The operational window of carbon nanotube electrical wires treated with strong acids and oxidants

Conventional metal wires suffer from a significant degradation or complete failure in their electrical performance, when subjected to harsh oxidizing environments, however wires constructed from Carbon Nanotubes (CNTs) have been found to actually improve in their electrical performance when subjected to these environments. These opposing reactions may provide new and interesting applications for CNT wires. Yet, before attempting to move to any real-world harsh environment applications, for the CNT wires, it is essential that this area of their operation be thoroughly examined. To investigate this, CNT wires were treated with multiple combinations of the strongest acids and halogens. The wires were then subjected to conductivity measurements, current carrying capacity tests, as well as Raman, microscopy and thermogravimetric analysis to enable the identification of both the limits of oxidative conductivity boosting and the onset of physical damage to the wires. These experiments have led to two main conclusions. Firstly, that CNT wires may operate effectively in harsh oxidizing environments where metal wires would easily fail and secondly, that the highest conductivity increase of the CNT wires can be achieved through a process of annealing, acetone and HCl purification followed by either H2O2 and HClO4 or Br2 treatment

Evolution of silver in a eutectic-based Bi2O3–Ag metamaterial

International audienceThe development of novel manufacturing techniques of nano-/micromaterials, especially metallodielectric materials, has enabled dynamic development of such fields as nanoplasmonics. However, the fabrication methods are still mostly based on time-consuming and costly top-down techniques limited to two-dimensional materials. Recently, directional solidification has been proposed and utilized for manufacturing of volumetric nanoplasmonic materials using the example of a Bi2O3–Ag eutectic-based nanocomposite. Here, we explain the evolution of silver in this composite, from the crystal growth through the post-growth annealing processes. Investigation with tunneling electron microscopy shows that silver initially enters the composite as an amorphous AgBiO3 phase, which is formed as a wetting layer between the grains of Bi2O3 primary phase. The post-growth annealing leads to decomposition of the amorphous phase into Bi2O3 nanocrystals and intergranular Ag nanoparticles, providing the tunable localized surface plasmon resonance at yellow light wavelengths

Conception et design d'un casque de haute securite pour repondre au cahier des charges et aux normes de securite et la protection au feu

Available from INIST (FR), Document Supply Service, under shelf-number : AR 16714 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEMinistere de l'Enseignement Superieur et de la Recherche, 75 - Paris (France)FRFranc

When eutectics meet plasmonics: Nanoplasmonic, volumetric, self-organized, silver-based eutectic

9 pags.; figs.© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Due to the development of novel manufacturing technologies and the increasing availability of nano-/micromaterials, plasmonics has become an emerging field in photonics research. Although the fabrication of metallic elements has already been widely demonstrated, the development of 3D plasmonic materials is progressing slowly. This paper reports the development of a self-organized, 3D nanoplasmonic eutectic composite that exhibits localized surface plasmon resonance at 595 nm. This eutectic composite is produced by directional solidification with the micro-pulling-down method and consists of a 3D, multiscale network of silver, nanometer-thick, micron-long sheets, and triangular cross-section microprecipitates embedded in a crystalline bismuth oxide matrix. Annealing at 600 °C further refined the structure and introduced metallic nanoparticles that exhibited plasmonic resonance in the optical region of the spectrum. This is the first demonstration of plasmonic behavior in a eutectic-based composite, which is engineered specifically for this purpose using a self-organization mechanism.he authors thank the Maestro Project (2011/02/A/ST5/00471) and the Preludium Project (2012/07/N/ST5/02428) from the National Science Centre, the Project operated within the Foundation for Polish Science Team Programme cofinanced by the EU European Regional Development Fund and the AFOSR Project 14RT0477: NOE Novel metamaterials and plasmonic materials properties enabled by the directional Eutectic solidification for support of this work.Peer Reviewe