Magnetorheological fluid with high stability and high fluidity and preparation method thereof

Abstract

The application relates to a magnetorheological fluid with high stability and high fluidity, which comprises 60-90 parts of magnetic particles, 10-40 parts of carrier liquid and 0.1-3 parts of additives in terms of weight parts. The magnetorheological fluid can realize the effects of low sedimentation rate, high stability, low zero-magnetic-field viscosity, good fluidity and the like by adding a certain proportion of dispersants and thixotropic agents. The preparation process is simple, the magnetorheological fluid can be prepared through one-step mixing, grinding and dispersing, and the magnetorheological fluid has the characteristics of low cost, small energy consumption, short cycle and high safety. The application further relates to a preparation method of the magnetorheological fluid with high stability and high fluidity.

Description

Technical Field

[0001] This invention relates to the field of smart materials technology, specifically to a magnetorheological fluid with high stability and high fluidity, and a method for preparing the magnetorheological fluid. Background Technology

[0002] Magnetorheological fluids (MRFs) are stable suspensions formed by dispersing magnetic particles in media such as oil, and are a type of magnetorheological smart material. In the absence of a magnetic field, the magnetic particles in the MRF are randomly suspended in the dispersion medium, exhibiting fluid properties. Under the influence of an external magnetic field, the MRF produces a significant magnetorheological effect, exhibiting properties similar to a solid. When the external magnetic field is removed, the fluid reverts to its original flow properties, demonstrating a rapid and reversible transition between liquid and semi-solid states.

[0003] Therefore, magnetorheological fluids, as high-performance smart materials, have been widely used in the automotive, construction, and vibration control fields in recent years. Sedimentation rate and zero-magnetic-field viscosity are important indicators for evaluating the performance of magnetorheological fluids. Existing technologies typically employ additives such as anti-sedimentation agents, thixotropic agents, surfactants, and dispersants to reduce the sedimentation rate while maintaining good fluidity at zero magnetic field. For example, patent CN117854872A discloses a magnetorheological fluid and its preparation method, which improves the anti-sedimentation performance of the magnetorheological fluid by adding organic amine compounds. However, organic amine additives are toxic and harmful, potentially posing safety issues. Patent CN101691518A discloses a magnetorheological fluid using polymeric microgels as anti-sedimentation agents. It utilizes the property that polymeric microgels can swell in their corresponding good solvents to form a three-dimensional network structure, thereby improving the sedimentation stability of the magnetorheological fluid. However, polymeric microgels need to be synthesized separately, resulting in complex production processes, long production cycles, and high production costs.

[0004] In view of this, there is an urgent need in the field to develop a magnetorheological fluid with low production cost, simple process, short cycle and high safety, high stability and high fluidity, in order to solve the problems existing in the prior art. Summary of the Invention

[0005] Based on the above facts, the purpose of this invention is to provide a magnetorheological fluid with high stability and high fluidity. By adding a certain proportion of dispersant and thixotropic agent, it can achieve the effects of low sedimentation rate, high stability, low viscosity at zero magnetic field, and good fluidity. Its preparation process is simple, requiring only one step of mixing, grinding, and dispersion, and features low cost, low energy consumption, short cycle time, and high safety.

[0006] A first aspect of the present invention provides a magnetorheological fluid with high stability and high fluidity, comprising, by weight:

[0007] 60-90 parts magnetic particles;

[0008] 10-40 parts of carrier liquid;

[0009] Additives: 0.1-3 parts.

[0010] magnetic particles

[0011] In this invention, the magnetic particles include, but are not limited to, spherical or ellipsoidal carbonyl iron, Fe, Co, Ni and their alloys, and the particle size of the magnetic particles is preferably 0.1-10 μm.

[0012] In some preferred embodiments of the present invention, the magnetic particles are preferably 70-90 parts by weight.

[0013] Specifically, the carbonyl iron is selected from one or more of BASF SQ, BASF CD, Jiangsu Tianyi Ultrafine Metal Powder Co., Ltd. RZE, and Jiangsu Tianyi Ultrafine Metal Powder Co., Ltd. MRF-R55.

[0014] carrier fluid

[0015] In this invention, the carrier liquid is selected from one or more of polyolefins, silicone oils, mineral oils, and synthetic oils. The carrier liquid has a low pour point, is not easily volatile, is non-toxic and harmless, and has high safety.

[0016] In some preferred embodiments of the present invention, the weight parts of the carrier liquid are preferably 15-40 parts.

[0017] Specifically, the carrier fluid is selected from one or more of the following: low-viscosity polyalphaolefin PAO2 provided by ExxonMobil, silicone oil provided by Dow Corning, and silicone oil provided by Huangshan Qiangli Chemical Co., Ltd.

[0018] additive

[0019] In this invention, the additives include at least a dispersant and a thixotropic agent, and may also include, but are not limited to, one or more of surfactants and lubricants. The dispersant is selected from one or a combination of organobentonite and acrylic resin, and the thixotropic agent is selected from one or a combination of polyurea compounds and silica.

[0020] In some preferred embodiments of the present invention, the additive is preferably 0.1-2 parts by weight, and the ratio of the thixotropic agent to the dispersant is any ratio between 1:1 and 1:5.

[0021] In some more preferred embodiments of the present invention, the thixotropic agent is silicon dioxide; even more preferably, the thixotropic agent is amorphous silicon dioxide with a particle size of 0.1-5 μm.

[0022] Specifically, the dispersant is selected from one or more of the following: MG-451 provided by Nippon Paint Industrial Coatings Co., Ltd.; CLAYMINTON 81 and CLAYMINTON 71 provided by Zhejiang Chang'an Renheng Technology Co., Ltd.; the thixotropic agent is selected from Nipsil E-1011 provided by Tosoh Silicon Chemical Co., Ltd.; DeuRheo 2810 provided by Hemings Chemical Co., Ltd.; BYK410 provided by BYK Additives (Shanghai) Co., Ltd.; and [the following is a list of dispersants / products ... One or more of the thixotropic agents C 803.

[0023] A second aspect of the present invention provides a method for preparing the magnetorheological fluid with high stability and high fluidity described in the first aspect of the present invention, comprising the following steps:

[0024] After stirring and mixing the magnetic particles, carrier liquid and additives, the mixture is ground with a three-roll mill until the fineness is less than 20 μm, thus obtaining the magnetorheological fluid with high stability and high fluidity.

[0025] Beneficial effects of the present invention

[0026] This invention addresses the shortcomings of existing technologies by providing a magnetorheological fluid with high stability and high fluidity. By adding a certain proportion of dispersant and thixotropic agent, it achieves low sedimentation rate, high stability, low viscosity at zero magnetic field, and good fluidity. Its preparation process is simple, requiring only one step of mixing, grinding, and dispersion, and features low cost, low energy consumption, short cycle time, and high safety. Detailed Implementation

[0027] To more clearly illustrate the present invention, the following detailed description, in conjunction with specific embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the following embodiments and comparative examples are conventional methods, and the raw materials and reagents used are products that can be purchased from conventional commercial channels.

[0028] The above technical solution will be described below with reference to specific embodiments.

[0029] Examples 1-6: Magnetorheological fluids with high stability and high fluidity 1-6

[0030] Magnetorheological fluids 1-6 with high stability and high fluidity were prepared according to Table 1, and the preparation steps are as follows:

[0031] After stirring and mixing the magnetic particles, carrier liquid and additives, the mixture is ground with a three-roll mill until the fineness is less than 20 μm to obtain the magnetorheological fluid 1-6 with high stability and high fluidity.

[0032] Comparative Examples 1-3: Magnetorheological fluids 1-3 used as comparative examples

[0033] Magnetorheological fluids 1-3 were prepared according to Table 1 as comparative examples. Except for the lack of corresponding components in some preparation steps, the other preparation steps were the same as those in Examples 1-3.

[0034] It should be noted that Comparative Example 1 does not contain a dispersant, Comparative Example 2 does not contain a thixotropic agent, and the ratio of thixotropic agent to dispersant in Comparative Example 3 is approximately 2.67:1, which is not within the range of 1:1 to 1:5. Therefore, Comparative Examples 1-3 are not within the protection scope of this invention.

[0035] Table 1 Formulations of Examples 1-6 and Comparative Examples 1-3

[0036]

[0037] The performance of the magnetorheological fluids obtained in Examples 1-6 and Comparative Examples 1-3 was tested, and the test results are shown in Table 2.

[0038] Table 2 Performance test results of Examples 1-6 and Comparative Examples 1-3

[0039]

[0040]

[0041] As shown in Table 2, the magnetorheological fluids obtained in Examples 1-6 exhibited low sedimentation rates and low zero-magnetic-field viscosity. This indicates that the present invention, while possessing a simple preparation process, low cost, low energy consumption, short cycle time, and high safety, can achieve low sedimentation rates, high stability, low zero-magnetic-field viscosity, and good fluidity in magnetorheological fluids. However, Comparative Examples 1-3, due to the amounts of dispersant and thixotropic agent not being within the scope of the present invention, resulted in magnetorheological fluids with issues regarding sedimentation rates and zero-magnetic-field viscosity.

[0042] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A magnetorheological fluid with high stability and high fluidity, comprising, by weight: 60-90 parts magnetic particles; 10-40 parts of carrier liquid; Additives: 0.1-3 parts.

2. The magnetorheological fluid with high stability and high fluidity according to claim 1, characterized in that, The magnetic particles include, but are not limited to, spherical or ellipsoidal carbonyl iron, Fe, Co, Ni and their alloys; preferably, the magnetic particles are 70-90 parts by weight.

3. The magnetorheological fluid with high stability and high fluidity according to claim 2, characterized in that, The particle size of the magnetic particles is preferably 0.1-10 μm.

4. The magnetorheological fluid with high stability and high fluidity according to claim 1, characterized in that, The carrier liquid is selected from one or more of polyolefins, silicone oils, mineral oils, and synthetic oils; preferably, the carrier liquid is 15-40 parts by weight.

5. The magnetorheological fluid with high stability and high fluidity according to claim 1, characterized in that, The additive includes a dispersant and a thixotropic agent, wherein the ratio of the thixotropic agent to the dispersant is any ratio between 1:1 and 1:5; the dispersant is selected from one or a combination of organobentonite and acrylic resin, and the thixotropic agent is selected from one or a combination of polyurea compound and silica; preferably, the additive is 0.1-2 parts by weight.

6. The magnetorheological fluid with high stability and high fluidity according to claim 5, characterized in that, The thixotropic agent is preferably silicon dioxide; more preferably, the thixotropic agent is amorphous silicon dioxide with a particle size of 0.1-5 μm.

7. The magnetorheological fluid with high stability and high fluidity according to claim 5, characterized in that, Optionally, the additives may include, but are not limited to, one or more of surfactants and lubricants.

8. A method for preparing a magnetorheological fluid with high stability and high fluidity as described in any one of claims 1-7, comprising the following steps: After stirring and mixing the magnetic particles, carrier liquid and additives, the mixture is ground with a three-roll mill until the fineness is less than 20 μm, thus obtaining the magnetorheological fluid with high stability and high fluidity.

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