Novel flexible conductive infrared emission curtain and preparation method and excitation method thereof

Abstract

The invention relates to the technical field of material science and engineering, and discloses a novel flexible conductive infrared emission curtain as well as a preparation method and an excitation method thereof, and the preparation method comprises the following steps: step 1, uniformly stirring and mixing a conductive infrared emission material, a high-temperature-resistant flexible substrate material, a dispersion medium, a dispersing agent and a conductive channel interface material to obtain a mixed material; drying into a cluster, and then pressing into a flexible sheet to obtain a flexible material; 2, placing a flexible material and an electrode material according to an ABA or AB structure to form a large-area conductive infrared emission curtain material; and 3, performing high-temperature treatment on the large-area conductive infrared emission curtain material to form the flexible conductive infrared emission curtain. According to the technical scheme, through overall optimization of the composition and the preparation process of the infrared emission curtain, the flexibility, the conductivity and the infrared emission efficiency of the infrared emission curtain can be considered, the excitation energy consumption can be remarkably reduced, and the application value is very high.

Description

Technical Field

[0001] The invention relates to the field of material science and engineering technology, and in particular to a novel flexible conductive infrared emitting curtain and a preparation method and an excitation method thereof. Background Art

[0002] Infrared technology has a wide range of applications in the military, medical, environmental protection, communications and other fields. In the military field, infrared stealth, infrared decoys and infrared communications can use infrared emission screens to enhance military strength; in the medical field, infrared radiation therapy and rehabilitation equipment can better fit the patient's body through flexible curtains, providing uniform and effective thermal therapy effects; it can also be used as an auxiliary heat source to assist thermal imaging equipment in more accurate detection of body surface temperature distribution; in addition, smart clothing, smart curtains and sun visors, and smart floor heating systems can all be achieved using infrared emission screens.

[0003] Traditional infrared radiation usually adopts a rigid structure, which is easily damaged by mechanical and environmental stress, limiting their application in complex environments; traditional radiation sources mostly use special materials and nanomaterials. Although they have excellent performance, the production process is complicated and it is difficult to achieve large-scale production; in addition, it is difficult to strike a balance between flexibility and conductivity. Highly conductive materials usually lack flexibility, while highly flexible materials have poor conductivity. This is a major technical bottleneck in the design and application of infrared emission screens; at the same time, traditional infrared radiators usually require higher energy input to achieve effective infrared radiation. This not only increases the cost of use, but also limits its application in portable and low-energy devices. Summary of the invention

[0004] The present invention aims to provide a novel flexible conductive infrared emitting curtain and a preparation method and an excitation method thereof, so as to solve the problems of high energy consumption and unsatisfactory infrared emitting efficiency of infrared emitting devices in the prior art.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a new type of flexible conductive infrared emitting curtain, comprising the following raw materials in parts by weight: 60 to 98.9 parts of conductive infrared emitting material, 0 to 30 parts of high temperature resistant flexible base material, 0.1 to 1 part of dispersion medium, and 1 to 10 parts of conductive channel interface material.

[0006] On the other hand, the present technology also provides a method for preparing a novel flexible conductive infrared emitting curtain, comprising the following steps:

[0007] Step 1: Evenly stir and mix the conductive infrared emitting material, the high temperature resistant flexible base material, the dispersion medium, the dispersant, and the conductive channel interface material, dry them into a mass, and then press them into a flexible sheet to obtain a flexible material;

[0008] Step 2: Place the flexible material and the electrode material in an ABA or AB structure to form a large-area conductive infrared emitting curtain material;

[0009] Step 3: subjecting the large-area conductive infrared emitting curtain material to high-temperature treatment to form a flexible conductive infrared emitting curtain.

[0010] On the other hand, the technical solution also provides a new type of excitation method for a flexible conductive infrared emitting curtain, which performs DC excitation, AC excitation or eddy current excitation on the flexible emitting curtain; after the infrared emitting curtain is excited, infrared emission of 2 to 14 μm can be achieved.

[0011] Preferably, as an improvement, in step 1, the conductive infrared emitting material is AB2O 4-δ Type spinel, AB2O 4-δ The purity of the spinel material is greater than 90%, and the particle size is 20nm~100μm.

[0012] Preferably, as an improvement, in step one, the high temperature resistant flexible substrate material is at least one of polytetrafluoroethylene, polyvinylidene fluoride, and high temperature resistant silicate; the dispersion medium is at least one of water, ethanol, and ethylene glycol; the dispersant is at least one of polyethylene glycol octylphenyl ether, polyethylene glycol, polyvinyl pyrrolidone, polyacrylate, and N-methylpyrrolidone; and the conductive channel interface material is at least one of carbon, silver, and gold.

[0013] Preferably, as an improvement, in step 1, the stirring speed is 600-1000 rpm, and the stirring time is 2-5 h.

[0014] Preferably, as an improvement, in step 1, the drying temperature is 70-100° C., the drying time is 0.5-2 h, and the thickness of the pressed sheet is 0.1-5 mm.

[0015] In this technical solution, the electrode material can be selected from highly conductive materials such as carbon, copper, nickel, titanium, and iron.

[0016] Preferably, as an improvement, a conductive chip is provided in the conductive coil, and the conductive chip is a conductive metal or a conductive carbon core.

[0017] Preferably, as an improvement, in step 2, the electrode material is pressed into the flexible material by a pressing method, the pressing method is stamping or rolling, and the stamping pressure is 1 to 5 MPa; the thickness of the roller is the sum of the thickness of the flexible material d1 and the thickness of the electrode material d2 minus 0.1 to 0.4 mm.

[0018] Preferably, as an improvement, in step three, the temperature of the high temperature treatment is 200-320° C., and the treatment time is 2-4 hours.

[0019] The principles and advantages of this solution are: in actual application, in this technical solution, in view of the high energy consumption and unsatisfactory infrared emission efficiency of the infrared emitting device in the prior art, the inventor creatively considers optimizing the form of the emitting material, taking the "flexible" material (curtain) as the entry point, and in view of the problem that the infrared emitting curtain in the prior art cannot take into account flexibility, conductivity and infrared radiation capacity. This solution comprehensively optimizes the raw material composition and preparation process of the curtain, adopts conductive wide-band mid-infrared emitting material and high-temperature resistant flexible substrate material, combined with dispersion medium and dispersant, optimizes the material mixing and processing process, and significantly improves the conductivity and infrared emission performance of the material. Among them, the flexible base material is selected from polytetrafluoroethylene with high temperature resistance, etc., which can provide a basic flexible skeleton for the infrared emitting material, while ensuring the working temperature of the material, and ensuring the infrared emissivity performance of the infrared emitting material itself; the dispersant can simultaneously disperse the infrared emitting material and the base material, and has good stability and compatibility; the selection of the conductive channel interface material, on the one hand, optimizes the problem of reduced material conductivity caused by doping with high temperature resistant flexible base materials; on the other hand, it forms a high-performance two-dimensional interface with the infrared emitting material, optimizes the infrared emissivity of the infrared emitting material, and enhances the infrared performance of the large-area conductive flexible emitting curtain. In terms of preparation technology, this technical solution uses the eddy current excitation principle to develop a new infrared emitting curtain excitation method. This method excites infrared emission through the heat generated by the eddy current, and has the advantages of low energy consumption and uniform heating; compared with the traditional electric heating method, eddy current excitation can significantly reduce energy consumption, improve infrared emission efficiency, and improve the portability of material use. In addition, the infrared emitting material exists in the form of powder, and the powders need to be stably combined through high temperature and high pressure. However, such a process cost is high and is not conducive to the realization of flexible design. To solve this problem, this technical solution first selects polytetrafluoroethylene as the bonding base material (polytetrafluoroethylene provides higher temperature stability and flexibility while minimizing the loss of infrared emissivity), and through the optimization of the pressing method, it can not only ensure the requirements of the flexible material for electrical conductivity and mechanical properties, but also ensure the integrity and uniformity of the overall structure of the material, reduce the risk of stratification or delamination, ensure close contact between the electrode and the infrared emitting material, improve the quality of electrical contact, and thus enhance the electrical conductivity and current transmission efficiency. Since polytetrafluoroethylene is added to this technical solution, it does not have electrical conductivity itself, which will significantly reduce the overall electrical conductivity of the curtain. This is also a unique secondary technical problem encountered by this technology in the research and development stage. Based on this, the inventor restores and enhances the conductivity of the curtain by doping with conductive powder, and achieves a balance between bonding strength and conductivity by optimizing the amount of addition. In the stage of optimizing the conductive powder, in the field of infrared emitting materials, commonly used materials include graphene, cordierite and silicon carbide. The inventor creatively selected AB2O 4-δSpinel materials are mainly used in the field of far-infrared emission. 4-δ After adjusting the purity, particle size of the spinel material and the particle size of the conductive graphite, the infrared emission band was successfully stabilized at 2-14 microns. In particular, based on the surface plasmon resonance effect, the spinel material and the carbon-containing material formed a more superior interface infrared emission area. This improvement not only improved the infrared emissivity of the screen, but also gave the material significant advantages in flexible design and high-temperature stability.

[0020] In the technical research and development stage, how to achieve uniform and efficient excitation of the infrared emission curtain is one of the difficulties of this technical solution. In order to achieve efficient excitation, this technical solution first tried the method of planar electrodes at the left and right ends, but there was a problem of uneven electrical excitation. Then the method of thermal excitation infrared (Comparative Example 1) was used. Although the thermal excitation effect was relatively uniform, the infrared emission efficiency of the product obtained in Comparative Example 1 was very low, and most of the energy was converted into heat and accumulated in the materials and equipment, affecting the normal use of the materials and equipment. Then a resistance wire excitation method was carried out, and voltage was directly applied to both sides of the material (Example 3). Due to the internal conductivity and polarization characteristics of the conductive infrared emission material, this method is difficult to form a uniform current, and the excitation effect is also uneven. Based on this, the inventor proposed a scheme for Z-axis electrode plate excitation, which requires the selection of suitable electrode plate materials while ensuring uniform electrical excitation, and the use of suitable processes to firmly combine the conductive electrode plate with the infrared emission material. The preferred material is copper mesh, and the use of a rolling process can effectively enhance the bonding strength between the electrode plate and the material and the electrical excitation effect; another solution is to use eddy current technology for electrical excitation. This solution generates uniform eddy currents by embedding a pressed coil in the material. It is necessary to ensure that the material has a high magnetic induction intensity, thereby achieving uniform electrical excitation of the infrared emission curtain (Example 1 and Example 2), ensuring the efficiency of electrical excitation and the flexibility of the material.

[0021] In summary, the beneficial effects of this technical solution are:

[0022] 1. The infrared emission curtain prepared by this technical solution has excellent conductivity and flexibility, and is widely used in large-area infrared emission applications, such as military, medical and construction fields, providing an important reference and foundation for the development of related technologies in the future.

[0023] 2. The infrared emission curtain prepared by this technical solution ensures the high-efficiency infrared emission performance and long-term stability of this product under a reasonable production process.

[0024] 3. In this technical solution, by optimizing the composition and preparation process of the infrared emission curtain, the flexibility, conductivity and infrared emission efficiency of the infrared emission curtain can be taken into account, and the excitation energy consumption can be significantly reduced, which has a very high application value.

[0025] 4. In this technical solution, the excitation method of the infrared emitting curtain is optimized, and the flexible emitting curtain is excited by direct current, alternating current or eddy current, that is, the infrared emitting curtain is excited by electric field, magnetic field or thermal field, especially by using the further optimized excitation method (set to Figure 2 (c) Using the method of magnetic field eddy current excitation), combined with the emission curtain material of the present technical solution, it is possible to achieve infrared emission of 2 to 14 μm, with high emission efficiency and more uniform emission. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a production process flow chart of the novel flexible conductive infrared emitting curtain.

[0027] Figure 2 This is a basic structural diagram of a new flexible conductive infrared emitting curtain in an embodiment of the present invention.

[0028] Figure 3 This is a comparison diagram of the excited infrared image in the embodiment of the present invention.

[0029] Figure 4 It is the volt-ampere characteristic curve in the embodiment of the present invention.

[0030] Figure 5 : is the power temperature curve in the embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following is further described in detail through specific implementations, but the implementation of the present invention is not limited thereto. Unless otherwise specified, the technical means used in the following implementations are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; the materials, reagents, etc. used can all be obtained from commercial channels.

[0032] like Figure 1 As shown: A method for preparing a novel flexible conductive infrared emitting curtain comprises the following steps:

[0033] Step 1: Mix the mixed conductive wide-band mid-infrared emission material, the high-temperature resistant flexible substrate structure material, the dispersion medium, the dispersant, and the conductive channel interface material in proportion and stir evenly, the stirring speed is 600-1000rpm, the stirring time is 2-5h, and after drying into a mass, use a double-roller machine to press it into a flexible sheet to obtain a flexible material; the drying temperature is 70-100°C, and the drying time is 0.5-2h; the thickness of the sheet is 0-5mm, and the sheet is pressed twice. The first time is to preliminarily press it into a sheet after drying, and pass the double-roller machine 10-100 times; the second time is to press it into a flexible material after standing for 1-n days;

[0034] Among them, the high temperature resistant flexible substrate structural material is 0-30wt%, the dispersant is 0.1-1wt%, the conductive channel interface material is 1-10wt%, and the balance is the mixed conductive wide-band mid-infrared emitting material. Since the dispersion medium is mostly volatile material, it only serves the purpose of dispersing the material. The amount used in this embodiment is not clearly required. In actual application, it shall be based on the ability to evenly mix the materials.

[0035] The hybrid conductive wide-band mid-infrared emitting material is an interface-regulated infrared emitting material. Based on the surface plasmon regulation effect, the emissivity of the material is adjusted so that the emissivity in the main infrared emission band reaches more than 90%. In the process of pressing into a flexible sheet, a high-temperature resistant base material is reasonably added to make the molded material flexible while ensuring the infrared emissivity.

[0036] The high temperature resistant flexible substrate structural material is at least one of polytetrafluoroethylene, polyvinylidene fluoride, and high temperature resistant silicate;

[0037] The dispersion medium is at least one of water, ethanol and ethylene glycol;

[0038] The dispersant is at least one of polyethylene glycol octylphenyl ether, polyethylene glycol, polyvinyl pyrrolidone, polyacrylate, and N-methylpyrrolidone;

[0039] The conductive channel interface material is at least one of carbon, silver and gold;

[0040] Step 2: stack the flexible material and the electrode material in an ABA or AB structure to form a large-area conductive infrared emitting curtain material; the electrode can be made of two mesh materials for DC or AC excitation; or a ring-shaped wire coil material can be used with a coil speed of n for high-frequency eddy current excitation; or a conductive chip can be placed in the conductive coil, and the conductive chip can be a conductive metal or a conductive carbon core;

[0041] The electrode material is pressed into the flexible material by a pressing method. A punching machine can be used with a pressing pressure of 1 to 5 MPa. A roller machine can be used with a roller thickness of 0.1 to 0.4 mm less than the sum of the thickness of the flexible material d1 and the thickness of the electrode material d2.

[0042] Step three, place the large-area conductive infrared emitting curtain material obtained in step two in a muffle furnace for high-temperature treatment to obtain a flexible conductive infrared emitting curtain, and electrically excite the infrared emitting curtain after high-temperature treatment; the treatment temperature is 200-320°C, and the treatment time is 2-4h (the infrared emitting curtain after high-temperature post-treatment only retains the infrared emitting material and the flexible material as the substrate).

[0043] Example 1

[0044] A preparation method of a new type of flexible conductive infrared emission curtain, comprising the following steps: mixing the conductive wide-band mid-infrared emission material ZX-23, Teflon emulsion, and alcohol in a mass ratio of 10:3:10, then adding 1% by mass of conductive carbon black (particle size 27-40nm), stirring and mixing evenly, drying into a mass, and using a rolling machine to press it into a 1mm thick flexible sheet, and cutting out a 70*70mm square for experiment. Press the electrode material 20 mesh copper mesh to both sides of the sheet (such as Figure 2 a), and finally placed in a muffle furnace and treated at 320°C for 1 hour, using DC or AC excitation for the material.

[0045] Example 2

[0046] A preparation method of a new type of flexible conductive infrared emission curtain, comprising the following steps: mixing the conductive wide-band mid-infrared emission material ZX-23, Teflon emulsion, and alcohol in a mass ratio of 10:3:10, adding 1% of conductive carbon black by mass, stirring and mixing evenly, drying into a mass, and using a rolling machine to press it into a 1mm thick flexible sheet, and cutting out a 70*70mm square for experiment. The electrode material copper wire is pressed into the sheet in the form of a coil (such as Figure 2 c), and finally placed in a muffle furnace and treated at 320°C for 1 hour, using high-frequency alternating current to form eddy current excitation.

[0047] Example 3

[0048] A preparation method of a new type of flexible conductive infrared emission curtain includes the following steps: mixing the conductive wide-band mid-infrared emission material ZX-23, Teflon emulsion, and alcohol in a mass ratio of 10:3:10, adding 1% of conductive carbon black by mass, stirring and mixing evenly, drying into a mass, and using a rolling machine to press it into a 1mm thick flexible sheet, cutting out a 70*70mm square for experiment. The electrode material nickel strip is fixed to both sides of the sheet, and finally placed in a muffle furnace, treated at 320℃ for 1 hour, and the material is excited by DC or AC.

[0049] Comparative Example 1

[0050] A preparation method of a new type of flexible conductive infrared emission curtain includes the following steps: mixing the conductive wide-band mid-infrared emission material ZX-23, Teflon emulsion, and alcohol in a mass ratio of 10:3:10, adding 1% of conductive carbon black by mass, stirring and mixing evenly, drying into a mass, and using a rolling machine to press it into a 1mm thick flexible sheet, and cutting out a 70*70mm square for experiment. Fix the heating resistor copper wire to the middle of the sheet, and then fix the electrode material nickel strip to both ends of the copper wire. Finally, place it in a muffle furnace and treat it at 320℃ for 1 hour, and use DC or AC excitation for the material.

[0051] Experimental Example 1 Infrared Imaging

[0052] The flexible conductive infrared emitting curtains prepared in the above-mentioned embodiments and comparative examples were subjected to infrared imaging tests using an infrared thermal imager. The results are as follows: Figure 3 As shown: From the comparison results of the excitation infrared images, the electric field formed by the excitation using the two-end electrode method in Example 3 is very uneven, and the movement of electrons is mainly concentrated around the electrode plate, resulting in a sharp increase in the excitation power density on both sides of the electrode plate, which can easily lead to material breakdown. Example 1, Example 2 and Comparative Example 1 use parallel plate uniform field, eddy current field and resistive thermal excitation to excite relatively uniformly. In particular, the parallel plate uniform field has the highest conversion efficiency, which can reach an infrared excitation power close to 1W / cm2.

[0053] Experimental Example 2: Measurement of volt-ampere characteristics

[0054] The volt-ampere characteristics of the flexible conductive infrared emitting curtains prepared in the above-mentioned embodiments and comparative examples were tested. The results are as follows: Figure 4 As shown in Example 1 and Example 2, the excitation mode of parallel plates and eddy currents is more suitable for constructing an infrared radiation space based on a 220V power grid system.

[0055] Experimental Example 3 Thermal Stability Test

[0056] The flexible conductive infrared emitting curtains prepared in the above-mentioned embodiments and comparative examples were subjected to thermal analysis and the results are as follows: Figure 5 As shown: Example 2 eddy current excitation has a higher excitation upper limit, and the reasonable layout of eddy current space can achieve the same excitation efficiency as the parallel plate uniform electric field. At the same time, considering the non-contact nature of the eddy current method excitation material preparation and the excitation circuit platform, the use of eddy current method excitation is more suitable for the construction of a portable infrared emission platform.

[0057] In summary, in order to solve the problem of large-area flexible infrared emission screens providing uniform electric excitation while ensuring flexibility, this technical solution attempts to use a large-area parallel conductive substrate and eddy current excitation, which is the research and development focus of this technical solution. First, the method of using electric excitation to heat and then thermally excite infrared was tried (Comparative Example 1). Although the thermal excitation effect is relatively uniform, the infrared emission efficiency of the product obtained in Comparative Example 1 is very low, and most of the energy is converted into heat and accumulated in the materials and equipment, affecting the normal use of the materials and equipment. Then a resistance wire excitation method was carried out, and voltage was directly applied to both sides of the material (Example 3). Due to the internal conductivity and polarization characteristics of the conductive infrared emission material, this method is difficult to form a uniform current, and the excitation effect is also uneven. Subsequently, parallel plates were used to construct a uniform electric field, and eddy currents were used (Examples 1 and 2) to achieve uniformity of electric excitation, ensure the efficiency of electric excitation and the flexibility of the material. However, the excitation method of the parallel plate uniform electric field in Example 1 is relatively troublesome in product production and daily maintenance. Compared with Example 2, the use of eddy current excitation achieves a portable product application solution at the expense of slight loss of excitation uniformity.

[0058] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A new type of flexible conductive infrared emitting curtain, characterized by: The invention comprises the following raw materials in parts by weight: 60 to 98.9 parts of conductive infrared emitting material, 0 to 30 parts of high temperature resistant flexible base material, 0.1 to 1 part of dispersion medium and 1 to 10 parts of conductive channel interface material.

2. The method for preparing a novel flexible conductive infrared emitting curtain according to claim 1, characterized in that: The steps include: Step 1: Evenly stir and mix the conductive infrared emitting material, the high temperature resistant flexible base material, the dispersion medium, the dispersant, and the conductive channel interface material, dry them into a mass, and then press them into a flexible sheet to obtain a flexible material; Step 2: Place the flexible material and the electrode material in an ABA or AB structure to form a large-area conductive infrared emitting curtain material; Step 3: subjecting the large-area conductive infrared emitting curtain material to high-temperature treatment to form a flexible conductive infrared emitting curtain.

3. The method for exciting a novel flexible conductive infrared emitting curtain according to claim 1, characterized in that: The flexible emission curtain is excited by direct current, alternating current or eddy current; after the infrared emission curtain is excited, infrared emission of 2 to 14 μm can be achieved.

4. The method for preparing a novel flexible conductive infrared emitting curtain according to claim 2, characterized in that: In step 1, the conductive infrared emitting material is AB2O 4-δ Type spinel, AB2O 4-δ The purity of the spinel material is greater than 90%, and the particle size is 20nm~100μm.

5. The method for preparing a novel flexible conductive infrared emitting curtain according to claim 4, characterized in that: In step one, the high temperature resistant flexible substrate material is at least one of polytetrafluoroethylene, polyvinylidene fluoride, and high temperature resistant silicate; the dispersion medium is at least one of water, ethanol, and ethylene glycol; the dispersant is at least one of polyethylene glycol octylphenyl ether, polyethylene glycol, polyvinyl pyrrolidone, polyacrylate, and N-methylpyrrolidone; and the conductive channel interface material is at least one of carbon, silver, and gold.

6. The method for preparing a novel flexible conductive infrared emitting curtain according to claim 5, characterized in that: In step 1, the stirring speed is 600-1000 rpm, and the stirring time is 2-5 hours.

7. The method for preparing a novel flexible conductive infrared emitting curtain according to claim 6, characterized in that: In step 1, the drying temperature is 70-100° C., the drying time is 0.5-2 h, and the thickness of the pressed sheet is 0.1-5 mm.

8. The method for preparing a novel flexible conductive infrared emitting curtain according to claim 7, characterized in that: A conductive chip is arranged in the conductive coil, and the conductive chip is a conductive metal or a conductive carbon core.

9. The method for preparing a novel flexible conductive infrared emitting curtain according to claim 8, characterized in that: In step 2, the electrode material is pressed into the flexible material by a pressing method, the pressing method being stamping or rolling, with a stamping pressure of 1 to 5 MPa; the thickness of the roller is the sum of the thickness of the flexible material d1 and the thickness of the electrode material d2 minus 0.1 to 0.4 mm.

10. The method for preparing a novel flexible conductive infrared emitting curtain according to claim 9, characterized in that: In step three, the temperature of the high temperature treatment is 200-320° C., and the treatment time is 2-4 hours.

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