Method for producing porous body, porous body, and heat transport device

Abstract

To provide a unidirectional porous body having superior properties.SOLUTION: A method for producing a porous body includes the steps of: applying a magnetic field 4 to a mixture 3 composed of a polymerizable compound precursor 1, which can be polymerized by light irradiation, and magnetic particles 2; emitting light 5 to the mixture 3 from a direction different from the direction parallel to the magnetic field 4; and removing the precursor 1 that has not polymerized.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a porous body, a porous body, and a heat transport device. [Background technology]

[0002] Unidirectional porous bodies with many pores extending in one direction are used in various fields. For example, unidirectional porous bodies such as alumina and titania are produced by anodizing. Unidirectional porous bodies such as iron and copper are produced by mold casting. Unidirectional porous bodies made of wet gel are produced by ice crystal templating. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] J. Appl. Phys. 40, L1217 (2001) [Non-Patent Document 2] Chem. Commun.7, 874-875 (2004) Summary of the Invention [Problem to be solved by the invention]

[0004] The present inventors have recognized that in order to utilize unidirectionally porous bodies in a wider range of fields, it is necessary to develop a technique for producing unidirectionally porous bodies with excellent properties.

[0005] The present disclosure has been made in view of such problems, and an object of the present disclosure is to provide a unidirectional porous body having excellent properties. [Means for solving the problem]

[0006] In order to solve the above problems, a method for producing a porous body according to one embodiment of the present disclosure includes the steps of applying a magnetic field to a mixture containing a polymer compound raw material that can be polymerized by irradiating it with light and magnetic particles, irradiating the mixture with light from a direction other than parallel to the magnetic field, and removing the unpolymerized raw material.

[0007] Another aspect of the present disclosure is a porous body comprising a base material of a polymer compound that can be polymerized by light irradiation, pores penetrating the base material from the front surface to the back surface, and magnetic particles present on the side surfaces of the pores.

[0008] Yet another embodiment of the present disclosure is also a porous body, which includes a base material of a polymer compound that can be polymerized by light irradiation, and pores that penetrate the base material from the front surface to the back surface and have an average pore diameter of 5 μm or more.

[0009] Yet another aspect of the present disclosure is a heat transport device comprising a heat medium, an evaporator for evaporating the liquid heat medium by heat received from the outside, a condenser for condensing the gaseous heat medium, a vapor pipe for transporting the gaseous heat medium from the evaporator to the condenser, and a liquid pipe for transporting the liquid heat medium from the condenser to the evaporator, the evaporator comprising a heat receiving part for receiving heat from the outside, and a porous body manufactured by the above manufacturing method or the above porous body provided between the liquid pipe and the heat receiving part. Effect of the Invention

[0010] According to the present disclosure, a unidirectionally porous body having excellent properties can be provided. [Brief description of the drawings]

[0011] [Figure 1] 1A to 1C are diagrams illustrating a schematic procedure for a method for producing a unidirectionally porous body according to an embodiment of the present disclosure. [Diagram 2] 1 is a diagram illustrating a schematic configuration of a heat transport device according to an embodiment of the present disclosure. [Diagram 3]FIG. 2 is a diagram showing an example of the configuration of a manufacturing apparatus for manufacturing a unidirectionally porous resin according to an embodiment of the present disclosure. [Figure 4] FIG. 1 shows an SEM image of the top surface of a sample before removal of magnetic nanoparticles. [Diagram 5] FIG. 1 shows an SEM image of a cross section of a sample before removal of magnetic nanoparticles. [Figure 6] 13A-13C show SEM images of the top and cross-section of an example sample before and after removal of magnetic nanoparticles. [Figure 7] 13A-13C are enlarged SEM images of the top surface of an example sample before and after removal of magnetic nanoparticles. [Figure 8] FIG. 13 shows the results of an experiment in which water droplets are dropped onto a sample surface. [Figure 9] FIG. 13 is a diagram showing SEM images of the top surface of a sample of an example when θ is set to 30°, 45°, and 60°. [Figure 10] FIG. 13 is a diagram showing the ellipticity of pores calculated from each SEM image. [Figure 11] FIG. 1 shows an SEM image of the top surface of a sample when the sample is irradiated with light from two opposing directions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] FIG. 1 is a schematic diagram showing a procedure of a method for producing a unidirectional porous body according to an embodiment of the present disclosure. Magnetic nanoparticles 2 are dispersed in a raw material 1 of a polymer compound that can be polymerized by irradiating light (step S1). A magnetic field 4 is applied to this mixture 3 to align the magnetic nanoparticles 2 in the magnetic field direction, and light 5 is irradiated from a direction different from the direction parallel to the magnetic field 4 (step S2). The raw material 1 in the part irradiated with the light 5 polymerizes and hardens, but the raw material 1 in the part not irradiated with the light 5 because it is in the shadow of the magnetic nanoparticles 2 does not polymerize. When the remaining raw material 1 is removed, a unidirectional porous resin 6 containing the magnetic nanoparticles 2 is obtained (step S3). This unidirectional porous resin 6 has a large number of unidirectional pores 7 that penetrate from the front surface to the back surface, and the side of each pore 7 contains the magnetic nanoparticles 2. When the magnetic nanoparticles 2 are removed from the unidirectional porous resin 6, a unidirectional porous resin 8 is obtained (step S4). This unidirectional porous resin 8 has both the magnetic nanoparticles 2 aligned in a chain shape in step S2 and their shadow areas as unidirectional pores 9 penetrating from the front surface to the back surface.

[0013] The polymer compound that can be polymerized by irradiation with light may include, for example, a photocurable resin. The photocurable resin may be, for example, an acrylic resin that uses radical polymerization of unsaturated double bonds, or an epoxy resin that uses cationic polymerization. The type of polymer compound may be selected depending on the application of the unidirectional porous resin 6 and the unidirectional porous resin 8.

[0014] The raw material 1 may contain a monomer or oligomer of a polymer compound. The number of monomers contained in the oligomer may be adjusted depending on the reaction rate of the polymerization reaction, etc. The number of monomers contained in the oligomer may be selected from the range of 2 to 10, for example.

[0015] The magnetic nanoparticles 2 may include a simple substance or a compound of ferromagnetic iron (Fe), cobalt (Co), nickel (Ni), gadolinium (Gd), etc. The magnetic nanoparticles 2 may include, for example, iron oxides such as magnetite (Fe3O4) and maghemite (γ-Fe2O3). The type of magnetic nanoparticles 2 may be selected according to the use of the unidirectional porous resin 6, and the diameter, shape, number, density, etc. of the pores 7 in the unidirectional porous resin 6 and the pores 9 in the unidirectional porous resin 8. The magnetic nanoparticles 2 may have a surface coated with a resin or the like. The magnetic nanoparticles 2 may have a surface functionalized. The functional group on the surface of the magnetic nanoparticles 2 may include a hydroxyl group, an amino group, a carboxyl group, etc.

[0016] The particle size of the magnetic nanoparticles 2 may be adjusted according to the use of the unidirectional porous resin 6 and the unidirectional porous resin 8. The particle size of the magnetic nanoparticles 2 may be selected, for example, from the range of several nm to several tens of μm. By using magnetic nanoparticles 2 having a large particle size, the diameter of the pores 7 in the unidirectional porous resin 6 and the pores 9 in the unidirectional porous resin 8 can be increased. In addition, by using magnetic nanoparticles 2 having a small particle size, the diameter of the pores 7 in the unidirectional porous resin 6 and the pores 9 in the unidirectional porous resin 8 can be reduced. The particle size of the magnetic nanoparticles 2 may be adjusted according to the diameter, shape, number, density, etc. of the pores 7 in the unidirectional porous resin 6 and the pores 9 in the unidirectional porous resin 8.

[0017] The mixture 3 may contain an aggregating agent for aggregating the magnetic nanoparticles 2 and a dispersing agent for dispersing the magnetic nanoparticles 2. By aggregating the magnetic nanoparticles 2 and then aligning them in the magnetic field direction, the diameters of the pores 7 in the unidirectional porous resin 6 and the pores 9 in the unidirectional porous resin 8 can be increased. In addition, by dispersing the magnetic nanoparticles 2 and then aligning them in the magnetic field direction, the diameters of the pores 7 in the unidirectional porous resin 6 and the pores 9 in the unidirectional porous resin 8 can be reduced. The type, amount, concentration, etc. of the aggregating agent and dispersing agent may be adjusted according to the diameter, shape, number, density, etc. of the pores 7 in the unidirectional porous resin 6 and the pores 9 in the unidirectional porous resin 8.

[0018] The mixture 3 may contain a photopolymerization initiator. The photopolymerization initiator may contain, for example, an alkylphenone-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, an oxime ester-based photopolymerization agent, a cationic photopolymerization initiator, etc. The type of the photopolymerization initiator may be selected depending on the type of the raw material 1, etc.

[0019] The mixture 3 may contain an additive. The additive may be selected depending on the physical, chemical, and mechanical properties required for the unidirectionally porous resin 6 and the unidirectionally porous resin 8.

[0020] The composition of the raw material 1 and the magnetic nanoparticles 2 in the mixture 3 may be adjusted depending on the application of the unidirectionally porous resin 6 and the unidirectionally porous resin 8.

[0021] The strength of the magnetic field 4 applied to the mixture 3 in step S2 may be adjusted depending on the diameter, shape, number, density, etc. of the pores 7 in the unidirectional porous resin 6 and the pores 9 in the unidirectional porous resin 8.

[0022] The wavelength and intensity of the light 5 irradiated to the mixture 3 in step S2 may be adjusted according to the characteristics of the raw material 1 and the physical, chemical, and mechanical properties required for the unidirectional porous resin 6 and the unidirectional porous resin 8.

[0023] The irradiation angle of the light 5 irradiated to the mixture 3 in step S2 may be tilted at a predetermined angle from a direction parallel to the magnetic field 4. The predetermined angle may be adjusted according to the diameter, shape, number, density, etc. of the pores 7 in the unidirectional porous resin 6 and the pores 9 in the unidirectional porous resin 8. The larger the diameter of the pores 7 and the pores 9, the larger the predetermined angle may be. The predetermined angle may be, for example, 1° or more, 2° or more, 3° or more, 4° or more, 5° or more, 6° or more, 7° or more, 8° or more, 9° or more, 10° or more, 15° or more, 20° or more, 25° or more, 30° or more, 35° or more, 40° or more, 45° or more, 50° or more, 55° or more, 60° or more, 65° or more, 70° or more, 75° or more, 80° or more, or 85° or more. The specified angle may be 85° or less, 80° or less, 75° or less, 70° or less, 65° or less, 60° or less, 55° or less, 50° or less, 45° or less, 40° or less, 35° or less, 30° or less, 25° or less, 20° or less, 15° or less, 10° or less, 9° or less, 8° or less, 7° or less, 6° or less, 5° or less, 4° or less, 3° or less, or 2° or less.

[0024] The irradiation angle of the light 5 may be adjusted so that the shadow of the magnetic nanoparticles 2 aligned in a chain shape falls on the chain of another magnetic nanoparticle 2. This allows a bundle of chains of a plurality of magnetic nanoparticles 2 to be the pores 7 and 9, and therefore the diameter of the pores 7 and 9 can be increased. Conversely, the irradiation angle of the light 5 may be adjusted so that the shadow of the magnetic nanoparticles 2 aligned in a chain shape does not fall on the chain of another magnetic nanoparticle 2.

[0025] In step S2, the mixture 3 may be irradiated with light 5 from a plurality of different directions. For example, the mixture 3 may be irradiated with light 5 from two opposing directions. This can reduce the shadows of the magnetic nanoparticles 2, thereby making it possible to reduce the diameters of the pores 7 and pores 9. The number of light beams 5, the irradiation direction, the wavelength, the intensity, etc. of each light beam 5 may be adjusted according to the diameter, shape, number, density, etc. of the pores 7 in the unidirectional porous resin 6 and the pores 9 in the unidirectional porous resin 8.

[0026] In step S3, the unreacted raw material 1 may be removed by washing the raw material 1 with a solvent in which the raw material 1 is soluble. This solvent may be ethanol, methanol, or the like.

[0027] In step S4, the magnetic nanoparticles 2 may be removed by treating them with a substance capable of dissolving, decomposing or chemically reacting with the magnetic nanoparticles 2. This substance may be an acid, such as hydrochloric acid.

[0028] The porous body according to the embodiment of the present disclosure includes a base material of a polymer compound that can be polymerized by irradiating light, pores penetrating the base material from the front surface to the back surface, and magnetic particles present on the side surfaces of the pores. This porous body is, for example, the above-mentioned unidirectional porous resin 6.

[0029] The porous body according to the embodiment of the present disclosure includes a base material of a polymer compound that can be polymerized by irradiating light, and pores that penetrate the base material from the front surface to the back surface and have an average pore diameter of 5 μm or more. This porous body is, for example, the above-mentioned unidirectional porous body resin 6 or unidirectional porous body resin 8. The average pore size may be 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, 5 μm or more, 6 μm or more, 7 μm or more, 8 μm or more, 9 μm or more, 10 μm or more, 11 μm or more, 12 μm or more, 13 μm or more, 14 μm or more, 15 μm or more, 16 μm or more, 17 μm or more, 18 μm or more, 19 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, 35 μm or more, 40 μm or more, 45 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, 90 μm or more, 100 μm or more.

[0030] The thickness of the base material may be 1 mm or more. The thickness of the base material may be 2 mm or more, 3 mm or more, 4 mm or more, 5 mm or more, 6 mm or more, 7 mm or more, 8 mm or more, 9 mm or more, 10 mm or more, 15 mm or more, 20 mm or more, 25 mm or more, 30 mm or more, 35 mm or more, 40 mm or more, 45 mm or more, 50 mm or more, 60 mm or more, 70 mm or more, 80 mm or more, 90 mm or more, or 100 mm or more.

[0031] The unidirectional porous resin 6 and the unidirectional porous resin 8 of the present disclosure can be used for heat transport, heat exchange, filters, and the like. In particular, since the unidirectional porous resin 6 contains magnetic nanoparticles 2, the position of the unidirectional porous resin 6 can be controlled and collected by a magnetic field. In addition, the unidirectional porous resin 6 and the unidirectional porous resin 8 of the present disclosure can be used in fields such as biotechnology and medicine, such as cell scaffold materials and biomaterials. In addition, the unidirectional porous resin 6 and the unidirectional porous resin 8 of the present disclosure can be used in sensor technology such as a moisture-in-oil sensor.

[0032] FIG. 2 is a schematic diagram showing a configuration of a heat transport device according to an embodiment of the present disclosure. The heat transport device 10 includes a heat medium 11, an evaporator 12, a condenser 13, a vapor pipe 14, and a liquid pipe 15. The heat medium 11 evaporates in the evaporator 12 by heat generated from a heating element 16, and condenses in the condenser 13 by heat radiation. That is, the heat medium 11 includes a substance having a boiling point lower than the temperature of the evaporator 12 that receives heat generated from the heating element 16, and a melting point higher than the temperature of the condenser 13 (for example, room temperature). The evaporator 12 receives heat generated from the heating element 16 and evaporates the heat medium 11. The condenser 13 radiates the heat transported by the heat medium 11 to condense the heat medium 11. The vapor pipe 14 transports the gaseous heat medium 11 evaporated in the evaporator 12 to the condenser 13. The liquid pipe 15 transports the liquid heat transfer medium 11 condensed in the condenser 13 to the evaporator 12 .

[0033] The evaporator 12 includes a heat receiving section 17 that receives heat generated from a heat generating body 16, and a unidirectional porous resin 18 provided between the liquid pipe 15 and the heat receiving section 17. The unidirectional porous resin 18 may include the above-mentioned unidirectional porous resin 6 or may include the unidirectional porous resin 8. The liquid heat medium 11 supplied from the liquid pipe 15 to the inside of the evaporator 12 is supplied to the heat receiving section 17 from the pores of the unidirectional porous resin 18 by capillary action, and is evaporated by the heat received by the heat receiving section 17. At this time, if the heat received by the heat receiving section 17 is conducted to the liquid pipe 15 side, the heat medium 11 also evaporates on the liquid pipe 15 side, and the gaseous heat medium 11 flows back through the liquid pipe 15. According to the heat transport device 10 of this embodiment, since a unidirectional porous body formed of a resin with low thermal conductivity is used, it is possible to suppress the conduction of heat from the heat receiving section 17 to the liquid pipe 15 side. Furthermore, since a unidirectional porous body is used, it is possible to suppress pressure loss in the heat transport device 10. This makes it possible to improve the heat transport efficiency in the heat transport device 10.

[0034] [Example] FIG. 3 shows an example of the configuration of a manufacturing apparatus for manufacturing a unidirectional porous resin according to an embodiment of the present disclosure. The manufacturing apparatus 20 includes a spacer 21, a magnet 22, a yoke 23, and a UV light source 24. The spacer 21 functions as a mounting table for mounting a sample 25 between the upper and lower magnets 22. The magnets 22 are provided above and below the sample 25, and apply a vertical magnetic field to the sample 25. The yoke 23 is made of soft iron or the like, and amplifies the magnetic force of the magnet 22. The UV light source 24 irradiates the sample 25 with ultraviolet light. The UV light source 24 is installed so as to irradiate the sample 25 with ultraviolet light from a direction tilted by an angle θ from the magnetic field direction of the magnet 22.

[0035] A unidirectional porous resin according to the embodiment was manufactured using the manufacturing apparatus 20 shown in FIG. 3. As the raw material 1, PAK-01-CL acrylic resin for UV nanoimprinting manufactured by Toyo Gosei Co., Ltd. was used. As the magnetic nanoparticles 2, Fe3O4 particles with a particle size of 70 to 250 nm were used. A magnetic field was applied for 10 minutes to the sample 25 to which 5% by weight of the magnetic nanoparticles 2 had been added, to align the magnetic nanoparticles 2. Then, ultraviolet light was irradiated from the UV light source 24 for 10 seconds. Unreacted raw material 1 was washed and removed with ethanol. Then, the sample was treated with hydrochloric acid to remove the magnetic nanoparticles 2. As Comparative Example 1, a sample was prepared by irradiating ultraviolet light without applying a magnetic field to the sample 25 to which 5% by weight of the magnetic nanoparticles 2 had been added. As Comparative Example 2, a sample was prepared by irradiating ultraviolet light while applying a magnetic field to the sample 25 to which no magnetic nanoparticles 2 had been added.

[0036] Fig. 4 shows an SEM image of the top surface of the sample before the magnetic nanoparticles 2 are removed. Fig. 5 shows an SEM image of the cross section of the sample before the magnetic nanoparticles 2 are removed. In the sample of the example, it was shown that a large number of through-holes with pore diameters of 3 to 11 µm were generated in the parts shaded by the magnetic nanoparticles 2. In the samples of Comparative Example 1 and Comparative Example 2, no such pores were generated.

[0037] 6 shows SEM images of the top surface and cross section of the sample of the example before and after removing the magnetic nanoparticles 2. In the sample of the example after removing the magnetic nanoparticles 2, it was shown that a large number of through-holes with pore diameters of 4 to 14 μm were generated. It was confirmed that by removing the magnetic nanoparticles 2 by hydrochloric acid treatment, the average pore diameter increased from 5.3 μm to 7.7 μm, but the shape was maintained.

[0038] Figure 7 is an enlarged SEM image of the top surface of the sample of the embodiment before and after the removal of the magnetic nanoparticles 2. This sample was irradiated with UV light from the right side of the figure at an angle of θ = 30°. In the sample before the magnetic nanoparticles 2 are removed, pores 7 are formed to the left of the magnetic nanoparticles 2 due to the shadow of the magnetic nanoparticles 2. In the sample after the magnetic nanoparticles 2 are removed, the area where the magnetic nanoparticles 2 were present has become pores 9.

[0039] The sample of the embodiment before and after removing the magnetic nanoparticles 2, and the sample of the comparative embodiment 1 after removing the magnetic nanoparticles 2 were placed on paper that turns red when it absorbs water, and 10 μL of water droplets were dropped on the upper surface. FIG. 8 shows the experimental results. In the sample of the embodiment, the water droplets reached the lower surface in 15 seconds and the paper turned red. In the sample of the comparative embodiment 1, no change was observed in the water droplets even after 5 minutes. In the sample of the embodiment, both before and after removing the magnetic nanoparticles 2, that is, in both the unidirectional porous resin 6 and the unidirectional porous resin 8, it was shown that there were pores penetrating from the upper surface to the lower surface.

[0040] Fig. 9 shows SEM images of the top surface of the sample of the embodiment when θ is set to 30°, 45°, and 60°. Fig. 10 shows the ellipticity of pore 7 and pore 9 calculated from each SEM image. It was shown that the larger θ is, the longer the shadow of the magnetic nanoparticle 2 is extended, and the greater the ellipticity of pore 7 and pore 9 is.

[0041] Figure 11 shows an SEM image of the top surface of sample 25 when ultraviolet light was irradiated onto the sample from two opposing directions. By irradiating ultraviolet light from both directions, the shadows of the magnetic nanoparticles 2 could be made smaller, and a unidirectional porous resin having pores inside the magnetic nanoparticles 2 could be produced.

[0042] The present disclosure has been described above based on examples. These examples are merely illustrative, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each treatment process, and that such modifications are also within the scope of the present disclosure. [Explanation of symbols]

[0043] 1 Raw material, 2 Magnetic nanoparticles, 3 Mixture, 4 Magnetic field, 5 Light, 6 Unidirectional porous resin, 7 Pores, 8 Unidirectional porous resin, 9 Pores, 10 Heat transport device, 11 Heat transfer medium, 12 Evaporator, 13 Condenser, 14 Steam pipe, 15 Liquid pipe, 16 Heat generating element, 17 Heat receiving part, 18 Unidirectional porous resin, 20 Manufacturing device, 21 Spacer, 22 Magnet, 23 Yoke, 24 UV light source, 25 Sample.

Claims

1. applying a magnetic field to a mixture containing a raw material of a polymer compound that can be polymerized by irradiating light and magnetic particles; irradiating the mixture with light from a direction different from a direction parallel to the magnetic field; removing unpolymerized raw materials; A method for producing a porous body comprising the steps of:

2. removing said particles. The method of claim 1 .

3. The angle between the direction in which the mixture is irradiated with light and the direction parallel to the magnetic field is 5° or more. The method according to any one of claims 1 to 2.

4. The direction of irradiating the mixture with light is adjusted so that the shadow of the particles aligned in a chain shape in the mixture falls on or does not fall on another particle aligned in a chain shape. The method according to any one of claims 1 to 2.

5. Irradiating the mixture with light from different directions The method according to any one of claims 1 to 2.

6. The mixture includes an agglomerating agent for agglomerating the particles or a dispersing agent for dispersing the particles. The method according to any one of claims 1 to 2.

7. A polymer compound base material that can be polymerized by irradiating light; A pore penetrating from the front surface to the back surface of the base material; a magnetic particle present on a side surface of the pore; A porous body comprising:

8. A polymer compound base material that can be polymerized by irradiating light; Pores penetrating from the front surface to the back surface of the base material and having an average pore diameter of 5 μm or more; A porous body comprising:

9. The thickness of the base material is 1 mm or more. The porous body according to any one of claims 7 to 8.

10. A heat transfer medium; an evaporator that evaporates the liquid heat medium by heat received from an outside; a condenser for condensing the gaseous heat transfer medium; a steam pipe for transporting the gaseous heat transfer medium from the evaporator to the condenser; A liquid pipe that transports the liquid heat transfer medium from the condenser to the evaporator; Equipped with The evaporator comprises: A heat receiving part that receives heat from the outside; A porous body manufactured by the manufacturing method according to any one of claims 1 to 2 or the porous body according to any one of claims 7 to 8, which is provided between the liquid pipe and the heat receiving part; Equipped Heat transport device.

Images