KR20110065600A - Fabrication of silica/tio2 nanotubes and their application to electrorheological fluid - Google Patents
Fabrication of silica/tio2 nanotubes and their application to electrorheological fluid Download PDFInfo
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- KR20110065600A KR20110065600A KR1020090122163A KR20090122163A KR20110065600A KR 20110065600 A KR20110065600 A KR 20110065600A KR 1020090122163 A KR1020090122163 A KR 1020090122163A KR 20090122163 A KR20090122163 A KR 20090122163A KR 20110065600 A KR20110065600 A KR 20110065600A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
- B01J19/10—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing sonic or ultrasonic vibrations
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/113—Silicon oxides; Hydrates thereof
- C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/113—Silicon oxides; Hydrates thereof
- C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
- C01B33/14—Colloidal silica, e.g. dispersions, gels, sols
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/14—Conductive material dispersed in non-conductive inorganic material
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
- H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
- H01B3/20—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances liquids, e.g. oils
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
Abstract
The present invention relates to a method for producing an electrorheological fluid using silica / titanium dioxide nanotubes, the inherent properties of one-dimensional type of silica / titanium dioxide nanotubes with high dielectric constant and thereby the electrorheological fluid through the polarization phenomenon of the electrorheological fluid An example of application to a fluid is given.
According to the present invention, it is possible to easily prepare silica / titanium dioxide nanotubes simply and economically through an interfacial sol-gel reaction using reverse phase emulsion polymerization and an additional surface charge. Furthermore, the silica / titanium dioxide nanotubes that can be prepared in the present invention are not limited in size and shape of the nanomaterials according to the size and shape of the silica used as a template, and the thickness is limited depending on the amount of the titanium dioxide precursor added. It is possible to manufacture without the electro-fluidic fluid composed of the silica / titanium dioxide nanotubes has a high degree of polarization compared to the conventional electro-fluidic fluid shows excellent stability and performance.
Titanium dioxide, silica, interfacial sol-gel reaction, nanotubes, electrofluidics
Description
The present invention provides silica / titanium dioxide nanotubes prepared using an interfacial sol-gel method, which occurs only on the surface of silica nanotubes through surface charges introduced into silica nanotubes. To the application of an electrorheological fluid.
Electrorheological fluid is a colloidal solution in which fine particles with polarity are dispersed in an insulating fluid. General term for fluid. The behavior of the electrofluidic fluid is due to the dielectric polarization of the dispersed particles by applying the electric field to the colloid in which the polarizable particles are dispersed in the solvent and by the mutual attraction of the dispersed particles. The particles result from the formation of a fiber or chain structure by an external electric field. The electro-fluidic fluid has been actively studied since it was first reported by Winslow in 1949 that the viscosity of the fluid changed depending on the strength of the electric field when the silica particles were dispersed in oil.
Electrorheological fluids can transform rheological properties by controlling the intensity of an external electric field applied and can be applied with great advantages such as low initial viscosity, high shear stress under low external field and low power consumption. In addition to replacing existing complex mechanical systems, the system can be miniaturized and lightened, or its structure as a whole, as well as the responsiveness of fluids to electric fields and the reversibility of rheological effects. It suggests a variety of potential applications, and a lot of research is being carried out as a scaffold for practical application of applications such as shock absorbers, engine mounts, and braking systems.
In recent years, titanium dioxide (TiO 2 ) has been actively studied and recognized for its application as a dispersed particle of an electrorheological fluid. In particular, due to the high polarization caused by the high dielectric constant 200 of titanium dioxide, and excellent environmental stability has attracted a lot of attention. In addition, nanometer-sized titanium dioxide has superior physical properties compared to conventional bulk materials due to its relatively high surface area.
Recently, after a lot of experiments and in-depth research, the team decided to use a micelle in the form of a cylinder by interacting with a surfactant and a metal salt, without using a method that is completely different from the existing manufacturing method, that is, expensive porous template. After the formation, it was confirmed that silica particles in the form of nanotubes can be prepared by hydrolysis of tetraethyl orthosilicate (TEOS) on the micelle surface (Adv. Mater. Vol. 16, pp. 799-). 802). In addition, the team confirmed that it is possible to coat titanium dioxide on silica nanoparticles using the interfacial sol-gel method, which occurs only on the surface of silica nanoparticles through the additional surface charges of the prepared silica nanoparticles. Application to the rheology fluid has led to the present invention.
Therefore, in order to apply the silica / titanium dioxide nanotubes to the electrorheological fluids through prior studies, it is necessary to study the dispersion method of the nanoparticles, and to improve the characteristics and commercialization of the electrorheological fluids. There is a strong demand for studies on the electrorheological properties, long-term dispersion stability, and prevention of aggregation due to surface modification.
An object of the present invention is to easily solve the problems of the prior art, and to easily introduce the silica / titanium dioxide nanotubes prepared in the electro-fluidic fluid based on the previous research in the electro-fluidic fluid, the electro-rheological characteristics according to the content of the nanoparticles and the electric field strength To check.
It is an object of the present invention to provide an electrorheological fluid constructed in such a manner.
After many experiments and in-depth studies, the present inventors easily manufactured silica / titanium dioxide, that is, a cylinder-shaped micelle was formed through interaction between a surfactant and a metal salt, and then produced through a hydration reaction. It was confirmed that the silica / titanium dioxide nanotubes could be prepared through the interfacial sol-gel reaction of the titanium dioxide precursor on the silica nanotubes, and thus, the present invention was applied to an electrorheological fluid.
Titanium tetraisopropoxide, titanium butoxide (titanium butoxide) using the interfacial sol-gel method which is limited only on the surface of silica nanotubes having a size of 1 nanometer to several micrometers ), Titanium dioxide is coated with titanium dioxide precursors of titanium ethoxide, titanium sulphate and titanium chloride to produce silica / nanotubes, and then applied as an electrorheological fluid. And characterization.
According to the present invention, a method for preparing silica / titanium dioxide nanotubes and applying them to an electrorheological fluid and examining its characteristics,
(A) dispersing the silica nanotubes prepared through the micelle in the form of a cylinder in a mixed solution of ethanol and acetonitrile;
(B) introducing an ammonium cation to the surface of the silica nanotubes by introducing an ammonia solution into the silica nanotube dispersion solution dispersed in the ethanol and acetonitrile mixed solution; And,
(C) adding a titanium dioxide precursor to the silica nanotube dispersion solution in which the ammonium cation is introduced such that the interfacial sol-gel reaction occurs after adsorption only on the surface of the silica nanotubes; And,
(D) dispersing the polymerized silica / titanium dioxide nanotubes in a silicon fluid using various dispersion methods to form an electrorheological fluid; And
(E) Electrorheological characteristics at various nanoparticle contents and external electric field strengths were measured using a rheometer connected to a DC power supply. It is composed of steps to consider.
The method for preparing silica / titanium dioxide nanotubes using the interfacial sol-gel method which proceeds to the surface of silica nanotubes by introducing additional ions into the silica nanotubes through the micelle in the form of cylinder according to the present invention has been reported so far. As an entirely new method without bars, it significantly reduces the problems caused by the conventional methods and can easily produce nanometer-sized titanium dioxide. It also has the advantage of being able to mass-produce silica / titanium dioxide nanotubes through a simple manufacturing method. Thus prepared silica / titanium dioxide nanotubes had high surface area and excellent dielectric constant, and thus could exhibit desired electrorheological properties even at a low particle content of 2.5 vol%. Therefore, it is considered that the application and the implementation of the electro-fluidic fluid with the advantages of the excellent dielectric constant, high polarization, etc. of the silica / titanium dioxide nanotubes.
Unless specifically stated in the specification, the numerical range of temperature, content, size, etc. means a range capable of optimizing the manufacturing method of the present invention.
The mixed solution of ethanol and acetonitrile used in step (A) is preferably 10 to 100 parts by weight based on 100 parts by weight of acetonitrile. If the amount of acetonitrile is 10 parts by weight or less and the titanium dioxide precursor may be present not only on the surface of the silica nanotubes but also on the solution, if it is 100 parts by weight or more, a problem arises in the dispersion of the silica nanotubes.
The diameter of the silica nanotubes is not particularly limited and is preferably 50 to 1000 nanometers. The length of the nanotubes is also not particularly limited and is preferably 4 to 50 micrometers.
When dispersing the silica nanotubes on the solution, it is preferably 1 to 20 parts by weight based on 100 parts by weight of ethanol. If the amount of the silica nanotubes is less than 1 part by weight, problems in the manufacturing process cost due to excessive use of the aqueous solution occur. If the amount is more than 20 parts by weight, the dispersion of the nanoparticles, which are not easily dispersed or finally produced in the ethanol solution, is difficult to disperse. It can't be entangled with each other.
The temperature for dispersing the silica nanotubes on the solution is not particularly limited, but it is preferred that the dispersion time is 10 to 100 minutes by proceeding at a temperature of 1 to 30 ° C.
The amount of the ammonia solution used in step (B) may be added up to one hundredth the same amount as that of the silica nanotubes, but is not limited to these ranges and may be more or less than the above ranges.
The temperature at which the adsorption occurs by introducing additional ammonium ions is not particularly limited, but proceeds at a temperature of 1 to 50 ℃, the stirring time for the adsorption is preferably 5 to 120 minutes.
The type of titanium dioxide precursor in step (C) is not limited to a specific precursor, but is not limited to titanium tetraisopropoxide, titanium butoxide, titanium ethoxide, titanium oxysulfate sulfate) and titanium chloride may be used as the precursor.
The amount of the precursor may be added at a weight ratio of one tenth to five times the silica nanotube, but is not limited to these ranges and may be more or less than the above range.
The reaction time required for the interfacial sol-gel reaction of the precursor of titanium dioxide is preferably 1 to 24 hours, like the general sol-gel reaction, but is not limited thereto, and may be shorter or longer than the above range depending on the type of precursor. The temperature required for the interface sol-gel reaction may be 5 to 60 ° C., but may be higher or lower than the above range depending on the type of precursor.
In step (D) the silica / titanium dioxide nanotubes are dispersed in a silicone fluid to form an electrorheological fluid. The type of dispersion method is not particularly limited, and most of the methods applicable to the dispersion method can be used. Among them, dispersion methods such as a shaker, a ball mill, a sonic generator, and an ultrasonic generator are preferable.
The silicone fluid uses a silicone oil having a viscosity of 20 cS to 500 cS and is not limited to these ranges, and may be higher or lower than the range.
The content of silica / titanium dioxide nanotubes dispersed in the silicone fluid is possible in the range of 2.5 vol% to 15.0 vol%, but may be higher or lower than the above range.
In step (E), a rheometer in which a DC power supply is connected is used as a device for checking the electrorheological characteristics. The rheometer is composed of a driving unit, a thermostat capable of temperature control and a processing unit of temperature, torque, and rotation speed measurement signals, and may be configured differently according to the type and measurement method of the rheometer, and are not particularly limited.
The commonly used measuring methods can be appropriately selected depending on the viscosity and the nature of the fluid, mainly Brookfield Viscometer, Cone-and-Plate rheometer, Parallel plate Viscometer Etc. are possible, and are not specifically limited.
The gap distance required for the measuring method is preferably 100 to 2000 μm, but is not limited thereto, and may be higher or lower than the above range depending on experimental requirements such as viscosity of the silicone oil or measurement temperature.
The measuring method may be measured in a range of 25 ° C. to 100 ° C., but is not particularly limited thereto and may be higher or lower than the above range.
The external electric field required for the measuring method can be varied from 0 kV / mm to 5.0 kV / mm, which can be controlled according to the electrical properties of the dispersed particles and can be higher or lower than the above range.
The electrorheological properties of the electrofluidic fluid can be observed at a shear rate of 10 −2 to 10 3 sec − 1 , but are not limited to these ranges, and are in the above range according to the characteristics of the particles dispersed in the silicone fluid and the type of the silicone fluid. It can be higher or lower.
Silica / titanium dioxide nanotubes applied to the method of the present invention have the feature of promoting the polarization phenomenon of the electro-fluidic fluid by using a high dielectric constant property, which is inherent to titanium dioxide. Thus, when dispersed in silicone oil for application as an electrorheological fluid, excellent stability can be expected, and the high surface area of the nanoparticles can obtain excellent electrorheological properties with small particle content through increased interaction with the fluid. Could be. However, the silica / titanium dioxide nanotubes according to the present invention are not limited to these exemplary applications, but can be applied and applied to various anticipated applications in the future, and their use does not depart from the scope of the present invention.
[Example]
Although specific examples of the present invention will be described with reference to the following Examples, the scope of the present invention is not limited thereto.
Example 1
Dissolve 0.7 g of silica nanotubes with a diameter of 50 nm and 5 μm in 50 ml of ethanol and 15 ml of acetonitrile, add 0.4 ml of ammonia solution, and add ammonium ions to the silica nanotubes with stirring for 2 hours. Allow it to adsorb. 2.1 ml of titanium tetraisopropoxide was added to the reaction solution, followed by stirring at room temperature for 6 hours to allow a limited interfacial sol-gel reaction only on the surface of the silica nanotubes. As a result of analyzing the prepared silica / titanium dioxide nanotubes using a transmission electron microscope, a layer of titanium dioxide having a thickness of about 3.0 nanometers was formed on the surface of the silica nanoparticles and the diameter increased to about 56 nanometers. I could confirm it. (Fig. 1)
[Example 2]
Using the same method as in Example 1, 2.8 ml of titanium tetraisopropoxide was introduced to allow a limited interfacial sol-gel reaction on the surface of the silica nanotubes, and analyzed using a transmission electron microscope. As a result, it was confirmed that a titanium dioxide layer of about 5 nanometers was formed, thereby producing silica / titanium dioxide nanotubes having a diameter of about 60 nanometers. As can be seen from the above results, it can be seen that the thickness of the titanium dioxide layer formed on the surface of the silica nanotubes is related to the addition amount of the titanium dioxide precursor introduced, and as the amount of the titanium dioxide precursor increases It can be seen that the thickness of the titanium layer becomes thicker.
Example 3
Using the same method as in Example 1, using 0.7 g of silica nanotubes with a diameter of 300 nm and a length of 5 μm, and introducing 3.0 ml of titanium tetraisopropoxide, titanium dioxide was limited to the surface sol on the surface of the silica nanotubes. The gel reaction occurred, and analysis using a transmission electron microscope revealed that a layer of titanium dioxide of about 4 nanometers was formed, resulting in the formation of silica / titanium dioxide nanotubes having a diameter of about 308 nanometers. .
Example 4
By using the same method as in Example 1, using 0.7 g of silica nanotubes with a diameter of 1000 nm and a length of 5 μm, and introducing 3.5 ml of titanium tetraisopropoxide, titanium dioxide was limited to the surface sol on the surface of the silica nanotubes. The gel reaction occurred, and the result of analysis using a transmission electron microscope showed that a layer of titanium dioxide of about 5 nanometers was formed, thereby producing silica / titanium dioxide nanotubes having a diameter of about 1010 nanometers. there was.
Example 5
Using the same method as in Example 1, 0.7 g of silica nanotubes having a diameter of 50 nm and 5 μm in length were introduced, and 2.1 ml of titanium butoxide was introduced to restrict titanium dioxide at the surface of the silica nanotubes. As a result, an analysis using a transmission electron microscope revealed that a titanium dioxide layer of about 7 nanometers was formed, thereby producing silica / titanium dioxide nanotubes having a diameter of about 64 nanometers.
Example 6
Using the same method as in Example 1, 0.7 g of silica nanotubes of 50 nm in diameter and 5 μm in length were introduced, and 2.1 ml of titanium oxysulfate was introduced to restrict titanium dioxide to interfacial sol-gel reaction on the surface of the silica nanotubes. As a result, an analysis using a transmission electron microscope revealed that a layer of titanium dioxide of about 8 nanometers was formed, thereby producing silica / titanium dioxide nanotubes having a diameter of about 66 nanometers.
Example 7
Using the same method as in Example 1, 0.7 g of silica nanotubes having a diameter of 50 nm and a length of 5 μm were used, and 2.1 ml of titanium ethoxide was introduced to restrict titanium dioxide to interfacial sol-gel reaction on the surface of the silica nanotubes. As a result, an analysis using a transmission electron microscope revealed that a layer of titanium dioxide of about 10 nanometers was formed, thereby producing silica / titanium dioxide nanotubes having a diameter of about 70 nanometers (FIG. 2). ).
Example 8
Using the same method as in Example 1, 0.7 g of silica nanotubes of 50 nm in diameter and 5 μm in length were introduced, and 2.1 ml of titanium chloride was introduced to restrict the interfacial sol-gel reaction on the surface of the silica nanotubes. When analyzed using a transmission electron microscope, a titanium dioxide layer of about 5 nanometers was formed, and it was confirmed that silica / titanium dioxide nanotubes having a diameter of about 60 nanometers were produced.
Example 9
The electrorheological properties of the silica / titanium dioxide nanotubes prepared by the above method were examined. First, silica / titanium dioxide nanotubes with a diameter of 50 nm and a length of 5 μm were dispersed in a silicon fluid (Poly (dimethylsiloxane)) having a viscosity of 100 cSt and a density of 0.97 g /
Example 10
We have examined the electrorheological properties according to the measurement temperature of the electrorheological fluid prepared by the above method. The magnitude and shear rate of the external electric field were 5 kV / mm and 0.1, respectively. The electrorheological properties were investigated at 2.5 vol% volume ratio of silica / titanium dioxide nanotubes of 50 nm in diameter and 5 μm in length, fixed at sec −1 . As a result, the shear stress value of 470 pa could be confirmed (FIG. 3).
Example 11
Experiment in the same manner as in Example 10, except that the magnitude and shear rate of the external electric field is 5 kV / mm and 0.1 The electrorheological properties were examined at a volume ratio of 5.0 vol% of silica /
Example 12
Experiment in the same manner as in Example 10, except that the magnitude and shear rate of the external electric field is 5 kV / mm and 0.1 The electrorheological properties were investigated at 10.0 vol% volume ratio of silica / titanium dioxide nanotubes of 50 nm in diameter and 5 μm in length, fixed at sec −1 . As a result, the shear stress value of 18600 pa was confirmed.
Example 13
Experiment in the same manner as in Example 10, except that the magnitude and shear rate of the external electric field is 5 kV / mm and 0.1 The electrorheological properties were investigated at 15.0 vol% volume ratio of silica / titanium dioxide nanotubes of 50 nm in diameter and 5 μm in length, fixed at sec −1 . As a result, the shear stress value of 68000 pa could be confirmed.
Example 14
The electrorheological properties of the silicone fluid of the electrofluidic fluid prepared by the above method were examined. The magnitude and shear rate of the external electric field were 5 kV / mm and 0.1, respectively. While fixed at sec -1 , the silica and titanium dioxide nanotubes having a diameter of 50 nm and a length of 5 μm were dispersed in a silicon fluid having a viscosity of 20 cSt at a volume ratio of 15.0 vol%, and the electrorheological properties were examined. As a result, the shear stress value of 54200 pa could be confirmed.
Example 15
Experiment in the same manner as in Example 14, except that the size and shear rate of the external electric field is 5 kV / mm and 0.1 While fixed at sec -1 , the silica and titanium dioxide nanotubes having a diameter of 50 nm and a length of 5 μm were dispersed in a silicon fluid having a viscosity of 250 cSt at a volume ratio of 15.0 vol%, and the electrorheological properties were examined. As a result, the shear stress value of 71020 pa could be confirmed.
Example 16
Experiment in the same manner as in Example 14, except that the size and shear rate of the external electric field is 5 kV / mm and 0.1 After fixing to sec -1 , the silica and titanium dioxide nanotubes having a diameter of 50 nm and a length of 5 μm were dispersed in a silicon fluid having a viscosity of 500 cSt at a volume ratio of 15.0 vol%, and the electrorheological properties were examined. As a result, the shear stress value of 73940 pa could be confirmed.
Example 17
The electrorheological properties of the electrorheological fluids prepared by the above method were examined. First, silica / titanium dioxide nanotubes of 50 nm in diameter and 5 μm in length were dispersed in a volume ratio of 15.0 vol% in a silicone fluid having a viscosity of 100 cSt, and then the size and shear rate of the external electric field were 5 kV / mm and 0.1, respectively. With the sec -1 fixed, the electrorheological properties at 50 ℃ were investigated. As a result, the shear stress value of 58640 pa could be confirmed.
Example 18
The experiment was carried out in the same manner as in Example 17, but the electrorheological characteristics at the measurement temperature of 75 ℃ were examined. As a result, the shear stress value of 46820 pa could be confirmed.
Example 19
The experiment was carried out in the same manner as in Example 17, but the electrorheological characteristics at the measurement temperature of 100 ℃ were examined. As a result, the shear stress value of 19730 pa was confirmed.
Example 20
We have examined the electrorheological properties according to the external electric field size of the electrorheological fluid prepared by the above method. First, silica / titanium dioxide nanotubes of 50 nm in diameter and 5 μm in length were dispersed in a volumetric content of 15.0 vol% in a silicone fluid having a viscosity of 100 cSt, and then the shear rate and measurement temperature were respectively 0.1. Electrorheological characteristics at the external electric field of 1.0 kV / mm with sec - 1 and 25 ℃ were investigated. As a result, the shear stress value of 14900 pa was confirmed. (Figure 4)
Example 21
The experiment was performed in the same manner as in Example 20, but the electrorheological characteristics at the external electric field of 2.0 kV / mm were examined. As a result, the shear stress value of 27400 pa could be confirmed.
[Example 22]
The experiment was performed in the same manner as in Example 20, but the electrorheological characteristics at an external electric field of 3.0 kV / mm were examined. As a result, the shear stress value of 40500 pa could be confirmed.
[Example 23]
The experiment was performed in the same manner as in Example 20, but the electrorheological characteristics at an external electric field of 4.0 kV / mm were examined. As a result, the shear stress value of 50500 pa could be confirmed.
Example 24
The experiment was performed in the same manner as in Example 20, but the electrorheological characteristics at an external electric field of 5.0 kV / mm were examined. As a result, the shear stress value of 68000 pa could be confirmed.
Those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above contents.
1 is a scanning electron microscopy photograph of silica / titanium dioxide nanotubes prepared by the present invention;
2 is a transmission electron microscopy photograph of silica / titanium dioxide nanotubes prepared by the present invention;
Figure 3 is the magnitude and shear rate of the external electric field measured in Example 10 of the present invention, respectively 5 kV / mm and 0.1 Shear stress change graph with particle content of silica /
4 is 30 vol% and 0.1, respectively, for the particle content and shear rate measured in Example 20 of the present invention. This is a graph of shear stress change of the rheological fluid according to the external electric field size of silica / titanium dioxide nanotubes of 50 nm in diameter and 5 μm in length, fixed at sec −1 .
Claims (12)
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013066562A2 (en) * | 2011-11-03 | 2013-05-10 | Baker Hughes Incorporated | Polarizable nanoparticles and electrorheological fluid comprising same |
| US8808567B2 (en) | 2011-11-03 | 2014-08-19 | Baker Hughes Incorporated | Magnetic nanoparticles and magnetorheological fluid comprising same |
| KR101682527B1 (en) | 2015-10-03 | 2016-12-06 | (주)마이크로텍시스템 | touch keypad combined mouse using thin type haptic module |
| CN112251269A (en) * | 2020-10-22 | 2021-01-22 | 青岛科技大学 | Titanic acid @ silicon dioxide core-shell type nano composite particle electrorheological fluid and preparation method thereof |
| KR20210130621A (en) * | 2020-04-21 | 2021-11-01 | 한국과학기술원 | Robot Gripper |
| KR20230046444A (en) * | 2021-09-30 | 2023-04-06 | 숭실대학교산학협력단 | Method for manufacturing electrorheological fluid using phosphorene |
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2009
- 2009-12-10 KR KR1020090122163A patent/KR20110065600A/en not_active Application Discontinuation
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013066562A2 (en) * | 2011-11-03 | 2013-05-10 | Baker Hughes Incorporated | Polarizable nanoparticles and electrorheological fluid comprising same |
| WO2013066562A3 (en) * | 2011-11-03 | 2013-07-18 | Baker Hughes Incorporated | Polarizable nanoparticles and electrorheological fluid comprising same |
| US8808567B2 (en) | 2011-11-03 | 2014-08-19 | Baker Hughes Incorporated | Magnetic nanoparticles and magnetorheological fluid comprising same |
| US9283619B2 (en) | 2011-11-03 | 2016-03-15 | Baker Hughes Incorporated | Polarizable nanoparticles comprising coated metal nanoparticles and electrorheological fluid comprising same |
| KR101682527B1 (en) | 2015-10-03 | 2016-12-06 | (주)마이크로텍시스템 | touch keypad combined mouse using thin type haptic module |
| KR20210130621A (en) * | 2020-04-21 | 2021-11-01 | 한국과학기술원 | Robot Gripper |
| CN112251269A (en) * | 2020-10-22 | 2021-01-22 | 青岛科技大学 | Titanic acid @ silicon dioxide core-shell type nano composite particle electrorheological fluid and preparation method thereof |
| KR20230046444A (en) * | 2021-09-30 | 2023-04-06 | 숭실대학교산학협력단 | Method for manufacturing electrorheological fluid using phosphorene |
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