Method for preparing hexagonal boron nitride film on stainless steel surface and reducing scale generation

Abstract

The invention discloses a method for preparing a hexagonal boron nitride film on a stainless steel surface and reducing incrustation generation, and belongs to the technical field of hexagonal boron nitride preparation and incrustation prevention. The method adopts plasma enhanced chemical vapor deposition equipment to prepare hexagonal boron nitride, and comprises the following specific steps: respectively and sequentially placing a stainless steel substrate and a precursor in a tubular furnace and a central area of a heating belt, and pre-vacuumizing to below 1Pa; nitrogen and hydrogen are introduced, and then the tubular furnace is heated to the target temperature 1; turning on a plasma generator, adjusting power, and pretreating the surface of the stainless steel substrate; raising the temperature of the heating belt to a target temperature 2, and starting to grow hexagonal boron nitride; closing the plasma generator, and cooling to obtain the hexagonal boron nitride film on the stainless steel surface. The hexagonal boron nitride film has the effect of reducing scale generation. The method for preparing the hexagonal boron nitride thin film is simple in process, good in repeatability, high in controllability, low in descaling cost, good in stability, clean and free of pollution.

Description

Technical Field

[0001] The present invention belongs to the technical field of hexagonal boron nitride preparation and scale prevention, and particularly relates to a method for preparing a hexagonal boron nitride thin film on the surface of stainless steel and reducing the formation of scale. Background Art

[0002] Scale is formed due to the precipitation of salts such as calcium and magnesium contained in water and adhesion to the surface of materials. The presence of scale greatly affects the material interface transfer process, resulting in a serious decline in the performance of materials. Stainless steel is a widely used metal alloy material, often used in transportation pipelines, heat exchangers, building materials, kitchen and bathroom appliances, etc. Due to the fact that most stainless steel components are in aqueous environments such as high temperature, acid-base, and humid heat for a long time, the scaling problem is very serious, leading to a significant attenuation of its performance, service life, etc. Therefore, developing anti-scaling materials and reducing the formation of scale on the surface of stainless steel is of great significance.

[0003] Hexagonal boron nitride is composed of nitrogen atoms and boron atoms in accordance with the sp 2 hybridization method. Its unique structure endows it with excellent properties such as good mechanical strength, electrical insulation, thermal conductivity, and chemical stability. More importantly, hexagonal boron nitride also has an atomically smooth surface without dangling bonds and trap charges, and extremely strong hydrophobicity, having broad application prospects in the fields of anti-corrosion and anti-scaling. Therefore, realizing the direct growth of a hexagonal boron nitride thin film on the surface of stainless steel is expected to solve the serious scaling problem. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing a hexagonal boron nitride thin film on the surface of stainless steel with simple process, good repeatability, and strong controllability, and at the same time provide a method for reducing the formation of scale on the surface of stainless steel with low cost, good stability, and clean and pollution-free.

[0005] According to one aspect of the present invention, a method for preparing a hexagonal boron nitride thin film on the surface of stainless steel is provided.

[0006] A plasma-enhanced chemical vapor deposition device is used, which sequentially includes a precursor heating zone, a single-temperature zone tubular furnace, a plasma generator, and a vacuum pump along the direction of gas inflow.

[0007] The specific preparation steps are as follows:

[0008] S1: Place the stainless steel substrate in the central area of the single-temperature zone tubular furnace, and place the precursor of hexagonal boron nitride in the central area of the heating zone, and pre-pump the vacuum to below 1 Pa;

[0009] S2: Introduce nitrogen and hydrogen, and then heat the tubular furnace to the target temperature 1;

[0010] S3: Turn on the plasma generator and adjust the power to pre-treat the surface of the stainless-steel substrate.

[0011] S4: Heat the heating tape to the target temperature 2 and start growing hexagonal boron nitride.

[0012] S5: Turn off the plasma generator, cool down, and obtain a hexagonal boron nitride thin film on the stainless-steel surface.

[0013] Preferably, the distance between the center of the single-zone tube furnace and the center of the heating tape is 45 - 60 cm; the distance between the center of the single-zone tube furnace and the center of the plasma generator is 35 - 50 cm.

[0014] Preferably, the precursor is an ammonia borane complex with a purity greater than 90%, and the mass is 10 - 300 mg.

[0015] Preferably, the nitrogen flow rate is 5 - 100 sccm, the hydrogen flow rate is 5 - 100 sccm, the target temperature 1 is 400 - 1000 °C, the power of the plasma generator is 30 - 150 W, the pre-treatment time of the plasma generator on the surface of the stainless-steel substrate is 5 - 15 min, the target temperature 2 is 65 - 90 °C, and the growth time is 5 - 30 min.

[0016] The directly grown hexagonal boron nitride thin film of the present invention is used to reduce the formation of water scale.

[0017] According to another aspect of the present invention, there is also provided a method for reducing the formation of water scale on the stainless-steel surface, that is, preparing a layer of hexagonal boron nitride thin film on the stainless-steel surface according to the method described in any one of the above.

[0018] The advantages of this method are:

[0019] 1. The preparation process of this method is simple, has good repeatability and strong controllability. The prepared hexagonal boron nitride thin film has good uniformity, few defects and high quality.

[0020] 2. This method uses the direct growth of hexagonal boron nitride thin film to achieve the effect of reducing the formation of water scale, with low cost, good stability, clean and pollution-free. At the same time, the water scale generated on the surface can be removed more easily. Description of the Drawings

[0021] Figure 1 It is a flow chart for preparing a hexagonal boron nitride thin film on the stainless-steel surface according to an embodiment of the present invention;

[0022] Figure 2 It is a Raman spectrum diagram of the hexagonal boron nitride thin film prepared on the stainless-steel surface according to Embodiment 1 of the present invention;

[0023] Figure 3 It is an anti-scaling effect diagram according to the embodiments and comparative examples of the present invention. Detailed implementation manners

[0024] To make the objectives, technical solutions and advantages of the present disclosure clearer and more understandable, the following further describes the present disclosure in detail with reference to specific embodiments and the accompanying drawings. However, the implementation manners of the present invention are not limited thereto.

[0025] Embodiment 1

[0026] A method for preparing hexagonal boron nitride film on the surface of stainless steel and reducing the formation of water scale, which uses a plasma-enhanced chemical vapor deposition device to prepare hexagonal boron nitride. The device includes a precursor heating zone, a single-temperature zone tubular furnace, a plasma generator, and a vacuum pump in the direction of gas inflow.

[0027] The preparation process is as follows:

[0028] S1: Adjust the distances between the center of the single-temperature zone tubular furnace and the centers of the heating zone and the plasma generator to 45 cm and 35 cm respectively. Then, place a stainless steel substrate with a size of 5 cm × 5 cm at the center of the tubular furnace in sequence, place 50 mg of ammonia borane complex with a purity of 95% at the center of the heating zone, close the system and turn on the vacuum pump to pre-pump the vacuum to below 1 Pa;

[0029] S2: Introduce 30 sccm of nitrogen and 10 sccm of hydrogen into the system. After the pressure stabilizes, heat the tubular furnace to 600 °C;

[0030] S3: Turn on the plasma generator and adjust the power to 60 W, and pre-treat the stainless steel surface for 10 min;

[0031] S4: Raise the temperature of the heating zone to 75 °C, and the precursor ammonia borane decomposes by heating, and the growth of hexagonal boron nitride begins, and the growth time is 15 min.

[0032] S5: Turn off the plasma generator, the heating zone, and the tubular furnace in sequence, and cool down to room temperature, thereby preparing a hexagonal boron nitride film on the surface of the stainless steel.

[0033] S6: Place the pure stainless steel and the hexagonal boron nitride / stainless steel samples in a saturated calcium sulfate solution at the same time. After standing for 3 h, take them out and observe the water scale precipitation on the surface.

[0034] Comparative Example 1

[0035] Prepare a hexagonal boron nitride film on the surface of stainless steel according to the steps of Embodiment 1. Compared with Embodiment 1, the difference is that: introduce 30 sccm of argon and 10 sccm of hydrogen, after the pressure stabilizes, heat the tubular furnace to 600 °C, and then set the power of the plasma generator to 60 W, and pre-treat the surface of the stainless steel substrate for 10 min, and other steps remain unchanged.

[0036] Comparative Example 2

[0037] Prepare a hexagonal boron nitride film on the stainless - steel surface according to the steps of Example 1. Different from Example 1, the steps are as follows: Introduce 30 sccm of nitrogen and 10 sccm of hydrogen. After the pressure is stable, heat the tube furnace to 600 °C, then set the power of the plasma generator to 60 W, and do not pre - treat the surface of the stainless - steel substrate. Keep other steps unchanged.

[0038] Comparative Example 3

[0039] Prepare a hexagonal boron nitride film on the stainless - steel surface according to the steps of Example 1. Different from Example 1, the steps are as follows: Heat the heating belt to 75 °C, the precursor ammonia borane decomposes by heating, and the growth of hexagonal boron nitride starts. The growth time is 60 min. Keep other steps unchanged.

[0040] The method for preparing a hexagonal boron nitride film on the stainless - steel surface provided by one aspect and embodiments of the present invention, such as Figure 2 is the Raman spectrum of the hexagonal boron nitride film prepared on the stainless - steel surface according to Example 1 of the present invention. The characteristic peak of hexagonal boron nitride can be observed at 1369 cm -1 to confirm the existence of hexagonal boron nitride. The Raman spectrum of the pure stainless - steel substrate is given as a comparison. Figure 1 And presented.

[0041] The method for reducing the formation of scale on the stainless - steel surface provided by one aspect and embodiments of the present invention, such as Figure 3 is the scale - prevention effect diagram of Example 1 of the present invention and Comparative Examples 1 - 3. Among them, Figure 3 (a) is pure stainless - steel, Figure 3 (b) is the hexagonal boron nitride / stainless - steel sample prepared according to Example 1 of the present invention, Figure 3 (c) - (e) are the photos of the hexagonal boron nitride / stainless - steel samples prepared according to Comparative Examples 1 - 3 after being placed in a calcium sulfate saturated solution for 3 h. It can be clearly observed from the figure that the scale formed on the hexagonal boron nitride / stainless - steel sample prepared according to Example 1 is much less than that on pure stainless - steel, showing the excellent scale - resistance performance of hexagonal boron nitride. The hexagonal boron nitride prepared under the conditions that nitrogen used for growth is changed to argon in Comparative Example 1, the surface of stainless - steel is not pre - treated in Comparative Example 2, and the growth time is too long in Comparative Example 3 can reduce the formation of scale, but their scale - prevention effects are all worse than that of Example 1.

[0042] So far, the method for preparing a hexagonal boron nitride film on the stainless - steel surface and reducing the formation of scale has been introduced.

[0043] The specific embodiments described above further elaborate on the object, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only for the specific embodiments of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a hexagonal boron nitride film on a stainless steel surface, characterized in that: A plasma enhanced chemical vapor deposition device is used, wherein a precursor heating belt, a single temperature zone tubular furnace, a plasma generator, and a vacuum pump are sequentially arranged along the direction of gas inflow; The method comprises the following steps: S1: Place the stainless steel substrate in the center of the single-temperature zone tube furnace, place the hexagonal boron nitride precursor in the center of the heating zone, and pre-evacuate to below 1 Pa; S2: introducing nitrogen and hydrogen, and then heating the tube furnace to the target temperature 1; S3: Turn on the plasma generator and adjust the power to pre-treat the surface of the stainless steel substrate; S4: raising the temperature of the heating belt to the target temperature 2 and starting to grow hexagonal boron nitride; S5: Turn off the plasma generator, cool down, and obtain a hexagonal boron nitride film on the stainless steel surface.

2. The method for preparing a hexagonal boron nitride film on a stainless steel surface according to claim 1, characterized in that: The distance between the center of the single-temperature zone tubular furnace and the center of the heating belt is 45 to 60 cm; the distance between the center of the single-temperature zone tubular furnace and the center of the plasma generator is 35 to 50 cm.

3. The method for preparing a hexagonal boron nitride film on a stainless steel surface according to claim 1, characterized in that: The precursor is an ammonia borane complex with a purity greater than 90%.

4. The method for preparing a hexagonal boron nitride film on a stainless steel surface according to claim 1, characterized in that: The nitrogen flow rate is 5-100 sccm, the hydrogen flow rate is 5-100 sccm, the target temperature 1 is 400-1000°C, the plasma generator power is 30-150W, the plasma generator pre-treats the surface of the stainless steel substrate for 5-15 minutes, the target temperature 2 is 65-90°C, and the growth time is 5-30 minutes.

5. Obtaining a hexagonal boron nitride film on a stainless steel surface according to the method described in any one of claims 1 to 4.

6. A method for reducing scale formation on the surface of stainless steel, characterized in that: A hexagonal boron nitride film is prepared on the surface of stainless steel according to the method described in any one of claims 1 to 4 to reduce scale formation.

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