Self-adaptive thermal management device of shape memory Janus array structure, preparation method of self-adaptive thermal management device and application of self-adaptive thermal management device in deep space probe

Abstract

The invention discloses a self-adaptive thermal management device of a shape memory Janus array structure, a preparation method of the self-adaptive thermal management device and application of the self-adaptive thermal management device in a deep space probe, and belongs to the technical field of self-adaptive thermal management. The problem that the heat dissipating capacity of a traditional radiation radiator with the single heat radiation characteristic cannot be adjusted is solved. The temperature response shape memory Janus array is adopted as a driver of the self-adaptive thermal management device, and switching of different thermal management modes under the condition of no external energy consumption is achieved. When the temperature is lower than the phase change temperature, the shape memory Janus array is in a pressed-down state, the low-emissivity coating coated on one side of the comb teeth is exposed, and the heat loss of infrared radiation is effectively inhibited by utilizing lower infrared emissivity. When the temperature is higher than the phase change temperature, the shape memory Janus array is in an inclined state, and the high-emissivity coating coated on the other side of the comb teeth is exposed, so that energy increase caused by solar radiation is prevented, and effective heat release is promoted.

Description

Technical Field

[0001] The present invention relates to an adaptive thermal management device with a shape memory Janus array structure, a preparation method thereof, and an application in a deep space probe, belonging to the technical field of adaptive thermal management. Background Art

[0002] Deep space exploration, as an important way for humans to explore the mysteries of the universe and expand the living space of humans, has received extensive attention in recent years. From exploring the planets within the solar system to exploring the outside, deep space exploration missions not only enhance our understanding of the universe but also promote the rapid development of aerospace technology. However, deep space exploration missions face a complex space thermal environment, which poses a serious challenge to the thermal management of spacecraft. During the process of a spacecraft transitioning from an Earth orbit to the orbit of another planet, the significant change in the space thermal environment requires the adoption of adaptive and diverse thermal management modes. Taking the deep space exploration of Venus as an example, the solar intensity near Venus is approximately twice that on Earth. Therefore, the thermal control strategies adopted by the spacecraft in the initial orbit around the Earth are fundamentally different from those used in the final orbit around Venus. The ability to switch between different thermal management modes ensures the stability of the performance of the instruments and equipment within the spacecraft. Intelligent thermal management technology is an important means to meet the requirement of the spacecraft to switch multiple thermal management modes in a complex and changeable thermal environment.

[0003] Currently, intelligent thermal management technology can be divided into passive thermal management technology and active thermal management technology. Passive thermal management technology, such as temperature-responsive thermally variable emissivity materials, can achieve adaptive thermal regulation of emissivity without increasing additional power consumption. However, common VO2-based phase change emissivity materials have problems such as limited emissivity adjustment range. Active thermal management technology, such as mechanical thermal control louvers, requires additional energy input to drive the switching of thermal management characteristics to ensure the stable operation of the spacecraft in a harsh environment. However, this technology relies on large and complex devices, which may lead to compatibility and modular assembly problems. Therefore, in order to address the urgent challenges of reducing power consumption and improving the reliability of spacecraft, it is necessary to promote the development of intelligent passive thermal management materials with adaptive temperature regulation capabilities. Summary of the Invention

[0004] The present invention solves the defect that the heat dissipation of a radiator with traditional single thermal radiation characteristics cannot be adjusted, and the influence of complex drive mechanisms such as motors on the performance of the radiator, and provides an adaptive thermal management device with a shape memory Janus array structure, a preparation method thereof, and an application in a deep space probe.

[0005] The technical solution of the present invention:

[0006] One of the objectives of the present invention is to provide an adaptive thermal management device, which is composed of a comb-shaped shape memory Janus array. The shape memory Janus array consists of a comb-shaped shape memory polymer matrix, and a low-emissivity coating and a high-emissivity white paint coating respectively coated on both sides of the comb teeth.

[0007] Further defined, the low-emissivity coating is a gold, silver, or aluminum thin film, and the coating thickness is 150 - 300 nm.

[0008] Further defined, the high-emissivity white paint coating is a ZnO-based silicone rubber coating, and the coating thickness is 100 - 500 um.

[0009] Further defined, the spacing between adjacent comb teeth of the comb-shaped memory polymer matrix is 2 mm; the material of the shape memory polymer matrix is shape memory polyurethane, shape memory epoxy resin, or shape memory polyimide.

[0010] Another objective of the present invention is to provide a preparation method for the above-mentioned adaptive thermal management device, which includes the following steps:

[0011] (1) Preparation of the shape memory polymer matrix;

[0012] First, prepare the shape memory polymer, and then use the template transfer method to prepare a shape memory polymer matrix with a comb-shaped array structure;

[0013] (2) Preparation of the shape memory Janus array;

[0014] First, spray the high-emissivity white paint coating on the shape memory polymer matrix by spraying; then, deposit the low-emissivity coating on one side of the comb-shaped array coated with the high-emissivity white paint coating by magnetron sputtering.

[0015] Further defined, the preparation method of the shape memory polymer in (1) is:

[0016] First, dissolve polycaprolactone diol in a dimethyl carbonate solution at 80 °C;

[0017] Then, maintain at 80 °C and add hexamethylene diisocyanate and dibutyltin dilaurate, and keep warm for 2 h to obtain a shape memory polymer precursor;

[0018] Finally, cool the shape memory polymer precursor to 60 °C, add dimethyl carbonate, stir for 1 h, add a dimethyl carbonate solution containing pentaerythritol tetrakis(3-mercaptopropionate), and keep warm and stir for 30 min to obtain the shape memory polymer.

[0019] It is further defined that the method for preparing a shape memory polymer matrix having a comb-like array structure by using a template transfer method in (1) is as follows: pouring a shape memory polymer into a mold made of polydimethylsiloxane, and keeping the mold warm at 80° C. for 72 hours under vacuum conditions to obtain a shape memory polymer matrix having a comb-like structure.

[0020] Further, the conditions for magnetron sputtering deposition of low emissivity coating in (2) are: the working gas is argon, the flow rate is 10-20sccm, the gas pressure is 10 -4 -10 -6 Pa, power is 50-100W, time is 15-20min.

[0021] It is further defined that the process parameters for preparing the high-emissivity white paint coating in (2) are: spraying distance 20-30 cm, spraying pressure 0.1-0.3 MPa, spray gun moving speed 10-20 cm / s, angle between spray gun and spraying surface 90°, and natural drying after spraying to obtain a high-emissivity white paint coating.

[0022] A third object of the present invention is to provide an application of the above-mentioned adaptive thermal management device, characterized in that it is specifically used for the preparation of an adaptive thermal management device based on infrared optical regulation.

[0023] Beneficial effects:

[0024] (1) The present invention uses a temperature-responsive shape memory Janus array as the driver of the adaptive thermal management device, which can realize the switching of different thermal management modes without external energy consumption. When the temperature is lower than the phase transition temperature, the shape memory Janus array is in an overwhelmed state, exposing the low-emissivity coating coated on one side of the comb teeth, and using the lower infrared emissivity to effectively suppress the heat loss of infrared radiation, ensuring the stability of the internal temperature of the spacecraft. When the temperature is higher than the phase transition temperature, the shape memory Janus array is in an inclined state, exposing the high-emissivity coating coated on one side of the comb teeth, minimizing the absorption of solar energy, preventing the increase of internal energy due to solar radiation, and promoting effective heat release through infrared radiation, avoiding excessive temperature inside the spacecraft, and achieving efficient thermal radiation heat dissipation.

[0025] (2) The thermal management mode switching of the adaptive thermal management device with a shape memory Janus array structure provided by the present invention completely relies on the temperature-responsive shape memory effect, enabling it to autonomously select and switch to the most suitable thermal management method according to the actual situation of the orbital space thermal environment. That is, compared with the traditional radiation radiator with a single thermal radiation characteristic, the adaptive thermal management device with a shape memory Janus array structure provided by the present invention can adaptively adjust the amount of heat dissipation according to the change in the power of internal electronic devices and the fluctuation of external thermal loads, and control the temperature of deep space exploration spacecraft within the operating temperature range. Description of the Drawings

[0026] Figure 1 It is a diagram showing the shape change of the Janus array during the heating process;

[0027] Figure 2 It is an in-situ 2D WAXS diagram of the deformation process of the Janus array under different thermal management modes;

[0028] Figure 3 It is an XRD spectrum of the low-emissivity coating (Ag / SMP) of the shape memory polymer matrix material (SMP) prepared in Example 1 and the shape memory Janus array (TAMSJ) prepared in step (2);

[0029] Figure 4 It is an SEM photograph of the low-emissivity coating prepared in Example 1;

[0030] Figure 5 It is a reflection spectrum diagram of the adaptive thermal management device prepared in Example 1 under different thermal management modes, where the blue line represents the radiative cooling mode with an emissivity of 0.90, and the red line represents the radiative heat preservation mode with an emissivity of 0.04. Detailed Embodiments

[0031] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe the detailed embodiments of the present invention in conjunction with the embodiments of the specification.

[0032] In the following description, many specific details are set forth to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0033] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation manner of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it an individual or selectively exclusive embodiment with other embodiments.

[0034] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods. The materials, reagents, methods and instruments used are all conventional materials, reagents, methods and instruments in this field, and can be obtained by those skilled in the art through commercial channels without special instructions.

[0035] Example 1

[0036] The preparation method of the self-adaptive thermal management device in this example includes the following steps:

[0037] (1) Preparation of the shape memory polymer matrix;

[0038] ① Preparation of the shape memory polymer

[0039] First, dissolve 20 g of polycaprolactone diol (Mn = 2000) in 30 mL of dimethyl carbonate solution at 80 °C;

[0040] Then, maintain at 80 °C and add 5.28 mL of methylene diisocyanate and 1.5 wt% (1.5% of the total mass of polycaprolactone diol, methylene diisocyanate and pentaerythritol tetrakis(3-mercaptopropionate)) of dibutyltin dilaurate catalyst, keep warm for 2 h to obtain the shape memory polymer precursor;

[0041] Finally, cool the shape memory polymer precursor to 60 °C, add 15 mL of dimethyl carbonate, stir for 1 h, add 10 mL of dimethyl carbonate solution containing 1.5 g of pentaerythritol tetrakis(3-mercaptopropionate), keep warm and stir for 30 min to obtain the shape memory polymer.

[0042] ② Preparation of the shape memory polymer matrix with a comb-like array structure;

[0043] Pour the shape memory polymer into a mold made of polydimethylsiloxane, keep warm under vacuum conditions at 80 °C for 72 h to obtain a shape memory polymer matrix with a comb-like structure, named SMP. The comb teeth size of the obtained shape memory polymer matrix is 5 cm × 5 cm × 10 mm, and the spacing between adjacent comb teeth is 2 mm.

[0044] (2) Preparation of the shape memory Janus array;

[0045] ① Preparation of the high emissivity white paint coating

[0046] The surface of the shape memory polymer matrix is cleaned. It is sprayed with a ZnO-based white paint (model: S781 thermal control white paint), and the pressure, spray pattern, and paint output of the spray gun are adjusted during trial spraying. During the spraying process, ensure that the distance between the spray gun and the array surface is 25 cm, the spraying pressure is 0.2 MPa, and the moving speed of the spray gun is 15 cm / s. Also, when spraying, keep the spray gun perpendicular to the spraying surface to avoid uneven spraying or sagging. After spraying, it is dried in a natural environment to obtain a shape memory polymer matrix coated with a high-emissivity white paint coating.

[0047] ② Preparation of low-emissivity coating

[0048] The shape memory polymer matrix coated with the high-emissivity white paint coating is heated to 80 °C (above the phase transition temperature), and a certain stress is applied to the shape memory array through a glass plate and weights. It is cooled to 20 °C (below the phase transition temperature) while maintaining the shape unchanged, so that the temporary shape is fixed. The surface of the shape memory polymer matrix coated with the high-emissivity white paint coating with the temporary shape is cleaned, and then placed on the magnetron sputtering stage. A silver target with a purity of 99.9% is installed on the target position of the magnetron sputtering equipment, and precise debugging is carried out to ensure that the distance between the target and the cathode is 5 cm and the angle is 30°. At the same time, check the parameters such as the magnetic field strength and uniformity of the magnetron sputtering system to ensure that the magnetic field can effectively confine electrons and improve the sputtering efficiency. High-purity argon gas (Ar) with a flow rate of 40 sccm is introduced into the plating bath as the working gas, and the gas pressure is 10 -5 Pa. The argon gas is ionized into argon ions (Ar+) under the action of the electric field. These argon ions bombard the surface of the silver target under the acceleration of the electric field, sputtering silver atoms from the target. The magnetron sputtering power supply is turned on, and the sputtering power is set to 100 W and the sputtering time is 20 min. During the sputtering process, after the silver atoms are sputtered from the target surface, they move towards the array surface under the action of the electric field and magnetic field and deposit on the surface to form a silver layer. A low-emissivity coating with a thickness of 100 μm is deposited on one side of the shape memory polymer matrix coated with the high-emissivity white paint coating to obtain a shape memory Janus array, named TAMSJ, where the low-emissivity coating is named Ag / SMP

[0049] The structure and performance of the obtained shape memory Janus array (Ag / SMP) are characterized, and the specific test results are as follows:

[0050] (1) Figure 3 XRD spectra of the shape memory polymer (SMP) prepared in step (1) and the low-emissivity coating (Ag / SMP) of the shape memory Janus array (TAMSJ) prepared in step (2). From Figure 3It can be seen that compared with SMP and Ag, Ag / SMP shows similar diffraction peaks. This observation indicates that Ag has been successfully combined with SMP. At the same time, the XRD pattern of Ag / SMP identifies diffraction peaks at 2θ = 38.12°, 44.27°, 64.43°, 77.47°, and 81.53°, which can be matched with the (111), (200), (220), (311), and (222) planes of Ag (PDF 04-0783). The characteristic peaks at 2θ = 21.37° and 23.65° correspond to the (110) and (200) crystal planes of PCL, respectively.

[0051] (2) Figure 4 SEM photograph of the low emissivity coating (Ag / SMP) of the shape memory Janus array (TAMSJ) prepared in step (2), by Figure 4 It can be seen that the surface of the silver film presents a flat morphology and has a dense structure. The smooth surface can improve the reflectivity of visible light and infrared light..

[0052] (3) Characterize the shape change of the shape memory Janus array under different thermal management modes. The specific test method is as follows: Heat the array with a temporary shape overriding state (the initial heating temperature is 50 °C, and the heating rate is 1 °C / min), and observe the shape change process of the array as the temperature increases. The test results are as Figure 1 shown, by Figure 1 It can be seen that as the temperature rises, the shape memory array gradually recovers from the temporary overriding state to the initial inclined state.

[0053] Furthermore, Figure 2 In-situ 2DWAXS diagram of the shape change process of the shape memory Janus array under different thermal management modes, by Figure 2 It can be seen that the shape recovery of the array benefits from the crystallization transformation of the polymer molecular chains inside the array.

[0054] Figure 5 Reflectance spectra of the shape memory Janus array under different thermal management modes, by Figure 5 It can be seen that the red line represents the heat preservation mode (<40 - 50 °C), indicating that the material has a low (<0.1) infrared emissivity and can reduce heat loss; the blue line represents the radiative cooling mode (>40 - 50 °C), indicating that the material has a high (>0.8) infrared emissivity and has a good radiative cooling effect.

[0055] In summary, the self-adaptive thermal management device prepared by the present invention can be used for the preparation of a self-adaptive thermal management device based on infrared optical regulation in deep space probes. Taking deep space exploration of Venus as an example, since the solar intensity near Venus is approximately twice that on Earth, the thermal control strategies adopted by the spacecraft in the initial orbit around the Earth are fundamentally different from those used in the final orbit around Venus. When the spacecraft orbits the Earth, the temperature-adaptive shape memory Janus array (TAMSJ) operates in a heat-insulating mode to maintain a stable internal temperature. At this stage, the Janus array is in a flipped state, exposing the radiation-insulating side with a low infrared emissivity (0.04). This configuration effectively suppresses heat loss due to infrared radiation and ensures the stability of the internal temperature of the spacecraft. When the spacecraft enters the Venus orbit, it encounters stronger solar radiation, and the TAMSJ automatically returns to the tilted state through its shape memory effect. This adjustment exposes the radiation-cooling side characterized by high solar reflectivity and infrared emissivity (0.90). This change not only minimizes the absorption of solar energy and prevents the increase of internal energy due to solar radiation, but also promotes effective heat release through infrared radiation, effectively avoiding excessive temperature inside the spacecraft. More importantly, the switching of the thermal management mode of the TAMSJ completely depends on the temperature-responsive shape memory effect, which endows the TAMSJ with intelligent characteristics, enabling it to autonomously select and switch to the most suitable thermal management method according to the actual situation of the space thermal environment during the on-orbit operation of the spacecraft, flexibly adjust its thermal radiation performance, achieve efficient thermal control, and control the temperature of the deep space exploration spacecraft within the working temperature range. Moreover, a reasonable polymer system can be flexibly selected according to the different orbital environments of the spacecraft.

[0056] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with this technology can make various modifications and decorations without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be defined by the claims.

Claims

1. An adaptive thermal management device, characterized in that, It is composed of a comb-shaped shape memory Janus array, and the shape memory Janus array consists of a comb-shaped shape memory polymer matrix, a low-emissivity coating and a high-emissivity white paint coating respectively coated on both sides of the comb teeth.

2. The adaptive thermal management device according to claim 1, wherein The low-emissivity coating is a gold, silver or aluminum thin film, and the coating thickness is 150 - 300 nm.

3. The adaptive thermal management device according to claim 1, wherein The high-emissivity white paint coating is a ZnO-based silicone rubber coating, and the coating thickness is 100 - 500 μm.

4. The adaptive thermal management device according to claim 1, wherein, The adjacent comb tooth spacing of the shape memory polymer matrix is 2 mm; the material of the shape memory polymer matrix is shape memory polyurethane, shape memory epoxy resin or shape memory polyimide.

5. A method for preparing the adaptive thermal management device according to any one of claims 1 to 4, characterized in that, It includes: (1) Preparation of the shape memory polymer matrix; Firstly, prepare the shape memory polymer, and then use the template transfer method to prepare a shape memory polymer matrix with a comb-shaped array structure; (2) Preparation of the shape memory Janus array; Firstly, spray the high-emissivity white paint coating on the shape memory polymer matrix by spraying; then, deposit the low-emissivity coating on one side of the comb-shaped array coated with the high-emissivity white paint coating by magnetron sputtering.

6. The preparation method according to claim 5, characterized in that, The preparation method of the shape memory polymer in (1) is: Firstly, dissolve polycaprolactone diol in dimethyl carbonate solution at 80 °C; Then, maintain at 80 °C and add hexamethylene diisocyanate and dibutyltin dilaurate, and keep warm for 2 h to obtain a shape memory polymer precursor; Finally, cool the shape memory polymer precursor to 60 °C, add dimethyl carbonate, stir for 1 h, add a dimethyl carbonate solution containing pentaerythritol tetra(3-mercaptopropionate), and keep warm and stir for 30 min to obtain the shape memory polymer.

7. The preparation method according to claim 5, characterized in that The method of using the template transfer method to prepare a shape memory polymer matrix with a comb-shaped array structure in (1) is: pour the shape memory polymer into a mold made of polydimethylsiloxane, and keep warm under vacuum conditions at 80 °C for 72 h to obtain a shape memory polymer matrix with a comb-shaped structure.

8. The preparation method according to claim 5, characterized in that, (2) The conditions for magnetron sputtering deposition of the low emissivity coating are as follows: the target material is elemental gold, silver or aluminum, the working gas is argon, the flow rate is 10-20 sccm, the air pressure is 10 -4 -10 -6 Pa, the power is 50-100 W, and the time is 15-20 min.

9. The preparation method according to claim 5, characterized in that, The process parameters for preparing the high-emissivity white paint coating in (2) are: spraying distance 20 - 30 cm, spraying pressure 0.1 - 0.3 MPa, spray gun moving speed 10 - 20 cm / s, the angle between the spray gun and the spraying surface is 90°, and after spraying, dry naturally to obtain the high-emissivity white paint coating.

10. Application of the adaptive thermal management device according to any one of claims 1 to 4, characterized in that It is used for the preparation of an adaptive thermal management device based on infrared optical regulation.

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