Crystalline Aluminum Oxide Films

Alwitt, Robert S.

doi:10.1016/b978-0-444-42252-1.50114-4

Cited by 23 publications

(42 citation statements)

References 10 publications

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“…At temperatures less than 100°C bayerite, α-Al(OH) 3 , is expected to form. At 100°C boehmite (γ-AlOOH) is the most probable hydroxide to form [28]. Examination of the boiled specimens prior to spraying by XPS in a previous study showed the presence of thick layers (N200 nm) of boehmite.…”

Section: Effects Of the Boiling Treatment On The Surface Chemistrymentioning

confidence: 96%

“…Examination of the boiled specimens prior to spraying by XPS in a previous study showed the presence of thick layers (N200 nm) of boehmite. For Al_BT, XPS results suggested that the hydroxide layer may have been partially dehydrated by the heat-treatment [33], most probably on its outer surface and may form several transition aluminas (γ-Al 2 O 3 , δ-Al 2 O 3 , κ-Al 2 O 3 ) [28]. It can also be expected that such a partial dehydration may occur during plasma spraying.…”

Section: Effects Of the Boiling Treatment On The Surface Chemistrymentioning

confidence: 98%

“…However, as explained above, γ-AlOOH is the expected phase following this boiling treatment as it results from the reaction of aluminum and water. Moreover, even if boehmite does transform into alumina, a complete transition would normally occur at a very high temperature (∼1200°C) [28], which is unlikely to occur even at 350°C or during the spraying process (which does not induce any melting of the substrate, the melting point of Al being at 649°C). Thus, the phase observed on sprayed and unsprayed, boiled and thermally treated specimens is most likely to be hydroxide γ-AlOOH.…”

Section: Effects Of the Boiling Treatment On The Surface Chemistrymentioning

confidence: 99%

“…Indeed, it has been shown that heating an alloy, such as 5052 Al, in air increases the thickness of the already present passivation layer of Al oxide (γ-Al 2 O 3 ) with, sometimes, the formation of an outer layer of MgO [27]. On the other hand, boiling aluminum in distilled water leads to the formation of an hydroxide layer, mainly boehmite (AlOOH) [28]. The treatments applied are expected to influence splat formation, by varying the substrate surface chemistry characteristics.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Study of the splat formation for plasma sprayed NiCr on aluminum substrate as a function of substrate condition

Brossard

Munroe

Tran

et al. 2010

Surface and Coatings Technology

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Section: Effects Of the Boiling Treatment On The Surface Chemistrymentioning

confidence: 96%

Section: Effects Of the Boiling Treatment On The Surface Chemistrymentioning

confidence: 98%

Section: Effects Of the Boiling Treatment On The Surface Chemistrymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Study of the splat formation for plasma sprayed NiCr on aluminum substrate as a function of substrate condition

Brossard

Munroe

Tran

et al. 2010

Surface and Coatings Technology

View full text Add to dashboard Cite

“…Dissolution of the oxide layer is caused mainly by the hydration reaction of the formed oxide layer as shown below (Alwitt and Takei 1983;Xu et al 1985;Shimizu et al 1992) 2Al…”

Section: 1cmentioning

confidence: 98%

Nanowires: properties, applications and synthesis via porous anodic aluminium oxide template

2007

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Quasi one-dimensional nanowires possess unique electrical, electronic, thermoelectrical, optical, magnetic and chemical properties, which are different from that of their parent counterpart. The physical properties of nanowires are influenced by the morphology of the nanowires, diameter dependent band gap, carrier density of states etc. Nanowires hold lot of promises for different applications. Basic electronic devices like junction diodes, transistors, FETs and logic gates can be fabricated by using semiconductor and superlattice nanowires. Thermoelectric cooling system can be fabricated by using metallic nanowires. Semiconductor nanowire junctions can be used for different opto-electronic applications. Moreover, periodic arrays of magnetic nanowires hold high potential for recording media application. Nanowires are also potential candidates for sensor and bio-medical applications.In the present article, the physical and chemical properties of nanowires along with their probable applications in different fields have been reviewed in detail. The review also includes highlights of the synthesis of nanowires via porous anodic aluminium oxide template since the technique is simple, cost-effective and a low temperature technique.

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TEMPO‐Oxidized Cellulose Nanofibers as Pseudocatalysts for in Situ and on‐Demand Hydrogen Generation via Aluminum Powder/Pure Water Reactions at a Temperature below 50 °C

Fugetsu

Yoshinaga

Kimura

et al. 2023

Adv Energy and Sustain Res

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Cellulose nanofibers (CNFs) prepared via 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO)‐mediated oxidation of the C6 primary hydroxyls of native cellulose to carboxylates are used as pseudocatalysts for enhancing the aluminum powder/pure water reactions. The Al powder/pure water reaction is a stepwise reaction. It starts from hydration of the outmost native Al2O3 thin layer and then the reaction of the inner metallic Al with water. At lower temperatures (<50 °C), OH− and Al3+ ions are the preliminary products of the native Al2O3 thin layer hydration. Once Al powders are mixed with pure water containing 0.1–0.5 wt% TEMPO‐CNFs, condensed networks consisting of TEMPO‐CNFs self‐establish over the native Al2O3 thin layer. Al3+ ions are captured by TEMPO‐CNFs via the formation of insoluble Al3+/TEMPO‐CNFs complexing nanostructures and the conjugated OH− ions are being restricted nearby the native Al2O3‐based thin layer via electrostatic repulsion. A highly alkaline condition (pH > 11) is dynamically generated, and as a result, the native Al2O3 thin layer dissolves rapidly via the reaction with OH− ions. The OH− ions function also as catalysts, accelerating the reaction of metallic Al with water. Al powders (2–200 μm) react promptly and a nearly 100% Al/H2 conversion is obtained at the reaction temperature below 50 °C.

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Crystalline Aluminum Oxide Films

Cited by 23 publications

References 10 publications

Study of the splat formation for plasma sprayed NiCr on aluminum substrate as a function of substrate condition

Study of the splat formation for plasma sprayed NiCr on aluminum substrate as a function of substrate condition

Nanowires: properties, applications and synthesis via porous anodic aluminium oxide template

TEMPO‐Oxidized Cellulose Nanofibers as Pseudocatalysts for in Situ and on‐Demand Hydrogen Generation via Aluminum Powder/Pure Water Reactions at a Temperature below 50 °C

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