Morphological study of magnesium hydroxide nanoparticles precipitated in dilute aqueous solution

Henrist, Catherine; Mathieu, Jean-Philippe; Vogels, Christopher M.; Rulmont, A.; Cloots, Rudi

doi:10.1016/s0022-0248(02)02068-7

Cited by 318 publications

(226 citation statements)

References 22 publications

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“…3) are strikingly similar to that reported for the synthesis of nanoscale Mg(OH) 2 by precipitation-based routes. [56][57][58][59] This suggest at least some of the Mg(OH) 2 formation from Mg corrosion in NaCl solutions results from Mg species dissolution and re-precipitation in the surface regions. Laminar morphologies present at the MgO-Mg(OH) 2 interface (Fig.…”

Section: Discussionmentioning

confidence: 96%

Film Breakdown and Nano-Porous Mg(OH)₂Formation from Corrosion of Magnesium Alloys in Salt Solutions

Brady

Rother

Anovitz

et al. 2015

J. Electrochem. Soc.

129

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Small angle neutron scattering (SANS) and scanning transmission electron microscopy (STEM) were used to study film formation by magnesium alloys AZ31B (Mg-3Al-1Zn base) and ZE10A (Elektron 717, E717: Mg-1Zn + Nd, Zr) in H 2 O and D 2 O with and without 1 or 5 wt% NaCl. No SANS scattering changes were observed after 24 h D 2 O or H 2 O exposures compared with as-received (unreacted) alloy, consistent with relatively dense MgO-base film formation. However, exposure to 5 wt% NaCl resulted in accelerated corrosion, with resultant SANS scattering changes detected. The SANS data indicated both particle and rough surface (internal and external) scattering, but with no preferential size features. The films formed in 5 wt% NaCl consisted of a thin, inner MgO-base layer, and a nano-porous and filamentous Mg(OH) 2 outer region tens of microns thick. Chlorine was detected extending to the inner MgO-base film region, with segregation of select alloying elements also observed in the inner MgO, but not the outer Mg(OH) 2 . Modeling of the SANS data suggested that the outer Mg(OH) 2 films had very high surface areas, consistent with loss of film protectiveness. Implications for the NaCl corrosion mechanism, and the potential utility of SANS for Mg corrosion, are discussed. Magnesium and its alloys are of great interest for a wide range of structural and functional applications, including lightweight automotive and aircraft structural materials, biomedical implants, fuel cells and hydrogen storage, batteries, etc.1-7 However, the high reactivity and rapid corrosion of Mg in many aqueous and humid environments is a key issue. [8][9][10][11] Of particular challenge and interest is the acceleration of Mg corrosion in the presence of salt species. Mechanisms of accelerated attack in salt solutions include enhanced local micro-galvanic coupling at alloy second phases and/or impurities (e.g. Fe, Ni, Cu etc.) and disruption of the MgO and/or Mg(OH) 2 base surface films by Cl-. 3,9,[12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Film formation by Mg alloys under aqueous conditions can be quite complex, involving MgO, Mg(OH) 2 , and MgCO 3 base phases, as well as complexes of those phases when alloy additions (e.g. Al) or environmental species (e.g. Cl-) become incorporated into parts or all of the film structure. [15][16][17]21,[27][28][29][30][31][32][33][34] In some cases, porous and even filiform-like corrosion films have been reported on bare or surface-modified Mg alloys. 11,14,16,18,24,[35][36][37][38] Small angle neutron scattering (SANS) has emerged as a powerful technique to assess structural and morphological features in the ∼1 to up to ∼200-300 nm feature size range (specific range accessed depends on the instrument capabilities and settings, as well as the nature of neutron scattering from the test samples). 39,40 Information can be obtained regarding size, morphology, and number density of scatterers (e.g. 2 nd phase precipitates, phase separation, grain structure, voids, pores, etc.), as well as surface area a...

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Section: Discussionmentioning

confidence: 96%

Film Breakdown and Nano-Porous Mg(OH)₂Formation from Corrosion of Magnesium Alloys in Salt Solutions

Brady

Rother

Anovitz

et al. 2015

J. Electrochem. Soc.

129

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“…8 There is an interesting experience of employing Mg(OH) 2 as a precursor for magnesium oxide refractory ceramics, 9 or as a flame retardant in various polymer compositions and smoke suppressants. [9][10][11] Note that the most of applications of the hydroxides are based mainly on the employing of their chemical properties that envisage the constituent metal cations and hydroxyl anions as principal participants in the target chemical transformations. At the same time, exploring the possibilities of unique physics of the bulk hydroxides at the microscopic (electronic) level has been difficult for a long time.…”

Section: Introductionmentioning

confidence: 99%

Materials properties of magnesium and calcium hydroxides from first-principles calculations

Pishtshev

Karazhanov

Klopov

2014

Computational Materials Science

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This work presents a study of ground state properties, electronic structure, dielectric and optical properties of magnesium and calcium hydroxides X(OH)2 (X = Mg and Ca) within PBE-GGA and range-separated hybrid functional schemes as well as by using GW approximation. The relevant HSE06 hybrid functional mixing parameters were determined from a self-consistent adjustment to the electronic dielectric constant ǫ∞. It was shown that the overall performance of our adaptation of the HSE06 functional via implementation of the modified amount of the Fock exchange is nearly best for the ground state properties as compared to other relevant HF and DFT methods. Structural stability of the crystalline X(OH)2 hydroxides has been considered in static and dynamic aspects. The most important factors describing the bonding situation have been investigated, and a crystalchemical integrity of the hydroxides has been analyzed. From electronic structure studies it was found that both materials are direct band gap insulators. Predictions for the fundamental band gaps were shown to be in the range of 7.7-8.3 eV for Mg(OH) 2 and 7.3-7.6 eV for Ca(OH) 2 . The origin of the conduction and valence band states near the band edges has been studied in terms of orbital and site projected density of states as well as by comparison with the X-ray photoelectron spectroscopy measurements. It was shown that effective masses of carriers at the Γ-point in vicinity of the band extreme are strongly anisotropic and for the electrons are similar to those in the ZnO crystal. Optical properties of the bulk X(OH)2 hydroxides have been investigated in terms of the real and imaginary parts of the optical dielectric function calculated in GW approximation. Electronic character of anisotropy of optical properties has been clarified. On the base of the obtained results the potential of applicability of the Mg(OH) 2 and Ca(OH) 2 crystalline hydroxides in semiconductor device engineering and optoelectronics has been analyzed.

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“…Qian et al obtained platelet-shaped particles using the hydrating method of MgO, made from the decomposition of magnesite [26]. The precipitation of a magnesium salt with an alkaline solution is another synthesis method that has been employed for obtaining brucite nanoparticles with different morphologies as globular agglomerates, platelet-shaped particles or hexagonal lamellas [27,28]. Song et al synthesized magnesium hydroxide nanoparticles with lamellar structure via one-step precipitation reaction with the aid of ultrasonic treatment [29].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and morpho-structural characterization of nanostructured magnesium hydroxide obtained by a hydrothermal method

Sierra-Fernández

Gomez-Villalba

Milošević

et al. 2014

Ceramics International

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Morphological study of magnesium hydroxide nanoparticles precipitated in dilute aqueous solution

Cited by 318 publications

References 22 publications

Film Breakdown and Nano-Porous Mg(OH)₂Formation from Corrosion of Magnesium Alloys in Salt Solutions

Film Breakdown and Nano-Porous Mg(OH)₂Formation from Corrosion of Magnesium Alloys in Salt Solutions

Materials properties of magnesium and calcium hydroxides from first-principles calculations

Synthesis and morpho-structural characterization of nanostructured magnesium hydroxide obtained by a hydrothermal method

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Morphological study of magnesium hydroxide nanoparticles precipitated in dilute aqueous solution

Cited by 318 publications

References 22 publications

Film Breakdown and Nano-Porous Mg(OH)2Formation from Corrosion of Magnesium Alloys in Salt Solutions

Film Breakdown and Nano-Porous Mg(OH)2Formation from Corrosion of Magnesium Alloys in Salt Solutions

Materials properties of magnesium and calcium hydroxides from first-principles calculations

Synthesis and morpho-structural characterization of nanostructured magnesium hydroxide obtained by a hydrothermal method

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Product

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Film Breakdown and Nano-Porous Mg(OH)₂Formation from Corrosion of Magnesium Alloys in Salt Solutions

Film Breakdown and Nano-Porous Mg(OH)₂Formation from Corrosion of Magnesium Alloys in Salt Solutions