Saddle-shaped aluminum oxide template for preparing nano material as well as preparation method and application of saddle-shaped aluminum oxide template

Abstract

The invention belongs to the field of alloy processing, and particularly relates to a saddle-shaped aluminum oxide template for preparing a nano material as well as a preparation method and application of the saddle-shaped aluminum oxide template. The inner surface and the outer surface of the template provided by the invention are both saddle surfaces, the circular-truncated-cone-shaped nano holes are radially and orderly arranged along the vertical direction of the surfaces of the saddle surfaces, and the nano hole arrays are respectively in a circular truncated cone shape and an inverted circular truncated cone shape along the directions of two main parabolas of the saddle surfaces; and the aperture size and the aperture change rate of the circular-truncated-cone-shaped nanopores can be adjusted by changing the anodic oxidation time and the curvatures of the two main parabolas of the saddle surface.

Description

Technical Field

[0001] The invention belongs to the field of alloy processing, and in particular relates to a saddle-surface-shaped alumina template for preparing nano materials, a preparation method and application thereof. Background Art

[0002] With the continuous development of science and technology, many new disciplines are constantly emerging. Nanomaterials is one of them. The preparation of nanomaterials is the basis of their application. At present, the methods used to prepare nanomaterials are: template method, vapor deposition method, photolithography, liquid phase method, ion beam etching method, etc. Among them, the template method is the most basic method. At present, there are about four relatively mature templates: carbon nanotubes, ion beam etched carbon films, biological micro micelles and alumina templates. Alumina templates have the characteristics of high pore density and adjustable nanopore aspect ratio (pore length / pore diameter), making it one of the most widely used templates. It is a nanopore array system obtained by placing 99.99% pure aluminum sheets in an appropriate acidic solution (such as oxalic acid, sulfuric acid or phosphoric acid, etc.) and anodizing. Since the early 1990s, people have successfully synthesized many nanostructured materials using alumina templates, such as nanofibers, nanorods, nanotubes and nanowires. These nanomaterials show attractive application prospects, and some have even gone out of the laboratory stage, such as carbon nanotube field emitters and semiconductor nanowire lasers.

[0003] However, the upper and lower surfaces of the planar alumina template are both flat, which is not conducive to the realization of nanomaterials as devices. Moreover, the nanopores in the planar alumina template are straight and parallel, and the nanomaterials assembled using this template have a single function. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a saddle-shaped alumina template for preparing nanomaterials, and the surface equation of the alumina template is:

[0005] Furthermore, in the surface equation, the value range of x is -3 cm to 3 cm; the value range of y is -2.5 cm to 2.5 cm; and the value range of z is -2 cm to 2 cm.

[0006] The present invention also provides a method for preparing the saddle-shaped alumina template, comprising the following steps:

[0007] (1) Winding a strip of high-purity aluminum sheet on the surface of a saddle surface mold and forming it into a saddle surface-shaped aluminum sheet through forging;

[0008] (2) The saddle-shaped aluminum sheet was polished in a mixture of ethanol and perchloric acid at a voltage of 14-15 volts and a temperature of 10 degrees Celsius;

[0009] (3) Take out the aluminum sheet and rinse it with deionized water for 3-5 times;

[0010] (4) placing the saddle-shaped aluminum sheet in an oxalic acid solution for anodizing;

[0011] (5) placing the aluminum sheet obtained in (4) in a solution of 1.6%wt phosphoric acid and 6%wt chromic acid at 60°C for 2 hours to remove the oxide layer on the aluminum sheet;

[0012] (6) The saddle-shaped aluminum sheet was anodized for a second time in a 0.3 M oxalic acid solution for 8 hours at a voltage of 40 V and a temperature of 5°C;

[0013] (7) placing the saddle-shaped aluminum oxide sheet obtained in (6) into a saturated mercuric chloride solution for 2 hours to remove the unoxidized aluminum layer in the middle;

[0014] (8) Rinse the saddle-shaped alumina sheet obtained in (7) with deionized water for 3-5 times and dry it at room temperature;

[0015] (9) placing the saddle-shaped alumina sheet obtained in (8) into a 0.1 M phosphoric acid solution at 30 degrees Celsius for 20 minutes to remove the barrier layer;

[0016] (10) The saddle-shaped alumina sheet obtained in (9) is rinsed with deionized water for 3-5 times and dried at room temperature to finally obtain a saddle-shaped alumina template.

[0017] Furthermore, the volume ratio of ethanol to perchloric acid in the mixed solution described in step (2) is 5:1.

[0018] Furthermore, the polishing conditions in step (2) are: voltage 14-15 volts, temperature 10 degrees Celsius, and time 4-5 minutes.

[0019] Furthermore, the concentration of the oxalic acid solution in step (4) is 0.3M.

[0020] Furthermore, the anodizing conditions in step (4) are: oxidation voltage 40 volts, temperature 5 degrees Celsius, and time 20 hours.

[0021] Furthermore, in step (5), the volume ratio of 1.6%wt phosphoric acid to 6%wt chromic acid is 1:1.

[0022] The invention also provides application of the saddle-surface-shaped alumina template prepared by the preparation method in preparing nanometer materials.

[0023] The present invention has the following beneficial effects:

[0024] The saddle-surface alumina template provided by the present invention has saddle surfaces on both the inner and outer surfaces of the template, and truncated cone-shaped nanopores are arranged in an orderly manner in a radial shape along the vertical direction of the saddle surface. The nanopore arrays along the two main parabolic directions of the saddle surface are truncated cones and inverted truncated cones respectively, and the pore size and pore size change rate of the truncated cone-shaped nanopores can be adjusted by changing the anodizing time and the curvature of the two main parabolas of the saddle surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A physical picture of the saddle-shaped aluminum sheet of the present invention after anodization. DETAILED DESCRIPTION

[0027] Now, various exemplary embodiments of the present invention are described in detail. The methods in the examples are conventional methods unless otherwise specified, and the reagents used are conventional commercial reagents or reagents prepared by conventional methods unless otherwise specified. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, features and embodiments of the present invention.

[0028] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0029] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0030] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0031] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0032] A saddle-shaped alumina template for preparing nanomaterials, wherein the surface equation of the alumina template is:

[0033] Furthermore, in the surface equation, the value range of x is -3 cm to 3 cm; the value range of y is -2.5 cm to 2.5 cm; and the value range of z is -2 cm to 2 cm.

[0034] The present invention also provides a method for preparing the saddle-shaped alumina template, comprising the following steps:

[0035] (1) Winding a strip of high-purity aluminum sheet on the surface of a saddle surface mold and forming it into a saddle surface-shaped aluminum sheet through forging;

[0036] (2) The saddle-shaped aluminum sheet was polished in a mixture of ethanol and perchloric acid at a voltage of 14-15 volts and a temperature of 10 degrees Celsius;

[0037] (3) Take out the aluminum sheet and rinse it with deionized water for 3-5 times;

[0038] (4) placing the saddle-shaped aluminum sheet in an oxalic acid solution for anodizing;

[0039] (5) placing the aluminum sheet obtained in (4) in a solution of 1.6%wt phosphoric acid and 6%wt chromic acid at 60°C for 2 hours to remove the oxide layer on the aluminum sheet;

[0040] (6) The saddle-shaped aluminum sheet was anodized for a second time in a 0.3 M oxalic acid solution for 8 hours at a voltage of 40 V and a temperature of 5°C;

[0041] (7) placing the saddle-shaped aluminum oxide sheet obtained in (6) into a saturated mercuric chloride solution for 2 hours to remove the unoxidized aluminum layer in the middle;

[0042] (8) Rinse the saddle-shaped alumina sheet obtained in (7) with deionized water for 3-5 times and dry it at room temperature;

[0043] (9) placing the saddle-shaped alumina sheet obtained in (8) into a 0.1 M phosphoric acid solution at 30 degrees Celsius for 20 minutes to remove the barrier layer;

[0044] (10) The saddle-shaped alumina sheet obtained in (9) is rinsed with deionized water for 3-5 times and dried at room temperature to finally obtain a saddle-shaped alumina template.

[0045] Furthermore, the volume ratio of ethanol to perchloric acid in the mixed solution described in step (2) is 5:1.

[0046] Furthermore, the polishing conditions in step (2) are: voltage 14-15 volts, temperature 10 degrees Celsius, and time 4-5 minutes.

[0047] Furthermore, the concentration of the oxalic acid solution in step (4) is 0.3M.

[0048] Furthermore, the anodizing conditions in step (4) are: oxidation voltage 40 volts, temperature 5 degrees Celsius, and time 20 hours.

[0049] Furthermore, in step (5), the volume ratio of 1.6%wt phosphoric acid to 6%wt chromic acid is 1:1.

[0050] After the above steps are completed for the saddle-shaped alumina template obtained by anodization in an oxalic acid solution under corresponding conditions, the truncated cone-shaped holes are arranged in an orderly manner in a radial shape along the direction perpendicular to the surface of the saddle surface; along the main parabola direction of the saddle surface represented by the black dotted line in the figure, the pore size and pore size change rate of the truncated cone-shaped nanopores gradually change: near point a shown in the figure, the minimum and maximum diameters of the truncated cone-shaped nanopores along the direction perpendicular to the template surface are 70nm and 90nm, respectively, and the rate of change of the nanopore size is 0.55nm / μm; near point b shown in the figure, the minimum and maximum diameters of the truncated cone-shaped nanopores along the direction perpendicular to the template surface are 65nm and 84nm, respectively, and the rate of change of the nanopore size is 0.52nm / μm; along the main parabola direction of the saddle surface represented by the white dotted line in the figure, the nanopore array presents an inverted truncated cone, and the pore size of the nanopores And the aperture change rate changes gradually: near point c shown in the figure, the maximum and minimum diameters of the inverted truncated cone nanopore along the direction perpendicular to the template surface are 80nm and 64nm respectively, and the nanopore diameter change rate is -0.44nm / μm. Near point d shown in the figure, the maximum and minimum diameters of the inverted truncated cone nanopore along the direction perpendicular to the template surface are 76nm and 61nm respectively, and the nanopore diameter change rate is -0.42nm / μm. Therefore, along the two main parabolic directions of the template, the orderly arranged nanopore array presents a truncated cone and an inverted truncated cone shape respectively. The pore size and aperture change rate of the truncated cone nanopore gradually change in the two-dimensional direction. The pore size and aperture change rate of the truncated cone nanopore can be adjusted by changing the curvature of the main parabola and the anodization time. Direct observation with a scanning electron microscope can confirm the feasibility of the method.

[0051] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A saddle-shaped alumina template for preparing nanomaterials, characterized in that: The surface equation of the alumina template is:

2. The saddle-shaped alumina template according to claim 1, characterized in that: In the surface equation, the value range of x is -3 cm to 3 cm; the value range of y is -2.5 cm to 2.5 cm; and the value range of z is -2 cm to 2 cm.

3. The method for preparing the saddle-shaped alumina template according to claim 1, characterized in that: The following steps are involved: (1) Winding a strip of high-purity aluminum sheet on the surface of a saddle surface mold and forming it into a saddle surface-shaped aluminum sheet through forging; (2) The saddle-shaped aluminum sheet was polished in a mixture of ethanol and perchloric acid at a voltage of 14-15 volts and a temperature of 10 degrees Celsius; (3) Take out the aluminum sheet and rinse it with deionized water for 3-5 times; (4) placing the saddle-shaped aluminum sheet in an oxalic acid solution for anodizing; (5) placing the aluminum sheet obtained in (4) in a solution of 1.6%wt phosphoric acid and 6%wt chromic acid at 60°C for 2 hours to remove the oxide layer on the aluminum sheet; (6) The saddle-shaped aluminum sheet was anodized for the second time in a 0.3 M oxalic acid solution for 8 hours at a voltage of 40 V and a temperature of 5°C; (7) placing the saddle-shaped aluminum oxide sheet obtained in (6) into a saturated mercuric chloride solution for 2 hours to remove the unoxidized aluminum layer in the middle; (8) Rinse the saddle-shaped alumina sheet obtained in (7) with deionized water for 3-5 times and dry it at room temperature; (9) placing the saddle-shaped alumina sheet obtained in (8) into a 0.1 M phosphoric acid solution at 30 degrees Celsius for 20 minutes to remove the barrier layer; (10) The saddle-shaped alumina sheet obtained in (9) is rinsed with deionized water for 3-5 times and dried at room temperature to finally obtain a saddle-shaped alumina template.

4. The method according to claim 3, characterized in that The volume ratio of ethanol to perchloric acid in the mixed solution described in step (2) is 5:

1.

5. The method according to claim 3, characterized in that: The polishing conditions in step (2) are: voltage 14-15 volts, temperature 10 degrees Celsius, and time 4-5 minutes.

6. The method according to claim 3, characterized in that The concentration of the oxalic acid solution in step (4) is 0.3M.

7. The method according to claim 3, characterized in that The anodizing conditions in step (4) are: oxidation voltage 40 volts, temperature 5 degrees Celsius, and time 20 hours.

8. The method according to claim 3, characterized in that The volume ratio of 1.6%wt phosphoric acid to 6%wt chromic acid in step (5) is 1:

1.

9. Use of the saddle-shaped alumina template obtained by the preparation method according to any one of claims 3 to 8 in the preparation of nanomaterials.

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