aluminum oxide properties. The presence of organic surfactants during the precipitation stage and under hydrothermal conditions is known to have a significant effect on the properties of aluminum oxide. Therefore, in this study, we modified the properties of the obtained hydroxide (and oxide after thermal decomposition) using the simplest surfactants—C3 organic alcohols having different numbers of the alcohol groups and, thus, boiling temperatures, densities, etc.
Cite:
Tikhov S.F.
, Potapova Y.V.
, Sadykov V.A.
, Fenelonov V.B.
, Yudaev I.V.
, Lapina O.B.
, Salanov A.N.
, Zaikovskii V.I.
, Litvak G.S.
Synthesis of Alumina Through Hydrothermal Oxidation of Aluminum Powder Conjugated with Surfactant-Directed Oriented Growth
Materials Research Innovations. 2005. V.9. N3. P.69-71. DOI: 10.1080/14328917.2005.11784899 WOS Scopus РИНЦ
Synthesis of Alumina Through Hydrothermal Oxidation of Aluminum Powder Conjugated with Surfactant-Directed Oriented Growth
Materials Research Innovations. 2005. V.9. N3. P.69-71. DOI: 10.1080/14328917.2005.11784899 WOS Scopus РИНЦ
Dates:
Submitted: | Jun 16, 2004 |
Accepted: | Jul 16, 2004 |
Published print: | Sep 1, 2005 |
Published online: | Oct 13, 2016 |
Identifiers:
Web of science | WOS:000232748000005 |
Scopus | 2-s2.0-27544463755 |
Elibrary | 13492628 |
Chemical Abstracts | 2005:1156153 |
Chemical Abstracts (print) | 144:417530 |
OpenAlex | W2265398977 |