Fabrication and magnetic characteristics of hybrid double walled nanotube of ferromagnetic nickel encapsulated conducting polypyrrole

Abstract

This letter is a report on hybrid double walled nanotubes (HDWNTs) of crystalline ferromagnetic nickel (Ni) nanotubes encapsulated conducting polypyrrole (PPy) nanotubes through a sequentially electrochemical synthetic method. Ferromagnetic Ni nanotubes were fabricated by an electrochemical deposition method outside the wall of the conducting PPy nanotubes. The formation and structure of HDWNTs of conducting PPy nanotubes and ferromagnetic Ni nanotubes were confirmed by transmission electron microscopy, high-resolution transmission electron microscopy, and elementary analysis. From the angular dependences of the magnetic hysteresis curves of the HDWNTs, the authors observed that the Ni nanotubes of the HDWNT systems had an anisotropic ferromagnetic nature with the maximum of coercivity and remanent-saturation magnetization when applying a magnetic field along the parallel direction of the tubes.

Distinguishing nanowire and nanotube formation by the deposition current transients

“…One should note that the preparation of NTs with small diameters (<60 nm) is a laborious process and very difficult to achieve [43], so most of the reports on magnetic measurements in NT arrays correspond to NTs with outer diameters of approximately 200 nm. For these nanostructures, one finds very small coercive fields (<100 Oe) and remanence (approximately 0.05) along the //-direction [8,20,21,26,28]. However, Wang et al .…”

“…These novel nanostructures have recently attracted much interest due to their inner functionalizable surfaces that can be used for drug delivery [23-25] and also owing to their interesting magnetic behavior [20-22]. In particular, Ni NTs have been prepared in nanoporous membranes by triblock copolymer-assisted hard-template method [26], electroplating [27], a sequential electrochemical synthetic method inside conducting polypyrrole NTs [8], and using chemically modified templates [28]. …”

“…In recent reports, the magnetic behavior of arrays of magnetic NTs was investigated [8,20-22,26-28]. Nevertheless, there are a number of different parameters that seem to lead to diverse results.…”

Light-Emitting Color Barcode Nanowires Using Polymers: Nanoscale Optical Characteristics

“…For the nanoscale coating Cu metal, the applied bias was potentiostatically at 0 V ( vs Ag/AgCl) for 10 min. A similar fabrication method for the nanoscale metal coating was reported previously . The LECB-NWs were homogeneously dispersed in methanol solution after removal of the Al 2 O 3 nanoporous template and then ultrasonicated for 3 s with a power of 70 W (BRANSON Co. Ultrasonic Cleaner).…”

Electrochemical synthesis and magnetism of magnetic nanotubes

“…The phase separation of Ni (shell) and Cu (core) may be attributed to the easier chemical complexation of the Ni cations on the pore walls through the hydroxyl groups (Wang et al, 2005a). Similar methods included the initial deposition of NWs inside porous templates followed by chemical etching of part of the template, creating in this way annular nanochannel membranes for the subsequent electrodeposition of metallic NTs, as represented in Figure 24.9 Mu et al, 2004;Chen et al, 2014;Park et al, 2007). Similar methods included the initial deposition of NWs inside porous templates followed by chemical etching of part of the template, creating in this way annular nanochannel membranes for the subsequent electrodeposition of metallic NTs, as represented in Figure 24.9 Mu et al, 2004;Chen et al, 2014;Park et al, 2007).…”