Preparation method of [400] single-orientation NiCo2O4 nano film

Abstract

The invention belongs to the technical field of perovskite nano materials, and discloses a preparation method of a [400] single orientation NiCo2O4 nano film. The preparation method comprises the following steps: adding cobalt salt and nickel salt into an organic solvent through a solution method to prepare a precursor solution containing cobalt and nickel, then spin-coating the precursor solution on a glass substrate, and finally synthesizing the NiCo2O4 nano film with [400] single orientation through a heat treatment method. The preparation process is simple, a binder does not need to be added, and repeatability is high. Meanwhile, the single-orientation thin film prepared by the ordered orientation processing method is beneficial for the heat-conducting elastomer to have excellent flexibility, can be bent randomly and has excellent comprehensive heat dissipation efficiency, so that the single-orientation thin film has a relatively great application prospect in the aspects of ballistic launching in a barrel weapon, ablation resistance of the surface of a projectile and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite nanomaterials, and specifically relates to a method for preparing a

[400] single-oriented NiCo2O4 nanofilm, which is specifically applicable to the field of ballistic launch of barreled weapons and anti-ablation of projectile surfaces. Background Art

[0002] In order to adapt to the modern warfare environment, it is necessary to significantly improve the performance indicators of artillery such as initial velocity and firing rate. As a result, the ablation and wear of the barrel has become increasingly serious, and the difference in internal ballistic performance corresponding to different life spans of the barrel has gradually increased. The presence of a large number of multi-oriented crystal planes in traditional metal materials and polycrystalline ceramics will lead to phonon scattering between different structural interfaces. The phonon scattering at the interface between the two phases will increase the interfacial thermal resistance, so it is often necessary to compound a large amount of high thermal conductivity materials to improve its thermal conductivity. In addition, the dispersion state of thermal conductive composite fillers in the matrix will affect the construction of the thermal conductive network. Disordered dispersion requires a high number of fillers to achieve ideal performance. At the same time, the density difference between the filler and the matrix caused by the excessive particle size or thickness will also hinder the construction of the thermal conductive network, which will inevitably affect the mechanical properties of the composite material while improving the thermal conductivity. Therefore, ordered orientation arrangement is conducive to the improvement of thermal conductivity in the orientation direction, while having good flexibility and mechanical strength.

[0003] Cobalt-based bimetallic oxide is a perovskite material with a spinel structure. Its structural formula is ACo2O4, where A is a divalent metal ion and O 2– Cubic close packing, Co 3+ The ions fill the octahedron center, A 2+ The ions are filled in the center of the tetrahedron, namely Co 3+ The ion is 6-coordinated, and A 2+ The ion is 4-coordinated. In the fields of ballistic launch of barreled weapons and anti-ablation of projectile surface, the modification of this type of material and the study of the influence of its microstructure on chemical properties and reaction mechanism have a great impact on promoting the practical application of cobalt-based bimetallic oxide materials.

[0004] Nickel cobalt oxide (NiCo2O4) has a variety of valence state conversion modes. Due to its good thermal conductivity, high stability of Co3O4 and high specific capacitance of NiO, it has become a research hotspot in the field of heat transfer. At the same time, due to its effective absorption bandwidth, it is also often used in the field of wave absorption. At present, NiCo2O4 with different structures such as nanowires, rods, sheets, microspheres, and meshes can be obtained by sol-gel method, liquid phase precipitation method, template method, hydrothermal method and electrospinning method, but there are differences in the atomic arrangement of different crystal faces of the same material.

[0005] In view of this, there is an urgent need for a NiCo2O4 nanofilm that can help improve the thermal conductivity in the orientation direction and has good flexibility for use in the field of ballistic launch of barreled weapons and anti-ablation of projectile surfaces. Summary of the invention

[0006] The present invention greatly improves the ablation and wear of the barrel in the existing harsh environment of high temperature and high pressure. In order to fully tap the potential of the artillery system and ensure the consistency of the ballistic performance of the barrel during different life cycles, it aims to provide a method for preparing a

[400] single-oriented NiCo2O4 nanofilm to prepare a single-oriented structure in which

[400] single-oriented crystals are tightly stacked together, which can ensure a high level of thermal conductivity of the film portion in contact with the heat source, so that the heat can be quickly transferred to the surface of the heat source along the horizontal heat conduction network to avoid local overheating.

[0007] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0008] A method for preparing a

[400] single-oriented NiCo2O4 nanofilm comprises the following steps:

[0009] Step 1, adding cobalt salt and nickel salt into an organic solvent, stirring at room temperature, adding ethanolamine, heating and stirring, and reacting to obtain a precursor solution containing cobalt and nickel after complete dissolution;

[0010] Step 2, spin-coating the precursor solution obtained in step 1 on a glass substrate, and placing it in an inert atmosphere for annealing, and after cooling to room temperature, obtaining a

[400] single-oriented NiCo2O4 nanofilm.

[0011] The invention uses glass as a substrate, first dissolves part of cobalt salt and nickel salt by organic solvent, then adds ethanolamine, heats and stirs to completely dissolve the cobalt salt and nickel salt to obtain a deep purple cobalt-nickel precursor solution. Then the cobalt-nickel precursor solution is spin-coated on the glass, and then the spin-coated glass is placed in an inert atmosphere for annealing treatment, and finally a

[400] single-oriented NiCo2O4 nanofilm is obtained.

[0012] Furthermore, in step 1, the cobalt salt includes cobalt acetate; the nickel salt includes nickel acetate; and the organic solvent includes ethylene glycol methyl ether.

[0013] Furthermore, in step 1, the molar ratio of the cobalt salt to the nickel salt is 1:1.

[0014] Furthermore, in step 1, the concentrations of the cobalt salt and the nickel salt are 0.125 mmol respectively.

[0015] Furthermore, in step 1, the stirring time at room temperature is 10-30 min, and the stirring rate is 300-500 rpm.

[0016] Furthermore, in step 1, the molar ratio of the cobalt salt to ethanolamine is 1:2.

[0017] Furthermore, in step 1, the heating and stirring temperature is 60-110° C., and the stirring time is 60-180 min.

[0018] Furthermore, in step 1, the precursor solution is a cobalt-nickel mixed solution.

[0019] Furthermore, in step 2, the glass is cleaned with deionized water, isopropyl ketone, and anhydrous ethanol in sequence and dried before use, and the area of ​​the clean glass is 1.5×2.0 cm.

[0020] Furthermore, in step 2, the spin coating volume is 220 μL / time, the spin coating rate is 800-1500 rpm for 3-7 s, 2000-4000 rpm for 15-30 s, and the spin coating is repeated 3-6 times.

[0021] Furthermore, in step 2, the inert atmosphere is an argon atmosphere, the temperature is 300-600° C., and the time is 1-4 h.

[0022] The present invention also provides a

[400] single-oriented NiCo2O4 nanofilm prepared by the preparation method as described above.

[0023] Compared with the prior art, the present invention has the following beneficial technical effects:

[0024] The present invention adopts a solution method to prepare a precursor solution containing cobalt and nickel, and spin-coats the solution on glass and obtains a

[400] single-oriented NiCo2O4 nanofilm after heat treatment. The method has the characteristics of simple preparation process, low cost, high preparation efficiency, no need to add a binder, and high repeatability, which provides strong support for studying the single-oriented atomic arrangement structure of NiCo2O4 materials and its influence on performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flow chart of a method for preparing a

[400] single-oriented NiCo2O4 nanofilm provided in an embodiment of the present invention.

[0026] Figure 2 This is the XRD image of the

[400] single-oriented NiCo2O4 nanofilm provided in Example 1 of the present invention.

[0027] FIG. 3 is an XRD image of the

[400] single-oriented NiCo2O4 nanofilm provided in Examples 2 and 3 of the present invention.

[0028] Figure 4This is the XRD image of the

[400] single-oriented NiCo2O4 nanofilm provided in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings of specific embodiments.

[0030] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with embodiments. The specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Modifications or equivalent substitutions based on the technical scheme of the present invention, without departing from the spirit and scope of the technical scheme of the present invention, should all be included in the protection scope of the present invention.

[0031] Example 1

[0032] This embodiment adopts an improved solution method to prepare

[400] single-oriented NiCo2O4 nanofilm.

[0033] Step 1: Add 0.311 g Co(CH3COO)2·4H2O and 0.311 g Ni(CH3COO)2·4H2O to 10 ml ethylene glycol methyl ether, stir at room temperature for 15 min, then slowly add 0.15 mL ethanolamine. Continue to heat the solution to 80°C in a water bath and stir the solution magnetically for 2 h until it becomes a dark purple transparent solution.

[0034] Step 2: A clean glass substrate is used as the substrate after being washed with deionized water, isopropyl ketone, and anhydrous ethanol and dried in sequence. The clean glass substrate has an area of ​​1.5×2.0 cm.

[0035] Step 3: Use a pipette to take 220 μL of the precursor solution obtained in step 1, and spin-coat it on a glass substrate at a speed of 800 rpm for 5 s and 2000 rpm for 20 s. Then, pretreat the spin-coated glass in air at 230°C for 10 min, repeat the spin coating four times, and finally anneal at 500°C for 2 h in an argon atmosphere. After naturally cooling to room temperature, a

[400] single-oriented NiCo2O4 nanofilm can be obtained.

[0036] In this embodiment, the prepared product was subjected to XRD test, and the results are as follows:

[0037] like Figure 2 As shown, Figure 2 After comparison with the standard card of NiCo2O4, it was found that the single orientation prepared in this embodiment matched the

[400] single orientation NiCo2O4, which means that this embodiment finally obtained a

[400] single orientation NiCo2O4 nanofilm with good crystallinity and no other impurity phases.

[0038] Example 2

[0039] This embodiment adopts an improved solution method to prepare a

[400] single-oriented NiCo2O4 nanofilm. The difference between this method and Example 1 is that the precursor solution is spin-coated on the glass substrate at a speed of 1500 rpm for 5 s and 4000 rpm for 20 s.

[0040] In this embodiment, the prepared product was subjected to XRD test, and the results are as follows:

[0041] As shown in Figure 3(a), Figure 2 After comparison, it was found that the

[400] single-oriented NiCo2O4 prepared in this embodiment had good crystallinity and no other impurity phases appeared, which shows that the spin coating rate has little effect on the formation of the material.

[0042] Example 3

[0043] This embodiment adopts an improved solution method to prepare

[400] single-oriented NiCo2O4 nanofilm. The difference between this method and Example 1 is that the spin-coated glass is first placed in air for pretreatment at 300°C for 10 minutes, and then the spin coating is repeated four times, and finally annealed at 500°C for 2 hours in an argon atmosphere.

[0044] In this embodiment, the prepared product was subjected to XRD test, and the results are as follows:

[0045] As shown in Figure 3(b), Figure 3 and Figure 2 After comparison, it is found that the

[400] single-oriented NiCo2O4 prepared in this embodiment has good crystallinity and no other impurity phases appear, which indicates that

[400] single-oriented NiCo2O4 nanofilm can also be produced by pretreatment at 300°C.

[0046] Comparative Example 1

[0047] This comparative example adopts an improved solution method to prepare a

[400] single-oriented NiCo2O4 nanofilm. The difference between this method and Example 1 is that 0.311g Co(CH3COO)2·4H2O, 0.311g Ni(CH3COO)2·4H2O and 0.4g PVP powder are added to 10ml ethylene glycol methyl ether, stirred at room temperature for 15min, and then 0.15mL ethanolamine is slowly added. The solution is continued to be heated to 80°C in a water bath and magnetically stirred for 2h until it becomes a dark purple transparent solution.

[0048] In this comparative example, the prepared product was subjected to XRD test, and the results are as follows:

[0049] like Figure 4 As shown, Figure 4 and Figure 2 After comparing with the standard card of NiCo2O4, it is found that the single orientation prepared in this embodiment matches the

[400] single orientation NiCo2O4, which means that this embodiment finally obtains a

[400] single orientation NiCo2O4 nanofilm with good crystallinity and no other impurity phases. This shows that the film-forming agent PVP powder has little effect on the formation of the substance.

[0050] It can be found from the above embodiments and comparative examples that the NiCo2O4 nanofilms prepared by the method of the present invention all have a

[400] single-oriented structure, and no film-forming agent PVP powder needs to be added during the preparation process of the present invention. The preparation process is simple, the film-forming effect is good, and the raw materials are easy to obtain.

[0051] From the above examples and comparative examples, it can be found that the method of the present invention can be used to prepare a NiCo2O4 nanofilm with a single orientation of

[400] , which has good crystallinity, and provides strong support for studying the single orientation atomic arrangement structure and physical and chemical properties of the material. In addition, the single orientation film prepared by the ordered orientation processing method helps the thermal conductive elastomer to have excellent flexibility, can be bent at will, and has excellent comprehensive heat dissipation efficiency, so that it has great application prospects in the ballistic launch of barreled weapons and the anti-ablation of projectile surfaces.

[0052] It should be noted that the above-described embodiments are only preferred embodiments of the present invention. For those skilled in the art, without departing from the principles of the present invention, the present invention may be modified, improved and replaced with equivalents, and these modifications, improvements and equivalent replacements are also considered to fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a [400] single-oriented NiCo2O4 nanofilm, characterized in that: The steps include: Step 1: Add cobalt salt and nickel salt to an organic solvent, stir at room temperature, add ethanolamine, heat and stir, and react to obtain a precursor solution containing cobalt and nickel after complete dissolution; Step 2: Spin-coat the precursor solution obtained in step 1 onto a glass substrate and place it under an inert atmosphere for annealing. After cooling to room temperature, a [400] single-oriented NiCo2O4 nanofilm is obtained.

2. The method for preparing a [400] single-oriented NiCo2O4 nanofilm according to claim 1, characterized in that: In step 1, the cobalt salt includes cobalt acetate; the nickel salt includes nickel acetate; and the organic solvent includes ethylene glycol methyl ether.

3. The method for preparing a [400] single-oriented NiCo2O4 nanofilm according to claim 1, characterized in that: In step 1, the molar ratio of the cobalt salt to the nickel salt is 1:

1.

4. The method for preparing a [400] single-oriented NiCo2O4 nanofilm according to claim 1, characterized in that: In step 1, the concentrations of the cobalt salt and the nickel salt are 0.125 mmol respectively.

5. The method for preparing a [400] single-oriented NiCo2O4 nanofilm according to claim 1, characterized in that: In step 1, the stirring time at room temperature is 10-30 min, and the stirring rate is 300-500 rpm.

6. The method for preparing a [400] single-oriented NiCo2O4 nanofilm according to claim 1, characterized in that: In step 1, the molar ratio of the cobalt salt to ethanolamine is 1:

2.

7. The method for preparing a [400] single-oriented NiCo2O4 nanofilm according to claim 1, characterized in that: In step 1, the heating and stirring is performed at a temperature of 60-110° C. and for a time of 60-180 min.

8. The method for preparing a [400] single-oriented NiCo2O4 nanofilm according to claim 1, characterized in that: In step 1, the precursor solution is a cobalt-nickel mixed solution.

9. The method for preparing a [400] single-oriented NiCo2O4 nanofilm according to claim 1, characterized in that: In step 2, the inert atmosphere is an argon atmosphere, the temperature is 300-600° C., and the time is 1-4 h.

10. A [400] single-oriented NiCo2O4 nanofilm prepared by the preparation method according to any one of claims 1-9.

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