TWI648530B - Rheometer - Google Patents

Abstract

The invention provides a rheometer which utilizes the interaction between a rod and a magnetic field to cause vibration of the rod, and the laser displacement system determines the displacement of the mirror caused by the vibration of the rod, and utilizes the vibration The voltage and phase difference calculate the rheological properties of the fluid to be tested, including the storage modulus and the dissipation modulus. Furthermore, the rheometer can be used for on-line measurements.

Description

Rheometer

This invention relates to a rheometer, and more particularly to an in-line rheometer.

The rheological behavior of a material involves the viscous behavior of the liquid and the elastic behavior of the solid. In general, a fully elastic system can instantaneously reach a balanced deformation when subjected to an external force, and after the external force is removed, the complete elastic body will release the energy stored by the external force for its work; and the fully viscous system is deformed after being subjected to an external force. It changes linearly with time, and after the external force is removed, the viscous body will dissipate its stored kinetic energy in the form of heat, which is irreversible. However, when the deformation property of the material is related to time, the rheological behavior of the material is between the fully elastic body and the complete viscous body, that is, the viscoelastic material in which the material has both elastic behavior and viscous behavior. And its reversibility will decrease as the time of external force increases.

A rheometer is an instrument used to measure the rheological behavior of a material, primarily to measure fluid material. The rheometer applies an external force to the material to be tested and measures its behavior (including irreversible flow deformation and reversible elastic deformation). One of the basic rheological properties of a viscosity fluid, which is a measure of the friction between fluid molecules. If the friction between the molecules is large, the fluid does not flow easily. Movement, therefore, viscosity can be considered as the extent to which the fluid resists flow. Viscosity is defined as the ratio of shear stress to shear strain gradient when a fluid is subjected to shear stress.

For Newtonian fluids, viscosity does not change with shear rate, while for non-Newtonian fluids, viscosity is a function of shear rate. Therefore, in the case of Newtonian fluid, the relationship between viscosity (η) and stress (τ) is as follows: (I):

If it is a non-Newtonian fluid, the viscosity needs to be changed to a function of time [η(t)] or called complex viscosity (η*). The relationship between viscosity and stress is as shown in the following formula (II), where formula (II) The storage modulus (G') and the loss modulus (G" are included in the following equations (III) and (IV):

G ' (ω)=ω η "( ω ) (III)

G"(ω)=ω η' ( ω ) (IV)

Therefore, the viscosity (η) and the viscoelastic modulus (G) are both a function of frequency and can be expressed by the following equations (V) and (VI):

Conventional rheometers include cone and plate, parallel plate, rotary and capillary. Capillary rheometers are one of the most widely used rheometers available today to measure the rheological properties of materials under superviews. The rotary rheometer generates shear force by rotation, and places the material to be tested under a relatively rotating fixture. The measurement of the shear flow is performed. However, the above-mentioned conventional rheometer cannot be used as an online instrument to provide online real-time rheological information. Although there are currently online instruments that provide online real-time measurement information, they are usually only a line viscometer. They only provide the viscosity coefficient of the material to be tested, and cannot further measure the storage modulus of the material to be tested. Dissipate the modulus.

In view of this, there is no need to provide an online instrument that provides information on the storage modulus and dissipation modulus to provide complete and instantaneous online rheological information.

One aspect of the present invention is to provide a rheometer that generates motion by a rod under the action of a magnetic field and senses the motion of the rod using an electro-radiation displacement system. Therefore, the rheological properties of the fluid can be measured by fluid-solid coupling of the rod to the fluid to be tested.

According to an aspect of the invention, there is provided a rheometer comprising a base, a container disposed on the base, a rod disposed in the container, a magnet fixed on the rod, and disposed on the rod Mirrors, complex arrays, and laser displacement systems. The wire is centered on the magnet and surrounds the rod. The container has a space for accommodating the fluid to be tested. The laser displacement system is used to determine the displacement of the mirror, which includes a laser source and a position sensor. The laser source is used to emit light to the mirror so that the mirror reflects the light back to the laser displacement system. The position sensor is used to sense the reflected light to determine the amount of displacement of the mirror.

According to an embodiment of the invention, the rheometer further comprises a line 圏 bracket and cable 圏 base. The cymbal bracket is used to fix the cymbal, and the cymbal base surrounds the base and is used to support the cymbal bracket.

According to an embodiment of the invention, the container comprises an inflow tube and an outflow tube. The inflow tube is provided on the bottom surface of the container and serves to allow fluid to flow into the container. The outflow tube system includes a hollow tube that communicates with the bottom surface and is used to allow fluid to drain from the container.

According to an embodiment of the invention, the rheometer further includes a signal generator for inputting current to the coil.

According to an embodiment of the invention, the laser displacement system is configured to measure the amount of vibration deformation of the rod according to the displacement amount of the mirror.

According to an embodiment of the invention, the vibration mode of the rod comprises twisting, bending and combinations thereof.

According to an embodiment of the invention, the rod comprises a plurality of elliptical holes, and the ratio of the major axis to the minor axis of the elliptical hole is 0.1 to 10.

According to an embodiment of the invention, the rheometer further includes a computer device, wherein the computer device is electrically connected to the laser displacement system and the signal generator. The computer device detects the viscoelastic modulus of the fluid according to the displacement of the mirror, wherein the viscoelastic modulus is calculated by the following formula (1): | G ^* | _LPVS = ( α × V _core - β × V _liquid ) × f ⁿ (1)

In the formula (1), | G ^* | _LPVS represents the viscoelastic modulus, f represents the frequency, α, β and n are the correction parameters, and V _core and V _liquid respectively represent the rods and the rods in the container. The amplitude voltage of the object and the fluid is calculated by the following equations (2) and (3): V _core = V _{core - In} / V _core-Out (2)

V _liquid = V _liquid-In / V _liquid-Out (3)

In the formula (2), V _core-In represents the amplitude voltage input when only the rod is present, and V _core-Out represents the amplitude voltage of the output; in the formula (3), V _liquid-In represents the inclusion of the rod And the amplitude voltage input when the fluid is in, and V _liquid-Out represents the amplitude voltage of the output.

According to an embodiment of the invention, the computer device is further configured to detect a loss tangent value of the fluid, which is calculated by the following formula (4): tan δ _LPVS = γ × | tan δ _{liquid -} tan δ _core | / f ^N (4)

In equation (4), δ _LPVS represents the loss tangent, f represents the frequency, γ and N are the correction parameters, and δ _core and δ _liquid represent the phase difference of only the rod and the fluid in the container, respectively. Calculated by the following equations (5) and (6): tan δ _core =|tan[( θ _core-Out - θ _core-In ) π /180]| (5)

Tan δ _liquid =|tan[( θ _liquid-Out - θ _liquid-In ) π /180]| (6)

In the formula (5), θ _core-In represents the phase angle input only when the rod is present, and θ _core-Out represents the phase angle of the output; in the formula (6), θ _liquid-In represents the fluid contained therein. The phase angle entered, and θ _liquid-Out represents the phase angle of the output.

According to an embodiment of the invention, the computer device is further configured to detect a storage modulus and a dissipation modulus of the fluid, wherein the storage modulus and the dissipation modulus are calculated by the following equations (7) and (8):

G " _LPVS = G' _LPVS ×tan δ _LPVS (8)

In equations (7) and (8), G' _LPVS represents the storage modulus, and G" _LPVS represents the dissipation modulus.

By using the rheometer of the present invention, on-line measurement can be performed, which is generated by the interaction force between the rod and the magnetic field, and the measurement is performed. The rheological properties of the fluid, including the viscoelastic modulus, the storage modulus, and the relationship between the dissipation modulus and the frequency.

100‧‧‧ rheometer

110/210‧‧‧ body part

120‧‧‧Base

130/230‧‧‧ Container

132‧‧‧Inflow pipe

134‧‧‧ Outflow tube

136‧‧‧ space

138/238‧‧‧ bottom surface

140/240‧‧‧ rods

150/250‧‧‧ magnet

160‧‧‧Mirror

170/270‧‧‧ coil

172‧‧‧ coil bracket

174‧‧‧Coil base

180‧‧‧Laser Displacement System

182‧‧‧Laser source

184‧‧‧ position sensor

290‧‧‧ fixed department

h/h ₁ /h ₂ ‧‧‧height

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; [Fig. 2A] to [Fig. 2D] are partial cross-sectional views showing a main portion of a rheometer according to some embodiments of the present invention; [Fig. 3A] is a view showing an embodiment according to an embodiment of the present invention. 2 and the relationship between the modulus of the viscoelastic modulus and the frequency of the first example; [Fig. 3B] is a diagram showing the relationship between the storage modulus and the frequency according to the first embodiment, the second embodiment and the first comparative example of the present invention; [Fig. 3C] FIG. 4A is a diagram showing the relationship between the dissipation modulus and the frequency according to the first embodiment, the second embodiment, and the first embodiment of the present invention; [FIG. 4A] FIG. 4A is a diagram showing the third embodiment, the fourth embodiment, and the second embodiment of the present invention. FIG. 4B is a diagram showing the relationship between the storage modulus and the frequency according to Embodiment 3, Embodiment 4 and Comparative Example 2 of the present invention; and [FIG. 4C] is based on the relationship between the storage modulus and the frequency according to Embodiment 3 of the present invention; The relationship between the dissipative modulus and the frequency of the third embodiment and the second embodiment of the present invention.

In view of the above, the present invention provides a rheometer that generates vibration by an interaction force between a rod and a magnetic field, and measures the rheological properties of the fluid to be tested, including the storage modulus and the dissipation mode. The relationship between numbers and frequencies.

Please refer to FIG. 1, which is a side elevational view of a rheometer 100 in accordance with an embodiment of the present invention. The rheometer 100 includes a body portion 110 and a laser displacement system 180. The body portion 110 includes a base 120, a container 130, a rod 140 disposed within the container 130, a magnet 150 secured to the rod 140, a mirror 160 disposed over the rod 140, and a plurality of arrays of turns 170. In one embodiment, the magnet 150 and the mirror 160 are disposed on opposite sides of the rod 140, respectively. The laser displacement system 180 includes a laser source 182 and a position sensor 184. In one embodiment, the container 130 is disposed on the base 120 and the container 130 has a space 136 for receiving a fluid to be tested.

In one embodiment, the container 130 can optionally include an inflow tube 132 and an outflow tube 134, wherein the inflow tube 132 is disposed on the bottom surface 138 of the container 130 to allow the fluid to be tested to flow into the container 130, and the outflow tube 134 is used. In order to discharge the fluid to be tested from the container. In one embodiment, the outflow tube 134 is a hollow tube having a height h that communicates with the bottom surface 138 to expel the fluid to be tested. The height h of the outflow pipe 134 can be adjusted according to the volume of the fluid to be tested. When the volume height of the fluid to be tested exceeds the height h, excess fluid to be tested will be discharged from the outflow pipe 134, thereby controlling the volume of the fluid to be measured during the measurement. .

In one embodiment, the turn 170 is centered around the magnet 150 and surrounds the wand 140. In one embodiment, the rheometer 100 can optionally include a signal generator (not shown) for inputting current to the coil 170. The coil 170 is caused to generate a uniform magnetic field and interacts with the magnet 150 on the rod 140 to drive the rod 140 to vibrate the rod 140. In an embodiment, the vibration mode of the rod 140 includes twisting, bending, and combinations thereof. In one embodiment, the turns 170 are two sets of Helmholtz coils, which may be a set of vertical turns and a set of horizontal turns. In an embodiment, the rheometer 100 can optionally include a coil bracket 172 and a coil base 174, wherein the coil bracket 172 can be used to fix the coil 170, and the coil base 174 can be disposed to surround the base 120, and To support the wire 圏 bracket 172.

In one embodiment, the laser displacement system 180 is used to determine the amount of displacement of the mirror 160, which utilizes a laser source 182 to emit laser light to the mirror 160, and the mirror 160 reflects the light back to the laser displacement system 180. The reflected light is sensed by the position sensor 184 to determine the amount of displacement of the mirror 160. In one embodiment, the amount of displacement of the mirror 160 is generated according to the vibration of the rod 140 described above. Therefore, the laser displacement system 180 measures the vibration generated by the vibration of the rod 140 according to the displacement amount of the mirror 160. The amount of deformation. In one embodiment, the laser light emitted by the laser source 182 is laser light having a wavelength of 632 nm.

The rheometer 100 can be used to measure the rheological properties of a non-Newtonian fluid or a colloidal suspension at different temperatures and frequencies. In one embodiment, the rheometer 100 measures a frequency ranging from 10 ^-6 Hz to 10 ⁶ Hz. In another embodiment, the rheometer 100 can measure a temperature ranging from 0 °C to 300 °C.

The rheometer 100 is a fluid-solid coupling interaction between the fluid to be tested and the rod 140 by the vibration of the rod 140, and then the measurement is to be tested. The rheological properties of the fluid (including the storage modulus and the dissipation modulus). Therefore, the design of the rod 140 can have an effect on the interaction of fluid-solid coupling. For example, when the contact area of the rod 140 with the fluid to be tested is increased, the interaction of fluid-solid coupling can be increased, thereby improving the measurement accuracy of the rheological properties of the fluid to be tested. In one embodiment, the rod 140 includes a plurality of elliptical holes, wherein the ratio of the major axis to the minor axis of the elliptical hole is 0.1 to 10. Controlling the ratio of the major axis to the minor axis of the elliptical hole can increase the contact stiffness of the rod 140 and the fluid to be tested, thereby increasing the sensitivity of the measurement, thereby reducing the elastic stiffness of the rod 140. Increase the accuracy of low frequency signals by increasing the amount. In an embodiment, the volume percentage of the elliptical holes may be from 0% to 99%, preferably from 40% to 70%. The contact area of the rod 140 with the fluid to be tested can also be increased by adjusting the volume percentage of the elliptical hole. In one embodiment, the cross-section of the rod 140 has a diameter of from about 0.1 mm to about 3 mm and the length of the rod 140 is from about 3 mm to about 30 mm. In another embodiment, the surface roughness of the rod 140 is from about 10 [mu]m to about 500 [mu]m by altering the disturbance of the fluid to be measured by the rod 140 to optimize the accuracy of detecting the rheological properties of the fluid to be tested. degree.

In an embodiment, the ratio of the rod 140 in the fluid to be tested is 10% to 100%, that is, the ratio of the height of the fluid to be tested in the space 136 to the height of the rod 140, which is determined according to the test. The viscosity of the fluid is adjusted differently. In general, when measuring a fluid with a higher viscosity, the proportion of the rod 140 in the fluid to be tested is lower; conversely, when measuring a fluid having a lower viscosity, the rod 140 is required to be tested more. When the fluid is in contact, the proportion of the rod 140 in the fluid to be tested is high. In an embodiment, the material of the rod 140 may be 矽 Gel, silicone, rubber, polymer [for example: polymethyl methacrylate (PMMA) or polyvinyl alcohol (PVA)], metal, alloy or ceramic.

The rheometer 100 can change the configuration of the body portion 110 according to the measurement requirements, including open type, closed type, closed line type and disposable type. 2A-2D, which are partial cross-sectional views of a body portion 210 of a rheometer in accordance with some embodiments of the present invention. 2A is a schematic view showing the configuration of the main body portion 210 of the open rheometer, wherein the height h ₁ of the rod 240 exceeds the height h _{2 of the} container 230, and the coil 270 remains centered on the magnet 250, and surrounds the rod. The object 240 is such that the turns 270 are above the container 230. Open rheometers are preferably used to measure fluids without pressure, such as fluids in open channels.

2B is a schematic view showing the configuration of the main body portion 210 of the closed rheometer, wherein the height h ₁ of the rod 240 is lower than the height h _{2 of the} container 230, and the coil 270 remains centered on the magnet 250, and surrounds the rod. The shape 240 is such that the turns 270 are not higher than the height h _{2 of the} container 230. A closed rheometer is preferably used to measure a pressurized fluid on-line, such as a fluid flowing within a closed tube. It should be noted that since the height h _{1 of the} closed rheometer is lower than the height h ₂ , the fluid measured by the closed rheometer must be transparent or translucent so that the laser can at least partially penetrate the fluid. And then reflected by the mirror (not shown in Figure 2B).

2C is a schematic view showing the configuration of the main body portion 210 of the closed-line rheometer, wherein the rod 240 is not in contact with the bottom surface 238 of the container 230, but is fixed by the top surface of the container 230. Rod 240 is protruding In the container 230, the magnet 250 is also above the container 230, and the coil 270 is also above the container 230. A closed-line rheometer is similar to a closed rheometer in that it is used to measure a pressurized fluid on-line. The difference is that the magnet 250 of the closed-line rheometer is attached to the vessel 230, and the mirror is also Above the container 230, a closed line rheometer can therefore be used to measure non-transparent fluid.

2D is a schematic view showing the configuration of the main body portion 210 of the disposable rheometer, wherein the rod 240 and the magnet 250 are connected to the upper fixing portion 290, and the rod 240 and the magnet 250 are also protruded from the container. 230, while the coil 270 is above the container 230. The disposable rheometer rod 240 is disposable, primarily for measuring fluids that can contaminate the rod 240, such as contaminating fluids or chemical reactions that may occur during the measurement process. And the solidified fluid.

In one embodiment, the rheometer 100 can optionally include a computer device (not shown), and the computer device is electrically connected to the laser displacement system 180 and the signal generator (not shown), and according to the mirror 160 The displacement amount is used to detect the amplitude voltage and the phase lags of the fluid to be tested, thereby obtaining the viscoelastic modulus, the storage modulus, and the dissipation modulus of the fluid to be tested. The rheometer 100 of the present invention is required to perform only the rod 140 (ie, the fluid to be tested is not added in the container) and the container 130 contains the fluid to be tested (ie, the rod 140 is contained in the container and is to be tested) Measurement when fluid).

First, the rheometer 100 calculates the amplitude voltages when only the rods 140 and the fluid to be tested are respectively calculated by V _core and V _liquid , and then calculates the fluid to be tested by using the following formula (1). The viscoelastic modulus. In one embodiment, the viscoelastic modulus measured by the rheometer 100 ranges from 0.1 N/m ² (Pa) to 10 ⁷ N/m ² .

| G ^* | _LPVS = ( α × V _core - β × V _liquid ) × f ⁿ (1)

In the formula (1), | G ^* | _LPVS represents the viscoelastic modulus, f represents the frequency, and α, β, and n are correction parameters. In one embodiment, both α and β are 0.1 and n is 2. However, the correction parameters may vary depending on the fluid to be tested or the different vibration modes, so the present invention does not limit the correction parameter values α, β, and n.

Among them, V _core and V _liquid are calculated by equations (2) and (3), respectively: V _core = V _core-In / V _core-Out (2)

V _liquid = V _liquid-In / V _liquid-Out (3)

In the formula (2), V _core-In represents the amplitude voltage input when only the rod is present, and V _core-Out represents the amplitude voltage of the output. In the formula (3), V _liquid-In represents an amplitude voltage input when a rod and a fluid are contained, and V _liquid-Out represents an amplitude voltage of the output. V _core-In and V _liquid-In are known from the input voltage signal, while V _core-Out and V _liquid-Out are obtained by the vibration deformation amount of the rod provided by the laser displacement system.

Furthermore, the rheometer 100 calculates the phase difference when only the rod 140 and the fluid to be tested are respectively calculated, which are represented by δ _core and δ _liquid , respectively, and further utilizes the tangent values of δ _core and δ _liquid and Equation (4) calculates the loss tangent of the fluid to be tested. The δ _core and δ _liquid systems are calculated using equations (5) and (6), respectively: tan δ _LPVS = γ × | tan δ _liquid -tan δ _core | / f ^N (4)

In equation (4), δ _LPVS represents the loss tangent of the fluid to be tested, f represents the frequency, and γ and N are the correction parameters. In one embodiment, γ is 10,000 and N is 1. However, the correction parameters may vary depending on the fluid to be tested or the different vibration modes, so the present invention does not limit the correction parameter values γ and N.

Tan δ _core =|tan[( θ _core-Out - θ _core-In ) π /180]| (5)

Tan δ _liquid =|tan[( θ _liquid-Out - θ _liquid-In ) π /180]| (6)

In the formula (5), θ _core-In represents the phase angle input when only the rod is present, and θ _core-Out represents the phase angle of the output. In the formula (6), θ _liquid-In represents the phase angle input when the fluid is contained, and θ _liquid-Out represents the phase angle of the output. θ _core-In and θ _liquid-In are the phase angle difference between the electromagnetic signal from the coil 170 and the signal provided by the signal generator after the input current, and θ _core-Out and θ _liquid-Out are at the input. After the current, the phase difference between the signal generated by the vibration of the rod 140 and the signal provided by the signal generator.

The viscoelastic modulus is derived from the storage modulus (G') and the loss modulus (G"), and the viscoelastic modulus is also related to the viscosity coefficient of the fluid to be tested. The relationship of formula (VI):

Furthermore, the phase difference and the storage modulus and the dissipation modulus have the following relationship:

Therefore, by using the above-mentioned viscoelastic modulus and phase difference, the storage modulus and the dissipation modulus can be obtained by using the following equations (7) and (8), respectively:

G " _LPVS = G' _LPVS × tan δ _LPVS (8).

As described above, the rheometer 100 of the present invention calculates the viscoelastic modulus, the storage modulus, and the dissipation modulus of the fluid to be tested by using the interaction of the fluid-solid coupling and the magnetic field, and using the amplitude voltage and the phase difference. Find the fluid to be tested Viscosity coefficient. Furthermore, the rheometer 100 is suitable for combination with other instruments to detect the rheological properties of the fluid to be tested on-line.

The following examples are used to illustrate the application of the present invention, and are not intended to limit the present invention. Those skilled in the art can make various changes without departing from the spirit and scope of the present invention. Retouching.

Polyvinyl alcohol aqueous solution Embodiment 1, Embodiment 2 and Comparative Example 1

The first embodiment, the second embodiment and the comparative example 1 respectively measure the viscoelasticity of a 5 wt% aqueous solution of polyvinyl alcohol by using the rheometer 100 provided by the present invention and a rheometer (Thermo Haake, Germany) currently on the market. The modulus, wherein the rheometer 100 utilizes two modes of vibration, namely bending (Example 1) and twisting (Example 2). Referring to FIG. 3A to FIG. 3C, FIG. 3A is a diagram showing the relationship between the modulus of the viscoelastic modulus and the frequency according to the first embodiment, the second embodiment and the first comparative example, and FIG. 3B is a diagram showing the relationship between the modulus of the viscoelastic modulus and the frequency according to the first embodiment of the present invention; FIG. 3C is a diagram showing the relationship between the dissipation modulus and the frequency according to the first embodiment, the second embodiment, and the first embodiment of the present invention. FIG.

As shown in FIG. 3A to FIG. 3C , the viscoelastic modulus, the storage modulus and the dissipation modulus of the polyvinyl alcohol measured in the first embodiment and the second embodiment are similar, indicating that the two vibration modes of the rheometer 100 are applicable. For measuring the rheological properties of polyvinyl alcohol. Furthermore, FIG. 3A shows that the viscoelastic modulus of the polyvinyl alcohol measured in the first embodiment and the second embodiment is similar to the viscoelastic modulus measured in the first comparative example. As shown in FIG. 3B and FIG. 3C, the storage modulus and the dissipation modulus of the polyvinyl alcohol measured in the first embodiment and the second embodiment are similar to those in the first embodiment, especially in the frequency region of 10 ⁰ Hz to 10 ² Hz. . Accordingly, the rheometer 100 has sufficient accuracy in measuring the viscoelastic modulus, the storage modulus, and the dissipation modulus of the polyvinyl alcohol.

Zirconium dioxide slurry Embodiment 3, Embodiment 4 and Comparative Example 2

The same measurement was carried out as the above aqueous solution of polyvinyl alcohol, the difference being that the measuring fluid was a zirconium dioxide slurry (ZrO ₂ slurry). 4A to FIG. 4C, FIG. 4A is a diagram showing the relationship between the modulus of the viscoelastic modulus and the frequency according to the third embodiment, the fourth embodiment and the second comparative example of the present invention; FIG. 4B is a diagram showing the relationship between the modulus of the viscoelastic modulus and the frequency according to the third embodiment of the present invention; FIG. 4C is a diagram showing the relationship between the dissipation modulus and the frequency according to Embodiment 3, Embodiment 4, and Comparative Example 2 of the present invention. FIG.

As shown in FIG. 4A, the change trend and the numerical value of the viscoelastic modulus of the zirconia measured in the third embodiment and the fourth embodiment are similar, and in the frequency section of 10 ⁰ Hz to 10 ² Hz, the third embodiment The viscoelastic modulus measured in the fourth embodiment and the second comparative example is also almost the same. As shown in FIG. 4B, the storage modulus curves of the zirconium dioxide measured in Example 3, Example 4 and Comparative Example 1 almost completely overlap. 4C shows that the dissipative modulus behavior of the zirconium dioxide measured in the third embodiment and the fourth embodiment is similar. Compared to Comparative Example 2, the dissipative modulus behavior seems to be slightly different, but in the frequency range of 10 ¹ Hz to 10 ² Hz, the values of the dissipative modulus are still almost the same.

According to the above embodiment, the two vibration modes of the rheometer of the present invention can be used to measure the rheological properties of the fluid, and the resulting rheological properties are also Similar to commercially available instruments. Furthermore, the rheometer of the present invention can not only measure the viscoelastic modulus, but also measure the storage modulus and dissipation modulus of the fluid, and can be used for on-line measurement to provide the rheological properties of the fluid in real time.

While the invention has been described above in terms of several embodiments, it is not intended to limit the scope of the invention, and the invention may be practiced in various embodiments without departing from the spirit and scope of the invention. The scope of protection of the present invention is defined by the scope of the appended claims.

Claims (9)

A rheometer comprising: a base; a container disposed on the base, wherein the container has a space for accommodating a fluid, and the container comprises: an inflow tube disposed on a bottom surface of the container And a first-stage outlet tube comprising a hollow tube communicating with the bottom surface for discharging the fluid from the container; a rod disposed in the container; a magnet, Fixed on the rod; a mirror disposed on the rod; a plurality of coils centered around the magnet, surrounding the rod; and a laser displacement system for determining the mirror a displacement amount, wherein the laser displacement system includes: a laser source for emitting a light to the mirror to cause the mirror to reflect the light back to the laser displacement system; and a position sensor for The light that is reflected is sensed to determine the amount of displacement of the mirror. The rheometer of claim 1, further comprising: a coil holder for fixing the coils; and a coil base surrounding the base for supporting the coil holder. The rheometer of claim 1, further comprising a signal generator for inputting current to the coils. The rheometer of claim 1, wherein the laser displacement system is configured to measure a vibration deformation amount of the rod according to the displacement amount of the mirror. The rheometer of claim 1, wherein the vibration mode of the rod comprises twisting, bending, and combinations thereof. The rheometer of claim 1, wherein the rod comprises a plurality of elliptical holes, and a ratio of a major axis to a minor axis of the elliptical holes is 0.1 to 10. The rheometer of claim 3, further comprising a computer device electrically connected to the laser displacement system and the signal generator to detect one of the fluids according to the displacement of the mirror The modulus of elasticity, wherein the viscoelastic modulus is calculated by the following formula (1): | G ^* | _LPVS = ( α × V _core - β × V _liquid ) × f ⁿ (1) In the formula (1), | G ^* | _LPVS stands for viscoelastic modulus, f stands for frequency, α, β, and n are correction parameters, and V _core and V _liquid represent the only rod in the container and the rod and the fluid, respectively. The amplitude voltage is calculated by the following equations (2) and (3): V _core = V _{core - In} / V _{core - Out} (2) V _liquid = V _{liquid - In} / V _{liquid - Out} (3) In the formula (2), V _core-In represents an amplitude voltage input only when the rod is present, and V _core-Out represents an amplitude voltage of the output; and in the formula (3), V _liquid-In represents the rod And the amplitude voltage input when the fluid is present, and V _liquid-Out represents the amplitude voltage of the output. The rheometer according to claim 7, wherein the computer device is further configured to detect a loss tangent of the fluid, which is calculated by the following formula (4): tan δ _LPVS = γ × | tan δ _liquid -tan δ _core |/ f ^N (4) In equation (4), δ _LPVS represents the loss tangent, f represents frequency, γ and N are correction parameters, and δ _core and δ _liquid represent the only one in the container The rod and the phase difference when the fluid is contained are calculated by the following formulas (5) and (6): tan δ _core =|tan[( θ _{core - Out} - θ _{core - In} )π/180]| (5) tan δ _liquid =|tan[( θ _{liquid - Out} - θ _{liquid - In} )π/180]| (6) In the formula (5), θ _core-In represents the input only when the rod is The phase angle, and θ _core-Out represents the phase angle of the output; in equation (6), θ _liquid-In represents the phase angle input when the fluid is contained, and θ _liquid-Out represents the phase angle of the output. The rheological device of claim 8, wherein the computer device is further configured to detect a storage modulus and a dissipation modulus of the fluid, wherein the storage modulus and the dissipation modulus are (7) and formula (8) calculation: G " _LPVS = G' _LPVS × tan δ _LPVS (8) In the equations (7) and (8), G' _LPVS represents the storage modulus, and G" _LPVS represents the dissipation modulus.