scholarly journals Coloring of Anodized Aluminum with Organic Pigment using Electrolytic Reduction of Surfactants with an Azobenzene Moiety

2015 ◽  
Vol 66 (7) ◽  
pp. 328-330 ◽  
Author(s):  
Tetsuo SAJI
2014 ◽  
Vol 805 ◽  
pp. 137-142 ◽  
Author(s):  
Guilherme José Turcatel Alves ◽  
Sandra Masetto Antunes ◽  
Andre Lazarin Gallina ◽  
Guilherme Arielo Rodrigues Maia ◽  
Paulo Rogério Pinto Rodrigues

The process of aluminum anodizing forms an oxide layer constituted of nanotubes where it is possible to insert compounds, amongst these are the pigments and dyes. This study has as its main aim to study the behavior of aluminum alloy 6000, anodized and dyed with monolite red in Na2SO4 0.5 mol L-1 and pH = 4. The techniques employed were: anodic potentiostatic polarization, open circuit potential, chemometry, polarization resistance and optical micrograph. The factorial planning was proposed using four variables (anodizing time, current density, electrolyte concentration, and dye), the response to the planning was the charge transfer resistance. Polarization curves revealed that the anodized and dyed aluminum samples are much more resistant than the non-anodized aluminum. Optical microscopy analyses demonstrated that the dissolution of dye occurs in the solution, but not enough to break the film. As the main result, efficient coloring of aluminum parts was verified with reduction in costs in relation to the energy employed in the process, associated to reduction in time spent for the anodizing process, which makes it suitable to increase industrial production of dyed aluminum parts.


AIAA Journal ◽  
2001 ◽  
Vol 39 ◽  
pp. 1944-1949
Author(s):  
Hirotaka Sakaue ◽  
John P. Sullivan

2018 ◽  
Author(s):  
Hakeem K. Henry ◽  
Sang Bok Lee

The PMo<sub>12</sub>-PPy heterogeneous cathode was synthesized electrochemically. In doing so, the PMo<sub>12</sub> redox-active material was impregnated throughout the conductive polymer matrix of the poly(pyrrole) nanowires. All chemicals and reagents used were purchased from Sigma-Aldrich. Anodized aluminum oxide (AAO) purchased from Whatman served as the porous hard template for nanowire deposition. A thin layer of gold of approximately 200nm was sputtered onto the disordered side of the AAO membrane to serve as the current collector. Copper tape was connected to the sputtered gold for contact and the device was sealed in parafilm with heat with an exposed area of 0.32 cm<sup>2</sup> to serve as the electroactive area for deposition. All electrochemical synthesis and experiments were conducted using a Bio-Logic MPG2 potentiostat. The deposition was carried out using a 3-electrode beaker cell setup with a solution of acetonitrile containing 5mM and 14mM of the phosphomolybdic acid and pyrrole monomer, respectively. The synthesis was achieved using chronoamperometry to apply a constant voltage of 0.8V vs. Ag/AgCl (BASi) to oxidatively polymerize the pyrrole monomer to poly(pyrrole). To prevent the POM from chemically polymerizing the pyrrole, an injection method was used in which the pyrrole monomer was added to the POM solution only after the deposition voltage had already been applied. The deposition was well controlled by limiting the amount of charge transferred to 300mC. Following deposition, the AAO template was removed by soaking in 3M sodium hydroxide (NaOH) for 20 minutes and rinsed several times with water. After synthesis, all cathodes underwent electrochemical testing to determine their performance using cyclic voltammetry and constant current charge-discharge cycling in 0.1 M Mg(ClO<sub>4</sub>)<sub>2</sub>/PC electrolyte. The cathodes were further characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), and x-ray photoelectron spectroscopy (XPS).


1985 ◽  
Vol 50 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Jaromír Hlavatý

The o-nitrobenzyl thiocyanate (I) behaves differently on the DME and on a large mercury pool electrode. Polarography did not give a sufficiently clear explanation of the reaction mechanism, only the preparative experiments yielded useful results. Whereas polarographic curves in solutions of Britton-Robinson buffer system with 50% by vol. ethanol exhibit two cathodic waves within the pH region 1-12, corresponding according to their height ratio to an uptake of 4 e and 2 e respectively, the controlled potential preparation electrolysis (CPE) and coulometry results indicate a more complicated reaction path. In the CPE carried out at the concentration of I 1 . 10 -2 mol/l the electroreductive splitting of CH2-SCN occurs as the first step. Nitrobenzyl radicals so formed react in the follow-up dimerization resulting in dibenzyl or toluene structures. Simultaneously or at a later stage the completion of the electrolytic reduction of the nitro group proceeds to the hydroxylamino group. In solution of 9 > pH > 1 the CPE of nitro compound I takes place by an ECEC mechanism yielding dibenzodiazocine III, its N-oxide IV and 2,2'-dimethylazoxybenzene (V). In course of preparative electrolysis in strongly acidic medium 2-amino-benzo(l,3)-thiazine-l-oxide (II) is formed by an EC mechanism.


2020 ◽  
Vol 27 (12) ◽  
pp. 1626-1634 ◽  
Author(s):  
Bo Wang ◽  
Chao-yi Chen ◽  
Jun-qi Li ◽  
Lin-zhu Wang ◽  
Yuan-pei Lan ◽  
...  

Vacuum ◽  
2021 ◽  
pp. 110450
Author(s):  
M. Zarka ◽  
B. Dikici ◽  
M. Niinomi ◽  
K.V. Ezirmik ◽  
M. Nakai ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1557
Author(s):  
Farkhod Azimov ◽  
Jihee Kim ◽  
Seong Min Choi ◽  
Hyun Min Jung

α-Fe2O3, which is an attractive material for supercapacitor electrodes, has been studied to address the issue of low capacitance through structural development and complexation to maximize the use of surface pseudocapacitance. In this study, the limited performance of α-Fe2O3 was greatly improved by optimizing the nanotube structure of α-Fe2O3 and its combination with polyaniline (PANI). α-Fe2O3 nanotubes (α-NT) were fabricated in a form in which the thickness and inner diameter of the tube were controlled by Fe(CO)5 vapor deposition using anodized aluminum oxide as a template. PANI was combined with the prepared α-NT in two forms: PANI@α-NT-a enclosed inside and outside with PANI and PANI@α-NT-b containing PANI only on the inside. In contrast to α-NT, which showed a very low specific capacitance, these two composites showed significantly improved capacitances of 185 Fg−1 for PANI@α-NT-a and 62 Fg−1 for PANI@α-NT-b. In the electrochemical impedance spectroscopy analysis, it was observed that the resistance of charge transfer was minimized in PANI@α-NT-a, and the pseudocapacitance on the entire surface of the α-Fe2O3 nanotubes was utilized with high efficiency through binding and conductivity improvements by PANI. PANI@α-NT-a exhibited a capacitance retention of 36% even when the current density was increased 10-fold, and showed excellent stability of 90.1% over 3000 charge–discharge cycles. This approach of incorporating conducting polymers through well-controlled nanostructures suggests a solution to overcome the limitations of α-Fe2O3 electrode materials and improve performance.


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