W-type ferrite and cluster MoS2 wave-absorbing anticorrosive material and preparation method thereof

Abstract

The invention provides a W-type ferrite and cluster MoS2 wave-absorbing anti-corrosion material and a preparation method thereof, and belongs to the field of wave-absorbing anti-corrosion materials.The method comprises the steps that metal nitrate and water are mixed, citric acid monohydrate and ammonia water are added to adjust the pH value, oil bath is conducted to a gel state, heat treatment is conducted after drying, and W-type ferrite powder is obtained; the preparation method comprises the following steps: mixing W-type ferrite powder, hexadecyl trimethyl ammonium bromide and water, and stirring; adding ammonium molybdate tetrahydrate and thioacetamide, stirring, and pouring into a hydrothermal kettle for hydrothermal reaction; after the reaction is completed, centrifuging, washing and drying to obtain W-type ferrite coated with cluster MoS2; and mixing and co-curing the W-type ferrite coated with the cluster MoS2, epoxy resin and a curing agent to obtain the W-type ferrite and cluster MoS2 wave-absorbing anticorrosive material. The wave-absorbing performance of pure resin is improved, and meanwhile the anti-corrosion performance in the severe environment is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of materials and relates to a wave-absorbing material, and in particular to a W-type ferrite@cluster MoS2 wave-absorbing and anti-corrosion material and a preparation method thereof. Background Art

[0002] After a long period of development, absorbing materials have been widely used in military and civilian fields. However, with the continuous exploration of human beings in military fields such as aviation, aerospace, ocean, and nuclear energy, materials with only absorbing functions can no longer meet the needs. New equipment has put forward higher requirements for absorbing materials in complex and harsh working environments. These materials must not only have the characteristics of "thin, wide, light, and strong", but also maintain stealth performance in harsh environments such as high temperature, heat conduction, high oxygen, and salt spray. The development of materials that can operate stably under these conditions has become the key to promoting the development of high-end equipment. The premature shedding of anti-corrosion coatings will accelerate the loss and elimination of equipment and increase maintenance costs. Therefore, the research on absorbing materials for harsh corrosive environments is a promising field. It not only has a wide range of application potential and significant economic value, but also its progress will have an important impact on military equipment, marine engineering, energy development, etc., and promote the progress of materials science.

[0003] Ferrite absorbers, as one of the most technologically mature absorbers, have always been the focus of research due to their excellent absorbency and simple preparation process, despite the disadvantage of high density. Due to its higher resistivity, the skin effect depth of ferrite in the microwave frequency band significantly exceeds that of metal conductors, which is conducive to the attenuation of electromagnetic waves inside it. In addition, as a magnetic loss absorber, its lower dielectric constant helps to achieve better impedance matching. Traditional absorbers often have only a single loss mechanism, such as dielectric loss or magnetic loss, which limits their performance in impedance matching and thus affects the wide application of materials. In order to overcome these limitations, researchers are exploring the combination of materials with electrical loss and magnetic loss characteristics through micro-nanoscale composite technology to achieve a significant improvement in microwave absorption performance. This composite absorber that combines multiple loss mechanisms has become one of the key directions of current research.

[0004] At present, the main strategy for achieving high-performance composite absorbing materials is to carefully design the microstructure and precisely control the proportion of each component. Although magnetic loss-type absorbing materials have some shortcomings, such as large density, easy aggregation between particles, and narrow effective absorption bandwidth, the introduction of electrical loss-type materials can effectively make up for these defects. In this complementary way, absorbing materials that are both lightweight and efficient can be developed to meet a wider range of application needs. Therefore, the present invention proposes a W-type ferrite @ cluster MoS2 absorbing and anti-corrosion material and a preparation method thereof, which combines magnetic loss-type materials and electrical loss-type materials to achieve better absorbing and anti-corrosion performance. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a W-type ferrite@cluster MoS2 wave absorbing and anti-corrosion material and a preparation method thereof.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a method for preparing a W-type ferrite@cluster MoS2 wave absorbing and anti-corrosion material, comprising the following steps:

[0008] Step 1: Mix metal nitrate with water, add citric acid monohydrate, adjust pH with ammonia water, oil bath to gel state, dry and heat treat to obtain W-type ferrite powder;

[0009] Step 2: Mix W-type ferrite powder, hexadecyltrimethylammonium bromide and water, and stir; add ammonium molybdate tetrahydrate and thioacetamide, stir and pour into a hydrothermal kettle for hydrothermal reaction; after the reaction is completed, centrifuge, wash and dry to obtain W-type ferrite coated with cluster MoS2;

[0010] Step 3: Mix the W-type ferrite coated with cluster MoS2 with epoxy resin and curing agent and co-curing to obtain W-type ferrite@cluster MoS2 microwave absorbing and anti-corrosion material.

[0011] Furthermore, in step 1, the metal nitrate includes barium nitrate, cobalt nitrate hexahydrate, neodymium nitrate hexahydrate and iron nitrate nonahydrate, and the mass ratio is (0.8-1):2:(0-0.2):16.

[0012] Furthermore, in step 1, the molar ratio of metal ions to citric acid monohydrate is 1:(1.2-1.5).

[0013] Furthermore, in step 1, the pH is adjusted to be neutral; and the oil bath temperature is (80-100)°C.

[0014] Furthermore, in step 1, the drying process is: keeping warm at 110-130° C. for 5-8 hours, then heating to 200-210° C. at a rate of 5° C. / min and keeping warm for 5-8 hours.

[0015] Furthermore, in step 1, the heat treatment process is: keeping at 400-500° C. for 2-5 hours, then heating to 1200-1400° C. at a rate of 5° C. / min and keeping at that temperature for 2-5 hours.

[0016] Furthermore, in step 2, the mixing ratio of W-type ferrite powder, hexadecyltrimethylammonium bromide, ammonium molybdate tetrahydrate, thioacetamide and water is 0.2g:0.05g:(0.4-0.5)g:(0.4-0.5)g:60ml.

[0017] Furthermore, in step 2, the hydrothermal temperature is 180-200° C., the hydrothermal time is 8-10 h, and the heating rate is 5° C. / min.

[0018] Furthermore, in the step 3, the mixing ratio of the W-type ferrite coated with cluster MoS2, epoxy resin and curing agent is 1.35g:1g:2g.

[0019] (II) The present invention also provides a W-type ferrite@cluster MoS2 absorbing and anti-corrosion material, which is prepared by the preparation method described above.

[0020] The beneficial effects of the present invention are:

[0021] (1) In the present invention, Nd in ferrite 3+ Ion substitution Ba 2+ Fe 3+ The ions are converted to Fe 2+ ions to balance the valence, which leads to interfacial polarization as Fe 2+ The dielectric constant increases with the increase of Nd ions. 3+ Can provide 3.2μB (spin magnetic moment), higher than Ba 2+ (0μB). Therefore, when Nd 3+ When doped, the magnetization intensity (Ms) increases, thereby optimizing electromagnetic parameters and improving the absorption performance;

[0022] (2) In the present invention, the 2D graphene-like layered structure of MoS2 makes the 2H-MoS2 nanosheets have a large specific surface area, which contains a large number of surface defects. The introduction of W-type flake ferrite not only increases the specific surface area and realizes more interface polarization loss, but also under the action of an external electric field, the valence electrons in 2H-MoS2 are excited to the conduction band as free electrons. The movement of free electrons inside the material will produce conduction loss. The composite of dielectric materials changes the W ferrite from a single loss mechanism to a multiple absorption loss mechanism, thereby improving the absorption performance;

[0023] (3) In the present invention, the layered structure of molybdenum disulfide provides it with excellent anti-corrosion performance. At the microscopic level, the molecular structure of molybdenum disulfide is composed of two layers of sulfur atoms and one layer of molybdenum atoms, forming a plane with low shear force. This structure enables molybdenum disulfide to form a protective layer during the friction process, effectively isolating moisture and air, thereby slowing down the corrosion process; and molybdenum disulfide has extremely high chemical stability at room temperature. This stability enables molybdenum disulfide to maintain its performance in a variety of environments and is not prone to chemical changes, thereby playing a long-term protective role in anti-corrosion coatings. The physical properties of ferrite, such as its high magnetic permeability, high resistivity and excellent magnetic frequency response, not only play a role in electromagnetic wave control, but also provide a physical basis for its application in the field of corrosion protection. The high magnetic permeability of ferrite helps to form a uniform magnetic field distribution in the coating, thereby inhibiting the penetration of corrosive media to a certain extent. In addition, the high resistivity of ferrite reduces the migration of charge on the surface of the material and reduces the possibility of electrochemical corrosion. At the same time, thanks to its compact crystal structure and low chemical activity, ferrite also has good chemical stability;

[0024] (4) The W ferrite@cluster MoS2 absorbing and anti-corrosion coating prepared by the preparation method of the present invention can achieve an effective bandwidth of 6.02 GHz and a reflection loss of -45.53 GHz at a thickness of 2 mm, and the anti-corrosion performance is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 are SEM images of Example 1 (right) and Comparative Example 1 (left);

[0026] Figure 2 1 is the wave absorption performance (left) and reflection loss curve (right) of Example 1;

[0027] Figure 3 The absorption performance (left) and reflection loss curve (right) of comparative example 1 are shown;

[0028] Figure 4 The absorption performance (left) and reflection loss curve (right) of comparative example 2 are shown;

[0029] Figure 51 and 2 are Nyquist plots of Example 1 (left), Comparative Example 1 (middle), and Comparative Example 2 (right). DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention and the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] Example 1

[0032] The embodiment of the present invention provides a method for preparing a W-type ferrite@cluster MoS2 wave absorbing and anti-corrosion material, comprising:

[0033] (I) Preparation of W-type ferrite powder

[0034] Take metal nitrates, which include barium nitrate, cobalt nitrate hexahydrate, neodymium nitrate hexahydrate and iron nitrate nonahydrate, and the mass ratio of barium nitrate, cobalt nitrate hexahydrate, neodymium nitrate hexahydrate and iron nitrate nonahydrate is 0.8:2:0.2:16.

[0035] The above metal nitrates were mixed with water, and citric acid monohydrate was added, with a molar ratio of metal ions to citric acid monohydrate of 1:1.5. The solution pH was adjusted to 7 with ammonia water, and the mixture was oil bathed at 80°C until it reached a gel state. The mixture was then kept at 120°C for 6 hours, and then heated to 200°C at a rate of 5°C / min and kept for 6 hours to dry the precursor to cause self-propagating combustion. The mixture was finally placed in a muffle furnace and kept at 450°C for 3 hours, and then heated to 1300°C at a rate of 5°C / min and kept for 3 hours. After the heat treatment, W-type ferrite powder was obtained.

[0036] (II) Preparation of MoS2-coated W-type ferrite

[0037] Mix W-type ferrite powder, hexadecyl trimethyl ammonium bromide and water, stir for 1 hour, add ammonium molybdate tetrahydrate and thioacetamide, and stir. The mixing ratio of W-type ferrite powder, hexadecyl trimethyl ammonium bromide, ammonium molybdate tetrahydrate, thioacetamide and water is 0.2g: 0.05g: 0.47g: 0.4g: 60ml.

[0038] After stirring, pour it into a hydrothermal kettle for hydrothermal reaction. The hydrothermal temperature is 200°C and the hydrothermal time is 8 hours. After the reaction is completed, centrifuge, wash and dry to obtain W-type ferrite coated with cluster MoS2.

[0039] (III) Preparation of W-type ferrite@cluster MoS2 absorbing and anti-corrosion materials

[0040] The cluster MoS2-coated W-type ferrite was mixed with E51 resin and curing agent (T-31 curing agent) at a mass ratio of 1.35:1:2, and fully stirred and co-cured to obtain a W-type ferrite@cluster MoS2 microwave absorbing and anti-corrosion material.

[0041] Example 2

[0042] The embodiment of the present invention provides a method for preparing a W-type ferrite@cluster MoS2 wave absorbing and anti-corrosion material, comprising:

[0043] (I) Preparation of W-type ferrite powder

[0044] Take metal nitrates, which include barium nitrate, cobalt nitrate hexahydrate, neodymium nitrate hexahydrate and ferric nitrate nonahydrate, and the mass ratio of barium nitrate, cobalt nitrate hexahydrate, neodymium nitrate hexahydrate and ferric nitrate nonahydrate is 0.9:2:0.1:16.

[0045] The above metal nitrates were mixed with water, and citric acid monohydrate was added, with a molar ratio of metal ions to citric acid monohydrate of 1:1.4. The solution pH was adjusted to 7 with ammonia water, and the mixture was oil bathed at 90°C until it reached a gel state. The mixture was then kept at 110°C for 8 hours, and then heated to 210°C at a rate of 5°C / min and kept for 5 hours to dry the precursor to allow self-propagating combustion. The mixture was finally placed in a muffle furnace and kept at 400°C for 5 hours, and then heated to 1200°C at a rate of 5°C / min and kept for 5 hours. After the heat treatment, W-type ferrite powder was obtained.

[0046] (II) Preparation of MoS2-coated W-type ferrite

[0047] Mix W-type ferrite powder, hexadecyl trimethyl ammonium bromide and water, stir for 1 hour, add ammonium molybdate tetrahydrate and thioacetamide, and stir. The mixing ratio of W-type ferrite powder, hexadecyl trimethyl ammonium bromide, ammonium molybdate tetrahydrate, thioacetamide and water is 0.2g: 0.05g: 0.4g: 0.5g: 60ml.

[0048] After stirring, pour it into a hydrothermal kettle for hydrothermal reaction. The hydrothermal temperature is 180°C and the hydrothermal time is 10 hours. After the reaction is completed, centrifuge, wash and dry to obtain W-type ferrite coated with cluster MoS2.

[0049] (III) Preparation of W-type ferrite@cluster MoS2 absorbing and anti-corrosion materials

[0050] The cluster MoS2-coated W-type ferrite was mixed with E51 resin and curing agent (T-31 curing agent) at a mass ratio of 1.35:1:2, and fully stirred and co-cured to obtain a W-type ferrite@cluster MoS2 microwave absorbing and anti-corrosion material.

[0051] Example 3

[0052] The embodiment of the present invention provides a method for preparing a W-type ferrite@cluster MoS2 wave absorbing and anti-corrosion material, comprising:

[0053] (I) Preparation of W-type ferrite powder

[0054] Take metal nitrates, which include barium nitrate, cobalt nitrate hexahydrate, neodymium nitrate hexahydrate and ferric nitrate nonahydrate, and the mass ratio of barium nitrate, cobalt nitrate hexahydrate, neodymium nitrate hexahydrate and ferric nitrate nonahydrate is 1:2:0:16.

[0055] The above metal nitrates were mixed with water, and citric acid monohydrate was added. The molar ratio of metal ions to citric acid monohydrate was 1:1.3. The solution pH was adjusted to 7 with ammonia water, and the mixture was oil bathed at 100°C until it was in a gel state. The mixture was then kept at 130°C for 5 hours, and then heated to 200°C at a rate of 5°C / min and kept for 6 hours to dry the precursor to cause self-propagating combustion. The mixture was finally placed in a muffle furnace and kept at 500°C for 2 hours, and then heated to 1400°C at a rate of 5°C / min and kept for 2 hours. After the heat treatment, W-type ferrite powder was obtained.

[0056] (II) Preparation of MoS2-coated W-type ferrite

[0057] Mix W-type ferrite powder, hexadecyl trimethyl ammonium bromide and water, stir for 1 hour, add ammonium molybdate tetrahydrate and thioacetamide, and stir. The mixing ratio of W-type ferrite powder, hexadecyl trimethyl ammonium bromide, ammonium molybdate tetrahydrate, thioacetamide and water is 0.2g: 0.05g: 0.5g: 0.48g: 60ml.

[0058] After stirring, pour it into a hydrothermal kettle for hydrothermal reaction. The hydrothermal temperature is 190°C and the hydrothermal time is 9 hours. After the reaction is completed, centrifuge, wash and dry to obtain W-type ferrite coated with cluster MoS2.

[0059] (III) Preparation of W-type ferrite@cluster MoS2 absorbing and anti-corrosion materials

[0060] The cluster MoS2-coated W-type ferrite was mixed with E51 resin and curing agent (T-31 curing agent) at a mass ratio of 1.35:1:2, and fully stirred and co-cured to obtain a W-type ferrite@cluster MoS2 microwave absorbing and anti-corrosion material.

[0061] Comparative Example 1

[0062] S1. Pour metal nitrate into water in a ratio of Ba(NO3)2:Co(NO3)2·6H2O:Nd(NO3)2·6H2O:Fe(NO3)3·9H2O=0.8:2:0.2:16, add citric acid monohydrate (the ratio of metal ions to citric acid monohydrate is 1:1.5), adjust the pH to 7 with ammonia water, and place in an 80°C oil bath until gelled. Keep the temperature at 120°C for 6 hours, then increase the temperature to 200°C for 6 hours and dry to make the precursor self-propagating combustion. Put it in a muffle furnace and keep the temperature at 450°C for 3 hours, then increase the temperature to 1300°C for 3 hours and burn it in air to obtain W-type ferrite powder.

[0063] S2. Add 1.35 g of the W-type ferrite in S1 to 3 g of E51 resin and curing agent (resin: curing agent = 1:2) and stir thoroughly to obtain a W-type ferrite anti-corrosion and wave-absorbing coating material.

[0064] Comparative Example 2

[0065] 3g of E51 resin and curing agent (resin: curing agent = 1:2) were fully stirred to obtain pure epoxy resin.

[0066] The morphologies of Example 1 and Comparative Example 1 were characterized by SEM. Figure 1 As shown. Figure 1 It can be seen that the pure ferrite without MoS2 coating is flaky with a smooth surface; the surface of the ferrite coated with MoS2 has a large number of nanosheet clusters adsorbed on it, the surface area is greatly increased, and the surface is rough.

[0067] After curing, the resins of Example 1, Comparative Example 1 and Comparative Example 2 were punched into coaxial rings with an outer diameter of 7.00 mm and an inner diameter of 3.04 mm. Electromagnetic parameter tests were performed on the resins of Example 1 and Comparative Example, and the absorption performance and reflection loss were calculated by transmission line theory and the measured electromagnetic parameters. The results are shown in FIG. Figures 2 to 4 As shown, the W ferrite @ cluster MoS2 resin composite material prepared in Example 1 reaches a maximum reflection bandwidth of 6.03 GHz at 2 mm. At 1.8 mm, there is a maximum reflection loss of -58.9 dB at 16.48 GHz. The maximum reflection bandwidth of the pure W ferrite resin prepared in Comparative Example 1 is 4.05 GHz, and the thickness is 6.3 mm at this time. At 10.0 mm, the maximum reflection loss reaches -22.94 dB at 8.82 GHz. The pure epoxy resin prepared in Comparative Example 2 is a wave-transmitting material, and its wave-absorbing performance is negligible. Regardless of the maximum reflection loss or the maximum effective absorption bandwidth, the W ferrite @ cluster MoS2 structure is dominant. The essential reason is that the large specific surface area can enhance the dielectric loss capacity, including conductivity loss and polarization loss, as well as the conductivity of MoS2 itself, so that the composite material can achieve multiple loss mechanisms.

[0068] Example 1 and Comparative Examples 1 and 2 were spin-coated on a small round iron sheet and placed in a salt spray corrosion chamber. The EIS Nyquist curves on the 0th, 2nd, 4th, 6th, and 8th days were measured respectively. Figure 5 As shown. It can be found that as the corrosion days increase, the arc radius of the curve decreases. However, for Example 1, a larger arc radius is still maintained after 8 days, and the radius impedance change value is smaller than that of Comparative Examples 1 and 2, indicating its good corrosion resistance.

[0069] In summary, the present invention provides a method for preparing an anti-corrosion and wave-absorbing coating by self-assembling molybdenum disulfide into clusters in W-type ferrite. By comparing the wave-absorbing and anti-corrosion properties with those of ferrite resin composite materials and pure resin, its excellent anti-corrosion and wave-absorbing dual-function application prospects can be demonstrated.

[0070] In this study, unless otherwise specified, the scientific terms and technical words used in the text are interpreted according to the common understanding of professionals in the field. In addition, the chemical reagents, materials and operating procedures used in the experiments are all standards generally recognized and adopted in the field.

[0071] It should be noted that the content described herein is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail through the above embodiments, professionals and technicians in this field can still adjust the described technical solutions based on these embodiments, or perform equivalent substitutions on certain technical features. All modifications, equivalent substitutions, improvements, etc. made within the scope of the basic principles and tenets of the present invention shall be regarded as part of the protection scope of the present invention.

Claims

1. A method for preparing a W-type ferrite@cluster MoS2 absorbing and anti-corrosion material, characterized in that: The following steps are involved: Step 1: Mix metal nitrate with water, add citric acid monohydrate, adjust pH with ammonia water, oil bath to gel state, dry and heat treat to obtain W-type ferrite powder; Step 2: Mix W-type ferrite powder, hexadecyltrimethylammonium bromide and water, and stir; add ammonium molybdate tetrahydrate and thioacetamide, stir and pour into a hydrothermal kettle for hydrothermal reaction; after the reaction is completed, centrifuge, wash and dry to obtain W-type ferrite coated with cluster MoS2; Step 3: Mix the W-type ferrite coated with cluster MoS2 with epoxy resin and curing agent and co-curing to obtain W-type ferrite@cluster MoS2 microwave absorbing and anti-corrosion material.

2. The method for preparing the W-type ferrite@cluster MoS2 absorbing and anti-corrosion material according to claim 1, characterized in that: In step 1, the metal nitrate includes barium nitrate, cobalt nitrate hexahydrate, neodymium nitrate hexahydrate and iron nitrate nonahydrate, and the mass ratio is (0.8-1):2:(0-0.2):

16.

3. The method for preparing the W-type ferrite@cluster MoS2 absorbing and anti-corrosion material according to claim 1, characterized in that: In the step 1, the molar ratio of metal ions to citric acid monohydrate is 1:(1.2-1.5).

4. The method for preparing the W-type ferrite@cluster MoS2 absorbing and anti-corrosion material according to claim 1, characterized in that: In the step 1, the pH is adjusted to be neutral; and the oil bath temperature is (80-100)°C.

5. The method for preparing the W-type ferrite@cluster MoS2 absorbing and anti-corrosion material according to claim 1, characterized in that: In step 1, the drying process is: Keep at 110-130°C for 5-8h, then increase the temperature to 200-210°C at 5°C / min and keep at this temperature for 5-8h.

6. The method for preparing the W-type ferrite@cluster MoS2 absorbing and anti-corrosion material according to claim 1, characterized in that: In step 1, the heat treatment process is: Keep at 400-500°C for 2-5h, then increase the temperature to 1200-1400°C at 5°C / min and keep at this temperature for 2-5h.

7. The method for preparing the W-type ferrite@cluster MoS2 absorbing and anti-corrosion material according to claim 1, characterized in that: In the step 2, the mixing ratio of W-type ferrite powder, hexadecyltrimethylammonium bromide, ammonium molybdate tetrahydrate, thioacetamide and water is 0.2g:0.05g:(0.4-0.5)g:(0.4-0.5)g:60ml.

8. The method for preparing the W-type ferrite@cluster MoS2 absorbing and anti-corrosion material according to claim 1, characterized in that: In the step 2, the hydrothermal temperature is 180-200° C., the hydrothermal time is 8-10 h, and the heating rate is 5° C. / min.

9. The method for preparing the W-type ferrite@cluster MoS2 absorbing and anti-corrosion material according to claim 1, characterized in that: In the step 3, the mixing ratio of the W-type ferrite coated with cluster MoS2, epoxy resin and curing agent is 1.35g:1g:2g.

10. The W-type ferrite@cluster MoS2 wave absorbing and anti-corrosion material obtained by the preparation method according to any one of claims 1 to 9.

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