阅读说明：本技术 磁流变液体及其制造方法 (Magnetorheological fluid and manufacturing method thereof ) 是由 芮祥鹏 徐嘉伟 于 2019-11-28 设计创作，主要内容包括：一种磁流变液体及其制造方法,其中磁流变液体系于一载体液内分散有一磁响应复合体,该磁响应复合体由一羰基铁粒子与一奈米粒子进行干式搅拌反应所形成,而该奈米粒子会以非连续方式分布于该磁响应复合体上,本发明不需添加各种添加剂,制造成本更低廉,不须使用大量的化学溶剂与药品,对环境友善,且制得的磁流变流体能应用在更高剪切应力的范围内。(A magneto-rheological liquid and its preparation method, wherein the magneto-rheological liquid is dispersed a magnetic response complex in a carrier liquid, the magnetic response complex is formed by a carbonyl iron particle and a nanoparticle through dry-type stirring reaction, and the nanoparticle can be distributed on the magnetic response complex in a discontinuous way.)

1. A magneto-rheological liquid is characterized in that a magnetic response complex is dispersed in a carrier liquid, and the magnetic response complex is formed by carrying out dry stirring reaction on carbonyl iron particles and nano particles, wherein the nano particles are discontinuously distributed on the magnetic response complex.

2. The magnetorheological fluid of claim 1, wherein the carrier fluid is one or a mixture of more than one of silicone oil, mineral oil, paraffin oil, water, and alcohols.

3. The magnetorheological fluid of claim 1, wherein the carbonyl iron particles have an average particle size of 0.1 to 20 μm.

4. The magnetorheological fluid of claim 1, wherein the nanoparticles are one or a mixture of iron oxide, cobalt oxide, nickel oxide, silicon oxide, titanium oxide, aluminum oxide, and zirconium oxide.

5. The magnetorheological fluid of claim 1, wherein the nanoparticles have an average particle size of 1 to 100 nm.

6. The magnetorheological fluid of claim 1, wherein the dry agitation is rotary, planetary, vertical, horizontal, diagonal or ball-milling solid state agitation.

7. The magnetorheological fluid of claim 1, wherein the discontinuous distribution is a random distribution of particles without substantial ring or layer structure and with a coarse grain feel.

8. The magnetorheological fluid of claim 1, wherein the magnetic response composite is blended in the carrier fluid at a concentration of 1 to 99 wt%.

9. The magnetorheological fluid of claim 8, wherein the magnetorheological fluid has a shear stress of greater than 1kPa, and wherein the higher the weight percent concentration of the magneto-responsive composite blended in the carrier fluid, the higher the shear stress.

10. A method for manufacturing magnetorheological fluid is characterized by comprising the following steps:

adding carbonyl iron particles into silicon monoxide particles to obtain a mixture;

dry-stirring the obtained mixture to react to form a magnetic response complex;

then adding a carrier liquid into the formed magnetic response complex;

finally, the magnetic response complex is dispersed in the carrier liquid to obtain a magnetorheological fluid.

11. The method of claim 10, wherein the dry stirring reaction is carried out in an environment of air or inert gas and at room temperature.

Technical Field

The present invention relates to a magnetorheological fluid and a method for preparing the same, and more particularly, to a composition having high shear stress and good dispersibility and a method for preparing the same.

Background

Magnetorheological fluids (magnetorheological fluids) generally include at least magnetically responsive particles and a carrier fluid, the magnetically responsive particles generally have a diameter of 0.01 to 500 μm, and behave as Newtonian fluids (Newtonian fluids) in the absence of a magnetic field and Bingham fluids (Bingham fluids) in the presence of a magnetic field, the shear stress of the magnetorheological fluids can generally vary to an extent of kPa or more, and the viscosity of the magnetorheological fluids can vary with the magnitude of the magnetic field, from fluid-like to solid-like, and are widely used as materials for controlling damping (damper), for example, smart dampers, shock absorbers, and the like of various devices such as automobiles.

However, the magnetic-responsive particles in magnetorheological fluids are large and brownian motion does not prevent settling and agglomeration of the particles, thus requiring the use of various means to prevent settling and agglomeration of the particles. For example, a method of adding a surfactant is adopted, but the method of adding a surfactant is not sufficient to resist sedimentation of particles in a carrier liquid because the density of the entire particles cannot be changed.

On the other hand, for example, in U.S. Pat. No. 6,203,717, a stable magnetorheological fluid is disclosed, which is doped with an organoclay to reduce the rate of particle precipitation. However, in this patent document, in order to uniformly mix a magnetic material such as organoclay and carbonyl iron powder with an organic oil such as silicone oil, various additives are required, and there is a problem that stability of these additives is required in addition to increase in manufacturing complexity and cost.

Further, for example, in taiwan patent No. I516610, a stable magnetorheological fluid is disclosed, in which carbonyl iron nanoparticles modified by a grafting reaction are uniformly mixed with acid-treated graphene or carbon nanotubes and organic oils such as silicone oil, and the carbonyl iron is required to be nano-sized and various nano-materials are added, so that the manufacturing complexity and cost are increased, and in addition, the shear stress may not be enough to cope with the application field requiring high shear stress.

In the above-mentioned methods for producing magnetorheological fluids, carbonyl iron is modified and then mixed with various additives and silicone oil to obtain a uniformly dispersed magnetorheological fluid. However, the above method requires relatively expensive production equipment, and is disadvantageous for mass and continuous production, and uses large amounts of chemical solvents and chemicals, is not environmentally friendly, and further, the applicable range of shear stress thereof is to be improved.

Therefore, the present invention should be an optimal solution if it can be developed without adding various additives, with lower manufacturing cost, without using a large amount of chemical solvents and chemicals, with environmental friendliness, and the magnetorheological fluid prepared can be applied in the technical field range of higher shear stress.

Disclosure of Invention

Therefore, the present invention is directed to provide a magnetorheological fluid and a method for manufacturing the same, which does not require the addition of various additives, has a lower manufacturing cost, does not require the use of a large amount of chemical solvents and chemicals, is environmentally friendly, and can be applied in a range of higher shear stress.

In order to achieve the above object, the present invention discloses a magnetorheological fluid, in which a magnetic response complex is dispersed in a carrier fluid, wherein the magnetic response complex is formed by a dry stirring reaction of carbonyl iron particles and nanoparticles, and the nanoparticles are discontinuously distributed on the magnetic response complex.

Wherein the carrier liquid is one or more of silicone oil, mineral oil, paraffin oil, water and alcohols.

Wherein the carbonyl iron particles have an average particle diameter of 0.1 to 20 μm.

Wherein the nanoparticles are one or more of iron oxide, cobalt oxide, nickel oxide, silicon oxide, titanium oxide, aluminum oxide, and zirconium oxide.

Wherein the average particle size of the nanoparticles is 1 to 100 nm.

Wherein the dry stirring is a rotary, planetary, vertical, horizontal, diagonal or ball-milling solid stirring.

Wherein, the discontinuous mode distribution refers to a structure that the particles are randomly distributed without obvious annular or layered structure and have rough granular feeling.

Wherein the magnetic response complex is mixed in the carrier liquid according to the concentration ratio of 1-99 wt%.

Wherein, the shearing stress of the magnetorheological fluid reaches more than 1kPa, and the higher the weight percentage concentration of the magnetic response compound body mixed in the carrier fluid is, the higher the shearing stress is.

Also discloses a method for manufacturing the magnetorheological fluid, which is characterized by comprising the following steps:

adding carbonyl iron particles into silicon monoxide particles to obtain a mixture;

dry-stirring the obtained mixture to react to form a magnetic response complex;

then adding a carrier liquid into the formed magnetic response complex;

finally, the magnetic response complex is dispersed in the carrier liquid to obtain a magnetorheological fluid.

The dry stirring reaction can be carried out in an environment of ordinary air or inert gas and at indoor temperature.

Through the above, the magnetorheological fluid and the manufacturing method thereof provided by the invention have the following technical effects:

(1) the magnetic response composite body has high shearing stress and good dispersity, the viscosity degree of the fluid can be changed along with the vibration, and the intelligent damper can be applied to various devices by changing the size of a magnetic field, changing the viscosity degree of the fluid and controlling damping.

(2) The magnetorheological fluid does not need to be added with various additives, has lower manufacturing cost, does not need to use a large amount of chemical solvents and medicines, is environment-friendly, and can be applied to the technical field range of higher shear stress.

Drawings

FIG. 1: the invention discloses a flow schematic diagram of a manufacturing method of magnetorheological fluid.

FIG. 2A is a schematic view of a low-magnification SEM image of a magnetorheological fluid of the present invention.

FIG. 2B: the schematic diagram of a high-magnification SEM image of the magnetorheological fluid is disclosed.

FIG. 3A: the sedimentation test curve of the invention is shown schematically.

FIG. 3B: schematic representation of sedimentation test samples of the present invention.

FIG. 4: the flow curves of the present invention are schematic.

Detailed Description

Other technical matters, features and effects of the present invention will become apparent from the following detailed description of preferred embodiments, which is to be read in connection with the accompanying drawings.

Referring to fig. 1, a schematic diagram of a method for manufacturing a magnetorheological fluid according to the present invention is shown, wherein the method comprises:

(1) adding carbonyl iron particles to nanoparticles to obtain a mixture 101;

(2) dry-stirring the obtained mixture to react to form a magnetic response complex 102;

(3) then adding a carrier liquid into the formed magnetic response complex 103;

(4) finally, the magneto-responsive composite is dispersed in the carrier fluid to obtain a magnetorheological fluid 104.

In step 101, carbonyl iron particles are added to nanoparticles (iron oxide, cobalt oxide, nickel oxide, silicon oxide, titanium oxide, aluminum oxide, or zirconium oxide), and step 101 may be performed in an air environment and under an inert gas (e.g., nitrogen or argon); furthermore, the environmental conditions of step 101 may be at room temperature.

In step 102, the mixture obtained in step 101 is subjected to a dry stirring reaction, and step 102 is also performed under an air environment and an inert gas (e.g., nitrogen or argon); the reaction conditions in step 102 may be such that the reaction is carried out by dry stirring at room temperature, wherein the dry stirring reaction is carried out by stirring the reaction material mainly in a solid state (for example, a rotary, planetary, vertical, horizontal, diagonal, or ball-milling stirring method).

The magnetic response complex formed in step 102 is a complex having a magnetic response characteristic, the magnetic response complex has a particle size of 0.1-20 μm (particle size of 0.1-0.5 μm, 0.5-1 μm, 1-2 μm, 2-3 μm, 3-4 μm, 4-5 μm, 5-6 μm, 6-7 μm, 7-8 μm, 8-9 μm, 9-10 μm, 10-11 μm, 11-12 μm, 12-13 μm, 13-14 μm, 14-15 μm, 15-16 μm, 16-17 μm, 17-18 μm, 18-19 μm, 19-20 μm) and a surface distribution of 1-100 nm (surface distribution of 1-5 nm, 5-10 nm, 10-15 nm, 15-20 nm, 25-25 nm, 30-40 nm, 45-50 nm, 45-40 nm, or more) 50-55 nm, 55-60 nm, 60-65 nm, 65-70 nm, 70-75 nm, 75-80 nm, 80-85 nm, 85-90 nm, 90-95 nm, 95-100 nm) and can be magnetically or non-magnetically responsive particles (such as iron oxide, cobalt oxide, nickel oxide, silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, etc.).

In step 103, a carrier fluid can be added to the magnetically-responsive composite obtained in step 102, wherein the carrier fluid can be an oily or aqueous carrier fluid (e.g., silicone oil, mineral oil, paraffin oil, water, alcohols, etc.), and the magnetically-responsive composite is blended into the carrier fluid at a concentration of 1 to 99 wt% (within one or more of 1 to 5 wt%, 5 to 10 wt%, 10 to 15 wt%, 15 to 20 wt%, 20 to 25 wt%, 25 to 30 wt%, 30 to 35 wt%, 35 to 40 wt%, 40 to 45 wt%, 45 to 50 wt%, 50 to 55 wt%, 55 to 60 wt%, 60 to 65 wt%, 65 to 70 wt%, 70 to 75 wt%, 75 to 80 wt%, 80 to 85 wt%, 85 to 90 wt%, 90 to 95 wt%, and 95 to 99 wt%).

In step 104, the magnetic-responsive composite is dispersed and mixed into the carrier liquid to obtain a magnetorheological fluid, wherein the magnetorheological fluid is a fluid with magnetic-responsive characteristics, and has low viscosity characteristics under the action of a non-magnetic field, i.e., the magnetorheological fluid is in a fluid state, and the viscosity of the magnetorheological fluid changes along with the magnitude of the magnetic field, which is also called as magnetorheological characteristics.

In addition, the magnetorheological fluid has the variable quantity of shear stress (yield stress) of more than 1kPa under the action of a magnetic field compared with the action of a non-magnetic field, and the shear stress refers to the force required by the Bingham fluid (Bingham fluid) to flow when the Bingham fluid is acted by the magnetic field.

In addition, the structure of the magnetic response composite body can reduce the substantial density of particles, improve the compatibility of the magnetic response composite body and carrier liquid, be easily dispersed in the carrier liquid and reduce the sedimentation rate.

In addition, the dry stirring method provides the effect that the magnetic response complex can be manufactured without organic chemicals or precursor medicines in the process of preparing the magnetic response complex. That is, the removal of organic chemicals or precursor chemicals and the removal of by-products or residues generated during the preparation process are not required, i.e., the yield is one hundred percent, and the environmental pollution is also reduced.

The first embodiment of the present disclosure is described as follows:

(1) 15g of carbonyl iron and 0.079g of nanoparticles (silica) are placed in a container, and optionally air, nitrogen or argon is introduced, wherein the mixture of carbonyl iron and nanoparticles (silica) is stirred at room temperature in a dry manner, optionally for several seconds or minutes, to obtain a magnetically responsive composite.

(2) The obtained magnetic-response complex was placed in a container, and 30.619g of a carrier liquid (silicone oil) was added to the container of the magnetic-response complex to disperse the magnetic-response complex in the carrier liquid (silicone oil) to obtain a magnetorheological fluid 2.

(3) In this example, a magnetic response composite was obtained by dry stirring reaction, and as a result, as shown in Scanning Electron Microscope (SEM) images of fig. 2A and 2B, it was clearly seen that silica particles were distributed on the surface of carbonyl iron.

(4) The magnetorheological fluid obtained in this example, formulated at 33 weight percent, was tested for settling and compared to magnetorheological fluid 1 (prepared from 15.079g of carbonyl iron and 30.619g of carrier fluid (silicone oil) as 33 weight percent magnetorheological fluid 1) by the following comparative analysis:

(a) the sedimentation test is performed by a laser beam penetrometer, when the magnetorheological fluid is penetrated by the laser beam, the sensor receives the energy of the laser beam, the lower the measured energy is, the better the dispersion is, after the energy measured by the sensor is subjected to data standardization, the energy intensity is represented as 0 at the lowest, and is represented as 1 at the highest.

(b) The results of the sedimentation test are shown in fig. 3A and 3B, and the dispersion of the magnetorheological fluid 2 of the present example is good even after a lapse of time, but the dispersion becomes worse as the lapse of time of the conventional magnetorheological fluid 1 is longer.

(c) Further, as shown in fig. 3A, in the initial period (0 hour), the energy intensity is shown to be 0, i.e., the magnetorheological fluid 1 and the magnetorheological fluid 2 are both in the dispersed state, in the final period (8 hours), the energy intensity of the magnetorheological fluid 1 is shown to be 0.57, i.e., the magnetorheological fluid is significantly settled, and further, the energy intensity of the magnetorheological fluid 2 is shown to be 0, i.e., the magnetorheological fluid is still in the dispersed state. The magnetorheological fluid state described above is shown in the sample images before and after the sedimentation test shown in fig. 3B.

The second embodiment of the present invention is described as follows:

(1) 15g of carbonyl iron and 0.079g of nanoparticles (silica) are placed in a container, and optionally air, nitrogen or argon is introduced, wherein the mixture of carbonyl iron and nanoparticles (silica) is stirred at room temperature in a dry manner, optionally for several seconds or minutes, to obtain a magnetically responsive composite.

(2) The obtained magnetic-responsive complex was placed in a container, and further, 2.661g of a carrier liquid (silicone oil) was added to the container of the magnetic-responsive complex to disperse the magnetic-responsive complex in the carrier liquid (silicone oil) to obtain a magnetorheological fluid 4.

(3) In the second example, mainly the shear stress test is performed, which is described as follows:

(a) the shear stress test uses a double-plate magnetorheological instrument (Physica MRC-301) and is provided with a current magnetic field controller, the current is controlled to be 5A during the test, the shear stress is plotted against the shear rate to obtain a flow curve, and the shear stress data is obtained from the curve.

(b) The comparative object (magnetorheological fluid 3) is carbonyl iron which is directly added with silicone oil, so that the carbonyl iron is dispersed in the silicone oil, the weight percentage concentration of the carbonyl iron is 85%, and the magnetorheological fluid 4 is the magnetic response composite obtained in the embodiment, and the silicone oil is added, so that the magnetic response composite is dispersed in the silicone oil, and the weight percentage concentration of the magnetic response composite is 85%.

(c) As can be seen from the flow curve of FIG. 4, the shear stress of the MR fluid 4 is 89-99 kPa, which is higher than that of the MR fluid 3 by 80-90 kPa, and this result is attributed to the better anti-settling and dispersing ability of the obtained magnetic response composite compared with carbonyl iron in the carrier liquid.

Compared with other conventional technologies, the magnetorheological fluid and the manufacturing method thereof provided by the invention have the following advantages:

(1) the magnetic rheological fluid and the manufacturing method thereof have high shearing stress and good dispersion by using the magnetic response complex, the viscosity degree of the fluid can be changed along with the vibration, the intelligent damper of various devices can be applied by changing the magnetic field and the viscosity degree of the fluid and controlling the damping, and furthermore, the magnetic rheological fluid can be applied to material separation, the bearing and the sealing of mechanical devices and the like due to the change of the viscosity.

(2) The magnetorheological fluid of the invention does not need to add various additives, has lower manufacturing cost, does not need to use a large amount of chemical solvents and medicines, is environment-friendly, and can be applied in the technical field range of higher shear stress.

(3) The present invention is not limited to the above embodiments, and those skilled in the art can understand the technical features and embodiments of the present invention and can not make various changes and modifications without departing from the spirit and scope of the present invention.