A manufacturing technology of a fiber membrane with daytime passive radiative cooling function

Abstract

The application relates to the technical field of fiber membrane manufacturing, and discloses a fiber membrane manufacturing technology with daytime passive radiation refrigeration function, which comprises the following steps: S1, preparing a mixed spinning solution; S11, adding a solute into a tetrahydrofuran solution to obtain a mixed solution with a mass fraction of a set value; S12, adding the mixed solution into a container, mixing for a set time at a set temperature, and obtaining the mixed spinning solution; S2, preparing a fiber membrane through a spinning process according to the prepared mixed spinning solution; S3, performing patterning manufacturing through image processing; the burden of a traditional refrigeration system is reduced, energy loss is further prevented, and the preparation conditions of a traditional manufacturing process, single fiber diameter, slow production speed and high operation technology are improved; and an electrode capable of being used for human biological signal detection is manufactured through a mask method, so that the heat exposure capacity of the electronic skin is improved.

Description

Technical Field

[0001] This invention relates to the field of fiber membrane manufacturing technology, and in particular to a fiber membrane manufacturing technology with daytime passive radiation cooling function. Background Technology

[0002] PDRC is a method of automatically reducing surface temperature by reflecting sunlight and radiating heat into the cold outer space. This cooling capacity does not require a large amount of energy, which may lead to high energy consumption. Although electrospinning can produce nanofibers, its production speed is generally low, especially compared with other traditional textile methods.

[0003] Various PDRC designs that have been developed to date, including complex emission coatings such as photonic structures, photonic crystals, polymer-dielectric composites on polymer and metal mirrors, are efficient but expensive and prone to corrosion. Some innovative textiles have been fabricated using electrospinning, but this process requires high voltage to generate a sufficient electric field to stretch and spray the polymer or solution. This means it requires relatively high electrical energy, thus limiting the feasibility of large-scale production. Secondly, operating electrospinning equipment typically requires a high degree of skill and experience to ensure stable fiber fabrication, which may require training and expertise. Furthermore, current electronic skin substrates are mostly transparent materials with poor heat exposure resistance, demonstrating that continuous and stable detection of subjects' health and movement information is not possible in real-world working environments.

[0004] Therefore, it is necessary to provide a fiber membrane manufacturing technology with daytime passive radiation cooling function to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a fiber membrane manufacturing technology with daytime passive radiation cooling function, in order to solve the problems mentioned in the background art, such as the relatively high power consumption of the prior art, which limits the feasibility of large-scale production; secondly, operating electrospinning equipment usually requires a high level of skill and experience, and on the other hand, the electronic skin substrate is mostly made of transparent material, which has poor heat exposure resistance.

[0006] Based on the above ideas, the present invention provides the following technical solution: a fiber membrane manufacturing technology with daytime passive radiation cooling function, comprising the following steps:

[0007] S1. Prepare the mixed spinning solution;

[0008] S11. Add solute to tetrahydrofuran solution to obtain a mixed solution with a mass fraction of a set value;

[0009] S12. Add the mixed solution to the container, mix at the set temperature for the set time to obtain the mixed spinning solution;

[0010] S2. Based on the prepared mixed spinning solution, prepare a fiber membrane through a spinning process;

[0011] S3. Patterning is achieved through image processing.

[0012] As a further aspect of the present invention: in S11,

[0013] The solute is a mixed solution of styrene-isoprene-styrene rubber and salicylic acid particles with a mass fraction of 25.2%.

[0014] As a further aspect of the present invention: in S12,

[0015] The mixed solution was added to a glass bottle and stirred at room temperature for 3 hours to obtain a mixed spinning solution.

[0016] As a further aspect of the present invention, the specific operation steps of S2 are as follows:

[0017] S21. Add the mixed spinning solution to the spinning machine to obtain the fiber fabric;

[0018] S22. Heat and dry the spun fiber fabric for a period of time to obtain a fiber membrane;

[0019] S23. Place the fiber membrane in ethanol to wash away excess salicylic acid.

[0020] As a further aspect of the present invention, the specific operation steps of S21 are as follows:

[0021] S211. The spinning machine includes a coaxial needle, an oil-water separator, a solution propeller, an air compressor, a connecting pipe, and a roller collector. The air compressor is used as the spinning power. The mixed spinning solution is placed in the solution propeller so that the mixed spinning solution reaches the tip of the coaxial needle.

[0022] S212. A collection plate is placed at a set distance from the bottom of the coaxial needle, allowing the mixed spinning solution from the previous minute to drip freely into the collection plate.

[0023] S213. After the mixed spinning solution stabilizes, the droplets at the coaxial needle tip end are drawn into multiple fiber fabrics under the action of airflow.

[0024] S214. Fix the metal needles on a computer-controlled movable slide rail for large-area spinning.

[0025] As a further aspect of the present invention, the specific operation steps of S3 are as follows:

[0026] S31. Sensor fabrication: Electronic ink is applied to one side of the fabric using a soft multi-head brush, and activated by cyclic overall stretching to obtain a passively cooled electronic skin electrode.

[0027] S32. A patterned circuit of a strain sensor was fabricated using a spray coating method. The resistance of the fabricated strain sensor was recorded to investigate its performance in detecting various strains, such as electrical stability and response time.

[0028] As a further aspect of the present invention, the mass ratio of the styrene-isoprene-styrene rubber to salicylic acid is 1:2.

[0029] As a further aspect of the present invention: the solution propulsion device is a computer injector, and the air compressor is an air pump.

[0030] As a further aspect of the present invention: the distance between the coaxial needle and the collecting plate in S212 is 15cm.

[0031] As a further aspect of the present invention: the air pump is turned on and the air pressure is adjusted to 0.1 MPa.

[0032] Compared with the prior art, the beneficial effects of the present invention are that it reduces the burden on the traditional refrigeration system and further prevents energy loss, while improving the traditional manufacturing process with its harsh preparation conditions, single fiber diameter, slow production speed, and high operating technology; and it also improves the thermal exposure capability of electronic skin by fabricating electrodes that can be used for human biosignal detection through the mask method.

[0033] Compared with the prior art, the beneficial effects of the present invention are that the high-efficiency airflow spinning technology designed in the present invention can directly and repeatedly manufacture uniform polymer micro-nano composite fibers without the need for external force to pull the fibers, reducing the problem of external electric field; the addition of salicylic acid achieves a bimodal distribution of 493nm and 2.34μm diameter, thus improving the narrow applicability caused by the single fiber diameter.

[0034] Compared with existing technologies, the advantages of this invention are that it uses an airflow-driven method to design and implement the fabrication of fiber membranes from multiple safe and stable components, enabling rapid production and reducing operational complexity caused by harsh working environments; the prepared flexible passive solar radiation cooling fiber membrane can achieve close contact with the human body, avoiding relative slippage caused by muscle contraction or human movement, while achieving 2311g m at 50℃. -2 day -1 Water vapor transmission rate.

[0035] Compared with the prior art, the beneficial effect of the present invention is that by using a fiber network with a wide diameter distribution in the radiation cooling process, the low reflectivity caused by a single diameter fiber is avoided, the intensity of reflected sunlight is improved, and ultimately a high reflectivity of 95.7% and a high emissivity of 93.3% are achieved.

[0036] Compared with the prior art, the beneficial effects of the present invention are that the rougher surface structure makes the wearable more stable, the maximum cooling effect of up to 10.8°C is achieved through the micro-nano fiber composite structure, and effective thermal management is achieved. It can still stably detect human bioelectric signals even under outdoor sunlight exposure, and high-quality waveforms are captured with flat baselines and characteristic P, Q, R, S and T features. In addition, the fabricated strain sensor has a fast response time of about 66ms and can display clear human motion trajectories. Attached Figure Description

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0038] Figure 1 This is a schematic diagram of the coaxial needle structure of the present invention;

[0039] Figure 2 This is a schematic diagram of the air pump structure of the present invention;

[0040] Figure 3 This is a schematic diagram of the electrode pattern of the present invention.

[0041] In the diagram: 1. Coaxial needle; 2. Computerized syringe; 3. Air pump; 4. Roller collector; 5. Connecting tube; 6. Electrode pattern. Detailed Implementation

[0042] Example 1

[0043] like Figures 1 to 3 As shown, a fiber membrane manufacturing technology with daytime passive radiation cooling function includes the following steps:

[0044] S1. Prepare the mixed spinning solution;

[0045] S11. First, a mixed solution of styrene-isoprene-styrene rubber, salicylic acid, and tetrahydrofuran with a mass fraction of 25.2% was prepared. The mass ratio of styrene-isoprene-styrene rubber to salicylic acid was 1:2. Unlike the past use of salicylic acid as a pore-forming agent, this design uses salicylic acid as a solute and dissolves it together with styrene-isoprene-styrene rubber in the solvent. By utilizing its crystallization phenomenon in tetrahydrofuran, the fiber diameter can be adjusted, avoiding the low reflectivity caused by single-diameter fibers, and improving the intensity of reflected sunlight. Ultimately, a high reflectivity of 95.7% and a high emissivity of 93.3% were achieved.

[0046] S12. Add the mixed solution to a glass bottle and stir at room temperature for 3 hours to obtain a mixed spinning solution;

[0047] S2. Based on the prepared mixed spinning solution, prepare a fiber membrane through a spinning process;

[0048] S21. Add the mixed spinning solution to the spinning machine to obtain the fiber fabric;

[0049] S211, Use Figure 2 The computer syringe 2 draws an appropriate amount of the mixed spinning solution, places it on the fixed stage, and adjusts the injection speed of the computer syringe 2 to 20 ml / h. Then, it is used... Figure 2 Connect the computer syringe 2 and the coaxial needle 1 to the connecting tube 5. The coaxial needle 1 should also be connected to the air pump 3. Then, take an appropriate amount of aluminum foil and wrap it around the roller receiver 4. Adjust the distance between the coaxial needle 1 and the roller receiver 4 to 20cm. After all preparations are completed, turn on the air pump switch and adjust the air pressure to 0.1MPa so that the mixed spinning solution reaches the tip of the coaxial needle 1.

[0050] S212. Place a collection plate 15cm away from the bottom of the coaxial needle 1, and let the mixed spinning solution from the previous minute drip freely into the collection plate;

[0051] S213. After the mixed spinning solution stabilizes, the droplets at the end of the coaxial needle 1 are drawn into multiple fiber fabrics under the action of the airflow.

[0052] S214. Fix the metal needles on a computer-controlled movable slide rail for large-area spinning.

[0053] S22. Remove the aluminum foil from the roller receiver 4 and dry it in a 50℃ oven for 3 hours to obtain a fiber membrane. The high-efficiency airflow spinning technology can directly and repeatedly manufacture uniform polymer micro-nano composite fibers without the need for external force to pull the fibers, reducing the problem of external electric field. The airflow-powered method is designed to prepare fiber membranes using multiple safe and stable components, enabling rapid production and reducing the operational complexity caused by harsh working environments.

[0054] S23. Then remove the fiber membrane and place it in ethanol to wash away excess salicylic acid.

[0055] When the styrene-isoprene-styrene rubber concentration is 3 wt%, a transparent film with particles is obtained. As the mass fraction of styrene-isoprene-styrene rubber increases, the film gradually becomes fibrous, with the fibers being most pronounced at 10 wt%. Furthermore, the bimodalization becomes more pronounced with the increase of the salicylic acid ratio. When the ratio of styrene-isoprene-styrene rubber to salicylic acid is 1:2, a passive radiation cooling fiber film with a fiber diameter distribution of 493 nm and 2.34 μm is obtained, which improves the narrow applicability caused by the single fiber diameter.

[0056] S3. Patterning is achieved using a masking method; a soft multi-headed brush is used to apply the coating to a fabric with a mask attached. The ECG electrode pattern is then determined based on the three-lead electrode testing system, such as... Figure 3 The electrode pattern 6 shown has an individual electrode diameter of 1 cm, serving as the test electrode, ground electrode, and reference electrode, respectively. The connecting lines are 2 mm wide with a 1 mm spacing. The electrodes can be adhered to with a transparent dressing, allowing for direct conformation to the human body's curves and close contact. The resulting flexible passive solar radiation cooling fiber membrane achieves a tight fit with the human body, preventing relative slippage caused by muscle contraction or movement. Simultaneously, it achieves 2311 g m at 50℃. -2 day -1 Water vapor transmission rate.

[0057] The rougher surface structure makes the wearable more stable. The micro-nano fiber composite structure achieves a maximum cooling effect of up to 10.8°C, realizing effective thermal management. It can still stably detect human bioelectric signals even under outdoor sunlight exposure. High-quality waveforms are captured with flat baselines and characteristic P, Q, R, S and T features. In addition, the fabricated strain sensor has a fast response time of about 66ms and can clearly display human motion trajectories.

Claims

1. A method for manufacturing a fibrous membrane having a daytime passive radiative cooling function, characterized by: It comprises the following steps: S1, preparing a mixed spinning solution; S11, adding a solute to a tetrahydrofuran solution to obtain a mixed solution with a mass fraction of a set value; In the S11, The solute is a mixed solution with a mass fraction of 25.2% of styrene-isoprene-styrene rubber and salicylic acid particles; The mass ratio of the styrene-isoprene-styrene rubber to the salicylic acid is 1:2; S12, adding the mixed solution to a container, mixing at a set temperature for a set time to obtain the mixed spinning solution; S2, preparing a fiber membrane through a spinning process according to the prepared mixed spinning solution; The specific operation steps of the S2 are as follows: S21, adding the mixed spinning solution to a spinning machine to obtain a fiber fabric; S22, heating and drying the fiber fabric spun for a period of time to obtain a fiber membrane; S23, placing the fiber membrane in ethanol to wash away excess salicylic acid; S3, patterning through image processing.

2. The method of claim 1, wherein the method further comprises: In the S12, The mixed solution is added to a glass bottle, stirred at room temperature for 3h to obtain the mixed spinning solution.

3. The method of claim 1, wherein the method further comprises: coating the surface of the fiber membrane with a reflective material. The specific operation steps of the S21 are as follows: S211, the spinning machine comprises a coaxial needle (1), an oil-water separator, a solution propeller, and an air compressor, a connecting pipe (5), and a roller collector (4), the air compressor is used as the spinning power, the mixed spinning solution is placed in the solution propeller, and the mixed spinning solution reaches the tip of the coaxial needle (1); S212, a collection plate is placed at a set distance from the bottom of the coaxial needle (1), the mixed spinning solution of the previous minute is freely dropped onto the collection plate; S213, after the mixed spinning solution is stabilized, the droplets at the port of the coaxial needle (1) are pulled into a plurality of fiber fabrics under the action of the airflow; S214, the metal needle is fixedly installed on a movable slide rail controlled by a computer for large-area spinning.

4. The method of claim 1, wherein the method further comprises: The specific operation steps of the S3 are as follows: S31, sensor manufacturing, using a soft multi-head brush to apply electronic ink to one side of the fabric, and activating by cyclic whole-body stretching to obtain a passive cooling electronic skin electrode; S32, a strain sensor pattern circuit is prepared using a spray coating method, and the resistance of the prepared strain sensor has been truly recorded to investigate its performance in detecting various strains, such as electrical stability and response time.

5. The method of claim 3, wherein the method further comprises: The solution propeller is a computer injector (2), and the air compressor is an air pump (3).

6. The method of claim 3, wherein the method further comprises: The distance between the coaxial needle (1) and the collection plate in the S212 is 15cm.

7. The method of claim 5, wherein the method further comprises: The air pump (3) is opened, and the air pressure is adjusted to 0.1MPa.

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