Anodic oxidation of 2-aminofluorene in CH 2 Cl 2 + 0.2 M Bu 4 NBF 4 : electrochemical behaviour of the derived oxidation products

1999 ◽  
Vol 3 (5) ◽  
pp. 293-298 ◽  
Author(s):  
Joëlle Rault-Berthelot ◽  
Marie Madeleine Granger
Keyword(s):  
Anodic Oxidation ◽  
Electrochemical Behaviour ◽  
Oxidation Products

Characterization of the corrosion or anodic oxidation products on zinc

1975 ◽  
Vol 3 (2) ◽  
pp. 129-138 ◽  
Author(s):  
G. Trabanelli ◽  
F. Zucchi ◽  
G. Brunoro ◽  
G. Gilli
Keyword(s):  
Anodic Oxidation ◽  
Oxidation Products

Electrochemical Oxidation of o-Amiophenol in the Presence of NaCI for Wastewater Treatment

2014 ◽  
Vol 900 ◽  
pp. 382-385
Author(s):  
Chun Hong Nie ◽  
Bao Hui Wang
Keyword(s):  
Wastewater Treatment ◽  
Electrochemical Oxidation ◽  
Anodic Oxidation ◽  
Experimental Results ◽  
Oxidation Products ◽  
Chlorinated Compounds ◽  
Oxidation Analysis

The electrochemical oxidation of o-Aminophenol in the presence o f NaCl for wastewater treatment was studied on Ti/IrO2-Ta2O5 , Ti/IrO2-Ta2O5-SnO2 and Ti/IrO2 anodes. The experimental results have shown that the presence of NaCl catalyses the anodic oxidation of o-Aminophenol due to the participation of electrogenerated ClO- in the oxidation. Analysis of the oxidation products has shown that initially organo chlorinated compounds are formed in the electrolyte.

scholarly journals Anodic behaviour of manganese germanide Mn5Ge3 in a sodium sulphate aqueous solution

2021 ◽  
Vol 23 (4) ◽  
pp. 535-542
Author(s):  
Irina L. Rakityanskaya ◽  
Danil A. Myasnikov ◽  
Anatoly B. Shein
Keyword(s):  
Oxide Film ◽  
Anodic Oxidation ◽  
Electrochemical Impedance ◽  
Electrochemical Behaviour ◽  
Czochralski Method ◽  
Sodium Sulphate ◽  
Two Component Systems ◽  
Anodic Behaviour ◽  
Microscopy Data ◽  
Manganese Germanide

Germanides are an interesting class of two-component systems which consist of metal and germanium. They are similar in their structure with silicides but have the specific properties. The target of the investigation was finding the main anodic electrochemical behaviour mechanisms for magnesium germanide Mn5Ge3 in an Na2SO4 aqueous solution.Electrochemical behaviour of manganese germanide obtained by Czochralski method was investigated by polarization curves and electrochemical impedance spectroscopy methods and accomplished by microscopy data. Individual manganese and germanium were investigated in the same way for comparison. It was established that in the anodic oxidation process germanium is the potential-determining component. The passivation process associated with the formation of surface oxide films was accomplished by the current density oscillations appearing due to the bad adhesion of oxide film to the surface of the sample, its imperfection and discontinuity. The nature of oxide film formed in the polarization process waspartially established. The dependence of the anodic behaviour of the sample on the sulphate concentration was established: in the diluted solutions the passivation occurs at more positive potentials than in the concentrated. This phenomenon can be explained by the different mechanisms of anodic oxidation in the solutions of different concentrations. 

Figuring and Finishing of Reaction-Sintered SiC by Anodic Oxidation Assisted Process

2014 ◽  
Vol 625 ◽  
pp. 570-575 ◽  
Author(s):  
Naoki Shimozono ◽  
Xin Min Shen ◽  
Hui Deng ◽  
Katsuyoshi Endo ◽  
Kazuya Yamamura
Keyword(s):  
Anodic Oxidation ◽  
Oxidation Rate ◽  
Uv Light ◽  
High Hardness ◽  
Oxidation Products ◽  
Ultrapure Water ◽  
Machine Material ◽  
Optical Components ◽  
Glass Lens ◽  
Polishing Tool

Reaction-sintered silicon carbide (RS-SiC) is a promising material for optical components used in space, or molds for precision glass lens because of its excellent properties. For processing of RS-SiC, diamond tools are utilized because RS-SiC is difficult-to-machine material due to its high hardness. In that case, subsurface damage (SSD) and scratches are inevitably introduced on the processed surface, and they deteriorate the qualities of products. To resolve these issues, we proposed a complex machining technique named anodic oxidation assisted process (AOAP), in which localized anodic oxidation and removal of the oxidation layer by grinding or polishing were combined, for figuring or polishing of RS-SiC without introducing any scratches and SSD. The grinding or polishing tool used in AOAP has a lower hardness than that of RS-SiC, but higher than that of the oxidation products. It is possible to figure the objective shape and polish the surface by changing the conditions including the oxidation time, the composition of electrolyte, the configuration of the cathode electrode, applied voltage, and so on. In our previous study, we found that RS-SiC was oxidized efficiently by anodic oxidation with various electrolytes such as phosphoric acid, ultrapure water, and a mixture of hydrochloric acid and hydrogen peroxide. In this research, we investigated the preliminary processing characteristics of AOAP for RS-SiC. We ascertained that irradiating UV light with photon energy higher than the band gap of processed materials is very effective for increasing the oxidation rate of anodic oxidation. And we proposed a novel polishing process of RS-SiC, which combining oxidation only SiC area in RS-SiC by anodic oxidation with the electrolyte of ceria slurry, with polishing by ceria slurry which removes both oxidized layer and unoxidized layer in RS-SiC. The results of investigation for the oxidation rate and the polishing rate of SiC, Si and SiO2 with ceria slurry implies that we can remove SiC grain and Si grain in RS-SiC at the same MRR by combing the anodic oxidation and polishing with ceria slurry at the same time, and obtain the smooth surface.

Formation and Characterization of Dispersed Mixed Iron-titanium Oxide Systems by Electrochemical Method

2020 ◽  
Vol 10 (1) ◽  
pp. 25-36
Author(s):  
Alexander F. Dresvyannikov ◽  
Irina O. Grigoryeva ◽  
Leniza R. Salemgaraeva
Keyword(s):  
Anodic Oxidation ◽  
Electrochemical Method ◽  
Structural Characteristics ◽  
Electrical Contact ◽  
Aqueous Media ◽  
Electrochemical Process ◽  
Oxide System ◽  
Oxidation Products ◽  
Anode Current Density ◽  
Oxide Systems

Aims: Anodic polarization behavior of a combined iron-titanium electrode (two metals in electrical contact with each other) in aqueous solutions containing halide ions (F- and Cl-) was studied. Methods: he joint anodic dissolution of titanium and iron with subsequent thermal treatment makes it possible to obtain precursors of a highly dispersed mixed oxide system Fe2O3-TiO2. The phase and elemental composition and structural characteristics of obtained products were examined using X-ray diffraction and scanning electron microscopy. It has been experimentally confirmed that via changing the anode current density, hydrofluoric acid concentration in electrolyte and ratio of the working surface area of contacting metals, it is possible to effectively control the rate of anodic reactions and phase composition and morphology of anodic oxidation products for iron and titanium components in a combined electrode. Results: The main results of this study are as follows: Electrochemical method for the synthesis of complex dispersed oxide system Fe2O3-TiO2 based on joint anodic oxidation of contacting metals in aqueous media was suggested. Relationships between parameters of the electrochemical process and characteristics of the synthesized oxide system were revealed. Conclusion: By varying the parameters of the electrolysis process, it is possible to prepare complex oxyhydroxides with different ratios of iron and titanium, which makes it possible to synthesize precursors of iron titanates of preset composition and structure.

Electrochemical behaviour of 3,3-sigmatropic systems - anodic oxidation of aryl allyl ethers and aryl propargyl ethers

1991 ◽  
Vol 32 (51) ◽  
pp. 7591-7592 ◽  
Author(s):  
S. Dhanalekshmi ◽  
K.K. Balasubramaniandy ◽  
C.S. Venkatachalamdy
Keyword(s):  
Anodic Oxidation ◽  
Electrochemical Behaviour ◽  
Allyl Ethers

scholarly journals An Insight into the Reactivity of the Electrogenerated Radical Cation of Caffeine

Electrochem ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 44-55
Author(s):  
Marta Feroci ◽  
Martina Bortolami ◽  
Isabella Chiarotto ◽  
Paola Di Matteo ◽  
Leonardo Mattiello ◽  
...  
Keyword(s):  
Current Efficiency ◽  
Radical Cation ◽  
Anodic Oxidation ◽  
Degradation Products ◽  
Oxidation Products ◽  
Coupling Reactions ◽  
Pt Electrode ◽  
Controlled Potential ◽  
Chromatographic Peaks ◽  
Insight Into

Controlled potential electrolyses of caffeine (CAF) were carried out at a Pt electrode in undried acetonitrile (ACN) and ACN-H2O and the products of the anodic oxidation were analyzed by HPLC-PDA-ESI-MS/MS. A higher current efficiency occurred in ACN-H2O, but an analogous chromatographic outline was found in both media, evidencing a reactive pathway of the electrogenerated radical cation CAF•+ with water, added or in trace, as nucleophile. No dimeric forms were evidenced, excluding any coupling reactions. Neither was 1,3,7-trimethyluric acid found, reported in the literature as the main oxidative route for CAF in water. Four main chromatographic peaks were evidenced, assigned to four proposed structures on the base of chromatographic and spectral data: a 4,5-diol derivative and an oxazolidin-2-one derivative were assigned as principal oxidation products, supporting a mechanism proposed in a previous work for the primary anodic oxidation of the methylxanthines olefinic C4 = C5 bond. Two highly polar degradation products were also tentatively assigned, that seemed generating along two different pathways, one opening the imidazolic moiety and another one opening the purinic one.

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