Deposited emulsion particles in the pores of aluminum oxide film

1978 ◽  
Vol 36 (1) ◽  
pp. 450-451
Author(s):  
Michio Ashida ◽  
Yasukiyo Ueda
Keyword(s):  
Oxide Film ◽  
Acid Solution ◽  
Barrier Layer ◽  
Colloidal Particles ◽  
Oxalic Acid Solution ◽  
Anodic Oxide ◽  
Anodic Oxide Film ◽  
Carbon Replica ◽  
Sectioning Method ◽  
Thin Sectioning

An anodic oxide film is formed on aluminum in an acidic elecrolyte during anodizing. The structure of the oxide film was observed directly by carbon replica method(l) and ultra-thin sectioning method(2). The oxide film consists of barrier layer and porous layer constructed with fine hexagonal cellular structure. The diameter of micro pores and the thickness of barrier layer depend on the applying voltage and electrolyte. Because the dimension of the pore corresponds to that of colloidal particles, many metals deposit in the pores. When the oxide film is treated as anode in emulsion of polyelectrolyte, the emulsion particles migrate onto the film and deposit on it. We investigated the behavior of the emulsion particles during electrodeposition.Aluminum foils (99.3%) were anodized in either 0.25M oxalic acid solution at 30°C or 3M sulfuric acid solution at 20°C. After washing with distilled water, the oxide films used as anode were coated with emulsion particles by applying voltage of 200V and then they were cured at 190°C for 30 minutes.

scholarly journals Lattice images of porous anodic oxide film formed on aluminum in chromic acid solution.

1989 ◽  
Vol 40 (12) ◽  
pp. 1361-1365
Author(s):  
Sachiko ONO ◽  
Tomoko KAWAGUCHI ◽  
Hideki ICHINOSE ◽  
Yoichi ISHIDA ◽  
Noboru MASUKO
Keyword(s):  
Oxide Film ◽  
Acid Solution ◽  
Chromic Acid ◽  
Anodic Oxide ◽  
Anodic Oxide Film ◽  
Lattice Images

Diagnosis of the Mechanism of Anodic Oxide Film Growth on Platinum in KOH

2016 ◽  
Vol 230 (1) ◽  
Author(s):  
Feixiong Mao ◽  
Pin Lu ◽  
Digby D. Macdonald
Keyword(s):  
Oxide Film ◽  
Electric Field ◽  
Layer Thickness ◽  
Diagnostic Criteria ◽  
Barrier Layer ◽  
Applied Voltage ◽  
Film Growth ◽  
Anodic Oxide ◽  
Anodic Oxide Film ◽  
Barrier Layer Thickness

AbstractDiagnostic criteria for growth of the anodic oxide film on platinum in KOH are reported. In this work, the analytical analysis of oxide film growth demonstrated that the electric field in the passive film formed anodically on platinum in KOH is constant, independent of the applied voltage and barrier layer thickness. This criterion intrinsically distinguishes the Point Defect Model (PDM) from the High Field Model (HFM). Unequivocally, the PDM provides a superior theoretical framework than does the HFM for interpreting oxide film growth on platinum. Importantly, we argue that the diagnostic criteria also apply to metal interstitial conduction, which is the mechanism proposed in the HFM for formation of the PtO oxide film on platinum, but with film growth occurring at the film/solution interface and with a thickness-dependent electric field, rather than being restricted to oxygen vacancy conductors alone, as originally derived for the PDM. Thus, the ability of the diagnostic criteria to differentiate between the HFM and the PDM, in this case, is a direct assessment of the dependence of the electric field strength on the applied voltage and barrier layer thickness, with the experimental results coming down unequivocally on the side of the PDM.

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