Synthesis of novel hierarchical micro/nanostructures AlOOH/AlFe and their application for As(V) removal

Hierarchical micro/nanostructured composites, which contain iron and/or its (hydr)oxides, demonstrate high rate and capacity of arsenic adsorption. The main objective of this paper is the use of novel low toxicity AlOOH/AlFe hierarchical micro/nanostructures for arsenic removal. AlOOH/AlFe composite was obtained by simple water oxidation in mild conditions using AlFe bimetallic nanopowder as a precursor. AlFe bimetallic nanopowder was produced by electrical explosive of two twisted wires in argon atmosphere. The productivity of the electrical explosion assembly was 50 g/h, with the consumption of the electrical energy was 75 kW·h/kg. AlFe bimetallic nanoparticles were chemically active and interacted with water at 60 °C. This nanocomposite AlOOH/AlFe is low cost and adsorbs more than 200 mg/g As(V) from its aqueous solution. AlOOH/AlFe composite has flower-like morphology and specific surface area 247.1 m2/g. The phase composition of nanostructures is present AlOOH boehmite and AlFe intermetallic compound. AlOOH/AlFe composite was not previously used for this. The flower-shape AlOOH morphology not only facilitated deliverability, but increased the As(V) sorption capacity by up to 200 mg/g. The adsorption kinetics has been found to be described by a pseudo-second-order equation of Lagergren and Weber-Morris models while the experimental adsorption isotherm is closest to the Freundlich model. This indicates the energy heterogeneity of the adsorbent surface and multilayer adsorption. The use of non-toxic nanostructures opens up new options to treat water affected by arsenic pollution

Metal nanoparticles in high-energetic materials practice

The large-scale production of metal nanopowders opens the prospect of their widespread use in energetic materials. Coating metal nanopowders with organic compounds makes it possible to overcome the limitations inherent in the nanopowders. The coating results in deagglomeration, improved chemical stability, and better compatibility, which enable the use of the metal nanopowders in high-energetic materials (HEMs). A partial or full change in micron-size aluminum in HEMs has shown a qualitative difference in the formation dependences of the particles-size distribution function at the nozzle output on their input parameters. The resulting losses of the full impulse in the nozzle for the considered variants of the nano-size aluminum use are integrally 2.6% lower in comparison with propellant formulations containing only conventional aluminum powder

Metal nanoparticles in high-energetic materials practice

The large-scale production of metal nanopowders opens the prospect of their widespread use in energetic materials. Coating metal nanopowders with organic compounds makes it possible to overcome the limitations inherent in the nanopowders. The coating results in deagglomeration, improved chemical stability, and better compatibility, which enable the use of the metal nanopowders in high-energetic materials (HEMs). A partial or full change in micron-size aluminum in HEMs has shown a qualitative difference in the formation dependences of the particles-size distribution function at the nozzle output on their input parameters. The resulting losses of the full impulse in the nozzle for the considered variants of the nano-size aluminum use are integrally 2.6% lower in comparison with propellant formulations containing only conventional aluminum powder

Non-isothermal oxidation of aluminum nanopowder coated by hydrocarbons and fluorohydrocarbons

Aluminum nanopowder (nAl) obtained by electrical explosion of wires and passivated/coated with hydrocarbons and fluorohydrocarbons is comprehensively characterized. Coatings of different natures (octadecanoic and hexadecanoic acid, (1,1,11) trihydroperfluoro-undecan-1-ol, FluorelTM + ester from esterification of (1,1,11) trihydroperfluoro-undecan-1-ol with furan-2,5-dione) were applied on the particle surface. The powders were studied by TEM, SEM, DSC-TGA, and BET specific surface area. The active aluminum content was determined by volumetric analyses. Coated nAl particles were compared to noncoated powder by the corresponding reactivity parameters obtained from DSC-TGA. It was found that while fatty acids have a weak effect on the non-isothermal oxidation behavior, fluoroelastomers shift the oxidation onset of nAl to higher temperatures by ∼20 ◦C for the first oxidation stage and by ∼100 ◦C for the second oxidation stage

Non-Isothermal Oxidation of Aluminum Nanopowder Coated by Hydrocarbons and Fluorohydrocarbons

Aluminum nanopowder (nAl) obtained by electrical explosion of wires and passivated/coated with hydrocarbons and fluorohydrocarbons is comprehensively characterized. Coatings of different natures (octadecanoic and hexadecanoic acid, (1,1,11) trihydroperfluoro-undecan-1-ol, FluorelTM + ester from esterification of (1,1,11) trihydroperfluoro-undecan-1-ol with furan-2,5-dione) were applied on the particle surface. The powders were studied by TEM, SEM, DSC-TGA, and BET specific surface area. The active aluminum content was determined by volumetric analyses. Coated nAl particles were compared to noncoated powder by the corresponding reactivity parameters obtained from DSC-TGA. It was found that while fatty acids have a weak effect on the non-isothermal oxidation behavior, fluoroelastomers shift the oxidation onset of nAl to higher temperatures by ∼20 ◦C for the first oxidation stage and by ∼100 ◦C for the second oxidation stage