Method for preparing highly ordered aluminum oxide template by asymmetric two-step anodization

A technology of secondary anodization and alumina template, applied in electrolytic coatings, surface reaction electrolytic coatings, coatings, etc., can solve the problems of limiting and restricting the scope of application, and achieve the effect of realizing modulation and expanding the scope of selection.

Inactive Publication Date: 2010-09-15
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in this method, the oxidation voltage of a certain type of electrolyte must be controlled within a certain range to prepare an ordered porous template (such as sulfuric acid is suitable for 20V ~ 25V, oxalic acid is suitable for 40V ~ 50V, and phosphoric acid It is suitable to prepare the template at an oxidation voltage of 130V ~ 190V), which limits the modulation of the microstructural parameters such as the pore spacing and pore diameter of the template, and also restricts its application range.

Method used

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  • Method for preparing highly ordered aluminum oxide template by asymmetric two-step anodization
  • Method for preparing highly ordered aluminum oxide template by asymmetric two-step anodization
  • Method for preparing highly ordered aluminum oxide template by asymmetric two-step anodization

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Embodiment 1

[0024] Under the protection of argon, 99.99wt% of the aluminum sheet was annealed at a high temperature, the annealing temperature was 500°C, and the annealing time was 3 hours; the surface oil was removed by ultrasonic cleaning in acetone for about 30 minutes, and then the Electrochemical polishing in absolute ethanol and perchloric acid for 5-8 minutes, the polishing voltage is 15-18V, and the temperature of the polishing solution is 20-25°C; the polished aluminum sheet is heated at a temperature of 5°C and a concentration of 4wt%. In sulfuric acid, carry out anodic oxidation for the first time with a voltage of 25V, and the oxidation time is 3 to 4 hours; soak the template oxidized for the first time in a mixed solution of 6wt% phosphoric acid and 1.8wt% chromic acid at room temperature for 24 hours , to completely remove the surface oxide film; in oxalic acid with a temperature of 5°C and a concentration of 0.4mol / L, the second anodic oxidation is performed at a voltage of ...

Embodiment 2

[0026] Under the protection of argon, 99.99wt% of the aluminum sheet was annealed at a high temperature, the annealing temperature was 500°C, and the annealing time was 3 hours; the surface oil was removed by ultrasonic cleaning in acetone for about 30 minutes, and then the Electrochemical polishing in absolute ethanol and perchloric acid for 5-8 minutes, the polishing voltage is 15-18V, and the temperature of the polishing solution is 20-25°C; the polished aluminum sheet is heated at a temperature of 5°C and a concentration of 4wt%. In sulfuric acid, carry out anodic oxidation for the first time with a voltage of 25V, and the oxidation time is 3 to 4 hours; soak the template oxidized for the first time in a mixed solution of 6wt% phosphoric acid and 1.8wt% chromic acid at room temperature for 24 hours , to completely remove the surface oxide film; in phosphoric acid with a temperature of 5°C and a concentration of 4wt%, conduct the second anodic oxidation with a voltage of 25V...

Embodiment 3

[0028] Under the protection of argon, 99.99wt% of the aluminum sheet was annealed at a high temperature, the annealing temperature was 500°C, and the annealing time was 3 hours; the surface oil was removed by ultrasonic cleaning in acetone for about 30 minutes, and then the Electrochemical polishing in absolute ethanol and perchloric acid for 5-8 minutes, the polishing voltage is 15-18V, the temperature of the polishing solution is 20-25°C; the polished aluminum sheet is kept at a temperature of 5°C and a concentration of 0.4mol / In the oxalic acid of L, carry out anodic oxidation for the first time with the voltage of 40V, and oxidation time is 3~4 hours; The template oxidized for the first time is immersed in the mixed solution of 6wt% phosphoric acid and 1.8wt% chromic acid at room temperature for 24 After hours, the surface oxide film is completely removed; in sulfuric acid with a temperature of 1°C and a concentration of 0.04wt%, the second anodic oxidation is performed at...

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Abstract

The invention discloses a method for preparing a highly ordered aluminum oxide template by asymmetric two-step anodization, which is characterized by comprising the following steps of: carrying out high-temperature annealing treatment on a highly pure aluminum sheet, and then carrying out electrochemistry polishing treatment, wherein the highly pure aluminum sheet has the purity being larger than or equal to 99.99wt%; anodizing for the first time in electrolyte by taking the highly pure aluminum sheet treated in the last step as the anode and a black lead as the cathode; dipping the highly pure aluminum sheet anodized for the first time into a mixed solution of phosphoric acid and chromic acid so as to remove an oxidation film on the surface of the highly pure aluminum sheet; anodizing for the second time in electrolyte different from the electrolyte for anodizing for the first time to obtain the aluminum oxide template, and then cleaning the aluminum oxide template to obtain the highly ordered aluminum oxide template. The invention widens the range of oxidation voltage for preparing aluminum oxide templates in electrolyte and realizes the modulation on the distance and the aperture between every two template holes to the larger extent.

Description

technical field [0001] The invention belongs to the technical field of preparing nanometer mesoporous materials, and relates to a method for preparing highly ordered alumina templates through asymmetric secondary anodic oxidation. technical background [0002] Aluminum is oxidized under different conditions, and aluminum oxide films with different morphological structures can be obtained. Oxidation in weak solubility (such as boric acid, tartaric acid, etc.) or neutral solution (various neutral salts) can obtain dense alumina film; oxidation in medium solubility solution (such as dilute sulfuric acid, oxalic acid, phosphoric acid, etc.) A porous aluminum oxide film can be obtained; when oxidized in a solution with strong solubility (such as nitric acid, hydrochloric acid, sodium hydroxide, etc.), it is generally difficult to form an aluminum oxide film because the formed oxide is quickly dissolved. Taking advantage of the fact that aluminum can be oxidized in a solution wit...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C25D11/12C25D11/16
Inventor 秦刚郭光华何凤英
Owner CENT SOUTH UNIV
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