Aluminum nanopowders produced by electrical explosion of wires and passivated by non-inert coatings: Characterisation and reactivity with air and water

Gromov, A. A.; Förter‐Barth, Ulrich; Teipel, Ulrich

doi:10.1016/j.powtec.2006.03.003

Cited by 94 publications

(34 citation statements)

References 9 publications

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“…In this work, alloy nanoparticles were fabricated by the electrical explosion of wires (EEW) method, which is a process of explosive destruction of a metal wire under the action of high density current. It has been successfully used to produce various pure metal and metal oxide particles such as Al, Fe, Ni, Si and Fe2O3 [20][21][22][23][24], as well as a few alloy nanoparticles (i.e., Al-Cu, Al-Ni) [25]. For alloy particles, coated metal wires were generally used where one metal component was electrodeposited onto the surface of another metal wire and EEW was subsequently applied [25].…”

Section: Introductionmentioning

confidence: 99%

Thermal-Chemical Characteristics of Al–Cu Alloy Nanoparticles

et al. 2015

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This work investigated the oxidation, ignition and thermal reactivity of alloy nanoparticles of aluminum and copper (nAlCu) using simultaneous thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) method. The microstructure of the particles was characterized with scanning electron microscope (SEM) and transmission electron microscope (TEM), and the elemental composition of the particles before and after the oxidation was investigated with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD).The particles were heated from room temperature to 1200 o C under different heating rates from 2 to 30 K/min in the presence of air. The complete oxidation process of the nAlCu was characterized by two exothermic and two endothermic reactions, and the reaction paths up to 1200 o C were proposed. An early ignition of nAlCu, in the temperature around 565 o C, was found at heating rates ≥ 8 K/min. The eutectic melting temperature of nAlCu was identified at ~ 546 o C, which played a critical role in the early ignition. The comparison of the reactivity with that of pure Al nanoparticles showed that the nAlCu was more reactive through alloying.

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Section: Introductionmentioning

confidence: 99%

Thermal-Chemical Characteristics of Al–Cu Alloy Nanoparticles

et al. 2015

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“…% Al2O3). 41,68 As described above for the Al foil, these relative amounts of Al and Al2O3 were also used to calculate thicknesses for the Al2O3 passivation layer by assuming an ideal spherical morphology and monodisperse 18 and 100 nm particle diameters (Table 1 and Supporting Information). This analysis showed that the conventionallysynthesized 18 nm and 100 nm Al NPs had 1.7 ± 0.2 and 5.2 ± 0.5 nm thick Al2O3 layers, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…The reference materials included a 100 nm aluminum metal foil, α-Al2O3, and γ-Al2O3. Aluminum nanoparticles (Al NPs) prepared with three different synthetic methodologies were also explored: core-shell Al NPs with 54 nm average diameters, prepared with a protective organic coating of oleic acid (Al-OA NPs); 40 bare Al NPs with 100 nm average diameters and no protective coating, prepared by the electrical explosion of wires (similar to ALEX®); 39,41 bare Al NPs with 18 nm average diameters 3 and no protective coating, prepared by pulsed laser ablation of Al targets in an organic solvent. 42,43 These analytes were specifically chosen because they provided a range of particle sizes, compositions, surface chemistries, and reactivities.…”

Section: Introductionmentioning

confidence: 99%

Chemical and Morphological Inhomogeneity of Aluminum Metal and Oxides from Soft X-ray Spectromicroscopy

Altman

Pemmaraju²,

Alayoǧlu³

et al. 2017

Inorg. Chem.

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ABSTRACT. Oxygen and aluminum K-edge X-ray absorption spectroscopy (XAS), imaging from a scanning transmission X-ray microscope (STXM), and first principles calculations were used to probe the composition and morphology of bulk aluminum metal, α-and γ-Al2O3, and several types of aluminum nanoparticles. The imaging results agreed with earlier transmission electron microscopy studies that showed a 2 to 5 nm thick layer of Al2O3 on all the Al surfaces. Spectral interpretations were guided by examination of the calculated transition energies, which agreed well with the spectroscopic measurements. Features observed in the experimental O and Al K-edge XAS were used to determine the chemical structure and phase of the Al2O3 on the aluminum surfaces. For unprotected 18 and 100 nm Al nanoparticles, this analysis revealed an oxide layer that was similar to γ-Al2O3 and comprised of both tetrahedral and octahedral Al coordination sites. For oleic-acid protected Al nanoparticles, only tetrahedral Al oxide coordination sites were observed.The results were correlated to trends in the reactivity of the different materials, which suggests that the structures of different Al2O3 layers have an important role in the accessibility of the underlying Al metal towards further oxidation.Combined, the Al K-edge XAS and STXM results provided detailed chemical information that was not obtained from powder X-ray diffraction or imaging from a transmission electron microscope.

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“…Ultra-fine powders of various pure metals have been produced by the EWE method. [16][17][18][19][20][21][22] Nevertheless, in the case of alloys and intermetallic alloys, the EWE process has obvious limitations in that the raw materials should be in the form of thin wires with a diameter of less than 1 mm. Because of this difficulty, the EWE method has been applied to only a limited number of alloys.…”

Section: Introductionmentioning

confidence: 99%

Characteristics of Fe-Cr-Al Alloy Nanopowders Prepared by Electrical Wire Explosion Process under Liquid Media

et al. 2011

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Fe-Cr-Al alloy nanopowders were successfully prepared by electrical wire explosion method in ethyl alcohol media. The formation of FeCr-Al alloy nanopowder was monitored by X-ray diffraction. The alloy powders have spherical shape and nanometer size. The alloy powders prepared by the electrical wire explosion method have main crystal structures of bcc Fe-Cr alloy. The geometric mean diameter and geometric standard deviation of an alloy powder formed from a wire with diameter of 0.1 mm were 10.2 nm and 1.62, respectively. However, the geometric mean diameter and geometric standard deviation of an alloy powder formed from a wire with diameter of 0.2 mm were 15.4 nm and 1.66, respectively. These values indicate that the particle size of the alloy powders prepared by the EWE method was increased with wire diameter. Fe, Cr, and Al components are uniformly dispersed inside the powder.

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Aluminum nanopowders produced by electrical explosion of wires and passivated by non-inert coatings: Characterisation and reactivity with air and water

Cited by 94 publications

References 9 publications

Thermal-Chemical Characteristics of Al–Cu Alloy Nanoparticles

Thermal-Chemical Characteristics of Al–Cu Alloy Nanoparticles

Chemical and Morphological Inhomogeneity of Aluminum Metal and Oxides from Soft X-ray Spectromicroscopy

Characteristics of Fe-Cr-Al Alloy Nanopowders Prepared by Electrical Wire Explosion Process under Liquid Media

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