JP2010145342A - Device and method for holding extremely fine fiber sample - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate preparing a sample of extremely fine fibers such as a nanofiber or the like. <P>SOLUTION: A plurality of ringlike holding parts 24 are mounted on pasteboard 22 having an opening 21 in a freely peelable manner. The ringlike holding parts 24 are arranged to provide stripe parts 23a and 23b for the purpose of determining pasting positions. A holding device is moved through a space where nanofibers are scattered when the nanofibers are manufactured by an electrospinning method and the nanofibers are mounted on the ringlike holding parts 24. Thereafter, the ringlike holding parts 24 are peeled from the pasteboard 22 and fixed to the upper and lower clamp parts of testing equipment so that the clamp parts and the nanofibers may be arranged on a straight line. Then, the ringike holding parts 24 are cut and the dynamical characteristics such as tensile strength or the like of the nanofiber L is tested. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ultrafine fiber sample gripping apparatus and gripping method used for performing a mechanical test of ultrafine fibers such as nanofibers.

  In general, a nanofiber is defined as a fibrous material having a diameter of several nm to several hundred nm and a length of 100 times or more of the diameter. Such nanofibers (ultrafine fibers) having a micro / nanoscale fiber diameter are attracting attention as advanced materials and have been used in various industrial fields. For example, it is used in engine filters, ultra-light and multifunctional disaster prevention fabrics, antibacterial masks, semiconductor clean room filters, electronic device materials, regenerative medical media for manufacturing artificial blood vessels, artificial muscles, and the like.

Since the use environment of nanofibers is not limited to the atmosphere, it is also used in liquids, and thus a long life is required in each environment. Therefore, it is desired to measure the mechanical properties (strength evaluation against tension, friction, bending, etc.) of the nanofiber with high accuracy. Specifically, a tensile strength test method for fibers is defined in JIS (Japan Industrial Standard) standards. It is necessary to prepare a sample for carrying out this strength test method.

  As a conventional test method, it is known that a plurality of nanofibers are collectively used as a sample, or a sample whose surface is coated with a resin to increase the strength is used. However, it has been difficult to accurately measure the mechanical properties of one nanofiber. For example, Patent Document 1 below describes a test apparatus that can measure the mechanical properties of a single nanofiber.

JP 2007-085737 A

  In the apparatus described in Patent Document 1, both ends of the nanofiber are inserted into the respective pores of the upper clamp and the lower clamp and fixed with an adhesive, thereby attaching the nanofiber to the test apparatus.

  However, the work of fixing the ultrafine nanofiber to the clamp is troublesome, and there is a problem that the nanofiber is cut during the attaching work. Therefore, a method is known in which a nanofiber of a sample is fixed to a gripping device in advance and the gripping device is attached to a test device.

  As shown in FIG. 1, the conventional gripping device has a configuration of a rectangular mount 2 having a rectangular opening 1. Both ends of the test nanofiber L are bonded to the center position of the mount 2 so as to cross the opening 1 at a right angle. And the vicinity of the position shown with a broken line is cut | disconnected and it cuts into the upper holder 3a and the lower holder 3b. Then, the upper holder 3a is fixed to the upper clamp of the test apparatus, and the lower holder 3b is fixed to the lower clamp part of the test apparatus. In the test apparatus, the mechanical properties of the nanofiber are measured by pulling the upper clamp upward.

  The method of using the mount 2 makes the work of fixing the nanofibers easier than the method of attaching the nanofibers directly to the upper clamp and the lower clamp. However, the work of fixing both ends of the nanofiber L is troublesome so that the direction connecting the fixing positions of both ends of the nanofiber L completely coincides with the pulling direction of the test apparatus. Furthermore, there existed a problem that the nanofiber L will fracture | rupture in an adhesion part during a test.

  It has been proposed to collect test nanofibers at the time of nanofiber production. Nanofibers produced by electrospinning or the like are manufactured. In the electrospinning method, as schematically shown in FIG. 2, a high voltage 8 of several thousand volts to several tens of thousands volts is applied between a raw material polymer solution in a container 6 having a nozzle 5 and a substrate 7. Static electricity breaks down the surface tension of the liquid surface of the polymer solution, and nano-sized fibers 9 are ejected from the nozzle 5. The ejected fibers 9 are randomly deposited on the substrate 7. The nanofibrous material 10 is formed on the substrate 7 by evaporation of the solvent and temperature decrease. If the nanofibrous material 10 is thin, it becomes a nanofiber coating, and if it is thick, it becomes a non-woven fabric.

  Nanofiber coatings and non-woven fabrics are expected to be used in many industrial fields such as energy, medical care, and semiconductors by taking advantage of nano-effects such as the nanospace created by nanofibers and the large surface area of the fibers themselves. Yes. Specifically, applications such as ultra-fine particle high-performance filters, masks that prevent the entry of viruses and bacteria, moisture-permeable and waterproof textiles, charge collection electrodes for fuel cells, solar cells, and the like are considered.

  By moving the gripping device 11 in the horizontal direction in the space where the nanofibers 9 ejected from the nozzle 5 are scattered, the test nanofibers can be collected. For example, the gripping device 11 is moved at a speed approximately equal to the flight speed of the nanofiber 9. As shown in FIG. 3, the gripping device 11 is formed by forming a plurality of rectangular openings 13 a, 13 b, 13 c, 13 d, and 13 e on a rectangular mount 12. By moving the gripping device 11 in the space where the nanofibers 9 are scattered, a large number of nanofibers adhere to the gripping device 11. The mount 12 has an adhesive surface, and after collecting the nanofibers, the adhesive surface is covered with another holder.

  Among the many nanofibers collected by the gripping device 11, a nanofiber whose direction connecting the fixed positions at both ends of the nanofiber completely matches the pulling direction of the test device is selected. That is, nanofibers orthogonal to the long side of the opening can be used as a sample. For example, the nanofiber L deposited on the opening 13c is selected. Both sides of the opening 13c are cut along the alternate long and short dash line to obtain a nanofiber for testing.

  Such a gripping device 11 has an advantage of not requiring an operation of fixing both ends of the nanofiber by a manual operation. However, in practice, since there are many nanofibers that obliquely cross the opening, there is a low probability that a nanofiber that can be used as a sample is obtained, and there is a problem in that the yield is poor.

  Accordingly, an object of the present invention is to provide an ultrafine fiber sample gripping apparatus and a gripping method capable of collecting and creating ultrafine fiber samples with a simple operation and high yield.

In order to solve the above-described problems, the present invention includes a mount,
A plurality of ring-shaped gripping portions that are releasably attached to the mount and have a non-adhesive surface that has adhesiveness;
It is an ultrafine fiber sample gripping device that moves in the flight space of ultrafine fibers during the production of ultrafine fibers and deposits the ultrafine fibers on the surface.

The present invention provides an ultrafine fiber sample gripping device including a mount and a plurality of ring-shaped gripping portions that are detachably attached to the mount and have a surface that is not bonded to the mount and has adhesiveness.
Move in the flight space of the ultrafine fiber during the production of the ultrafine fiber, and attach the ultrafine fiber to the surface,
Peel off the ring-shaped gripping part with extra fine fibers attached from the mount,
Attach the ring-shaped gripping part so that the extension direction of the center of the pull shaft by the pair of mounting parts of the test device and the length direction of one ultrafine fiber attached to the ring-shaped gripping part are aligned. Fixed to the
This is an ultrafine fiber sample gripping method in which a ring-shaped gripping part is cut at two positions intersecting with the extending direction of the sample fiber.

  According to the present invention, sample nanofibers can be easily collected by moving in a space where nanofibers are scattered during the production of ultrafine fibers such as nanofibers. The probability of what can be used as can be increased. That is, the yield can be improved.

  The best mode for carrying out the invention (hereinafter referred to as an embodiment) will be described below. The embodiments described below are preferred specific examples of the present invention, and various technically preferable limitations are given. However, the scope of the present invention is not limited to the present invention in the following description. Unless otherwise specified, the present invention is not limited to these embodiments.

<One embodiment>
"Gripping device"
One embodiment has a structure as shown in FIG. As shown in FIGS. 5A and 5B, a mount 22 having a rectangular opening 21 at the center is used. The opening 21 is not necessarily provided, but it is preferable that the opening 21 is opened when viewed over light or when viewed with a microscope. An adhesive layer is formed on one surface of the mount 22 by coating or the like. The stripe portions 23 a and 23 b for positioning are attached to the adhesive layer of the mount 22 along the long side of the mount 22. A region of the adhesive layer of the mount 22 that is not covered by the stripe portions 23a and 23b is exposed.

  A plurality of, for example, seven circular ring-shaped gripping portions 24a, 24b, 24c, 24d, 24e, 24f, and 24g are provided in a portion where the opening 21 is formed in the central region sandwiched between the stripe portions 23a and 23b. To be attached. In particular, when there is no need to individually distinguish a plurality of ring-shaped gripping portions, they are simply referred to as ring-shaped gripping portions 24. As shown in FIG. 5C, the ring-shaped gripping portion 24 has a circular opening 25 corresponding to the length of a desired nanofiber sample. The ring-shaped gripping part 24 is made of paper or synthetic resin. The mount 22, the stripe portions 23a and 23b, and the ring-shaped gripping portion 24 are made of an insulating material such as art paper or plastic.

  As shown in FIG. 5D, the ring-shaped gripping portion 24 is attached to the region where the adhesive layer of the mount 22 is exposed. The adhesive force of the adhesive layer is selected so that the ring-shaped gripping part 24 can be freely bonded / separated from the mount 22. The height of the ring-shaped gripping portion 24 is slightly higher than the height of the stripe portions 23a and 23b. Furthermore, an adhesive layer is provided on the side of the ring-shaped gripping portion 24 that is not bonded to the mount 22. The release paper covers the adhesive layer. Further, as will be described later, the ring-shaped gripping portion 24 capable of testing one fiber in one ring-shaped gripping portion 24 is taken out using the collected nanofibers. In this state, since the nanofiber L is lightly placed on the ring-shaped gripping portion 24, as shown in FIG. 5E, the nanofiber is held by thinly applying an adhesive to one side of another ring 30 having the same shape. The grip is reinforced by sticking to the surface.

"Nanofiber collection method"
With the above-described gripping device, test nanofibers are collected when the nanofibers are manufactured, for example, by electrospinning. Prior to collection, the release paper covering the adhesive layer is peeled off. As described above, the gripping device is moved in a space where the nanofibers ejected from the nozzles are scattered at a speed similar to the flight speed of the nanofibers. Since the nanofibers are scattered in the directions indicated by P1, P2, etc., the nanofibers adhere to the plurality of ring-shaped gripping portions 24 as shown in FIG.

  The ring-shaped gripping part to which nanofibers that can be used as a sample are attached is peeled off from the mount 22. As shown in FIG. 7A, the ring-shaped grip portion 24 to which the nanofibers L as the sample fibers are attached is peeled off from the mount 22. Any nanofiber that crosses the central opening of the ring-shaped gripping part 24 and is not located at a very short distance can be used as a sample. When other nanofibers are located at a very close distance, it is troublesome and difficult to cut one nanofiber.

  Then, the ring-shaped gripping portion 24 is connected to these clamp portions so that the line connecting the centers of the upper clamp portion 26a and the lower clamp portion 26b of the test apparatus for measuring the mechanical properties of the nanofiber and the nanofiber L coincide with each other. It is fixed to 26a and 26b.

  Since the nanofiber L is so thin that it cannot be seen with the naked eye, the attachment work of the ring-shaped gripping portion 24 to the upper clamp portion 26a and the lower clamp portion 26b is performed using a digital optical microscope with a magnification of about 1000 times. Made. In order to facilitate the attaching operation, marks 27a and 27b indicating the centers of the shafts are respectively attached to the clamp portions 26a and 26b. As indicated by the arrows, by rotating the ring-shaped gripping portion 24, the position is adjusted such that both ends of the nanofiber L are positioned at the centers of the clamp portions 26a and 26b.

  An example of the upper clamp part 26a is shown in FIG. A slit 28a is formed at the tip of the shaft, and a ring-shaped grip 24 having one end of the nanofiber L fixed therein is inserted into the slit 28a. The ring-shaped grip 24 is fixed in the slit 28a by a small screw 29. . The lower clamp part 26b has the same configuration as the upper clamp part 26a.

  After the position is adjusted and the ring-shaped gripping portion 24 is fixed to the clamp portions 26a and 26b, a part of the ring-shaped gripping portion 24 is cut off at a position indicated by a one-dot chain line in FIG. 8A. The state after excision is shown in FIG. 8B. In the test apparatus to be described later, when the upper clamp portion 26a is displaced upward and the displacement reaches a certain value, the nanofiber L is broken. From the relationship between displacement and tension, the mechanical properties (tensile strength, etc.) of the nanofiber L are measured.

  In the above-described embodiment of the present invention, the nanofiber collected as shown in FIGS. 8C, 8D, and 8E can be used as a sample. That is, as shown in FIG. 8C, the nanofiber L1 that obliquely crosses the opening 25 of the ring-shaped gripping portion 24 can be used as a sample. As shown in FIG. 8D, nanofibers L2 that intersect at a position off the center of the ring-shaped gripping part 24 can be used as a sample. As shown in FIG. 8E, one of the two nanofibers L3 and L4 attached to the ring-shaped grip portion 24 can be used as a sample.

  The nanofibers that can be used as the sample shown in FIG. 8 are not all examples, and nanofibers that are attached to the ring-shaped gripping portion 24 in a manner other than the illustrated example can be used as the sample. Therefore, according to the present invention, the ratio (yield) that can be used as a sample in the collected nanofibers can be increased, and the nanofibers can be measured efficiently.

"Schematic configuration of test equipment"
A test apparatus to which the nanofiber gripping apparatus according to the present invention can be applied will be described with reference to FIG. As shown in FIG. 9, a load sensor such as an electronic balance is accommodated in the test apparatus main body 101. The electronic balance has a resolution of about 0.01 mg (or 0.1 mg or more). Not only the electronic balance but also a load sensor having the same resolution may be used. Although not shown, a power cord for supplying power is led out from the main body 101, and an interface for connecting to a personal computer, for example, an RS-232C interface is connected to the main body 101.

  A pair of support columns 102a and 102b are provided perpendicularly to the test apparatus main body 101 at predetermined intervals, and a beam 103 is stretched between the tips of the support columns 102a and 102b. A mounting plate 104 is provided below the beam 310. A magnet unit 105 on the weighing surface of the electronic balance is disposed below the mounting plate 104. The magnet portion 105 on the weighing surface is configured to fix the lower holder 109 of the gripping device 107 placed by the magnetic force of the magnet.

  A movable part 106 (elevating stage) that is displaced in the vertical direction is attached to the lower part of the attachment plate 104 so as to be positioned above the magnet part 105 on the weighing surface. The movable part 106 has a motor as a drive source. The upper holder 108 of the gripping device 107 is fixed by the vise portion of the movable portion 106. The upper holder 108 is displaced in the vertical direction by the movable portion 106 at a predetermined speed. The movable portion 106 can be remotely controlled by a personal computer, and the movable portion 106 is moved up and down in accordance with a program installed in the personal computer.

  The extension line at the center of the upper clamp part 26 a included in the upper holder 108 and the extension line at the center of the lower clamp part 26 b included in the lower holder 109 coincide with each other. As described above with respect to the upper clamp portion 26a and the lower clamp portion 26b, the ring-shaped grip portion 24 (not shown in FIG. 9) to which both ends of the sample nanofiber L are fixed is attached.

  A switch such as a power switch 112 is provided on the front panel 111 of the test apparatus main body 101. You may provide the display part which displays the numerical value of the load measured on the front panel 111. FIG.

  FIG. 10 shows an example of a measurement result by a test apparatus, a load-displacement curve. For example, nylon (fiber diameter: 300 nm) collected by the electrospinning method was used as a sample. The test conditions are a sample length of 5 mm and a pulling speed of 5 μm / s. The upper holder 108 is displaced upward, and the load changes as the sample is pulled. When the sample breaks, the load changes abruptly. This test can test the tensile strength of the sample. Furthermore, the elastic modulus of the sample can be measured from the slope of the displacement-load curve. Furthermore, it is possible to test stress relaxation and creep.

"Gripping device"
As shown in FIG. 11, the upper holder 108 and the lower holder 109 are horizontally fixed from one side by a connecting fixture 67 before the grasping apparatus 107 is mounted on the test apparatus.

  The tips of the upper holder 108 and the lower holder 109 (that is, the upper clamp portion 26a and the lower clamp portion 26b) are provided with slits for inserting the ring-shaped grip portion 24 to which the sample fibers (for example, nanofibers) L are attached. Yes. The ring-shaped holding part 24 is inserted there and fixed with screws.

  The upper holder 108 and the lower holder 109 are provided with O-rings 61 and 62, respectively. The O-rings 61 and 62 are for intimate contact with an inner peripheral surface of a submerged test sleeve (not shown) and prevent liquid leakage. The sleeve is, for example, a transparent acrylic resin cylinder. When the sample is attached and when an in-liquid test is not performed, the sample is locked by an O-ring 61 provided in the upper holder. During the submerged test, it is lowered so as to be locked by the O-ring 62 provided in the lower holder.

"Procedure for attaching sample fiber to gripping device 107"
In a state where the upper holder 108 and the lower holder 109 are horizontally fixed by the holder connector 67, the ring-shaped gripping portion 24 to which the sample fiber L is previously applied is attached to each of the upper clamp portion 26a and the lower clamp portion 26b. Fix (see FIG. 8A). Then, the ring-shaped holding part 24 is cut | disconnected (refer FIG. 8B).

  In this way, the gripping device to which the sample fiber L is attached is attached to the test device. With the holder connector 67, the upper clamp part 26a, the lower clamp part 26b, and the sample fiber are held in a straight line, and the gripping device can be attached to the test apparatus while keeping this state.

  The bottom surface of the lower holder 109 is placed at a predetermined position of the magnet unit 105 on the weighing surface. Although not shown, a projection or the like for positioning the bottom surface of the lower holder 109 is formed on the magnet unit 105. Thereafter, the vise portion 70 attached to the vertical movable portion is lowered by the vertical movable portion and fixed by the vise portion. Finally, the holder connector 67 is removed.

"Modification"
The present invention is not limited to the above-described embodiment, and various modifications based on the technical idea of the present invention are possible. For example, the present invention can be applied not only to the electrospinning method but also to collecting a sample when producing nanofibers by a melt blown method or the like.

It is a top view which shows an example of the conventional nanofiber holding | grip apparatus. It is a basic diagram used for description of the method of collecting a nanofiber at the time of manufacture of a nanofiber. It is a top view which shows the other example of the conventional nanofiber holding | grip apparatus. 1 is a plan view of an embodiment of a nanofiber gripping device according to the present invention. It is a top view which shows each component of one embodiment of this invention. In one Embodiment of this invention, it is a top view which shows the state which the nanofiber adhered to the holding | grip apparatus. It is a perspective view used for description of an example of the upper clamp part in one embodiment of this invention. In one Embodiment of this invention, it is a basic diagram for demonstrating the method attached to a test apparatus. It is a perspective view used for schematic explanation of an example of a testing device which can apply this invention. It is a graph which shows an example of the test result by a test device. It is a perspective view which shows the state which mounted the holding apparatus which can apply this invention on the slider mechanism.

Explanation of symbols

L, L1 to L4... Nanofiber 22... Mount 24a to 24g... Ring-shaped gripping portion 26a... Upper clamp portion 26b. ..Holder connector 101... Test apparatus main body 105... Magnet part 107 on weighing surface... Gripping device 108.

Claims (3)

Mount and
A plurality of ring-shaped gripping portions that are releasably attached to the mount and have a surface that is not bonded to the mount and has adhesiveness;
An ultra-fine fiber sample gripping device that moves in the flight space of ultra-fine fibers during the production of ultra-fine fibers and adheres the ultra-fine fibers to the surface.   2. The ultrafine fiber sample gripping apparatus according to claim 1, wherein an opening is formed in the mount, and the opening is detachably attached to the mount so that the opening and a central opening of the ring-shaped gripping portion overlap each other. An ultrafine fiber sample gripping device comprising a mount and a plurality of ring-shaped gripping portions that are releasably attached to the mount and the surface that is not bonded to the mount has adhesiveness,
Move in the flight space of the ultrafine fiber at the time of producing the ultrafine fiber, adhere the ultrafine fiber to the surface,
The ring-shaped gripping part to which the ultrafine fibers are adhered is peeled off from the mount,
The ring-shaped gripping so that the extension direction of the center of the pulling shaft by the pair of mounting portions of the test apparatus and the length direction of the one ultrafine fiber attached to the ring-shaped gripping portion are aligned in a straight line. Fixing the part to the mounting part,
An ultrafine fiber sample gripping method in which the ring-shaped gripping portion is cut at two positions intersecting with the extending direction of the sample fiber.

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