JP2002062253A - Method and device for manufacturing colloid probe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily manufacture a colloid probe excellent in measuring precision constituted by bonding a spherical sample particle onto a probe of an atomic force microscope. SOLUTION: This method has a process for positioning the probe of the atomic force microscope, a needle for applying an adhesive, and a needle for depositing the spherical sample particle in respective prescribed positions, a process for depositing the adhesive of the adhesive applying needle onto the probe of the atomic force microscope by returning the probe of the microscope to the prescribed position hereinbefore after the adhesive is applied on the adhesive applying needle in the condition where the probe of the atomic force microscope is separated from the adhesive applying needle, and a process for bonding the spherical sample particle onto the probe of the atomic force microscope by bringing the probe of the microscope into contact with the spherical sample particle depositing needle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a colloid probe used for measuring the adhesion of spherical particles.

[0002]

2. Description of the Related Art In the field of handling powder, it is important to grasp various characteristic values of the powder. One of the characteristic values of the powder is an adhesive force between particles and an object to which the particles are attached. Conventionally, various methods for measuring the adhesive force have been devised, and methods for measuring the adhesive force of a single particle include a spring balance method and a centrifugal separation method. There are many issues to consider in seeking a strict relationship with.

Further, in the measurement of the tensile strength of a powder layer typified by the tensile rupture method, the shearing method, and the rupture rupture method, the adhesion F of a single particle is expressed by the Rumpf equation σz = (1−ε) / π・
k · F / Dp ² (however, the tensile rupture strength of the powder layer, the porosity of the powder layer, the adhesive strength of one particle, the coordination number of particles, and the average particle diameter are
Σz, ε, F, k, and Dp, respectively). However, the influence of the porosity ε on the powder layer is extremely large, and therefore, when the range of the measurement tensile force is determined, it is impossible to perform measurement over a wide void range. is there. In addition, there is a disadvantage that the effect of mechanical frictional resistance of the apparatus cannot be ignored in order to measure an extremely weak adhesive force.

In recent years, an atomic force microscope has been widely used as a method of directly measuring the interaction force of an object, and the measurement of the interaction between surfaces has become familiar, and the measurement object has been expanding. In an atomic force microscope, a cantilever probe (Si ₃
N ₄ , Si single crystal) is used, but in this case, it is difficult to confirm the shape of the probe or to measure the interaction with a homogeneous material, and it is difficult to quantitatively determine the measured interaction force.

[0005] Therefore, a colloid probe in which sample particles are fixed to the tip of a silicon nitride ceramic probe is provided. However, producing such a colloid probe was a manual operation using a microscope, a micrometer, and the like, and was a method that required considerable skill and time. Moreover, the obtained colloidal probe did not have very good accuracy of the measured adhesive force due to the non-uniformity of the adhesion of the sample particles to the probe.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and an object of the present invention is to make it possible to easily produce a colloidal probe having high measurement accuracy with a little skill. .

[0007]

That is, the present invention relates to a method for producing a colloidal probe for measuring the adhesion of spherical particles, comprising an atomic force microscope probe, an adhesive application needle and a spherical sample. After the step of positioning the particle attachment needle at a predetermined position and moving the atomic force microscope probe away from the adhesive application needle, applying the adhesive to the adhesive application needle, the atomic force microscope probe is moved to the above position. Returning the adhesive to the predetermined position and attaching the adhesive of the adhesive application needle to the atomic force microscope probe; and bringing the atomic force microscope probe into contact with the spherical sample particle attachment needle, thereby causing the spherical sample particle to be subjected to an atomic force. Bonding to a microscope probe.

The present invention also relates to an apparatus for producing a colloidal probe for measuring the adhesion of spherical particles, comprising: (a) an atomic force microscope probe, an adhesive application needle, and a spherical sample particle adhesion needle. Means for positioning it in a predetermined position and registering it in a microcomputer; (b) after applying the adhesive to the adhesive application needle after moving the atomic force microscope probe away from the adhesive application needle, Means for returning the atomic force microscope probe to the above registered position to attach the adhesive of the adhesive application needle to the atomic force microscope probe, and (c) attaching the atomic force microscope probe to a spherical sample particle attaching needle. And means for adhering the spherical sample particles to the atomic force microscope probe.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 is a schematic diagram for explaining an example of the apparatus for producing a colloid probe of the present invention. 1 is a digital microscope, 2 is an XY stage, 3 is a needle for attaching spherical sample particles, 4 is a needle for applying an adhesive, 5 is an atomic force microscope probe (hereinafter, referred to as an “AFM probe”), 6 Is a micromanipulator, and 7 is a micromanipulator joystick.

The sample targeted by the present invention is a spherical particle, and is preferably a spherical particle having a sphericity of 0.75 or more in order to make it easier to determine the conditions at the contact surface. If the sphericity of the particles is significantly smaller than 0.75, the contact with the object to be adhered does not become a point contact, so that the data may be largely dispersed.

Here, the sphericity is measured by a flow type particle image analyzer (for example, “FPIA-100” manufactured by Sysmex Corporation).
0 ”) can be measured as follows.
That is, the projected area (A) and the perimeter (PM) of the particle are measured from the particle image. Assuming that the area of a perfect circle corresponding to the perimeter (PM) is (B), the sphericity of the particle can be displayed as A / B. Therefore, assuming a perfect circle (radius r) having the same perimeter as the perimeter (PM) of the sample particles, PM =
Since 2πr and B = πr ² , B = π × (PM / 2
π) ^{2 and} the sphericity of each particle is sphericity = A / B
= A × 4π / (PM) ² .

For the adhesive used in the present invention, an elastic adhesive is not preferable because the adhesive force at the time of measurement is accurately detected. It is not preferable because the laser reflecting portion may be contaminated. In the present invention, a two-part cold curing resin-based adhesive capable of adjusting the curing time is preferable.

The AFM probe 5 is made of silicon nitride or Si single crystal. The material (for example, tungsten) of the spherical sample particle attaching needle 3 and the adhesive applying needle 4 is not particularly limited. In order to accurately perform the particle fixing operation, it is preferable that the radius of curvature of the tip of the spherical sample particle attaching needle 3 and the tip of the adhesive applying needle 4 is about 1 μm. These needles are fixed to a holder having a height adjustment function.

The micromanipulator system (micromanipulator 6 and micromanipulator joystick 7) used in the present invention has a minimum operation resolution of 0.1 in order to accurately fix particles to the tip of the AFM probe 5.
It is preferably about μm or less. An example of this is "MMS-77" manufactured by Shimadzu Corporation.

Further, the digital microscope 1 has
It is preferable that the probe has a resolution of about 500,000 pixels, a magnification of about 3000 times, and allows the shape of the tip of the probe to be clearly observed. As an example of this, "VHZ-4" manufactured by KEYENCE
50 ". Digital microscope 1 is XY
It is installed on a fixed base having a stage 2.

The procedure for producing the colloid probe of the present invention using the apparatus shown in FIG. 1 is as follows.

First, the AFM probe 5, the adhesive applying needle 4, and the spherical sample particle attaching needle 3 are positioned at predetermined positions and registered in the microcomputer. As an example of the predetermined position of each needle, the AFM probe 5 and the spherical sample particle attachment needle 3 face in parallel, and the adhesive application needle 4 faces in the vertical direction.

The spherical sample particles are previously attached to the tip of the spherical sample particle attaching needle 3. The number of the spherical sample particles to be attached to the spherical sample particle attaching needle 3 is AFM
When bonding the spherical sample particles to the probe 5, it is preferable that the number is set to several so as to easily aim at one particle. The spherical sample particles are attached to the spherical sample particle attaching needles 3 by inserting the spherical sample particle attaching needles 3 into the container containing the sample powder and bringing them into contact with the powder, and are removed so that the number of attached particles becomes several.

Next, after the AFM probe 5 is moved away from the adhesive application needle 4 and the adhesive is applied to the adhesive application needle 4, the AFM probe 5 is returned to the above registered position and the adhesive is applied. The adhesive of the application needle 4 is applied to the AFM probe 5. Here, the application of the adhesive to the AFM probe 5 can be performed by accurately operating the micromanipulator joystick 7. Since the application site is the tip of the probe, the contact time with the adhesive is preferably about 1 second.

Next, the AFM probe 5 is brought into contact with the spherical sample particle attaching needle 3, and the spherical sample particles are adhered to the AFM probe 5 and
Move the FM probe away. This operation is accurately performed by the micromanipulator joystick 7 to bring one particle into contact.

Finally, AFM with spherical sample particles adhered
Remove the probe 5 from the fixed holder.

The AFM probe 5 having the spherical sample particles adhered to the tip as described above can be used as a colloid probe for measuring the adhesive force of the spherical particles.

In order to measure the adhesive force of the spherical sample particles using the colloidal probe produced in the present invention, the colloidal probe is brought into contact with an object to be adhered, and the object to be adhered is gradually separated from the colloidal probe. A change in force applied to the colloid probe, that is, a characteristic curve (force curve) of the interaction is measured. The object to be attached is a mirror-like substrate such as stainless steel or a smooth substrate on which spherical particles of the same or different type as the spherical sample particles are fixed. When the object to be adhered is a substrate, the adhesion between the substrate material such as a pipe and the powder particles can be measured in the production process of the spherical particles and the like, and the adhesion itself between the powder particles can be measured in the case of particles.

FIG. 2 is a conceptual diagram showing a method for measuring the adhesion of spherical sample particles when the object to be adhered is a mirror surface substrate such as stainless steel using the colloid probe obtained by the present invention. In FIG. 2, 11 is an AFM probe (colloid probe) to which spherical sample particles are adhered, 12 is a spherical sample particle, 13 is a piezo, 14 is a sample fixing disk for an atomic force microscope, and 15 is a mirror-polished stainless steel plate , 16
Is a photodiode.

FIG. 3 shows an example of a force curve. This means that the force (force curve) acting on the AFM probe when the distance between the colloid probe and the stainless steel plate in the Z-axis direction (vertical direction on the paper) is changed by changing the voltage applied to the piezo 13 is represented by the photodiode. It is the figure measured from 16 outputs.

In FIG. 3, F _{A1 based on the} point A _{0 at} which no force acts on the AFM probe is the adhesion force of the spherical sample particles.

[0027]

The present invention will be described below more specifically with reference to examples.

(Embodiment) This embodiment is an example in which a colloid probe is manufactured by using an apparatus as shown in FIG.
In addition, spherical silica powder was used as sample particles.

(Manufacture of Colloid Probe) Procedure 1: An AFM probe 5 made of silicon nitride is fixed to a holder of a micromanipulator system, and a needle 4 for applying an adhesive is prepared.
And positioning the spherical sample particle attachment needle 3 at a predetermined position,
It was registered in the microcomputer. The spherical sample particle-adhering needle 3 is inserted into a container containing spherical silica powder in advance and brought into contact with the powder, so that the spherical sample particle-adhering needle 3 has silica particles (sphericity: 0.94, particle diameter: 6. 0μ
m) was attached, and the particles were removed so that the number of attached particles was 5. Procedure 2: After separating the AFM probe 5 from the adhesive application needle 4, apply a two-part room temperature curing resin adhesive (“EP-330” manufactured by Cemedine Co.) to the adhesive application needle 4, and then perform AFM.
The probe 5 was returned to the registered position, and the adhesive of the adhesive application needle 4 was adhered to the AFM probe 5 while enlarging about 3000 times with the digital microscope 1. Procedure 3: The AFM probe 5 is brought into contact with the spherical sample particle attachment needle 3, one spherical silica particle is adhered to the AFM probe 5, and A
FM probe was moved away. Procedure 4: The AFM probe 5 to which the spherical silica particles were adhered was removed from the holder of the micromanipulator system and dried at room temperature for 24 hours to produce a colloid probe.

Next, using the colloidal probe obtained as described above, the adhesive force is measured using a piping material (stainless steel), which is frequently contacted when producing spherical silica powder, as an object to be attached. Was.

First, as shown in FIG. 2, a stainless steel plate (surface-polished) using a two-liquid cold-setting resin adhesive ("EP-330" manufactured by Cemedine Co.) on a sample fixing disk 14 for an atomic force microscope. An object to be adhered) 15 was adhesively fixed.

Then, the distance between the stainless steel plate and the colloid probe was controlled by the applied piezo voltage, the force curve was measured, and the adhesion between the silica particles and the stainless steel plate was measured as follows (Experimental Example 1). ). In addition, instead of the silica particles, the adhesion was measured by the same method for the silica particles surface-treated with a metal alkoxide (Experimental Example 2). Furthermore, the adhesion to the stainless steel plate was measured using the silicon nitride AFM probe as it was (Experimental Example 3).

First, the speed of the piezo expansion / contraction cycle was set to 5.0 Hz in order to control the distance between the samples in the Z-axis direction. Next, the colloid probe and the stainless steel plate were separated, and the force and force curve acting on the probe when the distance in the Z-axis direction was changed were measured from the output of the photodiode 16. FIG. 3 shows an example of the result.

When the adhesive force (F _A1 ) was measured based on the point A ₀ at which the force no longer acts on the AFM probe, the adhesive force in Experimental Example 1 was 5.75 × 10 ¹ nN, and the adhesive force in Experimental Example 2 was 3.51. ×
10 ¹ nN, Experimental Example 3 was 5.19 × 10 ^-1 nN.

From the above results, in Experimental Example 1 using the spherical silica particles, the adhesive force was larger than that of the surface-modified silica particles (Experimental Example 2), suggesting a decrease in the adhesive force due to the surface modification. In addition, an adhesion of about 110 times was confirmed as compared with the AFM probe made of silicon nitride, which suggested that there was a large difference in the adhesion between the case where the probe was used as it was. From this fact, it is less clear whether the variation in the measured adhesive force depends on the probe or the adhesive force due to the non-uniformity of the adhesion of the manually produced colloidal probe so far. There was no
The difference in adhesion was evident in the probes manufactured according to the present invention.

[0036]

According to the present invention, a colloid probe with high measurement accuracy can be easily manufactured with only a little skill.

By using the colloidal probe produced according to the present invention, it is possible to measure the exact adhesion of one spherical sample particle. In addition, if an atomic force microscope that can be measured in a liquid is used, the exact interaction force of one particle in a solution whose conditions have been adjusted can be measured.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an apparatus for producing a colloid probe of the present invention.

FIG. 2 is a conceptual diagram showing a method for measuring the adhesion of spherical sample particles using a colloid probe obtained according to the present invention.

FIG. 3 is a diagram illustrating an example of a force curve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Digital microscope 2 XY stage 3 Spherical sample particle attachment needle 4 Adhesive application needle 5 Atomic force microscope probe (AFM probe) 6 Micromanipulator 7 Micromanipulator joystick 11 AFM probe with spherical sample particles adhered Needle (colloid probe) 12 Spherical sample particle 13 Piezo 14 Sample fixing disk for atomic force microscope 15 Mirror-polished stainless steel plate 16 Photodiode

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaya Yoshida 1 Shinkaicho, Omuta-shi, Fukuoka Denki Kagaku Kogyo Co., Ltd. Inside the Omuta Plant (72) Inventor Akira Kobayashi 1 Shinkaicho, Omuta-shi Fukuoka Pref. Omuta Factory

Claims (2)

[Claims] 1. A method for producing a colloid probe used for measuring the adhesion of spherical particles, comprising the steps of positioning an atomic force microscope probe, an adhesive application needle, and a spherical sample particle adhesion needle at predetermined positions. After the atomic force microscope probe is moved away from the adhesive application needle, the adhesive is applied to the adhesive application needle, and then the atomic force microscope probe is returned to the predetermined position to apply the adhesive. Attaching the adhesive of the needle to the atomic force microscope probe, contacting the atomic force microscope probe with the spherical sample particle attachment needle,
Bonding a spherical sample particle to an atomic force microscope probe. 2. An apparatus for producing a colloid probe used for measuring the adhesion of spherical particles, comprising: (a) an atomic force microscope probe, an adhesive application needle, and a spherical sample particle adhesion needle at predetermined positions. Means for positioning and registering the same in a microcomputer; (b) after moving the atomic force microscope probe away from the adhesive application needle, applying the adhesive to the adhesive application needle, and then using the atomic force microscope Means for returning the probe to the registered position and attaching the adhesive of the adhesive application needle to the atomic force microscope probe; (c) bringing the atomic force microscope probe into contact with the spherical sample particle attachment needle; Means for adhering spherical sample particles to an atomic force microscope probe.