CN102401633B - Detection method for detecting thickness of barrier layer of porous alumina film - Google Patents

Abstract

The invention provides a method for detecting the thickness of a barrier layer of a porous alumina film, which is characterized in that the method comprises judging whether the porous alumina film contains a barrier layer according to the transmission spectrum of the porous alumina film in the range of 200nm to 2500nm, Wherein, if the transmission spectrum oscillates within the range of 200nm to 2500nm, it is judged that the thickness of the barrier layer of the porous alumina film is greater than 0; The barrier layer has a thickness of 0. The method of the present invention is a non-destructive testing method, which can monitor and detect the removal degree of the barrier layer of the porous aluminum oxide film simply, quickly, efficiently, and without damage to the sample, and can be used as a product control and quality control method in large-scale production. important means of detection.

Description

Detection method of barrier layer thickness of porous aluminum oxide film

technical field

The invention relates to a method for detecting the thickness of a barrier layer of a porous aluminum oxide film.

Background technique

Since Masuda et al. invented the two-step anodic oxidation method (Science, 1995, 268, 1466-1468) in 1995 to prepare porous alumina with a large area and highly ordered honeycomb structure, porous alumina films have been widely used as templates. For the synthesis of highly ordered metal, semiconductor or polymer nanowires (nanotubes), since aluminum oxide is not conductive, it is necessary to remove the barrier layer of porous aluminum oxide film with acid solution before electrodepositing nanowires, and then sputter a Layers of metal thin films are electrodeposited as electrodes. Since the process of removing the barrier layer by acid corrosion is affected by many factors, it is difficult to control the removal degree of the barrier layer. Therefore, it is urgent to find a simple method for monitoring and detecting the removal degree of the barrier layer of the porous alumina film. .

Ultraviolet-visible-near-infrared spectroscopy detection technology has been used in many fields due to its advantages of simple sample preparation, wide range of detection objects, non-destructive detection, and fast detection speed. Jian Wang et al. (Thin Solid Films, 2008, 516, 7689～7694) tested the transmission spectrum of the porous alumina film with barrier layer by using the ultraviolet-visible-near-infrared spectroscopy detection technology, and calculated the refractive index, absorption coefficient and optical properties of the porous alumina film by using the transmission extremum envelope method. Energy gap. CN200510027581.9 uses a four-layer medium model to fit the transmission spectrum to obtain the thickness of the porous aluminum oxide film and the thickness of the barrier layer. Its spectrum test range is only 190nm to 900nm, but for the transmission spectrum No research has been carried out, so the above results can only be used to detect the thickness of the newly prepared porous alumina film and the thickness of the barrier layer. For the research on the detection of through-hole porous alumina films that are usually used to prepare nanowires by transmission spectroscopy, currently There are no literature and patent reports.

Contents of the invention

The object of the present invention is to provide a simple method for detecting the thickness of the barrier layer of a porous aluminum oxide film.

The inventors of the present invention have unexpectedly found that when the porous aluminum oxide film contains a barrier layer, its transmission spectrum will oscillate in the range of 200nm to 2500nm, and when the porous aluminum oxide film does not contain a barrier layer (that is, the barrier layer is completely removed) ), the transmission spectrum does not oscillate in the range of 200nm to 2500nm, thus completing the present invention.

The invention provides a method for detecting the thickness of the barrier layer of the porous alumina film, which is characterized in that the method comprises judging whether the porous alumina film contains a barrier layer according to the transmission spectrum in the range of 200nm to 2500nm of the porous alumina film, Wherein, if the transmission spectrum oscillates within the range of 200nm to 2500nm, it is judged that the thickness of the barrier layer of the porous alumina film is greater than 0; The barrier layer has a thickness of 0.

The present invention is based on the preparation of the porous alumina film, and uses the ultraviolet-visible-near-infrared spectrum detection technology to test the transmission spectrum of the porous alumina film and the film with the barrier layer removed, and the results of the transmission spectrum can be used to characterize the porous alumina film The thickness of the barrier layer and the through-porosity of the porous alumina film.

The method of the present invention is a non-destructive testing method, which can monitor and detect the removal degree of the barrier layer of the porous aluminum oxide film simply, quickly, efficiently, and without damage to the sample, and can be used as a product control and quality control method in large-scale production. important means of detection.

Description of drawings

Fig. 1 is the ultraviolet-visible-near-infrared transmission spectrum diagram of the porous aluminum oxide film obtained in Example 1.

Fig. 2 is the FESEM image of the back side of the porous aluminum oxide film obtained in Example 1.

FIG. 3 is a FESEM image of the barrier layer of the porous alumina film obtained in Example 1. FIG.

Fig. 4 is the ultraviolet-visible-near-infrared transmission spectrum diagram of the porous aluminum oxide film obtained in Example 3.

FIG. 5 is a FESEM image of the back surface of the porous aluminum oxide film obtained in Example 3.

FIG. 6 is a FESEM image of the barrier layer of the porous alumina film obtained in Example 3. FIG.

FIG. 7 is the ultraviolet-visible-near-infrared transmission spectrum of the porous aluminum oxide film obtained in Example 5.

FIG. 8 is a FESEM image of the back surface of the porous alumina film obtained in Example 5.

FIG. 9 is a FESEM topography image of the barrier layer of the porous alumina film obtained in Example 5. FIG.

FIG. 10 is the ultraviolet-visible-near-infrared transmission spectrum of the porous aluminum oxide film obtained in Example 7.

FIG. 11 is a FESEM image of the back surface of the porous alumina film obtained in Example 7.

FIG. 12 is a FESEM image of the barrier layer of the porous alumina film obtained in Example 7. FIG.

FIG. 13 is the ultraviolet-visible-near-infrared transmission spectrum of the porous aluminum oxide film obtained in Example 9.

FIG. 14 is a FESEM image of the back surface of the porous alumina film obtained in Example 9.

FIG. 15 is a FESEM image of the barrier layer of the porous alumina film obtained in Example 9. FIG.

FIG. 16 is the ultraviolet-visible-near-infrared transmission spectrum of the porous aluminum oxide film obtained in Example 11.

FIG. 17 is a FESEM image of the back surface of the porous alumina film obtained in Example 11.

FIG. 18 is a FESEM image of the barrier layer of the porous alumina film obtained in Example 11.

Detailed ways

The invention provides a method for detecting the thickness of the barrier layer of the porous alumina film, which is characterized in that the method comprises judging whether the porous alumina film contains a barrier layer according to the transmission spectrum in the range of 200nm to 2500nm of the porous alumina film, Wherein, if the transmission spectrum oscillates within the range of 200nm to 2500nm, it is judged that the thickness of the barrier layer of the porous alumina film is greater than 0; The barrier layer has a thickness of 0.

The inventors of the present invention have further found the following features

1. The detection method of the thickness of the barrier layer of the porous alumina thin film, wherein the transmission spectrum only oscillates in the range of 500nm to 2500nm, and the number of oscillation peaks is 17, then the through-porosity of the porous alumina thin film is 0, the thickness of the barrier layer is 80 nm to 90 nm.

2. The detection method of the thickness of the barrier layer of the porous alumina thin film, wherein the transmission spectrum only oscillates in the range of 1000nm to 2500nm, and the number of oscillation peaks is 16, then the through-porosity of the porous alumina thin film is 0, the thickness of the barrier layer is 65 nm to 75 nm.

3. The detection method for the thickness of the barrier layer of the porous alumina thin film, wherein the transmission spectrum only oscillates in the range of 1000nm to 2500nm, and the number of oscillation peaks is 8, then the through-porosity of the porous alumina thin film is 0, the thickness of the barrier layer is 30 nm to 40 nm.

4. The method for detecting the thickness of the barrier layer of the porous alumina thin film, wherein the transmission spectrum only oscillates in the range of 1500nm to 2500nm, and the number of oscillation peaks is 4, then the through-porosity of the porous alumina thin film is 50%-80%, the thickness of the blocking layer is 5nm-25nm.

5. The detection method of the thickness of the barrier layer of the porous aluminum oxide film described in the above feature 4, if the light transmittance is 70% to 80%, the through-porosity of the porous aluminum oxide film is 50% to 65%, and the barrier layer The thickness is about 15nm-25nm.

6. The method for detecting the thickness of the barrier layer of the porous aluminum oxide film described in feature 4 above, if the light transmittance is 85% to 90%, the through-porosity of the porous aluminum oxide film is 70% to 80%, and the barrier layer The thickness is about 5nm-10nm.

In the present invention, the through-porosity refers to the ratio of the number of through-holes to the total number of holes in the porous alumina film, and the said through-holes refer to holes without barrier layers.

In the method for detecting the thickness of the barrier layer of the porous aluminum oxide film, the transmission spectrum is an ultraviolet-visible-near-infrared transmission spectrum.

The method for detecting the thickness of the barrier layer of the porous aluminum oxide film above, wherein, the conditions for obtaining the transmission spectrum include scanning, the wavelength range can be 200nm to 2500nm, and the scanning rate is 900-950nm/min, preferably 924nm/min. min.

The method for detecting the thickness of the barrier layer of the porous aluminum oxide film according to the present invention, wherein the thickness of the porous aluminum oxide film is 1-30 microns. The thickness of the porous alumina film was measured by a field emission scanning electron microscope (Hitachi S4800).

The preparation method of the above-mentioned porous aluminum oxide film is known in the art, for example, it can be prepared by a method comprising the following steps:

1) Pretreatment

High-purity Al flakes (99.999%) were ultrasonically cleaned with acetone and deionized water (18.2 MΩ/cm) for 10 minutes, respectively, followed by a mixture of concentrated phosphoric acid, concentrated sulfuric acid, and concentrated nitric acid with a volume ratio of 7:1:2. Chemical polishing at 120°C for 1 minute.

2) The first step of anodizing

Put the aluminum sheet obtained in step 1) in an electrolytic cell of plexiglass or polytetrafluoroethylene, use graphite as the cathode, and the aluminum sheet as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.2M to 0.4M, under a voltage of 40V to 60V , When the ambient temperature is less than 10°C, the first anodic oxidation is carried out, and the oxidation time is 1 hour to 12 hours.

3) Corrode the oxide film once

Place the aluminum sheet obtained in step 2) in a mixed solution of phosphoric acid and chromic acid, and place it in an oven at 65° C. for 2 hours to 12 hours. The concentration of phosphoric acid is 5 wt%, and the concentration of chromic acid is 1.5 wt%.

4) The second step of anodizing

Place the corroded aluminum sheet obtained in step 3) in an electrolytic cell of plexiglass or polytetrafluoroethylene, with graphite as the cathode and the aluminum sheet as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.2M to 0.4M, at 40V to Under 60V voltage, the first step of anodic oxidation is carried out when the ambient temperature is less than 10°C, and the oxidation time is 1 minute to 30 minutes.

5) Peel off the aluminum substrate

Soak the product obtained in step 4) with saturated copper chloride, and take it out immediately when no bubbles emerge, to obtain an aluminum oxide film.

6) Remove the blocking layer

Soak the product obtained in step 5) in 5 wt% phosphoric acid aqueous solution for 5 minutes to 70 minutes.

The measurement of the porous aluminum oxide film of the present invention adopts ultraviolet-visible-near-infrared transmission spectrum detection, and the ultraviolet-visible-near-infrared spectrum of the porous aluminum oxide film is tested by transmission spectrum technology. The wavelength range of the test is 200nm ~ 2500nm.

The following examples will further illustrate the present invention.

Example 1

This embodiment is used to illustrate the detection method of the barrier layer thickness of the porous aluminum oxide film provided by the present invention

1. Preparation of Porous Alumina Films

1) Pretreatment

High-purity Al flakes with a purity of 99.999% (size 2cm*2cm*0.025cm, purchased from Beijing Mengtai Research Institute) were ultrasonically cleaned with acetone and deionized water (18.2MΩ/cm) for 10 minutes, and the volume ratio was 7 A 1:2 mixture of concentrated phosphoric acid, concentrated sulfuric acid and concentrated nitric acid was chemically polished at 120° C. for 1 minute.

2) The first step of anodizing

Put the aluminum flake obtained in step 1) in an electrolytic cell of plexiglass or polytetrafluoroethylene, use graphite as the cathode, and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, under a voltage of 60V, the ambient temperature is less than 10 The first anodic oxidation is carried out at ℃, and the oxidation time is 1 hour.

3) Corrode the oxide film once

Place the aluminum sheet obtained in step 2) in a mixed solution of phosphoric acid and chromic acid, and place it in an oven at 65° C. for 4 hours. The concentration of phosphoric acid is 5 wt%, and the concentration of chromic acid is 1.5 wt%.

4) The second step of anodizing

The corroded aluminum flake obtained in step 3) is placed in an electrolytic cell of plexiglass or polytetrafluoroethylene, with graphite as the cathode and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, under a voltage of 60V, the environment When the temperature is lower than 10°C, the second step of anodic oxidation is carried out, and the oxidation time is 5 minutes.

5) Peel off the aluminum substrate

The product obtained in step 4) is soaked with saturated copper chloride, and taken out immediately when no bubbles emerge, and an aluminum oxide film is obtained.

6) Remove the blocking layer

The product obtained in step 5) was soaked in 5wt% phosphoric acid aqueous solution for 5 minutes.

2. UV-visible-near-infrared spectroscopy test of porous alumina film

The ultraviolet-visible-near-infrared spectrum of the porous alumina film is tested by transmission spectroscopy. The test conditions are that the instrument used is the Lambda 950 series ultraviolet-visible-near-infrared spectrophotometer produced by Perkin Elmer, and the measurement method is scanning. The range is 200nm～2500nm, and the scan rate is 924nm/min. The results are shown in Figure 1, and the wavelength range used is 200nm-2500nm. The transmission spectrum oscillates in the range of 500nm-2500nm, and the number of oscillation peaks is 17. It is determined that the through-porosity of the porous alumina film is 0, and the thickness of the barrier layer is 80nm-90nm.

The morphology was observed with a field emission scanning electron microscope (Hitachi S4800) (see Figure 2 and Figure 3), which proved that the through-porosity of the porous alumina film was 0, and the thickness of the barrier layer was about 80nm-90nm. It is consistent with the result detected by the method of the present invention.

Example 2

1. Preparation of Porous Alumina Films

1) Pretreatment

High-purity Al flakes with a purity of 99.999% (size 2cm*2cm*0.025cm, purchased from Beijing Mengtai Research Institute) were ultrasonically cleaned with acetone and deionized water (18.2MΩ/cm) for 10 minutes, and the volume ratio was 7 A 1:2 mixture of concentrated phosphoric acid, concentrated sulfuric acid and concentrated nitric acid was chemically polished at 120° C. for 1 minute.

2) The first step of anodizing

Put the aluminum flake obtained in step 1) in an electrolytic cell of plexiglass or polytetrafluoroethylene, use graphite as the cathode, and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.4M, at a voltage of 40V, the ambient temperature is less than 10 The first anodic oxidation is carried out at ℃, and the oxidation time is 12 hours.

3) Corrode the oxide film once

The aluminum sheet obtained in step 2) was placed in a mixed solution of phosphoric acid and chromic acid, and placed in an oven at 65° C. for 12 hours. The concentration of phosphoric acid was 5 wt%, and the concentration of chromic acid was 1.5 wt%.

4) The second step of anodizing

The corroded aluminum flake obtained in step 3) is placed in an electrolytic cell of plexiglass or polytetrafluoroethylene, with graphite as the cathode and the aluminum flake as the anode, in an aqueous solution of oxalic acid electrolyte with a concentration of 0.4M, under 40V voltage, ambient When the temperature is lower than 10°C, the second step of anodic oxidation is carried out, and the oxidation time is 30 minutes.

5) Peel off the aluminum substrate

The product obtained in step 4) is soaked with saturated copper chloride, and taken out immediately when no bubbles emerge, and an aluminum oxide film is obtained.

6) Remove the blocking layer

Soak the aluminum sheet obtained in step 5) in 5 wt% phosphoric acid aqueous solution for 10 minutes.

2. UV-visible-near-infrared spectroscopy test of porous alumina film

The ultraviolet-visible-near-infrared spectrum of the porous alumina film is tested by transmission spectroscopy. The test conditions are that the instrument used is the Lambda 950 series ultraviolet-visible-near-infrared spectrophotometer produced by Perkin Elmer, and the measurement method is scanning. The range is 200nm～2500nm, and the scan rate is 924nm/min. The transmission spectrum oscillates in the range of 500nm-2500nm, and the number of oscillation peaks is 17. It is determined that the through-porosity of the porous alumina film is 0, and the thickness of the barrier layer is 80nm-85nm.

Observing the morphology with a field emission scanning electron microscope (Hitachi S4800) shows that the through-porosity of the porous aluminum oxide film is 0, and the thickness of the barrier layer is about 80nm to 85nm, which is consistent with the results detected by the method of the present invention.

Example 3

1. Preparation of Porous Alumina Films

1) Pretreatment

High-purity Al flakes with a purity of 99.999% (size 2cm*2cm*0.025cm, purchased from Beijing Mengtai Youyan) were ultrasonically cleaned with acetone and deionized water (18.2MΩ/cm) for 10 minutes, and a volume ratio of 7 A 1:2 mixture of concentrated phosphoric acid, concentrated sulfuric acid and concentrated nitric acid was chemically polished at 120° C. for 1 minute.

2) The first step of anodizing

Put the aluminum flake obtained in step 1) in an electrolytic cell of plexiglass or polytetrafluoroethylene, use graphite as the cathode, and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, under a voltage of 60V, the ambient temperature is less than 10 The first anodic oxidation is carried out at ℃, and the oxidation time is 8 hours.

3) Corrode the oxide film once

Place the aluminum sheet obtained in step 2) in a mixed solution of phosphoric acid and chromic acid, and place it in an oven at 65° C. for 4 hours. The concentration of phosphoric acid is 5 wt%, and the concentration of chromic acid is 1.5 wt%.

4) The second step of anodizing

The corroded aluminum flake obtained in step 3) is placed in an electrolytic cell of plexiglass or polytetrafluoroethylene, with graphite as the cathode and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, under a voltage of 60V, the environment When the temperature is lower than 10°C, the second step of anodic oxidation is carried out, and the oxidation time is 5 minutes.

5) Peel off the aluminum substrate

Soak the product obtained in step 4) with saturated copper chloride, and take it out immediately when no bubbles emerge, to obtain an aluminum oxide film.

6) Remove the blocking layer

The product obtained in step 5) was soaked in 5wt% phosphoric acid aqueous solution for 15 minutes.

2. UV-visible-near-infrared spectroscopy test of porous alumina film

The ultraviolet-visible-near-infrared spectrum of the porous alumina film is tested by transmission spectroscopy. The test conditions are that the instrument used is the Lambda 950 series ultraviolet-visible-near-infrared spectrophotometer produced by Perkin Elmer, and the measurement method is scanning. The range is 200nm～2500nm, and the scan rate is 924nm/min. The results are shown in Figure 4. The transmission spectrum oscillates in the range of 1000nm-2500nm, and the number of oscillation peaks is 16. It is determined that the through-porosity of the porous alumina film is 0, and the thickness of the barrier layer is 65nm-75nm.

Use field emission scanning electron microscope (Hitachi S4800) to observe morphology (referring to Fig. 5, Fig. 6), prove that the through-porosity of porous aluminum oxide thin film is 0, and the thickness of blocking layer is about 65nm～75nm, and adopts the method detection of the present invention The results were consistent.

Example 4

1. Preparation of Porous Alumina Films

1) Pretreatment

High-purity Al flakes with a purity of 99.999% (size 2cm*2cm*0.025cm, purchased from Beijing Mengtai Research Institute) were ultrasonically cleaned with acetone and deionized water (18.2MΩ/cm) for 10 minutes, and the volume ratio was 7 A 1:2 mixture of concentrated phosphoric acid, concentrated sulfuric acid and concentrated nitric acid was chemically polished at 120° C. for 1 minute.

2) The first step of anodizing

Put the aluminum flake obtained in step 1) in an electrolytic cell of plexiglass or polytetrafluoroethylene, use graphite as the cathode, and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.2M, under a voltage of 50V, the ambient temperature is less than 10 The first anodic oxidation is carried out at ℃, and the oxidation time is 8 hours.

3) Corrode the oxide film once

Place the aluminum sheet obtained in step 2) in a mixed solution of phosphoric acid and chromic acid, place it in an oven at 65°C for 4 hours, the concentration of phosphoric acid is 5wt%, and the concentration of chromic acid is 1.5wt%.

4) The second step of anodizing

The corroded aluminum flake obtained in step 3) is placed in an electrolytic cell of plexiglass or polytetrafluoroethylene, with graphite as the cathode and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.2M, under a voltage of 50V, the environment When the temperature is lower than 10°C, the second step of anodic oxidation is carried out, and the oxidation time is 15 minutes.

5) Peel off the aluminum substrate

Soak the product obtained in step 4) with saturated copper chloride, and take it out immediately when no bubbles emerge, to obtain an aluminum oxide film.

6) Remove the blocking layer

The product obtained in step 5) was soaked in 5wt% phosphoric acid aqueous solution for 20 minutes.

2. UV-visible-near-infrared spectroscopy test of porous alumina film

The ultraviolet-visible-near-infrared spectrum of the porous alumina film is tested by transmission spectroscopy. The test conditions are that the instrument used is the Lambda 950 series ultraviolet-visible-near-infrared spectrophotometer produced by Perkin Elmer, and the measurement method is scanning. The range is 200nm～2500nm, and the scan rate is 924nm/min. The transmission spectrum oscillates in the range of 1000nm-2500nm, and the number of oscillation peaks is 16. It is determined that the through-porosity of the porous alumina film is 0, and the thickness of the barrier layer is 65nm-75nm.

Observing the morphology with a field emission scanning electron microscope (Hitachi S4800) shows that the through-porosity of the porous aluminum oxide film is 0, and the thickness of the barrier layer is about 65nm to 75nm, consistent with the results detected by the method of the present invention.

Example 5

1. Preparation of Porous Alumina Films

1) Pretreatment

High-purity Al flakes with a purity of 99.999% (size 2cm*2cm*0.025cm, purchased from Beijing Mengtai Research Institute) were ultrasonically cleaned with acetone and deionized water (18.2MΩ/cm) for 10 minutes, and the volume ratio was 7 A 1:2 mixture of concentrated phosphoric acid, concentrated sulfuric acid and concentrated nitric acid was chemically polished at 120° C. for 1 minute.

2) The first step of anodizing

Put the aluminum flake obtained in step 1) in an electrolytic cell of plexiglass or polytetrafluoroethylene, use graphite as the cathode, and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, under a voltage of 60V, the ambient temperature is less than 10 The first anodic oxidation is carried out at ℃, and the oxidation time is 4 hours.

3) Corrode the oxide film once

Place the aluminum sheet obtained in step 2) in a mixed solution of phosphoric acid and chromic acid, and place it in an oven at 65° C. for 4 hours. The concentration of phosphoric acid is 5 wt%, and the concentration of chromic acid is 1.5 wt%.

4) The second step of anodizing

The corroded aluminum flake obtained in step 3) is placed in an electrolytic cell of plexiglass or polytetrafluoroethylene, with graphite as the cathode and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, under a voltage of 60V, the environment When the temperature is lower than 10°C, the second step of anodic oxidation is carried out, and the oxidation time is 1 minute.

5) Peel off the aluminum substrate

Soak the product obtained in step 4) with saturated copper chloride, and take it out immediately when no bubbles emerge, to obtain an aluminum oxide film.

6) Remove the blocking layer

The product obtained in step 5) was soaked in 5wt% phosphoric acid aqueous solution for 30 minutes.

2. UV-visible-near-infrared spectroscopy test of porous alumina film

The ultraviolet-visible-near-infrared spectrum of the porous alumina film is tested by transmission spectroscopy. The test method is the Lambda 950 series ultraviolet-visible-near-infrared spectrophotometer produced by Perkin Elmer. The measurement method is scanning, wavelength The range is 200nm～2500nm, and the scan rate is 924nm/min. The results are shown in Figure 7. The transmission spectrum only oscillates in the range of 1000nm-2500nm, and the number of oscillation peaks is 8. It is determined that the through-porosity of the porous alumina film is 0, and the thickness of the barrier layer is 30nm-40nm.

Observing the morphology (see Fig. 8, Fig. 9) with a field emission scanning electron microscope (Hitachi S4800), proves that the through-porosity of the porous aluminum oxide film is 0, and the thickness of the barrier layer is about 30nm～40nm, which is consistent with the result detected by the method of the present invention unanimous.

Example 6

1. Preparation of Porous Alumina Films

1) Pretreatment

High-purity Al flakes with a purity of 99.999% (size 2cm*2cm*0.025cm, purchased from Beijing Mengtai Research Institute) were ultrasonically cleaned with acetone and deionized water (18.2MΩ/cm) for 10 minutes, and the volume ratio was 7 A 1:2 mixture of concentrated phosphoric acid, concentrated sulfuric acid and concentrated nitric acid was chemically polished at 120° C. for 1 minute.

2) The first step of anodizing

Put the aluminum flake obtained in step 1) in an electrolytic cell of plexiglass or polytetrafluoroethylene, with graphite as the cathode and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.4M, at a voltage of 60V, the ambient temperature is less than 10 The first anodic oxidation is carried out at ℃, and the oxidation time is 4 hours.

3) Corrode the oxide film once

The aluminum sheet obtained in step 2) was placed in a mixed solution of phosphoric acid and chromic acid, and placed in an oven at 65° C. for 8 hours. The concentration of phosphoric acid was 5 wt%, and the concentration of chromic acid was 1.5 wt%.

4) The second step of anodizing

The corroded aluminum flake obtained in step 3) is placed in an electrolytic cell of plexiglass or polytetrafluoroethylene, with graphite as the cathode and the aluminum flake as the anode, in an aqueous solution of oxalic acid electrolyte with a concentration of 0.4M, under a voltage of 60V, the environment When the temperature is lower than 10°C, the second step of anodic oxidation is carried out, and the oxidation time is 20 minutes.

5) Peel off the aluminum substrate

Soak the product obtained in step 4) with saturated copper chloride, and take it out immediately when no bubbles emerge, to obtain an aluminum oxide film.

6) Remove the blocking layer

The product obtained in step 5) was soaked in 5wt% phosphoric acid aqueous solution for 35 minutes.

2. UV-visible-near-infrared spectroscopy test of porous alumina film

The ultraviolet-visible-near-infrared spectrum of the porous alumina film is tested by transmission spectroscopy. The test method is the Lambda 950 series ultraviolet-visible-near-infrared spectrophotometer produced by Perkin Elmer. The measurement method is scanning, wavelength The range is 200nm～2500nm, and the scan rate is 924nm/min. The transmission spectrum oscillates in the range of 1000nm-2500nm, and the number of oscillation peaks is 8. It is determined that the through-porosity of the porous alumina film is 0, and the thickness of the barrier layer is 30nm-40nm.

Observing the morphology with a field emission scanning electron microscope (Hitachi S4800) shows that the through-porosity of the porous aluminum oxide film is 0, and the thickness of the barrier layer is about 30nm to 40nm, which is consistent with the results detected by the method of the present invention.

Example 7

1. Preparation of Porous Alumina Films

1) Pretreatment

High-purity Al flakes with a purity of 99.999% (size 2cm*2cm*0.025cm, purchased from Beijing Mengtai Research Institute) were ultrasonically cleaned with acetone and deionized water (18.2MΩ/cm) for 10 minutes, and the volume ratio was 7 A 1:2 mixture of concentrated phosphoric acid, concentrated sulfuric acid and concentrated nitric acid was chemically polished at 120° C. for 1 minute.

2) The first step of anodizing

Put the aluminum flake obtained in step 1) in an electrolytic cell of plexiglass or polytetrafluoroethylene, use graphite as the cathode, and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, under a voltage of 60V, the ambient temperature is less than 10 The first anodic oxidation is carried out at ℃, and the oxidation time is 1 hour.

3) Corrode the oxide film once

Place the aluminum sheet obtained in step 2) in a mixed solution of phosphoric acid and chromic acid, place it in an oven at 65°C for 2 hours, the concentration of phosphoric acid is 5wt%, and the concentration of chromic acid is 1.5wt%.

4) The second step of anodizing

The corroded aluminum flake obtained in step 3) is placed in an electrolytic cell of plexiglass or polytetrafluoroethylene, with graphite as the cathode and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, under a voltage of 60V, the environment When the temperature is lower than 10°C, the second step of anodic oxidation is carried out, and the oxidation time is 5 minutes.

5) Peel off the aluminum substrate

Soak the product obtained in step 4) with saturated copper chloride, and take it out immediately when no bubbles emerge, to obtain an aluminum oxide film.

6) Remove the blocking layer

The product obtained in step 5) was soaked in 5wt% phosphoric acid aqueous solution for 40 minutes.

2. UV-visible-near-infrared spectroscopy test of porous alumina film

The ultraviolet-visible-near-infrared spectrum of the porous alumina film is tested by transmission spectroscopy. The test method is the Lambda 950 series ultraviolet-visible-near-infrared spectrophotometer produced by Perkin Elmer. The measurement method is scanning, wavelength The range is 200nm～2500nm, and the scan rate is 924nm/min. The results are shown in Figure 10, the transmission spectrum only oscillates in the range of 1500nm to 2500nm, the number of oscillation peaks is 4, the light transmittance is 70%, the through-porosity of the porous aluminum oxide film is determined to be 50%, and the barrier layer The thickness is 15nm-25nm.

Observing the morphology (referring to Fig. 11, Fig. 12) with a field emission scanning electron microscope (Hitachi S4800), proves that the through-porosity of the porous aluminum oxide film is 50%, and the thickness of the barrier layer is about 15nm～25nm, which is the same as that detected by the method of the present invention. The results were consistent.

Example 8

1. Preparation of Porous Alumina Films

1) Pretreatment

High-purity Al flakes with a purity of 99.999% (size 2cm*2cm*0.025cm, purchased from Beijing Mengtai Research Institute) were ultrasonically cleaned with acetone and deionized water (18.2MΩ/cm) for 10 minutes, and the volume ratio was 7 A 1:2 mixture of concentrated phosphoric acid, concentrated sulfuric acid and concentrated nitric acid was chemically polished at 120° C. for 1 minute.

2) The first step of anodizing

Put the aluminum flake obtained in step 1) in an electrolytic cell of plexiglass or polytetrafluoroethylene, with graphite as the cathode and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, at a voltage of 40V, the ambient temperature is less than 10 The first anodic oxidation is carried out at ℃, and the oxidation time is 12 hours.

3) Corrode the oxide film once

The aluminum sheet obtained in step 2) was placed in a mixed solution of phosphoric acid and chromic acid, and placed in an oven at 65° C. for 12 hours. The concentration of phosphoric acid was 5 wt%, and the concentration of chromic acid was 1.5 wt%.

4) The second step of anodizing

The corroded aluminum flake obtained in step 3) is placed in an electrolytic cell of plexiglass or polytetrafluoroethylene, with graphite as the cathode and the aluminum flake as the anode, in an aqueous solution of oxalic acid electrolyte with a concentration of 0.3M, under a voltage of 40V, the environment When the temperature is lower than 10°C, the second step of anodic oxidation is carried out, and the oxidation time is 10 minutes.

5) Peel off the aluminum substrate

Soak the product obtained in step 4) with saturated copper chloride, and take it out immediately when no bubbles emerge, to obtain an aluminum oxide film.

6) Remove the blocking layer

The product obtained in step 5) was soaked in 5wt% phosphoric acid aqueous solution for 45 minutes.

2. UV-visible-near-infrared spectroscopy test of porous alumina film

Utilize transmission spectrum technology to test the ultraviolet-visible-near-infrared spectrum (see accompanying drawing 22) of porous aluminum oxide film, test method is the Lambda 950 series ultraviolet-visible-near-infrared spectrophotometer that the instrument used is Perkin Elmer Company to produce, The measurement method is scanning, the wavelength range is 200nm～2500nm, and the scanning rate is 924nm/min. The transmission spectrum only oscillates in the range of 1500nm-2500nm, the number of oscillating peaks is 4, the light transmittance is 80%, the through-porosity of the porous aluminum oxide film is determined to be 65%, and the thickness of the barrier layer is 15nm-25nm.

Observing the morphology with a field emission scanning electron microscope (Hitachi S4800) shows that the through-porosity of the porous aluminum oxide film is 65%, and the thickness of the barrier layer is about 15nm to 25nm, which is consistent with the result detected by the method of the present invention.

Example 9

1. Preparation of Porous Alumina Films

1) Pretreatment

High-purity Al flakes with a purity of 99.999% (size 2cm*2cm*0.025cm, purchased from Beijing Mengtai Research Institute) were ultrasonically cleaned with acetone and deionized water (18.2MΩ/cm) for 10 minutes, and the volume ratio was 7 A 1:2 mixture of concentrated phosphoric acid, concentrated sulfuric acid and concentrated nitric acid was chemically polished at 120° C. for 1 minute.

2) The first step of anodizing

Put the aluminum flake obtained in step 1) in an electrolytic cell of plexiglass or polytetrafluoroethylene, use graphite as the cathode, and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, under a voltage of 60V, the ambient temperature is less than 10 The first anodic oxidation is carried out at ℃, and the oxidation time is 2 hours.

3) Corrode the oxide film once

Place the aluminum sheet obtained in step 2) in a mixed solution of phosphoric acid and chromic acid, place it in an oven at 65°C for 2 hours, the concentration of phosphoric acid is 5wt%, and the concentration of chromic acid is 1.5wt%.

4) The second step of anodizing

The corroded aluminum flake obtained in step 3) is placed in an electrolytic cell of plexiglass or polytetrafluoroethylene, with graphite as the cathode and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, under a voltage of 60V, the environment When the temperature is lower than 10°C, the second step of anodic oxidation is carried out, and the oxidation time is 5 minutes.

5) Peel off the aluminum substrate

Soak the product obtained in step 4) with saturated copper chloride, and take it out immediately when no bubbles emerge, to obtain an aluminum oxide film.

6) Remove the blocking layer

The product obtained in step 5) was soaked in 5wt% phosphoric acid aqueous solution for 50 minutes.

2. UV-visible-near-infrared spectroscopy test of porous alumina film

Utilize transmission spectrum technology to test the ultraviolet-visible-near-infrared spectrum (see accompanying drawing 22) of porous aluminum oxide film, test method is the Lambda 950 series ultraviolet-visible-near-infrared spectrophotometer that the instrument used is Perkin Elmer Company to produce, The measurement method is scanning, the wavelength range is 200nm～2500nm, and the scanning rate is 924nm/min. The results are shown in Figure 13, the transmission spectrum only oscillates in the range of 1500nm to 2500nm, the number of oscillation peaks is 4, the light transmittance is 85%, it is determined that the through-porosity of the porous alumina film is 70%, and the barrier layer The thickness is 5nm-10nm.

Observing the morphology (referring to Fig. 14, Fig. 15) with a field emission scanning electron microscope (Hitachi S4800), it is proved that the through-porosity of the porous aluminum oxide film is 70%, and the thickness of the barrier layer is about 5nm～10nm, which is the same as that detected by the method of the present invention. The results were consistent.

Example 10

1. Preparation of Porous Alumina Films

1) Pretreatment

High-purity Al flakes with a purity of 99.999% (size 2cm*2cm*0.025cm, purchased from Beijing Mengtai Research Institute) were ultrasonically cleaned with acetone and deionized water (18.2MΩ/cm) for 10 minutes, and the volume ratio was 7 A 1:2 mixture of concentrated phosphoric acid, concentrated sulfuric acid and concentrated nitric acid was chemically polished at 120° C. for 1 minute.

2) The first step of anodizing

Put the aluminum flake obtained in step 1) in an electrolytic cell of plexiglass or polytetrafluoroethylene, use graphite as the cathode, and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, under a voltage of 60V, the ambient temperature is less than 10 The first anodic oxidation is carried out at ℃, and the oxidation time is 4 hours.

3) Corrode the oxide film once

The aluminum sheet obtained in step 2) was placed in a mixed solution of phosphoric acid and chromic acid, and placed in an oven at 65° C. for 6 hours. The concentration of phosphoric acid was 5 wt%, and the concentration of chromic acid was 1.5 wt%.

4) The second step of anodizing

The corroded aluminum flake obtained in step 3) is placed in an electrolytic cell of plexiglass or polytetrafluoroethylene, with graphite as the cathode and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, under a voltage of 60V, the environment When the temperature is lower than 10°C, the second step of anodic oxidation is carried out, and the oxidation time is 10 minutes.

5) Peel off the aluminum substrate

Soak the product obtained in step 4) with saturated copper chloride, and take it out immediately when no bubbles emerge, to obtain an aluminum oxide film.

6) Remove the blocking layer

The product obtained in step 5) was soaked in 5 wt% phosphoric acid aqueous solution for 60 minutes.

2. UV-visible-near-infrared spectroscopy test of porous alumina film

The ultraviolet-visible-near-infrared spectrum of the porous alumina film is tested by transmission spectroscopy. The test method is the Lambda 950 series ultraviolet-visible-near-infrared spectrophotometer produced by Perkin Elmer. The measurement method is scanning, wavelength The range is 200nm～2500nm, and the scan rate is 924nm/min. The transmission spectrum only oscillates in the range of 1500nm-2500nm, the number of oscillating peaks is 4, the light transmittance is 90%, the through-porosity of the porous aluminum oxide film is determined to be 80%, and the thickness of the barrier layer is 5nm-10nm.

Observing the morphology with a field emission scanning electron microscope (Hitachi S4800) shows that the through-porosity of the porous aluminum oxide film is 80%, and the thickness of the barrier layer is about 5nm to 10nm, which is consistent with the result detected by the method of the present invention.

Example 11

1. Preparation of Porous Alumina Films

1) Pretreatment

High-purity Al flakes with a purity of 99.999% (size 2cm*2cm*0.025cm, purchased from Beijing Mengtai Research Institute) were ultrasonically cleaned with acetone and deionized water (18.2MΩ/cm) for 10 minutes, and the volume ratio was 7 A 1:2 mixture of concentrated phosphoric acid, concentrated sulfuric acid and concentrated nitric acid was chemically polished at 120° C. for 1 minute.

2) The first step of anodizing

Put the aluminum flake obtained in step 1) in an electrolytic cell of plexiglass or polytetrafluoroethylene, use graphite as the cathode, and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, under a voltage of 60V, the ambient temperature is less than 10 The first anodic oxidation is carried out at ℃, and the oxidation time is 3 hours.

3) Corrode the oxide film once

Place the aluminum sheet obtained in step 2) in a mixed solution of phosphoric acid and chromic acid, and place it in an oven at 65° C. for 3 hours. The concentration of phosphoric acid is 5 wt%, and the concentration of chromic acid is 1.5 wt%.

4) The second step of anodizing

The corroded aluminum flake obtained in step 3) is placed in an electrolytic cell of plexiglass or polytetrafluoroethylene, with graphite as the cathode and the aluminum flake as the anode, in an aqueous oxalic acid electrolyte solution with a concentration of 0.3M, under a voltage of 60V, the environment When the temperature is lower than 10°C, the second step of anodic oxidation is carried out, and the oxidation time is 5 minutes.

5) Peel off the aluminum substrate

Soak the product obtained in step 4) with saturated copper chloride, and take it out immediately when no bubbles emerge, to obtain an aluminum oxide film.

6) Remove the blocking layer

The product obtained in step 5) was soaked in 5wt% phosphoric acid aqueous solution for 70 minutes.

2. UV-visible-near-infrared spectroscopy test of porous alumina film

The ultraviolet-visible-near-infrared spectrum of the porous alumina film is tested by transmission spectroscopy. The test method is the Lambda 950 series ultraviolet-visible-near-infrared spectrophotometer produced by Perkin Elmer. The measurement method is scanning, wavelength The range is 200nm～2500nm, and the scan rate is 924nm/min. The results are shown in Figure 16, the transmission spectrum does not oscillate in the range of 200nm-2500nm, it is determined that the through-porosity of the porous alumina film is 100%, and the thickness of the barrier layer is 0nm.

Observing the morphology with a field emission scanning electron microscope (Hitachi S4800) (see Figure 17, Figure 18), it is proved that the through-porosity of the porous aluminum oxide film is 100%, and the thickness of the barrier layer is 0nm, which is consistent with the result detected by the method of the present invention.

Claims (10)

1. A detection method for the barrier layer thickness of a porous aluminum oxide film, characterized in that the method comprises judging whether the porous aluminum oxide film contains a barrier layer according to the transmission spectrum of the porous aluminum oxide film in the range of 200nm to 2500nm, wherein, If the transmission spectrum oscillates within the range of 200nm to 2500nm, it is judged that the thickness of the barrier layer of the porous alumina film is greater than 0; The thickness is 0. 2. the detection method of the barrier layer thickness of porous aluminum oxide thin film according to claim 1, wherein, transmission spectrum only oscillates in 500nm～2500nm scope, and the number of oscillation peaks is 17, then porous aluminum oxide thin film The through porosity is 0, and the thickness of the barrier layer is 80nm-90nm. 3. the detection method of the barrier layer thickness of porous aluminum oxide thin film according to claim 1, wherein, transmission spectrum only oscillates in 1000nm～2500nm scope, and the number of oscillation peaks is 16, then porous aluminum oxide thin film The through porosity is 0, and the thickness of the barrier layer is 65nm-75nm. 4. The detection method of the thickness of the barrier layer of the porous aluminum oxide film according to claim 1, wherein the transmission spectrum only oscillates in the range of 1000nm to 2500nm, and the number of oscillation peaks is 8, then the porous aluminum oxide film The through porosity is 0, and the thickness of the barrier layer is 30nm-40nm. 5. The detection method of the barrier layer thickness of porous aluminum oxide thin film according to claim 1, wherein, the transmission spectrum only oscillates in the range of 1500nm～2500nm, and the number of oscillation peaks is 4, then the porous aluminum oxide thin film The through-porosity is 50%-80%, and the thickness of the barrier layer is 5nm-25nm. 6. the detection method of the barrier layer thickness of porous aluminum oxide film according to claim 5, if light transmittance is 70%～80%, then the through-porosity of porous aluminum oxide film is 50%-65%, barrier layer The thickness is 15nm ~ 25nm. 7. the detection method of the barrier layer thickness of porous aluminum oxide film according to claim 5, if light transmittance is 85%～90%, then the through-porosity of porous aluminum oxide film is 70%-80%, barrier layer The thickness is 5nm ~ 10nm. 8. The method for detecting the thickness of the barrier layer of the porous alumina thin film according to any one of claims 1-7, wherein the transmission spectrum is an ultraviolet-visible-near-infrared transmission spectrum. 9. The method for detecting the thickness of the barrier layer of the porous alumina thin film according to claim 8, wherein the conditions for obtaining the transmission spectrum include a wavelength range of 200nm-2500nm, and a scan rate of 900-950nm/min. 10. The method for detecting the thickness of the barrier layer of the porous alumina film according to claim 8, wherein the thickness of the porous alumina film is 1-30 microns.

Images