Transformations of γ-alumina in aqueous suspensions

Carrier, Xavier; Marceau, Éric; Lambert, Jean-François; Che, Michel

doi:10.1016/j.jcis.2006.12.074

Cited by 135 publications

(65 citation statements)

References 40 publications

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“…As a matter of fact, it was shown by van de Water et al [18] by means of UV/Vis microspectroscopy that 5 min were enough for detecting Ni ions at the core of 3 mm g-Al 2 O 3 pellets initially impregnated with an acidified solution of Ni-ethylenediamine and Wang et al [7] reported that the ion uptake in a mesoporous alumina, although longer than in conventional alumina, occurred within a few minutes. Moreover, an equilibration time higher than 15 h would result in a profound modification of the surface properties of the alumina used in this work because it was shown previously that Al(OH) 3 precipitation could be observed in as little as 24 h. [19] Hence, the contact time used in this work results from the trade-off between the necessary diffusion of Ni complexes and the unwanted alumina alteration in aqueous solution.…”

Section: Discussionmentioning

confidence: 98%

Confinement in Nanopores at the Oxide/Water Interface: Modification of Alumina Adsorption Properties

Baca

Carrier

Blanchard

2008

Chemistry A European J

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There is limited knowledge on the influence of the pore size on surface phenomena (adsorption, dissolution, precipitation, etc.) at the oxide/water interface and a better understanding of the space confinement in nanoscale pores should have practical implications in different areas, such as transport of contaminants in the environment or heterogeneous catalyst preparation, to name a few. To investigate the modifications of the oxide adsorption properties at the oxide/water interface in a confined environment, the surface acidobasic and ion adsorption properties of six different aluminas (5 porous commercial aluminas with pore diameters ranging from 25 to 200 A and 1 non-porous alumina) were determined by means of acid-base titration and Ni(II) adsorption. It is shown that the confinement has a moderate impact on the alumina adsorption capacity because all materials have similar surface charging behaviours and ion saturation coverages. However, a confined geometry has a much larger impact on the ion adsorption constants, which decrease drastically when the average pore diameter decreases below 200 A. These results are discussed in terms of nanoscale pore space confinement.

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Section: Discussionmentioning

confidence: 98%

Confinement in Nanopores at the Oxide/Water Interface: Modification of Alumina Adsorption Properties

Baca

Carrier

Blanchard

2008

Chemistry A European J

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“…Solubility profiles for alumina were also calculated by using ChemEQL software (Carrier et al 2007; see Figure 32). Similarly, alumina appears metastable under acidic conditions.…”

Section: Alumina Solubilitymentioning

confidence: 99%

“…Similarly, alumina appears metastable under acidic conditions. Moreover, Carrier et al (2007) demonstrated that at a pH over 4, after a 10-h contact, the alumina suspension dissolved, leading to a supersaturated solution from which aluminum hydroxide particles precipitated and grew independently from the alumina surface. Thermodynamically stable gibbsite particles were formed in the acidic range, while bayerite became the predominant phase at a nearly neutral pH.…”

Section: Alumina Solubilitymentioning

confidence: 99%

Sorbent Selection Progress Report

Stepinski

Ziegler

Jerden

et al. 2009

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“…Another weight loss accompanying an endothermic peak was detected at 215°C. According to previous works studying on aluminum hydroxide, 22),23) the loss at 215°C was attributed to elimination of H 2 O from Al(OH) 3 . At 389°C, a weight loss with a strong exothermic peak appeared, which was due to decomposition of acetic acid used for peptization.…”

Section: Alumina Film 321 Gelation Of Alumina Solmentioning

confidence: 78%

Fabrication of transparent self-supporting alumina films by homogeneous precipitation process

Inoue

Kurebayashi

Hama

et al. 2013

J. Ceram. Soc. Japan

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This paper reports fabrication of transparent self-supporting alumina films by using homogeneous precipitation and peptization processes. White precipitate of aluminum hydroxide was prepared with a homogeneous precipitation method using aluminum nitrate and urea in aqueous solution. The obtained aluminum hydroxide precipitate was peptized by using acetic acid at room temperature, which resulted in production of a transparent alumina sol. The alumina sol was transformed to an alumina gel film by drying the sol at room temperature. The alumina film was amorphous or fine crystallites even after annealed at a temperature as high as 500°C, and was crystallized to £-Al 2 O 3 at 900°C.

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Transformations of γ-alumina in aqueous suspensions

Cited by 135 publications

References 40 publications

Confinement in Nanopores at the Oxide/Water Interface: Modification of Alumina Adsorption Properties

Confinement in Nanopores at the Oxide/Water Interface: Modification of Alumina Adsorption Properties

Sorbent Selection Progress Report

Fabrication of transparent self-supporting alumina films by homogeneous precipitation process

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