JP4975327B2 - Die and method for producing nanofiber using the same - Google Patents

Description

The present invention relates to the base and preparation how nanofibers using the same.

  A conventional electrospray ionization apparatus is described in Patent Document 1. This document describes an ion source for a mass spectrometer that includes a capillary into which a sample solution is introduced and a gas guide tube.

  This document describes the following. That is, the capillary is held and fixed by the capillary holding tube. In addition, the gas guide tube is a gas that flows along the outer periphery of the capillary and injects a gas having a predetermined gas flow velocity into the atmosphere at the tip of the capillary. The gas guide tube is composed of a gas guide tube tip portion and a gas guide tube tip holding portion. Furthermore, the capillary passes through the capillary holding tube so that the central axis of the capillary at the tip of the capillary coincides with the central axis of the opening that is formed at the tip of the gas guide tube and forms an outlet from which gas is ejected. And fixed to the gas guide tube tip end holding portion. A sample (solute molecule) for mass spectrometry is charged at the tip of a needle (capillary) to which a high voltage is applied. At this time, fine droplets are generated by spraying using a sheath gas such as nitrogen. Microdroplets containing solute molecules are introduced into the mass spectrometer while evaporating.

  On the other hand, in recent years, development of nanofibers using an electrospinning method has been promoted (Patent Document 2). According to Patent Document 2, an electrospinning method is described as follows: “When a polymer is dissolved in an electrolyte solution and a high voltage is applied when the polymer solution is discharged from a base, the polymer solution is forcibly broken by its electrostatic repulsion. Technology.

In Patent Document 2, a polymer alloy fiber composed of a hardly soluble polymer and an easily soluble polymer is prepared by melt spinning, and nanofibers are prepared by removing the easily soluble polymer from the polymer alloy fiber. Is described. In addition, a functional processing method is described in which the obtained nanofiber aggregate or dispersion is impregnated with a monomer and then polymerized or processed.
Japanese Patent Laid-Open No. 11-108897 JP 2005-36376 A

  However, in the method described in Patent Document 2, the design of the polymer alloy serving as the core portion is complicated, and there are limitations on the applicable materials. In addition, after the nanofibers are produced, the functional substance is nano-processed by post-processing. There is room for improvement from the viewpoint of stably controlling the structure of the composite material on the nanometer order because it is supported on the fiber.

  Then, this inventor earnestly examined about producing the nanofiber which has a heterophase structure stably by the electrospinning method mentioned above. Then, in the conventional electrospinning method using a single capillary tube, it was difficult to produce nanofibers having a heterogeneous structure.

  Moreover, even when trying to manufacture nanofibers using an ion source of a conventional electrospray ionization apparatus as described in Patent Document 1, it is improved in that a fine heterogeneous structure is stably manufactured. There was room.

  Therefore, the present inventor further examined this cause. As a result, it has been found that the conventional ion source may not have sufficient coaxial accuracy when holding a plurality of capillary tubes coaxially. There is also room for improvement in terms of durability of the capillary tube and ease of maintenance such as tube replacement.

According to the present invention,
A block made of a conductive material;
A fluid ejection portion provided in the block;
A first flow path provided inside the block and communicating with the ejection portion;
An annular second flow path that is provided inside the block and communicates with the ejection portion, is disposed coaxially with the first flow path and is provided so as to surround a side surface outer periphery of the first flow path;
Have
The flow path wall of the first flow path and the flow path wall of the second flow path are constituted by a part of the wall surface of the block, and the first flow path and the second flow path are formed of the block. The front end of the first flow path protrudes outside the block from the surface of the block, and the front end of the second flow path is more than the surface of the block. Protruding to the outside of the block, the tip of the first channel projects beyond the tip of the second channel to the outside of the block, and a die used for electrospinning is provided.

  In the present invention, the ejection part is an opening part from which the fluid supplied into the block is ejected. The ejection part should just be provided in the block, for example, may be provided in the surface of the block, and may be provided in the surface vicinity of the block.

  Moreover, the ejection part may include a first ejection part that ejects the first fluid supplied to the first flow path and a second ejection part that ejects the second fluid supplied to the second flow path. The second ejection part has a planar shape surrounding the outer periphery of the first ejection part. The first ejection part and the second ejection part may be provided so that the first fluid and the second fluid are ejected concentrically from the ejection part. For example, the first ejection part and the second ejection part May be arranged in the same plane, or may be arranged in different planes.

  The conventional ion source described above in the section of the background art has a configuration in which individually formed capillary tubes are coaxially arranged and fixed in a subsequent process. For this reason, as described above, there is room for improvement in accuracy when the capillary tubes are arranged coaxially.

  On the other hand, in the base of the present invention, the first flow path and the second flow path are provided inside the block. The flow path wall of the first flow path and the flow path wall of the second flow path are both constituted by a part of the wall surface of the block, and the first flow path and the second flow path are one part of the block. It is isolated by a partition wall. Such wall surfaces and partition walls are formed by processing a block. For this reason, according to the present invention, it is not necessary to align the first flow path and the second flow path in the subsequent process, arrange them coaxially, and fix them. Therefore, even when each flow path is fine, the first flow path and the second flow path are reliably formed at predetermined positions, and the axial shake of the flow path can be suppressed.

  Here, when it is going to manufacture the nanofiber which has a heterogeneous structure using an electrospinning method, it is calculated | required that the axial alignment of a flow path should be performed with high precision and an axial shake should be suppressed. Even in such a case, by using the base of the present invention, it is possible to stabilize the nanofiber in which the phase formed from the first fluid and the phase formed from the second fluid are concentrically arranged by suppressing the shaft shake. Can be obtained.

Moreover, according to the present invention,
A block made of a conductive material;
A fluid ejection portion provided in the block;
A first flow path provided inside the block and communicating with the ejection portion;
An annular second flow path that is provided inside the block and communicates with the ejection portion, is disposed coaxially with the first flow path and is provided so as to surround a side surface outer periphery of the first flow path;
Have
The first flow path and the second flow path are formed by drilling the block from the surface of the block, and the tip of the first flow path protrudes outside the block from the surface of the block. The tip of the second channel protrudes outside the block from the surface of the block, and the tip of the first channel protrudes outside the block from the tip of the second channel. And a base used in the electrospinning method is provided.

  In the present invention, the first channel and the second channel are formed by drilling a block. For this reason, even when the flow path is fine, it is possible to reliably form the first flow path and the second flow path at predetermined positions, and to suppress the axial shake of the first flow path and the second flow path. Further, unlike the case where the plurality of flow paths are constituted by separate tubular members, the first flow path and the second flow path are aligned, arranged coaxially, and do not need to be fixed.

  In the present invention, since the block is made of a conductive material, fine machining by electric discharge machining is possible. Since electric discharge machining is non-contact machining, the machining accuracy of the first channel and the second channel can be further improved by using this. In the present invention, the material of the block may be a metal, for example.

  In the present invention, since the block is made of a conductive material, a voltage can be applied to the block.

  For example, in the base of the present invention, while supplying the first fluid to the first flow path and supplying the second fluid to the second flow path, a predetermined voltage is applied to the block, and the first fluid and The second fluid may be used by being ejected from the ejection part.

  Further, according to the present invention, there is provided a method for producing nanofibers using the die of the present invention, wherein the first fluid is supplied to the first channel and the second fluid is supplied to the second channel, There is provided a method for producing nanofibers, including a step of applying a predetermined voltage to the base and ejecting the first fluid and the second fluid from the ejection part.

  In the present invention, the first channel and the second channel are formed in the block. Further, a predetermined voltage is applied to the block, and the first fluid and the second fluid are ejected from the ejection part. For this reason, it is more suitably used as a capillary head in the electrospinning method.

  In the present invention, the first fluid and the second fluid may be supplied from different supply ports to the first channel and the second channel, respectively. If it does in this way, a nozzle can be made the composition which was further excellent in manufacture stability.

  In this invention, the front-end | tip of said 1st flow path may protrude outside the said block rather than the surface of the said block. By doing so, it is possible to prevent the first fluid droplets from accumulating in the ejection part. For this reason, the first fluid can be more stably ejected from the ejection portion.

  In the present invention, the tip of the flow path refers to the end located on the jet outlet side among the ends of the flow path.

  In this invention, the front-end | tip of said 2nd flow path may protrude outside the said block rather than the surface of the said block. By doing so, it is possible to prevent the second fluid droplets from accumulating in the ejection part. For this reason, the second fluid can be more stably ejected from the ejection portion.

  In this invention, the front-end | tip of said 1st flow path may protrude outside the said block rather than the front-end | tip of said 2nd flow path. By so doing, spinning can be more reliably generated when applied to electrospinning. For this reason, when it uses for manufacture of nanofiber, the manufacture stability of nanofiber can further be improved.

  In the present invention, in the vicinity of the ejection portion, a liquid reservoir is provided on the side of the second flow path, and the liquid reservoir is provided in the block and is formed by removing a predetermined region of the block. The recessed part made may be sufficient. By carrying out like this, the excess fluid ejected from the ejection part can be removed more effectively, and it can prevent it from accumulating near the ejection part.

  It should be noted that any combination of these components, or a conversion of the expression of the present invention between a method, an apparatus, and the like is also effective as an aspect of the present invention.

For example, by the method for producing nanofibers of the present invention described above above, it is possible to obtain a nano-fibers.

In the present invention, the nanofiber refers to a fiber having a diameter of nanometer order. Here, the diameter is, for example, the number average fiber diameter. In the present invention , the number average fiber diameter of the nanofibers can be, for example, 5 nm or more and 950 nm or less.

  According to the present invention, a fine heterogeneous structure having a clear boundary can be stably produced by the electrospinning method using the above-described die. For this reason, according to the present invention, nanofibers having a heterogeneous structure with a clear interface can be stably obtained.

In the present invention, the heterophasic structure refers to a structure having two adjacent phases and a clear boundary between these phases. The phase contained in the heterophase structure is, for example, a solid region. Specifically, Oite this onset bright, a core extending in the direction of the central axis of the nanofibers, and a coating layer formed on the outside of the core may contain.

Further, Oite this onset bright, a core extending in the direction of the central axis of the nanofibers, and a plurality of nanoparticles attached to the outside of the core may contain.
In the present invention, the nanoparticle refers to a particle having a particle diameter of nanometer order. Here, the particle diameter is, for example, the number average particle diameter. In the present invention, the number average particle diameter of the nanoparticles can be, for example, 5 nm or more and 950 nm or less.

Further, in the present invention, a hollow region extending in the direction of the central axis of those said nanofiber, an annular region surrounding a periphery of the hollow region may contain. The hollow region may be formed inside the nanofiber, or a part thereof may be exposed to the outside of the nanofiber. For example, the hollow region may communicate with the outside of the nanofiber at both ends of the nanofiber. Since the nanofiber of the present invention is obtained by an electrospinning method, even when the nanofiber has a hollow region, the production stability is excellent, and the fiber diameter and the variation in the diameter of the hollow region are suppressed. .

  As described above, according to the present invention, a die in which a plurality of flow paths are coaxially and stably formed with high accuracy is realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

(First embodiment)
In the present embodiment, the configuration of the base will be described.
FIG. 2 is a perspective view showing the configuration of the base of this embodiment. 3 is a cross-sectional view taken along line AA ′ of FIG. 4 (a) and 4 (b) are diagrams schematically showing the vicinity of the ejection port 113 of FIG. 3 in an enlarged manner. 4B and FIG. 5 are cross-sectional views taken along the line BB ′ of FIG.

  The base 100 shown in FIGS. 2 to 5 is provided with a block 102 made of a conductive material, a fluid ejection portion (ejection port 113) provided in the block 102, an inside of the block 102, and an ejection port 113. The first flow path 105 (FIG. 2) that communicates with the first flow path is provided inside the block 102 and communicates with the ejection port 113, is disposed coaxially with the first flow path 105, and surrounds the outer periphery of the side surface of the first flow path 105. And an annular second flow path 111 provided in the. The base 100 is an integrally formed coaxial capillary head in which a first channel 105 and a second channel 111 are provided coaxially.

  The block 102 is a block having a predetermined shape, and is a rectangular parallelepiped block in the present embodiment. The material of the block 102 may be a conductive material, but is, for example, an iron alloy such as iron or stainless steel, or another metal. The front end surface 119, the rear end surface 123, and the side surface 125 of the block 102 are, for example, rectangular with a side length of 5 mm to 50 mm.

  The base 100 is constituted by a continuously integrated block 102. In this specification, continuous integration means that it is integrally formed as a continuous body. Moreover, it is preferable that the block 102 is made of a single member and does not have a joint portion. If the block 102 is a continuously integrated member, for example, a predetermined coating or the like may be applied to the wall surface of the block 102.

  Further, the block 102 includes a bulky support part and a partition part that separates the first flow path 105 and the second flow path 111 as a part of the block 102. Further, the support portion includes a first wall portion constituting the side wall of the first flow path 105 and a second wall portion constituting the side wall of the second flow path 111. That is, in the block 102, the first wall portion, the second wall portion, and the partition wall portion are formed continuously and integrally.

  In the base 100, the flow path wall of the first flow path 105 and the flow path wall of the second flow path 111 are constituted by a part of the wall surface of the block 102. The first flow path 105 and the second flow path 111 are isolated by a partition wall (first capillary 106) that forms part of the block 102. If it carries out like this, the flow-path wall of the nozzle | cap | die 100 by which the several fine flow path was coaxially arrange | positioned can be made strong.

  The first flow path 105 and the second flow path 111 have a shape having a substantially constant inner diameter along the extending direction of the flow path, and are arranged concentrically. The first fluid 105 and the second fluid 111 are supplied with the first fluid (fluid A) and the second fluid (fluid B) from different supply ports, respectively. Fluid A and fluid B can each be a different material. Moreover, the fluid A and the fluid B may be any of solid, liquid, and gas, respectively.

  The block 102 communicates with the first flow path 105, communicates with the first supply port (the end of the first supply unit 101) that supplies the fluid A into the first flow path 105, and the second flow path 111. A second supply port for supplying the fluid B into the two flow paths 111 (an end portion of the second supply unit 107) is provided, and the second supply unit 107 and the first supply unit 101 are spaced apart from each other. ing.

  In the base 100, the supply direction of the fluid A from the first supply part 101 to the first flow path 105 is the direction in which the central axis of the first flow path 105 extends, and the second supply part 107 to the second flow path 111. The direction in which the fluid B is supplied is different from the direction in which the central axis of the second flow path 111 extends.

  The second supply unit 107 and the first supply unit 101 are provided on different surfaces of the block 102. By so doing, it is possible to improve the ease of processing when forming each flow path in the block 102. At this time, the fluid A and the fluid B are introduced into the block 102 from different surfaces. The fluid A is introduced into the first supply unit 101. The fluid A supplied to the first supply unit 101 reaches the first flow path 105 via the first connection unit 103. Further, the fluid B is introduced into the second supply unit 107. The fluid B supplied to the second supply unit 107 reaches the second flow path 111 via the second connection unit 109.

  The first flow path 105 is an area inside the first capillary 106 that forms a part of the block 102. The first capillary 106 has a protrusion 115 that protrudes from the front end surface 119 of the block 102. The cross-sectional shape of the first channel 105 is circular, and the inner diameter of the first capillary 106 is, for example, not less than 0.05 mm and not more than 3 mm. Further, the first flow path 105 extends from the front end surface 119 toward the inside of the block 102. The first flow path 105 communicates with the first connection unit 103 and the first supply unit 101.

  The first connection part 103 and the first supply part 101 are tubular areas formed by removing predetermined areas of the block 102. The 1st supply part 101, the 1st connection part 103, and the 1st flow path 105 are arrange | positioned coaxially. Further, when viewed from the front end surface 119, the cross-sectional areas of the first flow path 105, the first connection portion 103, and the first supply portion 101 are increased in this order. The first supply unit 101 communicates with an opening provided in the rear end surface 123 of the block 102.

  The second flow path 111 is an annular region between the first capillary 106 and the second capillary 121. The second capillary 121 forms a part of the block 102 and is provided on the outer side of the first channel 105 and coaxially with the first channel 105. The inner diameter of the second capillary 121 is, for example, larger than the inner diameter of the first capillary 106, and is, for example, 3 mm or less. The second flow path 111 communicates with the second connection portion 109, and the second connection portion 109 communicates with the second supply portion 107.

  The second connection part 109 and the second supply part 107 are tubular areas formed by removing predetermined areas of the block 102. The second connection portion 109 and the second supply portion 107 are formed to extend perpendicularly to the extending direction of the second flow path 111. The second supply unit 107 communicates with an opening provided on the side surface 125 of the block 102.

  The spout 113 is provided near the surface of the block 102. The ejection port 113 is an opening through which the fluid supplied into the block 102 is ejected, and includes a first ejection port 112 and a second ejection port 114 (FIG. 4A). The first channel 105 communicates with the first jet port 112, and the second channel 111 communicates with the second jet port 114. The position of the second jet port 114 coincides with the surface (front end surface 119) of the block 102, and the first jet port 112 is disposed outside the block 102 with respect to the second jet port 114. In the present embodiment, the spout 113 is provided in a plurality of planes, but the whole spout 113 may be provided in the same plane.

  In the base 100, the tip of the first capillary 106 protrudes from the surface (front end surface 119) of the block 102. For this reason, the front-end | tip of the 1st flow path 105 protrudes on the outer side of the block 102 rather than the front-end surface 119. The tip of the first channel 105 protrudes outside the block 102 from the tip of the second channel 111. That is, the end portion of the first capillary 106 protrudes toward the outside of the block 102 from the end portion of the second capillary 121 to form a protruding portion 115. By doing in this way, when using for an electrospinning method, the spinning of the fluid A and the fluid B can be produced reliably.

  In addition, a liquid reservoir 117 is provided on the side of the second flow path 111 in the vicinity of the tip of the second flow path 111. The liquid reservoir 117 is an annular recess that is provided in the block 102 and formed by removing a predetermined region of the block 102. The planar shape of the recess is, for example, an annular shape surrounding the first flow path 105.

  By providing the liquid reservoir 117, excess fluid overflowing from the first flow path 105 and the second flow path 111 can be efficiently guided into the liquid reservoir 117. For this reason, in the vicinity of the spout 113, the droplet of the fluid A or the fluid B can be prevented from accumulating on the end face of the block 102. Therefore, when applied to a capillary head in the electrospinning method, the fluid can be reliably spun at the ejection port 113.

  The liquid reservoir 117 may be configured to be able to discharge excess fluid overflowing from the first flow path 105 and the second flow path 111 in the vicinity of the ejection port 113, and communicates with the second flow path 111. Alternatively, it may be provided separately from the second flow path 111.

  The base 100 shown in FIGS. 2 to 5 is obtained by processing the block 102. By processing the block 102, the wall surface and the partition in the block 102 are formed. The first flow path 105 and the second flow path 111 are formed by drilling the block 102 from the surface of the block 102. More specifically, the first flow path 105 and the second flow path 111 are obtained, for example, by engraving the block 102 from a predetermined surface of the block 102 by non-contact processing.

  By engraving the block 102 using non-contact machining such as electric discharge machining or laser machining, the machining accuracy of the flow path can be further improved. Further, in the base 100, the first flow path 105 and the second flow path 111 are formed by carving from a predetermined surface of the block 102. There is no need for positioning. Moreover, it is the structure by which the axial shake of the flow path was suppressed.

  Since the block 102 is made of a conductive material, the first flow path 105 and the second flow path 111 can be stably formed with high accuracy in the block 102 by using, for example, electric discharge machining.

Next, the effect of this embodiment is demonstrated.
In the base 100, a plurality of flow paths are provided on the same axis. The flow path walls of the plurality of flow paths are constituted by a part of the wall surface of the block 102. Further, these flow paths are isolated by a partition wall forming a part of the block 102. For this reason, it is not necessary to align the capillaries on the same axis in a later process such as use. Further, the strength of the channel wall is excellent even when the channel is fine. For this reason, even when the liquid is supplied to each flow path in a pressurized state, it is possible to suppress the shake of each capillary. Therefore, according to the base 100, various types of pressurized fluid can be ejected from a predetermined region with good controllability.

  Here, the conventional ionization apparatus by the electrospray method has a structure in which thin capillary tubes having different inner diameters are arranged on the same axis. Therefore, this configuration and the configuration of the present embodiment will be compared and described.

  FIG. 12 is a diagram showing an outline of the electrospray ionization method. In FIG. 12, a first capillary 201 and a second capillary 203 are coaxially arranged as two capillary tubes having different diameters. By applying a predetermined voltage to these capillaries, the fluid 205 in the first capillary 201 is ejected toward the target 207 provided in the MS section. A sheath gas is supplied into the second capillary 203.

  However, these capillary tubes are composed of metal thin tubes. For this reason, the durability of the capillary tube may not be sufficiently obtained. Moreover, there was a concern that the work was complicated and time-consuming when replacing the capillary tube. For this reason, there was room for improvement in terms of durability and maintainability of the capillary tube.

  In addition, it may be difficult to maintain a state in which a plurality of capillary tubes are precisely maintained coaxially. For this reason, when a capillary tube made of two independent members is fixed on the same axis, there is room for improvement in terms of the accuracy of the capillary tube on the same axis when precise axial alignment is required.

  According to the study of the present inventors, when the electrospinning method is applied to the production of nanofibers having a heterogeneous structure, particularly high alignment accuracy of the flow path is necessary. For this reason, when a capillary tube as shown in FIG. 12 is used, it is difficult to obtain a nanometer-order heterophase structure with good reproducibility.

  In contrast, in the present embodiment, the first flow path 105 and the second flow path 111 are formed by processing the block 102 without using a plurality of capillary tubes as independent members. The flow path wall of the first flow path 105 and the flow path wall of the second flow path 111 are configured by a part of the wall surface of the block 102, and the first flow path 105 and the second flow path 111 are formed of the block 102. Since the capillaries are separated by the first capillaries 106 constituting a part, these capillaries can be stably formed at predetermined positions. For this reason, unlike the case where the two capillaries are formed as separate members and are arranged coaxially and fixed, the first flow path 105 and the second flow path 111 are reliably formed at predetermined positions, and the shaft shakes. Can be suppressed. Further, since the first capillary 106 and the second capillary 121 form a part of the block 102, their strength can be improved. Therefore, durability and maintainability of these capillaries can be improved.

  Moreover, in this embodiment, since the block 102 is comprised with the electrically-conductive material, the nozzle | cap | die 100 can be manufactured using electrical discharge machining. Since it can be manufactured by non-contact machining such as electric discharge machining, it has a configuration excellent in machining accuracy in micromachining.

  Therefore, the base 100 of the present embodiment is sufficient even when it is required to perform channel alignment with particularly high precision, as in the case of producing nanofibers having a heterogeneous structure using an electrospinning method. It is applicable to. Also, in terms of the block 102 being a conductive material, the die 100 can be suitably used for manufacturing nanofibers having a fine heterogeneous structure obtained by electrospinning.

  The electrospinning method is a method for producing nano-sized ultrafine fibers using the same principle as the electrospray ionization method. By using the die 100 as a capillary head in the electrospinning method, various types of fluid can be stably supplied on the same axis with high accuracy and ejected from the ejection port 113. For this reason, by applying the die 100 to the electrosping method, nanofibers having a heterogeneous structure can be stably produced with a high yield. At this time, the base 100 supplies the fluid A to the first flow path 105 and supplies the fluid B to the second flow path 111 while applying a predetermined voltage to the block 102 to eject the fluid A and the fluid B from the jet outlet. 113 is used by being ejected.

  Examples of nanofibers having a heterophase structure include various high-functional multilayer nanofibers such as nanofibers having a hollow structure, photocatalyst nanofibers, and high-strength nanofibers. If the base 100 is used, such highly functional nanofibers can be extended and stably manufactured with a high yield. In addition, as a highly functional multilayer nanofiber, the multilayer nanofiber which has arrange | positioned the raw material from which a physical or chemical property differs on the same axis | shaft is mentioned, for example.

(Second embodiment)
In 1st embodiment, the structure of a nozzle | cap | die can also be set as the following structures.
Fig.11 (a) and FIG.11 (b) are figures which show another structure of a nozzle | cap | die. Fig.11 (a) is the figure which looked at the nozzle | cap | die from the side surface. FIG. 11B is an enlarged view showing the vicinity of the protruding portion 115 in FIG.

  The basic configuration of the base shown in FIGS. 11A and 11B is the same as that of the base 100 shown in FIGS. However, in this embodiment, instead of providing the liquid reservoir 117, the front end surface 119 of the block 102 is retracted toward the inside of the block 102. The second capillary 121 and the first capillary 106 both protrude from the front end surface 119. In the present embodiment, the first connection portion 103 is not provided, and the first flow path 105 is directly connected to the first supply portion 101.

  In the base shown in FIG. 11A and FIG. 11B, the tip of the second flow path 111 protrudes toward the outside of the block 102 from the end face of the block 102, and the first jet nozzle 112 and The second jet ports 114 are all located outside the block 102 with respect to the front end surface 119. As a result, when applied to the electrospinning method, it is possible to prevent the droplets ejected from the ejection port 113 from becoming too large to be spun.

  Also in this embodiment, the same effect as the first embodiment can be obtained. For this reason, it can use suitably for manufacture of the nanofiber as described in embodiment mentioned later, for example. In addition, according to the present embodiment, the second capillary 121 is also projected from the front end surface 119, so that the spinning of the fluid ejected from the projecting portion 115 can be generated more reliably.

  In the following embodiments, examples of nanofibers having a heterogeneous structure obtained when the die described in the above embodiments is applied to an electrospinning method will be described. Examples of such nanofibers include multifunctional multiphase nanofibers. In the following, the case where the base 100 described in the first embodiment is used will be described as an example, but the base described in the second embodiment may be used.

(Third embodiment)
FIG. 1 is a perspective view showing the configuration of the nanofiber of this embodiment. The nanofiber 110 is a fiber having a heterogeneous structure (core 131 and shell layer 133) obtained by an electrospinning method. The heterophasic structure includes a first phase (core 131) extending along the center axis of the fiber and a second phase (shell layer) arranged outside the core 131 in a cross section perpendicular to the extending direction of the core 131. 133). The shell layer 133 is a coating layer that is provided in contact with the core 131 and covers the outer periphery of the side surface of the core 131.

The core 131 is a region made of the first material.
The shell layer 133 is an area that is provided in contact with the core 131 and covers the outer periphery of the side surface of the core 131. The core 131 and the shell layer 133 are arranged coaxially. Further, the core 131 and the shell layer 133 are simultaneously formed by the same process. The shell layer 133 is made of a second material different from the core 131.

The material of the core 131 and the shell layer 133 is not particularly limited as long as it is a material that can be electrospun. For example, an organic polymer material such as polyaniline, or an inorganic material such as silica, titania, or zirconia is used.
Examples of the combination of materials for the core 131 and the shell layer 133 include a combination in which one of the core 131 and the shell layer 133 is an inorganic material such as silica and the other is an organic polymer material. The core 131 and the shell layer 133 may be made of different organic polymer materials.

  From the viewpoint of further improving the production stability, the diameter of the nanofiber 110 is, for example, 5 nm or more, preferably 10 nm or more, and more preferably 50 nm or more. The diameter of the nanofiber 110 is, for example, 950 nm or less, preferably 500 nm or less, more preferably 200 nm or less, from the viewpoint of increasing the specific surface area of the nanofiber 110.

  Furthermore, the diameter of the core 131 is, for example, 2 nm or more, preferably 5 nm or more, more preferably 10 nm or more, from the viewpoint of further improving the manufacturing stability of the core 131. The diameter of the core 131 is, for example, 200 nm or less, preferably 100 nm or less, and more preferably 50 nm or less, from the viewpoint of further miniaturizing the nanofiber phase structure.

  From the viewpoint of suppressing variation in the thickness of the shell layer 133, the thickness of the shell layer 133 is, for example, 2 nm or more, preferably 5 nm or more, and more preferably 10 nm or more. Further, the thickness of the shell layer 133 is, for example, 500 nm or less, preferably 300 nm or less, and more preferably 100 nm or less, from the viewpoint of reducing the diameter of the nanofiber.

  The nanofiber 110 is produced by an electrospinning method. However, it is difficult to obtain the nanofiber 110 having such a multilayer cross-sectional structure by a conventional electrospinning method.

  Therefore, in this embodiment, a capillary having a coaxial structure is used and two kinds of raw materials are used. Thereby, the manufacture of nanofibers with higher functionality than the nanofibers made of a single raw material is realized. In addition, it is possible to stably manufacture nanofibers in which two materials having conflicting attributes are formed concentrically.

  Specifically, the nanofiber 110 is manufactured using the die described above in the first or second embodiment. Hereinafter, an example of a method for manufacturing the nanofiber 110 will be described using the case where the base 100 of the first embodiment is used as an example.

  The nanofiber 110 of the present embodiment supplies the fluid A to the first flow path 105 of the base 100, supplies the fluid B to the second flow path 111, and applies a predetermined voltage to the base 100 so that the fluid A and It is obtained by ejecting the fluid B from the ejection port 113.

  FIG. 7A and FIG. 7B are diagrams for explaining a method of manufacturing the nanofiber 110 using the base 100. FIG. 7A shows a state in which the fluid A and the fluid B are ejected from the ejection port 113 of the base 100. FIG. 7B is a view showing a cross section taken along the line C-C ′ of FIG.

  As shown in FIGS. 7A and 7B, the nanofiber 110 supplies two different fluids (fluid A and fluid B) to the base 100, and the base 100, the target (earth), It is obtained by applying a direct current voltage during electrospinning. The fluid A includes the material of the core 131 or a precursor thereof. The fluid B includes the material of the shell layer 133 or a precursor thereof. When the material of the core 131 or the shell layer 133 is, for example, an organic polymer material, the fluid supplied to the base 100 is a solution or melt of the polymer. When the material of the core 131 or the shell layer 133 is an inorganic material, the fluid supplied to the base 100 is a sol-gel solution of the inorganic material.

  FIG. 6 is a view for explaining how to use the base 100. Specifically, FIG. 6 schematically shows a connection example of the base 100 to the fluid A and fluid B supply systems. As shown in FIG. 6, the needle adapter 127 is fixed to the side surface 125 of the block 102. The needle adapter 127 is a connection member having a hollow portion communicating with the second supply portion 107 (not shown in FIG. 6). The second tube 151 is connected to a luer adapter 129 that is engaged with and communicates with the needle adapter 127. The second tube 151 is connected to the second syringe pump 153, and the fluid B is pumped by the second syringe pump 153 and supplied to the second supply unit 107 at a predetermined speed.

  Although not shown in FIG. 6, a needle adapter (not shown) is also fixed to the rear end surface 123. The first tube 155 is connected to a luer adapter (not shown) fitted to the needle adapter. The first tube 155 is connected to the first syringe pump 157. The fluid A is pumped by the first syringe pump 157 and supplied into the first supply unit 101 at a predetermined speed.

For example, when the core 131 of the nanofiber 110 is a polycarbonate of a thermally decomposable polymer and the shell layer 133 is silica, the nanofiber 110 is manufactured under the following conditions.
Inner diameter of the first capillary 106: 100 μm
Inner diameter of second capillary 121: 500 μm
Protruding length of the protruding portion 115 in the extending direction of the first capillary 106: 100 μm
Fluid A: 10 mass% dichloromethylene solution or melt of polycarbonate Fluid B: Silica sol-gel solution Applied voltage: 5.0 kV

  Thereby, for example, a nanofiber 110 having a two-layer structure in which the core 131 has a diameter of 50 nm and the shell layer 133 has a thickness of 50 nm is obtained. By using the die 100 in which the two flow paths are integrally formed on the same axis, variation in the thickness of the core 131 of the nanofiber 110 and variation in the thickness of the shell layer 133 can be suppressed. For this reason, the nanofiber 110 having a nano-order fine core-shell structure can be stably manufactured with a high yield. The diameter of the core 131 and the thickness of the shell layer 133 can be controlled more precisely by adjusting the viscosity of the fluid A and the fluid B.

  Here, in the conventional electrospinning method, since single-phase nanofibers are obtained, it has been difficult to realize functions having different properties such as heat resistance and durability in a single nanofiber. Moreover, it was difficult to produce the nanofibers of this embodiment using an ion source in conventional electrospray ionization.

  On the other hand, in this embodiment, it becomes possible by using the nozzle | cap | die 100 to implement | achieve the function from which a characteristic differs with a single nanofiber. For this reason, the application range of nanofiber products can be greatly expanded. In addition, by using high-functional multi-phase nanofibers instead of conventional single-phase nanofibers, it is possible to produce high-performance products with higher sensitivity and higher strength.

(Fourth embodiment)
In 3rd Embodiment, although the nanofiber which has a multilayer structure was demonstrated, the core 131 part may be a hollow area | region.

  FIG. 8 is a perspective view showing the configuration of the nanofiber of this embodiment. The nanofiber 120 illustrated in FIG. 8 has a configuration in which a hollow region (hollow portion 135) extending in the central axis direction of the nanofiber 120 is provided in the shell layer 133 having an annular cross section. The shell layer 133 is an annular region that surrounds the periphery of the hollow portion 135. The material of the shell layer 133 is, for example, an inorganic material that can be electrospun. Further, various organic polymer materials that can be electrospun may be used. Examples of the material of the shell layer 133 include those described above in the third embodiment.

  The nanofiber 120 is manufactured using the manufacturing method of the nanofiber 110 of 3rd embodiment, for example. At this time, a thermally decomposable polymer is used for the fluid A used for the inner layer, and a silica sol gel is used for the fluid B used for the outer layer. And the nanofiber 110 is produced with the electrospinning method mentioned above. Thereafter, the nanofiber 110 is heated under a predetermined condition to evaporate the thermally decomposable polymer of the core 131 to form the hollow portion 135. Thereby, the hollow tube-shaped nanofiber 120 is obtained.

According to this embodiment, the hollow nanofiber 120 excellent in controllability of the fiber diameter and the diameter of the hollow portion 135 is obtained.
The obtained nanofiber 120 can be applied to, for example, a biomolecule single molecule detection channel.

(Fifth embodiment)
In the third embodiment, the nanofiber 110 in which the shell layer 133 is provided on the outer side of the core 131 is illustrated. However, the region disposed in the core 131 is not limited to the shell layer-like region. It can also be a region composed of particles. In the present embodiment, a nanofiber having such a configuration will be described.

FIG. 9 is a perspective view showing the configuration of the nanofiber of this embodiment. The nanofiber 130 illustrated in FIG. 9 includes a core 141 extending in the center axis direction of the fiber and a plurality of nanoparticles 145 attached to the side surface of the core 141.
The core 141 which is the first phase is a region constituted by the first material. The second phase is a region constituted by fine particles (nanoparticles 145) attached to the core 141.

  Examples of the material of the core 141 and the nanoparticles 145 include those described above in the first embodiment. The material of the nanoparticle 145 can be selected according to the function to be imparted to the nanofiber 130. For example, as the nanofiber 130, a material having a catalytic function such as a photocatalyst can be used. Nanofibers in which such a material is immobilized on the surface of the core 141 can be suitably used as a fiber material having a photocatalytic function.

  The diameter of the nanoparticle 145 is, for example, 1 nm or more, preferably 5 nm or more, from the viewpoint of photoactivity. In addition, the diameter of the nanoparticles 145 is, for example, 20 nm or less, preferably 10 nm or less, from the viewpoint of increasing the specific surface area of the nanoparticles 145.

  The nanofiber 130 can be manufactured using, for example, the method described in the third embodiment. For example, when the nanofiber 130 in which the titanium oxide nanoparticles 145 are attached to the surface of the core 141 made of silica is manufactured as follows. That is, silica sol-gel is used for the fluid A used for the inner layer, and an aqueous solution of polyvinyl pyrrolidone (PVP) mixed with titanium oxide is used for the fluid B used for the outer layer. And nanofiber is produced with the electrospinning method mentioned above. FIG. 10 is a perspective view showing a configuration of the obtained nanofiber 140. The nanofiber 140 includes a core 141 and a coating layer 143 that covers the outer periphery of the side surface of the core 141.

  Subsequently, the nanofibers 140 are heated under predetermined conditions to evaporate PVP. As a result, titanium oxide particles in the aqueous solution are deposited and adsorbed onto the nanofiber made of silica, that is, the core 141. In this way, the nanofiber 130 shown in FIG. 9 is obtained.

  The obtained nanofiber 130 has photocatalytic reactivity with titanium oxide. For this reason, it has a function which decomposes | disassembles organic substance by irradiating the nanofiber 130 with an ultraviolet-ray. Such photocatalyst nanofibers can be applied to, for example, harmful substance decomposition filters having very high reactivity.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

  For example, in the above embodiment, the base in which the two channels of the first channel 105 and the second channel 111 are coaxially described has been described as an example. It is good also as a structure by which the above flow path is provided and this flow path is arrange | positioned coaxially with another flow path. At this time, the third channel is an annular channel provided so as to surround the outer periphery of the side surface of the second channel 111. If a die in which three or more flow paths are continuously formed on the same axis in the block 102 is used, for example, a nanofiber having a structure in which three or more layers are laminated concentrically in the fiber radial direction Can be manufactured. The nanofibers can be further enhanced in function by appropriately selecting three or more layers of materials.

  Moreover, in the above, the example which applies a nozzle | cap | die to an electrospinning method was shown, However, The nozzle | cap | die in the above embodiment can also be applied to the capillary head for the electrospray ionization apparatus of a mass spectrometer, for example.

  In the above, the fiber diameter can be measured, for example, by observation with an electron microscope.

It is a perspective view which shows the structure of the nanofiber in embodiment. It is a perspective view which shows the structure of the nozzle | cap | die used for manufacture of the nanofiber in embodiment. It is A-A 'sectional drawing of the nozzle | cap | die of FIG. It is a figure which shows the structure of the jet nozzle vicinity of a nozzle | cap | die of FIG. FIG. 5 is a B-B ′ cross-sectional view of FIG. 4. It is a figure explaining the usage method of a nozzle | cap | die of FIG. It is a figure explaining the manufacturing method of the nanofiber in embodiment. It is a perspective view which shows the structure of the nanofiber in embodiment. It is a perspective view which shows the structure of the nanofiber in embodiment. It is a perspective view which shows the structure of the nanofiber in embodiment. It is sectional drawing which shows the structure of the nozzle | cap | die used for manufacture of the nanofiber in embodiment. It is a figure explaining the structure of the conventional electrospray ionization apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Base 101 1st supply part 102 Block 103 1st connection part 105 1st flow path 106 1st capillary 107 2nd supply part 109 2nd connection part 110 Nanofiber 111 2nd flow path 112 1st jet nozzle 113 Jet nozzle 114 1st Two spouts 115 Protruding part 117 Liquid reservoir 119 Front end face 120 Nanofiber 121 Second capillary 123 Rear end face 125 Side face 127 Needle adapter 129 Luer adapter 130 Nanofiber 131 Core 133 Shell layer 135 Hollow part 140 Nanofiber 141 Core 143 Cover layer 145 Nanoparticle 151 Second tube 153 Second syringe pump 155 First tube 157 First syringe pump

Claims (7)

A block made of a conductive material;
A fluid ejection portion provided in the block;
A first flow path provided inside the block and communicating with the ejection portion;
An annular second flow path that is provided inside the block and communicates with the ejection portion, is disposed coaxially with the first flow path and is provided so as to surround a side surface outer periphery of the first flow path;
Have
The flow path wall of the first flow path and the flow path wall of the second flow path are constituted by a part of the wall surface of the block, and the first flow path and the second flow path are formed of the block. The front end of the first flow path protrudes outside the block from the surface of the block, and the front end of the second flow path is more than the surface of the block. A base that protrudes to the outside of the block, the tip of the first flow path protrudes to the outside of the block from the tip of the second flow path, and is used for the electrospinning method . A block made of a conductive material;
A fluid ejection portion provided in the block;
A first flow path provided inside the block and communicating with the ejection portion;
An annular second flow path that is provided inside the block and communicates with the ejection portion, is disposed coaxially with the first flow path and is provided so as to surround a side surface outer periphery of the first flow path;
Have
The first flow path and the second flow path are formed by drilling the block from the surface of the block, and the tip of the first flow path protrudes outside the block from the surface of the block. The tip of the second channel protrudes outside the block from the surface of the block, and the tip of the first channel protrudes outside the block from the tip of the second channel. A base used for electrospinning . In the base according to claim 1 or 2,
While supplying the first fluid to the first flow path and supplying the second fluid to the second flow path, a predetermined voltage is applied to the block to cause the first fluid and the second fluid to flow through the ejection part. A base used by ejecting from the base. The base according to claim 3,
A base in which the first fluid and the second fluid are supplied to the first channel and the second channel from different supply ports, respectively. The base according to any one of claims 1 to 4,
In the vicinity of the ejection part, a liquid reservoir is provided on the side of the second flow path,
A base that is a recess formed by removing a predetermined region of the block while the liquid reservoir is provided in the block. The base according to any one of claims 1 to 5,
A base in which the second fluid supplied from the second flow path is either solid or liquid. A method for producing nanofibers using the die according to any one of claims 1 to 6 ,
The first fluid is supplied to the first channel, the second fluid is supplied to the second channel, a predetermined voltage is applied to the base, and the first fluid and the second fluid are supplied to the ejection part. The manufacturing method of nanofiber including the process made to eject from.