Manufacturing method of radiation refrigeration component

Abstract

A manufacturing method of a radiation refrigeration component comprises the steps that firstly, radiation refrigeration particles and a high-molecular polymer are evenly mixed to obtain a blend, and then the blend is made into a radiation refrigeration blend film; 2, the surface of the radiation refrigeration blended membrane and the surface of cement-based slurry are attached and make full contact, and a radiation refrigeration-cement-based complex is obtained; and step 3, carrying out first maintenance on the radiation refrigeration-cement-based composite body under the conditions that the temperature is 50-100 DEG C and the relative humidity is greater than or equal to 90% until the cement-based slurry in the radiation refrigeration-cement-based composite body is preliminarily cured, and then carrying out second maintenance under the conditions that the temperature is normal and the relative humidity is greater than or equal to 90% so as to obtain the radiation refrigeration-cement-based composite body. And the radiation refrigeration component is obtained until the cement-based slurry in the radiation refrigeration-cement-based composite body is fully cured. Therefore, the radiation refrigeration effect is good in durability.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a component, belonging to the field of building component preparation, and particularly to a method for manufacturing a radiative cooling component. Background Technology

[0002] Cement-based materials are among the most widely used materials in building structures. However, traditional cement materials have high heat capacity and strong heat absorption, leading to a significant increase in surface temperature under sunlight, exacerbating building energy consumption and the urban heat island effect. To address this issue, radiative cooling materials offer a zero-energy passive cooling solution that can effectively reduce the surface temperature of traditional cement materials. Currently, this function is mainly achieved through surface coating, where the radiative cooling material is made into a coating and applied to the surface of a cured cement substrate. However, the radiative cooling functional layer formed by this method has only a physical adhesion to the cement substrate, with weak interfacial chemical bonding, resulting in easy detachment of the radiative cooling layer and poor durability of the radiative cooling effect.

[0003] Chinese patent application No. 202510677727.1, filed on May 26, 2025, discloses a photovoltaic heat dissipation enhanced radiation cooling cement-based composite material, its preparation method, and its application. The composite material comprises white Portland cement, radiation cooling particles, and water. The radiation cooling particles include alpha alumina and barium sulfate, with the mass fraction of the radiation cooling particles relative to the total solids content of the composite material being 30%-60%, and the mass ratio of alpha alumina to barium sulfate being 1:1 to 2:1. The average particle size of the radiation cooling particles is 0.3-10 μm. The mass fraction of white Portland cement relative to the total solids content of the composite material is 40%-70%. Although this patent solves the problem of easy detachment of the radiation cooling layer, it still has the following drawbacks:

[0004] The radiative cooling effect of this design is difficult to maintain in the long term due to surface contamination, chemical weathering, and pore blockage of the cement substrate, resulting in poor durability of the radiative cooling effect.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this patent application and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to overcome the defects and problems of poor durability of radiative cooling effect in the prior art, and to provide a method for manufacturing a radiative cooling component with better durability of radiative cooling effect.

[0007] To achieve the above objectives, the technical solution of the present invention is: a method for manufacturing a radiative cooling component, the method comprising the following steps:

[0008] Step 1: The radiation-cooling particles are uniformly mixed with the polymer to obtain a blend, and then the blend is made into a radiation-cooling blend film;

[0009] Step 2: The surface of the above-mentioned radiation cooling blended membrane is attached to the surface of the cement-based slurry and brought into full contact to obtain a radiation cooling-cement-based composite.

[0010] Step 3: The above-mentioned radiation cooling-cement-based composite is subjected to a first curing at a temperature of 50-100℃ and a relative humidity of ≥90% until the cement-based slurry in the radiation cooling-cement-based composite is initially cured. Then, a second curing is carried out at room temperature and a relative humidity of ≥90% until the cement-based slurry in the radiation cooling-cement-based composite is fully cured to obtain the radiation cooling component.

[0011] In the first step, the mass of the radiation-cooled particles is 1% to 5% of the mass of the polymer.

[0012] In the third step, the temperature of the first curing is at least 5°C higher than the glass transition temperature of the polymer.

[0013] The radiation-cooling particles are inorganic radiation-cooling micro / nano particles.

[0014] The glass transition temperature of the polymer is 50-95℃.

[0015] The polymer is any one or any combination of polylactic acid, polyethylene terephthalate, and polyvinyl alcohol.

[0016] In the second step, the step of bringing the surface of the above-mentioned radiation-cooled blended film into full contact with the surface of the cementitious slurry means:

[0017] First, the surface of the above-mentioned radiation cooling blend membrane is attached to the surface of the cement-based slurry. Then, the interface air bubbles are removed by vibration or pressing, so that the surface of the cement-based slurry and the surface of the above-mentioned radiation cooling blend membrane are in full contact.

[0018] In the third step, the first curing of the above-mentioned radiation cooling-cement-based composite at a temperature of 50-100℃ and a relative humidity of ≥90% until the cement-based slurry in the radiation cooling-cement-based composite is initially cured means:

[0019] The above-mentioned radiation cooling-cement-based composite was subjected to high temperature and high humidity curing for 2 to 48 hours at a temperature of 50-100℃ and a relative humidity of ≥90%.

[0020] In the third step, the second curing under normal temperature and relative humidity ≥90% conditions until the cement-based slurry in the radiant cooling-cement composite is fully cured to obtain the radiant cooling component refers to:

[0021] The radiative cooling component is obtained by curing it for 7 to 28 days at a temperature of 20-30℃ and a relative humidity of ≥90%.

[0022] The radiative cooling component is manufactured according to any one of the manufacturing methods in claims 1-6;

[0023] The application method is as follows: the radiation cooling component is used as a building component. Under sunlight, the radiation cooling particles on the surface of the radiation cooling component reflect solar radiation and radiate heat outward through the 8-13μm atmospheric window band, thereby reducing the surface temperature of the building component.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. A method for manufacturing a radiative cooling component according to the present invention, the method comprising: firstly, uniformly mixing radiative cooling particles with a polymer to obtain a blend; then, forming the blend into a radiative cooling blend film; next, attaching and fully contacting the surface of the radiative cooling blend film with the surface of a cement-based slurry to obtain a radiative cooling-cement-based composite; then, subjecting the radiative cooling-cement-based composite to a first curing at a temperature of 50-100℃ and a relative humidity ≥90% until the cement-based slurry in the radiative cooling-cement-based composite has initially solidified; and then subjecting it to a second curing at room temperature and a relative humidity ≥90% until the cement-based slurry in the radiative cooling-cement-based composite has fully solidified, thereby obtaining a radiative cooling component. When sunlight irradiates the radiative cooling component, the radiative cooling particles on the surface of the radiative cooling component can efficiently reflect solar energy and simultaneously radiate heat into the low-temperature outer space through an atmospheric window (8-13μm), thereby directly reducing the surface temperature of the radiative cooling component, thus achieving the effects of building energy conservation and mitigating the urban heat island effect. The advantages of the present invention also include:

[0026] Firstly, the initial curing process promotes the swelling of the radiation-cooling blended film and the formation of microscopic transport channels, enabling radiation-cooling particles to migrate directionally to the surface of the cement matrix. Simultaneously, during the continuous hydration of the cement, the migrating radiation-cooling particles are in situ encapsulated and anchored by newly formed hydration products, thereby forming a firmly bonded radiation-cooling functional layer on the matrix surface. This fundamentally overcomes the problem of easy detachment caused by weak interfacial bonding in surface coating methods, and the radiation-cooling particles are physically protected by cement hydration products, improving the durability of the radiation-cooling effect.

[0027] Therefore, the present invention not only has a passive cooling effect, but also has good durability of radiative cooling effect.

[0028] 2. In the method for manufacturing a radiative cooling component of the present invention, the aforementioned radiative cooling-cement-based composite is cured at high temperature and high humidity for 2 to 48 hours under conditions of 50-100℃ and relative humidity ≥90%. During application, this high temperature and high humidity environment effectively stimulates the chain segment movement ability of the polymer, causing the blended film to swell and expand its pores. This provides sufficient momentum and channels for the migration of radiative cooling particles from the film to the cement matrix, ensuring that the radiative cooling particles can be efficiently and fully released and migrate to the surface of the cement matrix, thereby forming a uniform and complete radiative cooling functional layer on the matrix surface. Unlike surface coating methods that require secondary construction after the cement is completely cured, the present invention achieves in-situ formation and bonding of the radiative cooling functional layer and the matrix during the cement curing stage, effectively simplifying the production process and improving preparation efficiency. Therefore, the present invention not only has good durability of the radiative cooling effect but also improves preparation efficiency.

[0029] 3. In the method for manufacturing a radiation-cooling component according to the present invention, the mass of the radiation-cooling particles is 1% to 5% of the mass of the polymer. In application, the radiation-cooling particles are effectively encapsulated and pre-dispersed by the molecular chains of the polymer, forming a uniformly structured radiation-cooling blend film. During subsequent curing, this blend film swells and expands its pores, triggering and controlling the directional migration and orderly release of the radiation-cooling particles to the surface of the cement matrix. Ultimately, a uniformly distributed and firmly bonded radiation-cooling functional layer is formed on the matrix surface. Compared to directly incorporating and dispersing radiation-cooling particles into the entire cement matrix, the present invention pre-disperses the radiation-cooling particles uniformly in the blend film, avoiding significant waste of radiation-cooling particles within the matrix, reducing the amount of radiation-cooling particles used, and lowering raw material costs. Therefore, the present invention not only improves preparation efficiency but also reduces raw material costs.

[0030] 4. In the manufacturing method of the radiative cooling component of this invention, the component is cured for 7 to 28 days under conditions of 20-30℃ and relative humidity ≥90%. During application, under these curing conditions, the cement particles are fully hydrated, and the hydration products continuously grow and intertwine to form a dense three-dimensional network structure, thus fully densifying the cement matrix and achieving good mechanical properties. Simultaneously, the radiative cooling particles that have migrated to the surface are further encapsulated and anchored in situ by the continuously generated hydration products, achieving synchronous formation and firm bonding between the functional layer and the cement matrix. Furthermore, since the radiative cooling particles are released to the surface through a blending film rather than directly incorporated into the entire cement paste, interference with the cement hydration process is minimized. While ensuring the radiative cooling function, the cement matrix can fully utilize its inherent hydration hardening characteristics, thereby endowing the material with radiative cooling functionality while protecting the inherent mechanical properties of the cement matrix. Therefore, this invention not only reduces raw material costs but also possesses superior mechanical properties. Attached Figure Description

[0031] Figure 1 This is a flowchart of the method of the present invention.

[0032] Figure 2 This is a schematic diagram illustrating the preparation principle of the present invention. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] See Figure 1 — Figure 2 A method for manufacturing a radiative cooling component, the method comprising the following steps:

[0035] Step 1: The radiation-cooling particles are uniformly mixed with the polymer to obtain a blend, and then the blend is made into a radiation-cooling blend film;

[0036] Step 2: The surface of the above-mentioned radiation cooling blended membrane is attached to the surface of the cement-based slurry and brought into full contact to obtain a radiation cooling-cement-based composite.

[0037] Step 3: The above-mentioned radiation cooling-cement-based composite is subjected to a first curing at a temperature of 50-100℃ and a relative humidity of ≥90% until the cement-based slurry in the radiation cooling-cement-based composite is initially cured. Then, a second curing is carried out at room temperature and a relative humidity of ≥90% until the cement-based slurry in the radiation cooling-cement-based composite is fully cured to obtain the radiation cooling component.

[0038] In the first step, the mass of the radiation-cooled particles is 1% to 5% of the mass of the polymer.

[0039] In the third step, the temperature of the first curing is at least 5°C higher than the glass transition temperature of the polymer.

[0040] The radiation-cooling particles are inorganic radiation-cooling micro / nano particles.

[0041] The glass transition temperature of the polymer is 50-95℃.

[0042] The polymer is any one or any combination of polylactic acid, polyethylene terephthalate, and polyvinyl alcohol.

[0043] In the second step, the step of bringing the surface of the above-mentioned radiation-cooled blended film into full contact with the surface of the cementitious slurry means:

[0044] First, the surface of the above-mentioned radiation cooling blend membrane is attached to the surface of the cement-based slurry. Then, the interface air bubbles are removed by vibration or pressing, so that the surface of the cement-based slurry and the surface of the above-mentioned radiation cooling blend membrane are in full contact.

[0045] In the third step, the first curing of the above-mentioned radiation cooling-cement-based composite at a temperature of 50-100℃ and a relative humidity of ≥90% until the cement-based slurry in the radiation cooling-cement-based composite is initially cured means:

[0046] The above-mentioned radiation cooling-cement-based composite was subjected to high temperature and high humidity curing for 2 to 48 hours at a temperature of 50-100℃ and a relative humidity of ≥90%.

[0047] In the third step, the second curing under normal temperature and relative humidity ≥90% conditions until the cement-based slurry in the radiant cooling-cement composite is fully cured to obtain the radiant cooling component refers to:

[0048] The radiative cooling component is obtained by curing it for 7 to 28 days at a temperature of 20-30℃ and a relative humidity of ≥90%.

[0049] The radiative cooling component is manufactured according to any one of the manufacturing methods in claims 1-6;

[0050] The application method is as follows: the radiation cooling component is used as a building component. Under sunlight, the radiation cooling particles on the surface of the radiation cooling component reflect solar radiation and radiate heat outward through the 8-13μm atmospheric window band, thereby reducing the surface temperature of the building component.

[0051] The following are supplementary descriptions of the present invention:

[0052] The preparation principle of the radiative cooling component of this invention includes two key processes: the swelling and pore expansion of the polymer membrane, and the penetration and fixation of radiative cooling particles. In the swelling and pore expansion stage of the polymer membrane, the high-temperature environment during the first curing process provides energy to the polymer chain segments, enhancing their mobility and increasing the intermolecular distance, leading to membrane swelling. Simultaneously, the alkaline environment formed by cement hydration reacts with the polar groups in the polymer, disrupting the regular arrangement of the molecular chains, further expanding the intermolecular gaps, and forming a connected pore network, creating channels for the diffusion of radiative cooling particles. In the penetration and fixation stage of the radiative cooling particles: as the pore structure of the polymer membrane expands, the radiative cooling particles, due to their own thermal motion and concentration gradient... Driven by the pores, the radiative cooling particles migrate from the interior of the polymer membrane to the surface of the cement matrix. The pore network in the cement-based material provides a path for the further penetration of the radiative cooling particles. At the same time, the continuously generated cement hydration products (such as CSH gel and Ca(OH)2 crystals) gradually encapsulate and anchor the radiative cooling particles that have migrated to the cement matrix in its three-dimensional network structure, ultimately achieving a firm bond between the radiative cooling particles and the cement matrix. These radiative cooling particles, fixed on the surface of the cement matrix, effectively reflect solar radiation under sunlight conditions and radiate heat outward through atmospheric windows (8-13 μm) due to their high solar reflectivity (especially in the visible and near-infrared bands) and strong mid-infrared emission capability, thereby achieving passive cooling.

[0053] In the third step of this invention, the preliminary curing refers to the fact that the cement-based slurry in the radiation cooling-cement-based composite has completed final setting, and at the same time, the radiation cooling particles have completed effective penetration into the surface of the cement matrix.

[0054] In the third step of this invention, "fully cured" means that the hydration reaction of the cement-based slurry in the radiation cooling-cement composite has been fully completed, resulting in stable mechanical properties.

[0055] The polymer described in this invention is a polymer with film-forming properties.

[0056] The inorganic radiation-cooled micro / nanoparticles described in this invention are any one or a combination of inorganic radiation-cooled nanoparticles and inorganic radiation-cooled microparticles.

[0057] Example 1:

[0058] See Figure 1 — Figure 2 A method for manufacturing a radiative cooling component, the method comprising the following steps:

[0059] Step 1: The radiation-cooling particles are uniformly mixed with the polymer to obtain a blend, and then the blend is made into a radiation-cooling blend film;

[0060] Step 2: The surface of the above-mentioned radiation cooling blended membrane is attached to the surface of the cement-based slurry and brought into full contact to obtain a radiation cooling-cement-based composite.

[0061] Step 3: The above-mentioned radiation cooling-cement-based composite is subjected to a first curing at a temperature of 50-100℃ and a relative humidity of ≥90% until the cement-based slurry in the radiation cooling-cement-based composite is initially cured. Then, a second curing is carried out at room temperature and a relative humidity of ≥90% until the cement-based slurry in the radiation cooling-cement-based composite is fully cured to obtain the radiation cooling component.

[0062] Example 2:

[0063] The basic content is the same as in Example 1, except that in the first step, the mass of the radiation-cooled particles is 1% to 5% of the mass of the polymer.

[0064] When applying this material, the mass percentage of radiation-cooling particles should be controlled between 1% and 5% to balance radiation-cooling function and material processing stability. This ratio ensures sufficient concentration of radiation-cooling particles within the blend film, creating a concentration gradient during curing to drive the particles to diffuse fully into the cement matrix. It also ensures the particles are effectively encapsulated by polymer chains, preventing precipitation during storage. If the percentage is less than 1%, the total amount of particles is insufficient, and the desired radiation-cooling effect cannot be achieved on the cement matrix surface after release and diffusion. If the percentage is greater than 5%, excessive particles tend to agglomerate in the blend, leading to deterioration of the blend film's mechanical properties, increased brittleness, and potentially uneven radiation-cooling effect during processing. Furthermore, during curing, some excess particles cannot migrate completely and may remain in the film or accumulate on the cement surface, resulting in waste, uneven radiation-cooling effect, poor wear resistance, and weakened interfacial bonding.

[0065] Example 3:

[0066] The basic content is the same as in Example 1, except that in the third step, the temperature of the first curing is at least 5°C higher than the glass transition temperature of the polymer.

[0067] In application, the temperature of the first curing step is set at least 5°C above the glass transition temperature (Tg) of the polymer. This stimulates the movement of polymer chain segments, thereby optimizing the transfer and distribution of radiative cooling particles from the blend film to the cement matrix. When the temperature is below or only reaches Tg, the polymer chain segments lack sufficient mobility, and the intermolecular gaps are limited, restricting the migration and diffusion of radiative cooling particles into the cement matrix, thus affecting the uniformity of the distribution of radiative cooling particles on the cement matrix surface. However, when the temperature of the first curing step is increased to at least 5°C above Tg, the polymer chain segments gain sufficient kinetic energy, expanding the intermolecular gaps and enhancing the diffusion driving force of radiative cooling particles. This synergistically promotes the release of radiative cooling particles from the blend film and their penetration into the cement matrix surface, achieving a uniform distribution of radiative cooling performance and forming a stable radiative cooling functional layer. Furthermore, this temperature range ensures functional effectiveness while also considering process feasibility and economy, avoiding a significant increase in energy consumption and equipment requirements due to excessively high temperatures.

[0068] Example 4:

[0069] The basic content is the same as in Example 1, except that the radiation-cooling particles are inorganic radiation-cooling micro-nano particles.

[0070] Inorganic radiation-cooling micro-nanoparticles are chosen for application because: First, they possess high solar reflectivity and high emissivity in the mid-infrared atmospheric window (8-13 μm), providing the optical basis for efficient radiation cooling; second, their large specific surface area at the micro-nano scale not only enhances optical performance but also ensures uniform dispersion of particles in the polymer matrix and effective migration to the cement matrix; third, the excellent thermal / chemical stability of radiation-cooling nanoparticles ensures stable performance in harsh curing environments with high temperature and humidity and allows them to firmly bind with cement hydration products.

[0071] Specifically, the inorganic radiation cooling micro-nano particles are any one or any combination of Al2O3, SiO2, TiO2, ZnO, Y2O3, ZrO2, and BaSO4. By selecting inorganic radiation cooling micro-nano particles with different properties, the composite material can meet different application requirements. For example, when nano BaSO4 or TiO2 is selected, its extremely high solar reflectivity makes it suitable for building exterior walls, roofs, and other scenarios, achieving significant surface cooling. When nano ZnO or Al2O3 is selected, its high solar reflectivity and high emissivity in the mid-infrared atmospheric window (8-13μm) make it suitable for road, square, and other ground paving, achieving efficient passive cooling.

[0072] Example 5:

[0073] The basic content is the same as in Example 1, except that the glass transition temperature of the polymer is 50-95℃.

[0074] When applying this temperature setting, it is primarily based on considerations of applicability and economy: on the one hand, the temperature range covers most polymeric materials suitable for this process, such as polylactic acid (PLA), polyethylene terephthalate (PET), and polyvinyl alcohol (PVA), ensuring a wide range of material options; on the other hand, this range matches the first curing temperature (50-100℃), eliminating the need for process conditions far exceeding 100℃, thereby effectively controlling energy consumption and equipment costs, and avoiding a decline in production economics due to excessively high temperatures.

[0075] Example 6:

[0076] The basic content is the same as in Example 1, except that the polymer is any one or any combination of polylactic acid, polyethylene terephthalate, and polyvinyl alcohol.

[0077] In application, the selection of polymers is based on their ability to regulate the release behavior of radiative cooling particles under high temperature and high humidity curing conditions: when polylactic acid (PLA) is selected, its relatively low glass transition temperature and rapid chain segment movement in humid and hot environments help radiative cooling particles migrate rapidly to the cement matrix surface during the first curing stage, making it suitable for scenarios requiring the rapid construction of an efficient radiative cooling functional layer; when polyethylene terephthalate (PET) is selected, its high thermal stability and moderate hydrophilicity can ensure effective particle release while giving the blended film good mechanical strength, which is conducive to the formation of a stable and uniform functional layer; when polyvinyl alcohol (PVA) is selected, its strong hydrophilicity and film-forming properties can promote the retention and transport of interfacial moisture in the early curing stage, thus serving as a good transfer medium to optimize the migration path and fixation effect of radiative cooling particles in the cement hydration environment; by blending and combining the above polymers with different properties, the release kinetics of radiative cooling particles can be further regulated, achieving precise control of the radiative cooling function construction process and meeting the specific requirements of different application environments for the functional layer formation rate and structural morphology.

[0078] Example 7:

[0079] The basic content is the same as in Example 1, except that: in the first step, the preparation method of the blend is any one of the following: the first method: uniformly mixing the polymer and the radiation-cooling particles by solution blending to obtain the blend; the second method: uniformly mixing the polymer and the radiation-cooling particles by melt blending to obtain the blend.

[0080] When applying this technology, a suitable blending method can be selected based on the physical properties of the polymer, the properties of the radiation-cooled particles, and the requirements of the production process. The specific steps are as follows:

[0081] For the solution blending method: first, the radiation-cooled particles are dispersed in an organic solvent to form a primary suspension; simultaneously, the polymer material is dissolved in the same solvent system to form a homogeneous solution; then, the primary suspension and the homogeneous solution are mixed and subjected to a secondary dispersion treatment to obtain the blend; wherein, the organic solvent is specifically ethanol, N,N-dimethylformamide (DMF), etc.; the dispersion treatment is performed using an ultrasonic cell disruptor with an ultrasonic power of 200-400W, a primary dispersion time of 30-60 minutes, and a secondary dispersion time of 10-20 minutes;

[0082] For the melt blending method: First, the polymer is premixed with radiation-cooled particles and a dispersant at a temperature below the polymer's melting point; then, the premix is ​​placed in a melt blending device for melt blending; then, under shearing action, the components are micro-dispersed to obtain a blend; wherein, the dispersant is specifically stearic acid, the melt blending device is specifically a twin-screw extruder, and the premix is ​​fully melted and micro-dispersed under the conveying and strong shearing action of the screw (mechanical shearing rate of 50 to 300 rpm);

[0083] Both solution blending and melt blending processes described above are mature and efficient, easy to operate, require minimal equipment, and are readily scalable for mass production. Simultaneously, they ensure uniform pre-dispersion of radiative cooling particles within the polymer matrix. During subsequent curing, the uniformly distributed radiative cooling particles within the blended film migrate synchronously and consistently into the cement matrix through the film's pore channels, thereby forming a uniformly distributed and continuous radiative cooling functional layer on the cement-based surface. This uniform and complete radiative cooling functional layer effectively avoids efficiency reduction caused by uneven distribution of radiative cooling particles, allowing the radiative cooling component to fully exert its cooling effect.

[0084] Example 8:

[0085] The basic content is the same as in Example 1, except that in the first step, the method for making the blend into a radiation-cooled blend film is any one of casting, blow molding, or calendering.

[0086] When applying the mixture, select the appropriate film-forming technology based on the form of the blend (solution or melt) and the product requirements:

[0087] For casting film formation, it is suitable for blends obtained by solution blending. Specifically, the blend solution is poured onto a flat substrate surface (such as a glass plate or stainless steel strip), and the thickness of the wet film is controlled by a scraper to make the blend solution spread evenly. Then, it is left to stand at 20-30℃ to allow the solvent to evaporate, and after curing into a film, it is peeled off from the substrate surface to obtain a radiation cooling blend film with uniform thickness.

[0088] For blow molding, it is suitable for blended melts obtained by melt blending. Specifically, the blended melt is extruded through an annular die to form a tubular film preform, while compressed air is introduced into the film preform to inflate it. By controlling the inflation ratio and traction speed, the film is cooled and shaped by a cooling air ring and then wound up to obtain a tubular or slit and flattened radiation-cooled blended film.

[0089] For calendering film formation, it is applicable to blended materials obtained by melt blending. Specifically, the melt blend is fed into the gap of a multi-roll calender. By adjusting the roll temperature, roll speed and roll gap, the blend is stretched through multiple rolls and continuously calendered to produce a radiation-cooled blended film with uniform thickness.

[0090] In addition, since the above-mentioned processes such as casting, blow molding, and calendering are all mature and efficient processes, they are easy to operate, have low equipment requirements, and are easy to scale up for production.

[0091] Example 9:

[0092] The basic content is the same as in Example 1, except that in the second step, the water-cement ratio of the cement-based slurry is 0.2-0.5.

[0093] In application, the cement-based slurry can be formulated into cement paste, mortar, or concrete slurry according to the application scenario requirements. The preparation of the cement-based slurry adopts conventional processes in the field: first, the dry components of the cement-based materials are uniformly mixed, then deionized water is added, and then the mixture is mixed in a mixer at a speed of 200±50 rpm for 3-5 minutes to obtain a uniform cement-based slurry. The dry components include cement, fine aggregate, coarse aggregate, and additives. The additives include water-reducing agents and retarders.

[0094] The water-cement ratio is set based on a comprehensive consideration of ensuring the workability of the slurry, its final mechanical strength, and the efficient formation of the radiative cooling functional layer. When the water-cement ratio is below 0.2, the slurry is too dry and hard, with insufficient fluidity, which obstructs the migration channels of radiative cooling particles to the cement surface. When the water-cement ratio is above 0.5, the slurry is prone to bleeding and segregation during the molding process, resulting in a loose internal structure and a significant decrease in strength. Furthermore, excessive porosity will weaken the stability of the radiative cooling functional layer and affect its durability. Therefore, controlling the water-cement ratio within the range of 0.2-0.5 is the key to ensuring that the slurry has good formability and interfacial bonding ability, while ensuring that the cement matrix obtains sufficient mechanical properties.

[0095] Example 10:

[0096] The basic content is the same as in Example 1, except that in the second step, the step of attaching the surface of the above-mentioned radiation cooling blend film to the surface of the cement-based slurry and making them in full contact means: first attaching the surface of the above-mentioned radiation cooling blend film to the surface of the cement-based slurry, and then removing interface air bubbles by vibration or pressing, so that the surface of the cement-based slurry and the surface of the above-mentioned radiation cooling blend film are in full contact.

[0097] When applying this product, depending on the location of the required radiative cooling functional layer, any of the following bonding methods can be used:

[0098] First lay the membrane and then pour the slurry: First, lay the radiation cooling blended membrane flat at the predetermined position at the bottom or side wall of the mold, ensuring that the blended membrane completely adheres to the mold surface without wrinkles; then slowly pour the cement-based slurry into the mold along the mold wall; if the blended membrane is at the bottom of the mold, the blended membrane is initially compacted by the weight of the slurry.

[0099] First pour the slurry and then lay the membrane: First, pour the cement-based slurry into the mold to the predetermined height, and then use slight vibration to make the surface of the slurry initially flat; then, spread the radiation cooling blend membrane flat on the surface of the slurry, and use the fluidity of the slurry to achieve initial adhesion;

[0100] After the initial bonding is completed, it is necessary to remove air bubbles at the interface. This process can be carried out using any of the following methods:

[0101] Pressing: Apply uniform pressure to the surface of the blended film manually or mechanically to remove air between it and the cementitious slurry interface, ensuring full contact between the two; specifically, the mechanical device is a small roller press tool;

[0102] Vibration: Mechanical vibration is performed using a vibration table with a vibration frequency of 30Hz to 50Hz and a vibration time of 30 seconds to 3 minutes to eliminate interface bubbles and ensure full contact between the two. Insufficient vibration time (less than 30 seconds) will result in residual interface bubbles, affecting the uniformity of the radiative cooling effect. Excessive vibration time (more than 3 minutes) may cause material segregation or membrane displacement. Preferably, the mechanical vibration time is 1 minute.

[0103] Example 11:

[0104] The basic content is the same as in Example 1, except that in the third step, the first curing of the above-mentioned radiation cooling-cement-based composite at a temperature of 50-100℃ and a relative humidity of ≥90% until the cement-based slurry in the radiation cooling-cement-based composite is initially cured means that the above-mentioned radiation cooling-cement-based composite is cured at a high temperature and high humidity for 2 to 48 hours at a temperature of 50-100℃ and a relative humidity of ≥90%.

[0105] During application, the temperature range for the first curing stage is set at 50-100℃ to promote the movement of polymer chain segments, thereby driving the migration and release of radiative cooling particles, while avoiding the formation of structural defects in the matrix due to excessive water evaporation. When the temperature is below 50℃, the movement of polymer chain segments is insufficient, and the radiative cooling particles cannot obtain enough kinetic energy to overcome intermolecular forces and be released from the blend film. When the temperature is above 100℃, it may cause excessive evaporation of moisture inside the cement matrix, resulting in structural defects and affecting the final strength. A relative humidity of not less than 90% ensures the moisture environment required for the cement hydration reaction, avoiding strength loss due to early water loss. The curing time of 2 to 48 hours ensures that the radiative cooling particles are fully released from the blend film and effectively penetrate into the surface of the cement matrix. If the time is insufficient (less than 2 hours), the radiative cooling particles will not be able to enter the cement matrix well, resulting in insufficient or uneven radiative cooling effect. On the other hand, excessive curing time (more than 48 hours) will reduce production efficiency. This stage continues until the cement slurry has initially solidified and formed a stable radiative cooling functional layer, at which point the second curing stage can begin.

[0106] Example 12:

[0107] The basic content is the same as in Example 1, except that in the third step, the second curing under normal temperature and relative humidity ≥90% until the cement-based slurry in the radiation cooling-cement composite is fully cured to obtain the radiation cooling component means that the component is cured for 7 to 28 days under the conditions of temperature 20-30℃ and relative humidity ≥90%.

[0108] In application, the ambient temperature is set to 20-30℃ because this range is the standard temperature range for cement hydration reaction. This ensures the stable progress of the hydration reaction while also taking into account both standard laboratory curing (20±2℃) and general construction site environmental conditions, resulting in good engineering applicability. If the temperature is too low (below 20℃), the hydration rate will be significantly slowed down, thus affecting strength development. If the temperature is too high (above 30℃), it may cause excessively rapid evaporation of moisture, which is not conducive to long-term strength growth. The relative humidity is set to ≥90% because maintaining a high humidity environment is key to ensuring continuous and sufficient cement hydration. This humidity effectively prevents the loss of paste moisture, avoiding the risk of hydration cessation, strength reduction, and cracking due to water loss. If the humidity is too low (relative humidity below 90%), the cement matrix will be affected by insufficient internal moisture, affecting its final mechanical properties and potentially causing drying shrinkage microcracks. The curing time is set at 7 to 28 days because this time range covers the critical cycle of cement strength development. After 7 days of curing, cement-based materials can usually reach most of their design strength. Continue curing for 28 days, and the strength and performance can further develop to a stable state to meet the testing requirements of national standards. Insufficient curing time will result in the failure to fully realize the strength and durability. The second curing is mainly to provide a stable post-hydration environment for the radiant cooling components, which is a key step to ensure that they obtain the expected mechanical properties and durability, thereby meeting the requirements of high-quality finished products.

[0109] Example 13:

[0110] The basic content is the same as in Embodiment 1, except that: the radiative cooling component is manufactured according to any one of the manufacturing methods in claims 1-6; the application method is: the radiative cooling component is used as a building component, and under sunlight, the radiative cooling particles on the surface of the radiative cooling component reflect solar radiation and radiate heat outward through the 8-13μm atmospheric window band, thereby reducing the surface temperature of the building component.

[0111] In application, this material can be prepared or installed into building components with different functions according to specific application scenarios, utilizing its cooling function to achieve different beneficial effects:

[0112] As a building envelope application: the radiative cooling component can be directly manufactured into building envelope components such as building exterior wall panels and roof panels; in such applications, the radiative cooling particles on the surface of the radiative cooling component can continuously reflect solar radiation and radiate heat outward through atmospheric windows, thereby reducing the surface temperature of the building envelope, reducing heat transfer to the interior, and thus achieving the effect of reducing the summer air conditioning cooling load and realizing building energy conservation.

[0113] As a ground paving system application: This radiative cooling component can be widely used in ground paving such as urban roads, squares, sidewalks and park trails; in such applications, this radiative cooling component can effectively reduce the surface temperature and directly improve the outdoor thermal comfort of pedestrians; at the same time, by reducing the heat storage and re-radiation of large areas of hardened ground, it can alleviate the urban heat island effect from the source.

[0114] Large-scale application in major infrastructure projects: The radiative cooling component can be applied to large-scale infrastructure projects such as large parking lots, municipal engineering areas, and transportation hub plazas. In such applications, the large-scale use of the radiative cooling component can generate a synergistic cooling effect on a regional scale, resulting in more significant energy-saving effects and regional environmental cooling benefits, with particularly outstanding environmental and economic benefits.

[0115] Example 14:

[0116] The basic content is the same as in Example 1, except that:

[0117] Step 1: First, place 120g of polylactic acid (PLA) in a twin-screw extruder for melting (the melting temperature is 180-190℃). Simultaneously, mix 30g of nano-BaSO4 with 1g of stearic acid and add the mixture to the extruder. The stearic acid acts as a dispersant to improve the dispersibility of the nanoparticles. Melt-blend for 15-20 minutes at a screw speed of 80-100 r / min to obtain a blend. Then, use a blow molding machine to form a radiation-cooled blended film with a thickness of 2mm.

[0118] Step 2: First, pour a cement-based slurry with a water-cement ratio of 0.35 into a 50mm×50mm×10mm mold and smooth the surface of the slurry. Then, immediately cover the surface of the cement-based slurry with the above-mentioned radiation cooling blend membrane. Remove interfacial air bubbles by vibration or pressing to ensure that the surface of the radiation cooling blend membrane is in full contact with the surface of the cement-based slurry, thus obtaining a radiation cooling-cement-based composite. The cement-based slurry is made of Portland cement and water.

[0119] Step 3: Move the mold containing the radiation cooling-cement-based composite into a constant temperature and humidity curing chamber and cure it for 12 hours at 70℃ and 95% relative humidity. After demolding the preliminarily cured radiation cooling-cement-based composite, transfer it to a standard curing environment (temperature 20℃, relative humidity ≥90%) and continue curing for 14 to 28 days to obtain the radiation cooling component.

[0120] In application, the performance of the obtained radiative cooling component is tested: the surface temperature change of the specimen is tested under simulated sunlight; the specimen is made from the radiative cooling component; the experiment shows that the surface temperature of the specimen is reduced by 3-5℃ compared with the traditional cement specimen, and the reflectivity is significantly improved, exhibiting excellent radiative cooling performance.

[0121] The above description is only a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. Any equivalent modifications or changes made by those skilled in the art based on the content disclosed in the present invention should be included within the scope of protection set forth in the claims.

Claims

1. A method for manufacturing a radiative cooling component, characterized in that: The manufacturing method includes the following steps: Step 1: The radiation-cooling particles are uniformly mixed with the polymer to obtain a blend, and then the blend is made into a radiation-cooling blend film; Step 2: The surface of the above-mentioned radiation cooling blended membrane is attached to the surface of the cement-based slurry and brought into full contact to obtain a radiation cooling-cement-based composite. Step 3: The above-mentioned radiation cooling-cement-based composite is subjected to a first curing at a temperature of 50-100℃ and a relative humidity of ≥90% until the cement-based slurry in the radiation cooling-cement-based composite is initially cured. Then, a second curing is carried out at room temperature and a relative humidity of ≥90% until the cement-based slurry in the radiation cooling-cement-based composite is fully cured to obtain the radiation cooling component.

2. The method for manufacturing a radiative cooling component according to claim 1, characterized in that: In the first step, the mass of the radiation-cooled particles is 1% to 5% of the mass of the polymer.

3. The method for manufacturing a radiative cooling component according to claim 1, characterized in that: In the third step, the temperature of the first curing is at least 5°C higher than the glass transition temperature of the polymer.

4. The method for manufacturing a radiative cooling component according to claim 1, characterized in that: The radiation-cooling particles are inorganic radiation-cooling micro / nano particles.

5. A method for manufacturing a radiative cooling component according to claim 1, characterized in that: The glass transition temperature of the polymer is 50-95℃.

6. A method for manufacturing a radiative cooling component according to claim 1, characterized in that: The polymer is any one or any combination of polylactic acid, polyethylene terephthalate, and polyvinyl alcohol.

7. A method for manufacturing a radiative cooling component according to any one of claims 1-6, characterized in that: In the second step, the step of bringing the surface of the above-mentioned radiation-cooled blended film into full contact with the surface of the cementitious slurry means: First, the surface of the above-mentioned radiation cooling blend membrane is attached to the surface of the cement-based slurry. Then, the interface air bubbles are removed by vibration or pressing, so that the surface of the cement-based slurry and the surface of the above-mentioned radiation cooling blend membrane are in full contact.

8. A method for manufacturing a radiative cooling component according to any one of claims 1-6, characterized in that: In the third step, the first curing of the above-mentioned radiation cooling-cement-based composite at a temperature of 50-100℃ and a relative humidity of ≥90% until the cement-based slurry in the radiation cooling-cement-based composite is initially cured means: The above-mentioned radiation cooling-cement-based composite was subjected to high temperature and high humidity curing for 2 to 48 hours at a temperature of 50-100℃ and a relative humidity of ≥90%.

9. A method for manufacturing a radiative cooling component according to any one of claims 1-6, characterized in that: In the third step, the second curing under normal temperature and relative humidity ≥90% conditions until the cement-based slurry in the radiant cooling-cement composite is fully cured to obtain the radiant cooling component refers to: The radiative cooling component is obtained by curing it for 7 to 28 days at a temperature of 20-30℃ and a relative humidity of ≥90%.

10. A method for applying a radiative cooling component, characterized in that: The radiative cooling component is manufactured according to any one of the manufacturing methods in claims 1-6; The application method is as follows: the radiation cooling component is used as a building component. Under sunlight, the radiation cooling particles on the surface of the radiation cooling component reflect solar radiation and radiate heat outward through the 8-13μm atmospheric window band, thereby reducing the surface temperature of the building component.

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