A magnetic mineral fiber material and a method for producing the same

Abstract

The application belongs to the technical field of magnetic materials, and particularly discloses a kind of magnetic mineral fiber materials and its preparation method.The application obtains the magnetic crystal with uniform particle size by calcining ferroferric oxide and ball milling, and obtains the stannate modified ferroferric oxide particles by hydrothermal reaction of the magnetic crystal with stannate, and the magnetic mineral fiber material is prepared by mixing the stannate modified ferroferric oxide particles with amino silane coupling agent, which effectively solves the problems in the preparation of magnetic fiber material in the prior art, such as complex operation, high cost, uncontrollability of the particle size of the used magnetic nanoparticles, and the inability of the magnetic properties of the obtained magnetic material to exist stably for a long time.The preparation method provided by the application is simple and easy to operate, the raw material cost is low, the obtained magnetic mineral fiber material has excellent performance, and the magnetic properties are adjustable, which provides a new idea for the application of magnetic functional materials.

Description

Technical Field

[0001] This invention relates to the field of magnetic materials technology, and specifically discloses a magnetic mineral fiber material and its preparation method. Background Technology

[0002] Basalt fiber is an environmentally friendly inorganic fiber material and one of the key fibers that my country is developing. Basalt fiber has properties close to carbon fiber, but its price is several times or even tens of times lower. In civil engineering, it can partially replace expensive carbon fiber for structural reinforcement, reducing my country's reliance on carbon fiber in structural reinforcement projects. It can also be combined with various resins to form composite materials for use in wind turbine blades, vehicle and ship hull structures, corrosion-resistant and pressure-resistant pipes and tanks, as well as printed circuit board substrates, all exhibiting excellent mechanical properties and corrosion resistance.

[0003] Magnetic materials, due to their high mechanical and electrical responsiveness to magnetic fields, have been widely used in biomedicine, wearable devices, flexible actuators, and environmental remediation. In recent years, they have gradually become a research hotspot. In particular, how to integrate various magnetic materials (including hard and soft magnetic materials) into fibers in a highly controllable manner in terms of distribution, concentration, and structure is the key to introducing magnetic functions into soft robots, smart materials, biomedicine, and other applications.

[0004] Existing technologies report methods for preparing magnetic basalt fibers, which involve dispersing oleic acid-modified amorphous Fe-Zr-B magnetic nanoparticles in a basalt fiber sizing agent to obtain a magnetic sizing agent. This magnetic sizing agent is then used to impregnate and coat basalt fibers to obtain magnetic basalt fibers. However, the magnetic nanoparticles used are amorphous, the process is complex, the particle size is uncontrollable, the cost is high, and the resulting magnetic material is difficult to maintain long-term magnetic stability. Therefore, providing a simple, high-performance, and controllable magnetic fiber material is of great significance for the research and development of magnetic functional materials. Summary of the Invention

[0005] To address the problems of complex operations, uncontrollable nanoparticle size, high cost, and difficulty in maintaining long-term magnetic stability in the preparation of magnetic fiber materials using existing technologies, this invention provides a magnetic mineral fiber material and its preparation method. This invention involves inorganically modifying magnetic crystals to enable them to maintain stable magnetism over a long period. The modified particles are then mixed with an aminosilane coupling agent and coated onto inorganic mineral fibers to obtain the magnetic mineral fiber material. This preparation method is simple to operate, uses inexpensive raw materials, and produces a magnetic mineral fiber material with excellent performance, exhibiting controllable and long-term stable magnetism.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] The first aspect of this invention provides a method for preparing magnetic mineral fiber materials, comprising at least the following steps:

[0008] Step 1: Under an inert atmosphere, calcine iron oxide (Fe3O4) and then ball mill it to obtain magnetic iron oxide crystals.

[0009] Step 2: Disperse the magnetic crystals of iron oxide in a methanol solution, add pH adjuster and stannate, mix well, carry out hydrothermal reaction, filter, and dry to obtain stannate-modified iron oxide particles.

[0010] Step 3: Mix the tin salt modified iron oxide particles with an aminosilane coupling agent evenly to obtain a magnetic wetting agent;

[0011] Step 4: Impregnate the inorganic mineral fibers in the magnetic wetting agent and dry them to obtain magnetic mineral fiber material.

[0012] Compared to existing technologies, this invention designs and prepares a magnetic mineral fiber material. This material is obtained by uniformly mixing tin salt-modified iron oxide particles with an aminosilane coupling agent and then coating it onto inorganic mineral fibers. The iron oxide particles are obtained through a co-precipitation method. However, ordinary co-precipitation methods cannot control the particle size of the resulting magnetic crystals, leading to inconsistent particle sizes and making it impossible to obtain a fiber material with uniform and controllable magnetic properties. To address this, the inventors creatively propose calcining the obtained magnetic crystals in an inert atmosphere. At high temperatures, this not only removes impurities trapped on the crystal surface obtained through the co-precipitation method but also activates the oxides in the magnetic crystals, promoting recrystallization towards a more uniform particle size and stable crystal form, thereby improving the mechanical strength of the crystals. Ball milling after calcination can further obtain crystal particles with uniform particle size, but the magnetic properties of the magnetic crystal are difficult to maintain for a long time. During use, contact with metal can easily lead to a weakening or even gradual loss of magnetism. Therefore, this invention uses stannate to modify it, coating its surface with a layer of tin hydroxide particles through a hydrothermal reaction. This not only allows it to maintain stable magnetism for a long time, but the hydroxyl groups on the surface of tin hydroxide can also combine with inorganic mineral fibers through an aminosilane coupling agent to form more stable chemical bonds, ensuring the stability of the obtained magnetic mineral fiber material. The magnetic mineral fiber material preparation process provided by this invention is simple and low in cost, and the magnetism of the obtained magnetic mineral fiber material can be controlled according to the content of magnetic crystal particles, providing a new idea for the application of magnetic functional materials.

[0013] Preferably, in step one, the calcination temperature is 350℃-450℃, and the calcination time is 2h-3h.

[0014] High-temperature calcination in an inert atmosphere can not only remove impurities trapped on the crystal surface due to co-precipitation, but also activate oxides in magnetic crystals, promoting their recrystallization towards uniform particle size and stable crystal form, thereby improving the mechanical strength of the crystal.

[0015] Preferably, in step three, the ball milling speed is 750 r / min-850 r / min, and the ball milling time is 30 min-50 min.

[0016] Preferably, in step three, the particle size of the obtained magnetite magnetic crystal is 80nm-110nm.

[0017] Preferably, in step two, the mass ratio of the magnetite, pH adjuster and stannate is 10-20:0.5-1.5:1.

[0018] Preferably, in step two, the mass-to-volume ratio of the magnetite magnetic crystal to the methanol solution is 0.5g-1g:50mL-100mL.

[0019] Preferably, in step two, the temperature of the hydrothermal reaction is 140℃-220℃, and the reaction time is 24h-48h.

[0020] Preferably, in step two, the mass concentration of the methanol solution is 60%-75%.

[0021] In step two, the pH adjuster is dipotassium hydrogen phosphate.

[0022] In step two, the stannate is any one of sodium stannate, potassium stannate, or magnesium stannate.

[0023] Preferably, in step three, the aminosilane coupling agent is either KH-792 or KH-560.

[0024] Preferably, in step three, the mass ratio of the tin salt modified iron oxide particles to the aminosilane coupling agent is 0.5-5:100.

[0025] Preferably, in step three, the mixing is carried out by a combination of ultrasonic dispersion and mechanical stirring.

[0026] More preferably, the ultrasonic dispersion frequency is 30kHz-40kHz, and the ultrasonic dispersion time is 10min-15min.

[0027] More preferably, the mechanical stirring speed is 1200 r / min-1500 r / min, and the mechanical stirring time is 15 min-20 min.

[0028] Preferably, in step four, the inorganic mineral fiber is basalt fiber.

[0029] Preferably, in step four, the coating thickness of the magnetic sizing agent in the magnetic mineral fiber material is 1μm-3μm.

[0030] A second aspect of the present invention provides a magnetic mineral fiber material, which is prepared using the preparation method of the magnetic mineral fiber material.

[0031] Preferably, the magnetic mineral fiber material has tunable magnetism.

[0032] Furthermore, the adjustable magnetism is positively correlated with the content of magnetic crystal particles.

[0033] This invention prepares magnetic mineral fiber materials by coating an aminosilane coupling agent containing inorganic modified particles onto inorganic mineral fibers. This effectively solves the problems in the preparation of magnetic fiber materials in the prior art, such as complex operation, uncontrollable particle size of nanoparticles, high cost, and difficulty in maintaining long-term magnetic stability. The preparation method of this magnetic mineral fiber material is simple to operate, has low raw material cost, and produces magnetic mineral fiber materials with excellent performance and controllable magnetism. Attached Figure Description

[0034] Figure 1 The VSM spectra of the magnetic mineral fiber materials obtained in Examples 1-6 are shown. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] This embodiment provides a magnetic mineral fiber material, and the specific preparation method is as follows:

[0038] Step 1: Under an inert atmosphere, calcine iron oxide at 400℃ for 2.5h, cool, and then ball mill at 800r / min for 40min to obtain magnetic iron oxide crystals with a particle size of 100nm.

[0039] Step 2: Disperse 1g of the magnetic ferric oxide crystal in 80mL of 70% methanol solution, add 0.08g of dipotassium hydrogen phosphate and 0.1g of sodium stannate, mix well, and carry out a hydrothermal reaction at 180℃ for 32h. Filter and dry to obtain tin salt modified ferric oxide particles.

[0040] Step 3: Mix the 0.5g tin salt modified iron oxide particles and 100g aminosilane coupling agent KH-792, disperse them at an ultrasonic frequency of 35kHz for 13min, and then mechanically stir them at a speed of 1400r / min for 18min to obtain a magnetic wetting agent containing 0.5% tin salt modified iron oxide particles by mass.

[0041] Step 4: Impregnate the inorganic mineral fibers in the magnetic sizing agent and allow them to dry naturally to obtain a magnetic mineral fiber material. The coating thickness of the magnetic sizing agent in the magnetic mineral fiber material is measured to be 3 μm.

[0042] Example 2

[0043] This embodiment provides a magnetic mineral fiber material, and the specific preparation method is as follows:

[0044] Step 1: Under an inert atmosphere, calcine iron oxide at 400℃ for 2.5h, cool, and then ball mill at 800r / min for 40min to obtain magnetic iron oxide crystals with a particle size of 90nm.

[0045] Step 2: Disperse 1g of the magnetic ferric oxide crystal in 70mL of 70% methanol solution, add 0.09g of dipotassium hydrogen phosphate and 0.1g of sodium stannate, mix well, and carry out a hydrothermal reaction at 200℃ for 32h. Filter and dry to obtain tin salt modified ferric oxide particles.

[0046] Step 3: Mix the 1g tin salt modified iron oxide particles and 100g aminosilane coupling agent KH-792, disperse them at an ultrasonic frequency of 35kHz for 13min, and then mechanically stir them at a speed of 1400r / min for 18min to obtain a magnetic wetting agent containing 1% by mass of tin salt modified iron oxide particles.

[0047] Step 4: Impregnate the inorganic mineral fibers in the magnetic sizing agent and allow them to dry naturally to obtain a magnetic mineral fiber material. The coating thickness of the magnetic sizing agent in the magnetic mineral fiber material is measured to be 3 μm.

[0048] Example 3

[0049] This embodiment provides a magnetic mineral fiber material, and the specific preparation method is as follows:

[0050] Step 1: Under an inert atmosphere, calcine iron oxide at 400℃ for 2.5h, cool, and then ball mill at 800r / min for 40min to obtain magnetic iron oxide crystals with a particle size of 85nm.

[0051] Step 2: Disperse 1g of the magnetic ferric oxide crystal in 80mL of 65% methanol solution, add 0.08g of dipotassium hydrogen phosphate and 0.1g of potassium stannate, mix well, and carry out a hydrothermal reaction at 190℃ for 32h. Filter and dry to obtain tin salt modified ferric oxide particles.

[0052] Step 3: Mix the 2g tin salt modified iron oxide particles and 100g aminosilane coupling agent KH-792, disperse them at an ultrasonic frequency of 35kHz for 13min, and then mechanically stir them at a speed of 1400r / min for 18min to obtain a magnetic wetting agent containing 2% tin salt modified iron oxide particles by mass.

[0053] Step 4: Impregnate the inorganic mineral fibers in the magnetic sizing agent and allow them to dry naturally to obtain a magnetic mineral fiber material. The coating thickness of the magnetic sizing agent in the magnetic mineral fiber material is measured to be 2.5 μm.

[0054] Example 4

[0055] This embodiment provides a magnetic mineral fiber material, and the specific preparation method is as follows:

[0056] Step 1: Under an inert atmosphere, calcine iron oxide at 410℃ for 2.5h, cool, and then ball mill at 780r / min for 40min to obtain magnetic iron oxide crystals with a particle size of 110nm.

[0057] Step 2: Disperse 1g of the magnetic ferric oxide crystal in 80mL of 75% methanol solution, add 0.09g of dipotassium hydrogen phosphate and 0.1g of sodium stannate, mix well, and carry out a hydrothermal reaction at 180℃ for 32h. Filter and dry to obtain tin salt modified ferric oxide particles.

[0058] Step 3: Mix the 3g tin salt modified iron oxide particles and 100g aminosilane coupling agent KH-792, disperse them at an ultrasonic frequency of 35kHz for 13min, and then mechanically stir them at a speed of 1400r / min for 18min to obtain a magnetic wetting agent containing 3% tin salt modified iron oxide particles by mass.

[0059] Step 4: Impregnate the inorganic mineral fibers in the magnetic sizing agent and allow them to dry naturally to obtain a magnetic mineral fiber material. The coating thickness of the magnetic sizing agent in the magnetic mineral fiber material is measured to be 2.8 μm.

[0060] Example 5

[0061] This embodiment provides a magnetic mineral fiber material, and the specific preparation method is as follows:

[0062] Step 1: Under an inert atmosphere, calcine iron oxide at 400℃ for 2.5h, cool, and then ball mill at 800r / min for 40min to obtain magnetic iron oxide crystals with a particle size of 100nm.

[0063] Step 2: Disperse 1g of the magnetic ferric oxide crystal in 80mL of 75% methanol solution, add 0.1g of dipotassium hydrogen phosphate and 0.1g of sodium stannate, mix well, and carry out a hydrothermal reaction at 190℃ for 32h. Filter and dry to obtain tin salt modified ferric oxide particles.

[0064] Step 3: Mix the 4g tin salt modified iron oxide particles and 100g aminosilane coupling agent KH-792, disperse them at an ultrasonic frequency of 35kHz for 13min, and then mechanically stir them at a speed of 1400r / min for 18min to obtain a magnetic wetting agent containing 4% tin salt modified iron oxide particles by mass.

[0065] Step 4: Impregnate the inorganic mineral fibers in the magnetic sizing agent and allow them to dry naturally to obtain a magnetic mineral fiber material. The coating thickness of the magnetic sizing agent in the magnetic mineral fiber material is measured to be 3 μm.

[0066] Example 6

[0067] This embodiment provides a magnetic mineral fiber material, and the specific preparation method is as follows:

[0068] Step 1: Under an inert atmosphere, calcine iron oxide at 410℃ for 2.5h, cool, and then ball mill at 800r / min for 40min to obtain magnetic iron oxide crystals with a particle size of 105nm.

[0069] Step 2: Disperse 1g of the magnetic ferric oxide crystal in 80mL of 65% methanol solution, add 0.1g of dipotassium hydrogen phosphate and 0.1g of sodium stannate, mix well, and carry out hydrothermal reaction at 210℃ for 32h. Filter and dry to obtain tin salt modified ferric oxide particles.

[0070] Step 3: Mix the 5g tin salt modified iron oxide particles and 100g aminosilane coupling agent KH-792, disperse them at an ultrasonic frequency of 35kHz for 13min, and then mechanically stir them at a speed of 1400r / min for 18min to obtain a magnetic wetting agent containing 5% tin salt modified iron oxide particles by mass.

[0071] Step 4: Impregnate the inorganic mineral fibers in the magnetic sizing agent and allow them to dry naturally to obtain a magnetic mineral fiber material. The coating thickness of the magnetic sizing agent in the magnetic mineral fiber material is measured to be 3 μm.

[0072] Comparative Example 1

[0073] This comparative example provides a magnetic basalt fiber material that, compared to Example 1, has not undergone stannate modification. The specific preparation method is as follows:

[0074] Step 1: Under an inert atmosphere, calcine iron oxide at 400℃ for 2.5h, cool, and then ball mill at 800r / min for 40min to obtain magnetic iron oxide crystals with a particle size of 100nm.

[0075] Step 2: Mix the 0.5g magnetite magnetic crystal and 100g aminosilane coupling agent KH-792, disperse at an ultrasonic frequency of 35kHz for 13min, and then mechanically stir at a speed of 1400r / min for 18min to obtain a magnetic wetting agent containing 0.5% magnetite magnetic crystal by mass.

[0076] Step 4: Impregnate the inorganic mineral fibers in the magnetic sizing agent and allow them to dry naturally to obtain a magnetic mineral fiber material. The coating thickness of the magnetic sizing agent in the magnetic mineral fiber material is measured to be 3 μm.

[0077] Comparative Example 2

[0078] This comparative example provides a magnetic mineral fiber material, which omits step one compared to Example 1. The specific preparation method is as follows:

[0079] Step 1: Disperse 1g of iron oxide particles in 80mL of 70% methanol solution, add 0.08g of dipotassium hydrogen phosphate and 0.1g of sodium stannate, mix well, and carry out hydrothermal reaction at 180℃ for 32h. Filter and dry to obtain stannate-modified iron oxide particles.

[0080] Step 2: Mix the 0.5g inorganic modified particles and 100g aminosilane coupling agent KH-792, disperse them at an ultrasonic frequency of 35kHz for 13min, and then mechanically stir them at a speed of 1400r / min for 18min to obtain a magnetic wetting agent containing 0.5% by mass of stannic acid modified iron oxide particles.

[0081] Step 3: The inorganic mineral fibers are impregnated in the magnetic sizing agent and dried naturally to obtain magnetic mineral fiber material. The coating thickness of the magnetic sizing agent in the magnetic mineral fiber material is 3 μm, as determined by testing.

[0082] To further demonstrate the technical effects of the magnetic mineral fiber materials obtained in this invention, the magnetic mineral fiber materials obtained in Examples 1-6 were subjected to single-filament fiber strength tests and VSM (vibrating sample magnetometer) tests. The test results are shown in Table 1 and... Figure 1 As shown.

[0083] Table 1. Monofilament strength and saturation magnetization of Examples 1-6 and Comparative Examples 1-2

[0084]

[0085] According to Table 1 and Figure 1 It can be seen that the magnetic mineral fiber materials provided in Examples 1-6 of the present invention have high single-filament strength, and the saturation magnetization intensity increases with the increase of the content of magnetic crystal particles, thus realizing the controllable magnetism of the material.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the production of a magnetic mineral fibre material, characterized in that: At least comprising the following steps: Step one, calcining the ferroferric oxide obtained by coprecipitation method under inert atmosphere, and obtaining ferroferric oxide magnetic crystal after ball milling; Step two, dispersing the ferroferric oxide magnetic crystal in a methanol solution, adding a pH regulator and a stannate, mixing uniformly, performing hydrothermal reaction, filtering, and drying to obtain stannate-modified ferroferric oxide particles; Step three, mixing the stannate-modified ferroferric oxide particles with an aminosilane coupling agent uniformly to obtain a magnetic infiltrant; Step four, impregnating inorganic mineral fibers in the magnetic infiltrant and drying to obtain a magnetic mineral fiber material.

2. The method of producing a magnetic mineral fiber material according to claim 1, characterized by: In step one, the calcination temperature is 350-450°C, and the calcination time is 2-3h; and / or In step one, the ball milling speed is 750-850r / min, and the ball milling time is 30-50min.

3. The method of producing a magnetic mineral fiber material according to claim 1, characterized by: In step one, the particle size of the obtained ferroferric oxide magnetic crystal is 80-110nm.

4. The method of producing a magnetic mineral fiber material according to claim 1, characterized by: In step two, the mass ratio of the ferroferric oxide magnetic crystal, the pH regulator, and the stannate is 10-20:0.5-1.5:1; and / or In step two, the mass-volume ratio of the ferroferric oxide magnetic crystal to the methanol solution is 0.5-1g:50-100mL.

5. The method of producing a magnetic mineral fiber material according to claim 1, characterized by: In step two, the hydrothermal reaction temperature is 140-220°C, and the hydrothermal reaction time is 24-48h.

6. A method for the production of a magnetic mineral fibre material according to any one of claims 1 or 4, characterised in that: In step two, the mass concentration of the methanol solution is 60-75%; and / or In step two, the pH regulator is dipotassium hydrogen phosphate; and / or In step two, the stannate is any one of sodium stannate, potassium stannate, or magnesium stannate.

7. The method of producing a magnetic mineral fiber material according to claim 1, characterized by: In step three, the aminosilane coupling agent is any one of KH-792 or KH-560; and / or In step three, the mass ratio of the stannate-modified ferroferric oxide particles to the aminosilane coupling agent is 0.5-5:

100.

8. The method of producing a magnetic mineral fiber material according to claim 1, characterized by: In step three, the mixing is performed by a combination of ultrasonic dispersion and mechanical stirring.

9. The method of producing a magnetic mineral fiber material according to claim 1, characterized by: In step four, the inorganic mineral fibers are basalt fibers; and / or In step four, the coating thickness of the magnetic infiltrant in the magnetic mineral fiber material is 1-3μm.

10. A magnetic mineral fiber material, characterized by: The magnetic mineral fiber material is prepared by the method of any one of claims 1-9.

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