Self-repairing material applied to phase change temperature control and preparation method thereof

Abstract

The application relates to the technical field of functional fibers, and relates to a self-repairing material applied to phase change temperature control and a preparation method thereof.The self-repairing material comprises, from inside to outside, a phase change energy storage layer, a shaping constraint layer, a physical protection layer and a self-repairing shell layer, wherein the phase change energy storage layer is prepared from an amphiphilic phase change material, a surfactant and water, the shaping constraint layer is polyethylene glycol, the physical protection layer is tin quantum dots, and the self-repairing shell layer is collagen nanofiber.The preparation method comprises the following steps: mixing the amphiphilic phase change material, the surfactant and water to form a mixed solution, then shaping and drying the mixed solution to obtain a phase change micellar fiber; and then immersing and drying the phase change micellar fiber in polyethylene glycol solution, tin quantum dot dispersion and collagen nanofiber dispersion in sequence to obtain the self-repairing material.The self-repairing material has high phase change temperature control capability, high mechanical strength, high self-repairing efficiency and excellent stability.

Description

Technical Field

[0001] This invention relates to the field of functional fiber technology, specifically to a self-healing material for phase change temperature control and its preparation method. Background Technology

[0002] In fields such as wearable devices, smart sensors, and biomedical materials, there is an unprecedented demand for phase change materials (PCMs) related to the management of human body temperature, humidity, and comfort. The functionalization and intelligentization of PCMs have become a cutting-edge research hotspot in materials science. Among them, PCM temperature-regulating materials, due to their ability to absorb or release a large amount of latent heat during phase transitions to achieve bidirectional temperature regulation, have seen initial applications in cold environments for sports, work, and daily warmth. However, in the process of in-depth research and widespread application, both traditional textile materials and existing PCM temperature-regulating materials have revealed many insurmountable design flaws and technical bottlenecks.

[0003] Traditional textile materials, including cotton, linen, wool, down, and hollow synthetic fibers, primarily rely on the static insulation properties of the fibers themselves to achieve heat preservation or heat dissipation. This passive thermal protection mechanism has significant limitations. Firstly, the insulation performance of traditional textile materials is fixed and cannot dynamically respond to changes in ambient temperature or fluctuations in human metabolic heat production. When ambient temperature changes drastically, wearers are prone to feeling cold due to excessive heat loss or discomfort due to stuffiness, indicating a relative thermal hysteresis and heat transfer inertia. Secondly, traditional textile materials inevitably suffer physical damage such as mechanical wear, punctures, and tears during long-term use. Once the material structure is damaged, the integrity of its insulation layer is broken, leading to a sharp decline in localized insulation performance. This damage is usually permanent and cannot self-repair, severely shortening the material's lifespan and reducing its protective reliability.

[0004] To overcome the shortcomings of passive temperature control in traditional textile materials, phase change temperature-controlled materials have been proposed. These materials typically employ microencapsulation technology to implant the phase change material into fibers or coat it onto the fabric surface. While this technology achieves active temperature regulation to some extent, it still faces several design drawbacks in practical applications, as follows: 1. The incompatibility between phase change temperature control capability and mechanical properties. Most existing phase change temperature control materials are low-molecular-weight organic compounds with extremely low mechanical strength. Introducing these materials into textiles typically requires a high proportion of microencapsulation or composite spinning. Simultaneously, pursuing high phase change energy storage density often necessitates increasing the amount of phase change temperature control material, which severely disrupts the continuity of the matrix material, leading to a significant decrease in the mechanical properties of the fiber or coating (such as tensile strength, elongation at break, and abrasion resistance). Conversely, prioritizing mechanical strength limits the amount of phase change temperature control material, resulting in insufficient heat storage capacity to meet the temperature control requirements under long-term or extreme environments. This contradiction between high energy storage and high strength is one of the core pain points in current material design.

[0005] 2. Problems exist regarding leakage and insufficient stability of phase change materials. Even with microencapsulation technology, existing phase change materials are prone to microcapsule wall rupture under long-term use or when subjected to external forces such as compression, bending, and friction, leading to leakage of the core phase change material. Leakage of the phase change material not only results in the loss of temperature control function, but the leaked organic matter may also contaminate the skin or inner layer of clothing, causing skin allergies or bacterial growth. Furthermore, during repeated phase change cycles (solid-liquid phase change), the material is prone to supercooling or phase separation, leading to phase change temperature drift, a gradual decline in heat storage efficiency, and poor long-term stability.

[0006] 3. Existing phase change materials lack self-healing capabilities. Whether it's physical damage to the matrix material (such as scratches or holes) or functional damage to the microcapsules encapsulating the phase change material (such as capsule wall rupture), once these damages occur, they rapidly spread and lead to localized or even overall performance failure. In special protective or harsh environments, such non-self-healing micro-damage can pose serious safety hazards. The inability of the phase change materials used to actively repair damage means high maintenance costs and difficulty in meeting the demands of high-reliability applications. Summary of the Invention

[0007] The purpose of this invention is to provide a self-healing material for phase change temperature control and its preparation method. Based on a micro-dense structure, high-strength and high-thermal-conductivity functional materials are precisely compounded with phase change substances. While enhancing the mechanical properties of the material, a stable and effective heat conduction pathway is established. At the same time, a bio-based nanofiber skeleton structure is introduced to endow the material with self-healing function, thus possessing the advantages of high phase change temperature control capability, high mechanical strength, high self-healing efficiency, and excellent stability.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A self-healing material for phase change temperature control includes, from the inside out, a phase change energy storage layer, a shaping and constraint layer, a physical protection layer, and a self-healing outer shell layer. The shaping and constraint layer is bonded to the outer surface of the phase change energy storage layer through non-covalent bonding. The physical protection layer is bonded to the outer surface of the shaping and constraint layer through adsorption. The self-healing outer shell layer is bonded to the outer surface of the physical protection layer through a wet-dry method.

[0009] Furthermore, the phase change energy storage layer is prepared using amphiphilic phase change materials, surfactants, and water; the shaping and confinement layer is polyethylene glycol; the physical protection layer is tin quantum dots; and the self-healing outer shell layer is collagen nanofibers.

[0010] Furthermore, based on the total mass of the amphiphilic phase change material, surfactant, and water, the mass fraction of the amphiphilic phase change material is 10-20%, the mass fraction of the surfactant is 1-5%, and the remainder is water.

[0011] Furthermore, the amphiphilic phase change material is one of hexadecyl alcohol, octadecyl alcohol, hexadecanoic acid, octadecanoic acid, hexadecylamine, and octadecylamine.

[0012] Furthermore, the surfactant is one of sodium carboxymethyl cellulose, cationic guar gum, and sodium polyacrylate.

[0013] This invention also provides a method for preparing the self-healing material for phase change temperature control, comprising the following steps: Step 1: Mix the amphiphilic phase change material, surfactant, and water to form a mixed solution, and then shape and dry the mixed solution to obtain phase change micelle fibers used as a phase change energy storage layer; Step 2: The phase change micelle fibers are sequentially impregnated in polyethylene glycol solution, tin quantum dot dispersion, and collagen nanofiber dispersion, and dried each time they are impregnated to obtain a self-healing material for phase change temperature control.

[0014] Furthermore, in step 1, the specific process for obtaining the phase change micelle fibers is as follows: Step 1.1: Mix the amphiphilic phase change material, surfactant, and water at 25°C to form a mixed solution; Step 1.2: Place the mixed solution in a syringe and expel it outward at a rate of 1-20 mm / s to obtain a linear sample; Step 1.3: Immerse the linear sample in methanol and perform water extraction with methanol for 3 hours, then dry at 80°C to obtain phase change micelle fibers.

[0015] Furthermore, in step 2, the specific process for obtaining the self-healing material is as follows: Step 2.1: The phase change micelle fibers are impregnated in a polyethylene glycol solution for 48 hours, and then dried at 80°C for 24 hours. Step 2.2: The phase change micelle fibers treated in step 2.1 are immersed in a tin quantum dot dispersion for 24 hours, and then dried at 80°C for 24 hours. Step 2.3: The phase change micelle fibers treated in step 2.2 are immersed in collagen nanofiber dispersion for 12 hours, and then dried at 70-95°C for 24 hours to obtain a self-healing material for phase change temperature control.

[0016] Further, in step 2, the polyethylene glycol solution contains 1-5% polyethylene glycol by mass, the tin quantum dot dispersion contains 1-10% tin quantum dots by mass, and the collagen nanofiber dispersion contains 1-10% collagen nanofibers by mass.

[0017] Further, in step 2, the polyethylene glycol solution is a solution of polyethylene glycol dissolved in ethanol, the tin quantum dot dispersion is a dispersion of tin quantum dots dispersed in ethanol, and the collagen nanofiber dispersion is a dispersion of collagen nanofibers dispersed in ethanol.

[0018] The beneficial effects of this invention are: 1. The phase change energy storage layer of the present invention uses an amphiphilic phase change material as a substrate. Through the structural induction effect of a surfactant, the amphiphilic phase change material can be aligned in the radial direction. Then, axial extrusion pressure is applied to the amphiphilic phase change material through a syringe, so that the amphiphilic phase change material and the surfactant are tightly assembled and shaped into linear phase change micelle fibers. The phase change micelle fibers are mainly used to provide stable latent heat of phase change, while having excellent bending freedom, forming natural extensibility and drape. They can not only be effectively configured on the complex surfaces of different products, but also closely conform to the complex curves of the human body, without forming a hard or restrictive feeling during movement.

[0019] 2. The shaping and restraining layer of this invention uses polyethylene glycol (PEG) as the substrate. PEG generates electrostatic attraction with the amphiphilic phase change material through its multiple non-covalent hydrogen bonds. The non-covalent hydrogen bonds have a specific linear orientation. When PEG and the amphiphilic phase change material are in close contact, a large number of van der Waals forces are generated, causing PEG to tightly pack and adhere to the outer surface of the phase change micelle fiber, forming a hierarchical structure that stably restrains and shapes the phase change micelle fiber. The synergistic effect of non-covalent hydrogen bonds and van der Waals forces ensures the connection stability between PEG and the phase change micelle fiber. At the same time, both non-covalent hydrogen bonds and van der Waals forces are non-covalent weak interactions, allowing PEG and the phase change micelle fiber to both separate and reconnect. The phase change micelle fiber has dynamic adjustability during bending deformation, thereby ensuring that the phase change micelle fiber has excellent bending flexibility.

[0020] 3. The physical protective layer of this invention uses tin quantum dots as the substrate. As a nanomaterial, tin quantum dots have a huge specific surface area and a large number of surface defects. These surface defect points have high energy and strong activity. Combined with the surface passivation layer or interface barrier layer of tin quantum dots, they will induce an equivalent dipole effect, causing tin quantum dots to self-adsorb onto the outer surface of phase change micelle fibers, forming a highly dense and stable hierarchical structure. This hierarchical structure not only effectively increases the external contact area of ​​phase change micelle fibers, but also has excellent physical protection effect. At the same time, it restricts the movement of phase change micelle fibers at the macroscopic level, constitutes a leak-free encapsulation of phase change materials, maintains stable phase change temperature control capability, and extends the service life of materials.

[0021] 4. The self-healing outer shell layer of this invention uses collagen nanofibers as the substrate. Collagen nanofibers have good affinity for the phase change energy storage layer, the shaping and constraint layer, and the physical protection layer, thus easily integrating with them. In a wet state, collagen nanofibers become a soft, adhesive membrane structure that can effectively diffuse into the defect gaps of different structural levels. In a dry state, collagen nanofibers become a hard, rigid membrane structure with high strength, which can fully fill the defect gaps of different structural levels. The above-mentioned wet-dry stitching process can realize the self-healing treatment and encapsulation protection of phase change micelle fibers, giving this material a strong self-healing ability. At the same time, the wet-dry stitching process is simple and quick, and has a high self-healing efficiency. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the preparation process of a self-healing material for phase change temperature control according to the present invention.

[0023] Figure 2 This is a scanning electron microscope image of the self-healing material for phase change temperature control prepared in Example 1 of the present invention.

[0024] Figure 3 This is a scanning electron microscope image of the self-healing material applied to phase change temperature control according to Embodiment 2 of the present invention.

[0025] Figure 4 This is a scanning electron microscope image of the self-healing material applied to phase change temperature control according to Embodiment 3 of the present invention.

[0026] Figure 5 This is a scanning electron microscope image of the self-healing material applied to phase change temperature control according to Embodiment 4 of the present invention.

[0027] Figure 6 This is a scanning electron microscope image of the self-healing material applied to phase change temperature control according to Embodiment 5 of the present invention.

[0028] Figure 7 This is a scanning electron microscope image of the self-healing material applied to phase change temperature control according to Embodiment 6 of the present invention.

[0029] Figure 8 This is a scanning electron microscope image of the self-healing material applied to phase change temperature control according to Embodiment 7 of the present invention.

[0030] Reference numerals: 1. Phase change energy storage layer; 2. Shaping constraint layer; 3. Physical protection layer; 4. Self-healing outer layer. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0032] In the description of the embodiments of this application, the words "for example" or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design that is described as "for example" or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design options. Rather, the use of the words "for example" or "for instance" is intended to present the relevant concepts in a specific manner.

[0033] Example 1:

[0034] In this embodiment, as Figure 1 As shown, this invention provides a self-healing material for phase change temperature control and its preparation method, as detailed below: The self-healing material comprises, from the inside out, a phase change energy storage layer, a shaping and constraint layer, a physical protective layer, and a self-healing outer shell layer. The shaping and constraint layer is bonded to the outer surface of the phase change energy storage layer through non-covalent bonding. The physical protective layer is bonded to the outer surface of the shaping and constraint layer through adsorption. The self-healing outer shell layer is bonded to the outer surface of the physical protective layer through a wet-dry method. The phase change energy storage layer is prepared from hexadecyl alcohol, sodium carboxymethyl cellulose, and water. Based on the total mass of hexadecyl alcohol, sodium carboxymethyl cellulose, and water, the mass fraction of hexadecyl alcohol is 10%, the mass fraction of sodium carboxymethyl cellulose is 1%, the shaping and constraint layer is polyethylene glycol, the physical protective layer is tin quantum dots, and the self-healing outer shell layer is collagen nanofibers.

[0035] The method for preparing the self-healing material includes the following steps: Step 1.1: Mix the hexadecyl alcohol, sodium carboxymethyl cellulose, and water at 25°C to form a mixed solution; Step 1.2: Place the mixed solution in a syringe and expel it outward at a rate of 1 mm / s to obtain a linear sample; Step 1.3: Immerse the linear sample in methanol and perform water extraction with methanol for 3 hours, then dry it at 80°C to obtain phase change micelle fibers used as a phase change energy storage layer; Step 2.1: The phase change micelle fibers are impregnated in a polyethylene glycol solution for 48 hours, and then dried at 80°C for 24 hours to obtain self-supporting phase change micelle fibers. The polyethylene glycol solution is a solution of polyethylene glycol dissolved in ethanol, and the mass fraction of polyethylene glycol in the solution is 1%. Step 2.2: The self-supporting phase change micelle fiber is impregnated in a tin quantum dot dispersion for 24 hours, and then dried at 80°C for 24 hours to obtain a core-shell structured phase change fiber. The tin quantum dot dispersion is a dispersion of tin quantum dots in ethanol, and the mass fraction of tin quantum dots in the dispersion is 1%. Step 2.3: The core-shell structured phase change fiber is impregnated in a collagen nanofiber dispersion for 12 hours, and then dried at 70°C for 24 hours to obtain a self-healing material for phase change temperature control. The collagen nanofiber dispersion is a dispersion of collagen nanofibers in ethanol, and the mass fraction of collagen nanofibers in the dispersion is 1%.

[0036] Example 2:

[0037] In this embodiment, as Figure 1As shown, this invention provides a self-healing material for phase change temperature control and its preparation method, as detailed below: The self-healing material comprises, from the inside out, a phase change energy storage layer, a shaping and constraint layer, a physical protective layer, and a self-healing outer shell layer. The shaping and constraint layer is bonded to the outer surface of the phase change energy storage layer through non-covalent bonding. The physical protective layer is bonded to the outer surface of the shaping and constraint layer through adsorption. The self-healing outer shell layer is bonded to the outer surface of the physical protective layer through a wet-dry method. The phase change energy storage layer is prepared from octadecyl alcohol, cationic guar gum, and water. Based on the total mass of the octadecyl alcohol, cationic guar gum, and water, the mass fraction of octadecyl alcohol is 20%, the mass fraction of cationic guar gum is 5%, the shaping and constraint layer is polyethylene glycol, the physical protective layer is tin quantum dots, and the self-healing outer shell layer is collagen nanofibers.

[0038] The method for preparing the self-healing material includes the following steps: Step 1.1: Mix the octadecyl alcohol, cationic guar gum, and water at 25°C to form a mixed solution; Step 1.2: Place the mixed solution in a syringe and expel it outward at a rate of 20 mm / s to obtain a linear sample; Step 1.3: Immerse the linear sample in methanol and perform water extraction with methanol for 3 hours, then dry it at 80°C to obtain phase change micelle fibers used as a phase change energy storage layer; Step 2.1: The phase change micelle fibers are impregnated in a polyethylene glycol solution for 48 hours, and then dried at 80°C for 24 hours to obtain self-supporting phase change micelle fibers. The polyethylene glycol solution is a solution of polyethylene glycol dissolved in ethanol, and the mass fraction of polyethylene glycol in the solution is 5%. Step 2.2: The self-supporting phase change micelle fiber is impregnated in a tin quantum dot dispersion for 24 hours, and then dried at 80°C for 24 hours to obtain a core-shell structured phase change fiber. The tin quantum dot dispersion is a dispersion of tin quantum dots in ethanol, and the mass fraction of tin quantum dots in the dispersion is 10%. Step 2.3: The core-shell structured phase change fiber is impregnated in a collagen nanofiber dispersion for 12 hours, and then dried at 90°C for 24 hours to obtain a self-healing material for phase change temperature control. The collagen nanofiber dispersion is a dispersion of collagen nanofibers in ethanol, and the mass fraction of collagen nanofibers in the dispersion is 10%.

[0039] Example 3:

[0040] In this embodiment, as Figure 1 As shown, this invention provides a self-healing material for phase change temperature control and its preparation method, as detailed below: The self-healing material comprises, from the inside out, a phase change energy storage layer, a shaping and constraint layer, a physical protective layer, and a self-healing outer shell layer. The shaping and constraint layer is bonded to the outer surface of the phase change energy storage layer through non-covalent bonding. The physical protective layer is bonded to the outer surface of the shaping and constraint layer through adsorption. The self-healing outer shell layer is bonded to the outer surface of the physical protective layer through a wet-dry method. The phase change energy storage layer is prepared from hexadecanoic acid, sodium polyacrylate, and water. Based on the total mass of hexadecanoic acid, sodium polyacrylate, and water, the mass fraction of hexadecanoic acid is 15%, the mass fraction of sodium polyacrylate is 5%, the shaping and constraint layer is polyethylene glycol, the physical protective layer is tin quantum dots, and the self-healing outer shell layer is collagen nanofibers.

[0041] The method for preparing the self-healing material includes the following steps: Step 1.1: Mix the hexadecanoic acid, sodium polyacrylate, and water at 25°C to form a mixed solution; Step 1.2: Place the mixed solution in a syringe and expel it outward at a rate of 15 mm / s to obtain a linear sample; Step 1.3: Immerse the linear sample in methanol and perform water extraction with methanol for 3 hours, then dry it at 80°C to obtain phase change micelle fibers used as a phase change energy storage layer; Step 2.1: The phase change micelle fibers are impregnated in a polyethylene glycol solution for 48 hours, and then dried at 80°C for 24 hours to obtain self-supporting phase change micelle fibers. The polyethylene glycol solution is a solution of polyethylene glycol dissolved in ethanol, and the mass fraction of polyethylene glycol in the solution is 2%. Step 2.2: The self-supporting phase change micelle fiber is impregnated in a tin quantum dot dispersion for 24 hours, and then dried at 80°C for 24 hours to obtain a core-shell structured phase change fiber. The tin quantum dot dispersion is a dispersion of tin quantum dots in ethanol, and the mass fraction of tin quantum dots in the dispersion is 7%. Step 2.3: The core-shell structured phase change fiber is impregnated in a collagen nanofiber dispersion for 12 hours, and then dried at 80°C for 24 hours to obtain a self-healing material for phase change temperature control. The collagen nanofiber dispersion is a dispersion of collagen nanofibers in ethanol, and the mass fraction of collagen nanofibers in the dispersion is 8%.

[0042] Example 4:

[0043] In this embodiment, as Figure 1 As shown, this invention provides a self-healing material for phase change temperature control and its preparation method, as detailed below: The self-healing material comprises, from the inside out, a phase change energy storage layer, a shaping and constraint layer, a physical protective layer, and a self-healing outer shell layer. The shaping and constraint layer is bonded to the outer surface of the phase change energy storage layer through non-covalent bonding. The physical protective layer is bonded to the outer surface of the shaping and constraint layer through adsorption. The self-healing outer shell layer is bonded to the outer surface of the physical protective layer through a wet-dry method. The phase change energy storage layer is prepared from octadecanoic acid, sodium polyacrylate, and water. Based on the total mass of the octadecanoic acid, sodium polyacrylate, and water, the mass fraction of octadecanoic acid is 15%, the mass fraction of sodium polyacrylate is 1%, the shaping and constraint layer is polyethylene glycol, the physical protective layer is tin quantum dots, and the self-healing outer shell layer is collagen nanofibers.

[0044] The method for preparing the self-healing material includes the following steps: Step 1.1: Mix the octadecanoic acid, sodium polyacrylate, and water at 25°C to form a mixed solution; Step 1.2: Place the mixed solution in a syringe and expel it outward at a rate of 18 mm / s to obtain a linear sample; Step 1.3: Immerse the linear sample in methanol and perform water extraction with methanol for 3 hours, then dry it at 80°C to obtain phase change micelle fibers used as a phase change energy storage layer; Step 2.1: The phase change micelle fibers are impregnated in a polyethylene glycol solution for 48 hours, and then dried at 80°C for 24 hours to obtain self-supporting phase change micelle fibers. The polyethylene glycol solution is a solution of polyethylene glycol dissolved in ethanol, and the mass fraction of polyethylene glycol in the solution is 4%. Step 2.2: The self-supporting phase change micelle fiber is impregnated in a tin quantum dot dispersion for 24 hours, and then dried at 80°C for 24 hours to obtain a core-shell structured phase change fiber. The tin quantum dot dispersion is a dispersion of tin quantum dots in ethanol, and the mass fraction of tin quantum dots in the dispersion is 6%. Step 2.3: The core-shell structured phase change fiber is impregnated in a collagen nanofiber dispersion for 12 hours, and then dried at 85°C for 24 hours to obtain a self-healing material for phase change temperature control. The collagen nanofiber dispersion is a dispersion of collagen nanofibers in ethanol, and the mass fraction of collagen nanofibers in the dispersion is 7%.

[0045] Example 5:

[0046] In this embodiment, as Figure 1 As shown, this invention provides a self-healing material for phase change temperature control and its preparation method, as detailed below: The self-healing material comprises, from the inside out, a phase change energy storage layer, a shaping and constraint layer, a physical protective layer, and a self-healing outer shell layer. The shaping and constraint layer is bonded to the outer surface of the phase change energy storage layer through non-covalent bonding. The physical protective layer is bonded to the outer surface of the shaping and constraint layer through adsorption. The self-healing outer shell layer is bonded to the outer surface of the physical protective layer through a wet-drying method. The phase change energy storage layer is prepared from hexadecylamine, sodium carboxymethyl cellulose, and water. Based on the total mass of the hexadecylamine, sodium carboxymethyl cellulose, and water, the mass fraction of hexadecylamine is 15%, the mass fraction of sodium carboxymethyl cellulose is 3%, the shaping and constraint layer is polyethylene glycol, the physical protective layer is tin quantum dots, and the self-healing outer shell layer is collagen nanofibers.

[0047] The method for preparing the self-healing material includes the following steps: Step 1.1: Mix the hexadecylamine, sodium carboxymethyl cellulose, and water at 25°C to form a mixed solution; Step 1.2: Place the mixed solution in a syringe and expel it outward at a rate of 15 mm / s to obtain a linear sample; Step 1.3: Immerse the linear sample in methanol and perform water extraction with methanol for 3 hours, then dry it at 80°C to obtain phase change micelle fibers used as a phase change energy storage layer; Step 2.1: The phase change micelle fibers are impregnated in a polyethylene glycol solution for 48 hours, and then dried at 80°C for 24 hours to obtain self-supporting phase change micelle fibers. The polyethylene glycol solution is a solution of polyethylene glycol dissolved in ethanol, and the mass fraction of polyethylene glycol in the solution is 3.5%. Step 2.2: The self-supporting phase change micelle fiber is impregnated in a tin quantum dot dispersion for 24 hours, and then dried at 80°C for 24 hours to obtain a core-shell structured phase change fiber. The tin quantum dot dispersion is a dispersion of tin quantum dots in ethanol, and the mass fraction of tin quantum dots in the dispersion is 7.5%. Step 2.3: The core-shell structured phase change fiber is impregnated in a collagen nanofiber dispersion for 12 hours, and then dried at 95°C for 24 hours to obtain a self-healing material for phase change temperature control. The collagen nanofiber dispersion is a dispersion of collagen nanofibers in ethanol, and the mass fraction of collagen nanofibers in the dispersion is 7.5%.

[0048] Example 6:

[0049] In this embodiment, as Figure 1 As shown, this invention provides a self-healing material for phase change temperature control and its preparation method, as detailed below: The self-healing material comprises, from the inside out, a phase change energy storage layer, a shaping and constraint layer, a physical protective layer, and a self-healing outer shell layer. The shaping and constraint layer is bonded to the outer surface of the phase change energy storage layer through non-covalent bonding. The physical protective layer is bonded to the outer surface of the shaping and constraint layer through adsorption. The self-healing outer shell layer is bonded to the outer surface of the physical protective layer through a wet-dry method. The phase change energy storage layer is prepared using octadecylamine, cationic guar gum, and water. Based on the total mass of the octadecylamine, cationic guar gum, and water, the mass fraction of octadecylamine is 20%, the mass fraction of cationic guar gum is 4%, the shaping and constraint layer is polyethylene glycol, the physical protective layer is tin quantum dots, and the self-healing outer shell layer is collagen nanofibers.

[0050] The method for preparing the self-healing material includes the following steps: Step 1.1: Mix the octadecylamine, cationic guar gum, and water at 25°C to form a mixed solution; Step 1.2: Place the mixed solution in a syringe and expel it outward at a rate of 6 mm / s to obtain a linear sample; Step 1.3: Immerse the linear sample in methanol and perform water extraction with methanol for 3 hours, then dry it at 80°C to obtain phase change micelle fibers used as a phase change energy storage layer; Step 2.1: The phase change micelle fibers are impregnated in a polyethylene glycol solution for 48 hours, and then dried at 80°C for 24 hours to obtain self-supporting phase change micelle fibers. The polyethylene glycol solution is a solution of polyethylene glycol dissolved in ethanol, and the mass fraction of polyethylene glycol in the solution is 2%. Step 2.2: The self-supporting phase change micelle fiber is impregnated in a tin quantum dot dispersion for 24 hours, and then dried at 80°C for 24 hours to obtain a core-shell structured phase change fiber. The tin quantum dot dispersion is a dispersion of tin quantum dots in ethanol, and the mass fraction of tin quantum dots in the dispersion is 10%. Step 2.3: The core-shell structured phase change fiber is impregnated in a collagen nanofiber dispersion for 12 hours, and then dried at 70°C for 24 hours to obtain a self-healing material for phase change temperature control. The collagen nanofiber dispersion is a dispersion of collagen nanofibers in ethanol, and the mass fraction of collagen nanofibers in the dispersion is 10%.

[0051] Example 7:

[0052] In this embodiment, as Figure 1 As shown, this invention provides a self-healing material for phase change temperature control and its preparation method, as detailed below: The self-healing material comprises, from the inside out, a phase change energy storage layer, a shaping and constraint layer, a physical protective layer, and a self-healing outer shell layer. The shaping and constraint layer is bonded to the outer surface of the phase change energy storage layer through non-covalent bonding. The physical protective layer is bonded to the outer surface of the shaping and constraint layer through adsorption. The self-healing outer shell layer is bonded to the outer surface of the physical protective layer through a wet-dry method. The phase change energy storage layer is prepared from octadecyl alcohol, sodium polyacrylate, and water. Based on the total mass of octadecyl alcohol, sodium polyacrylate, and water, the mass fraction of octadecyl alcohol is 20%, the mass fraction of sodium polyacrylate is 3%, the shaping and constraint layer is polyethylene glycol, the physical protective layer is tin quantum dots, and the self-healing outer shell layer is collagen nanofibers.

[0053] The method for preparing the self-healing material includes the following steps: Step 1.1: Mix the octadecyl alcohol, sodium polyacrylate, and water at 25°C to form a mixed solution; Step 1.2: Place the mixed solution in a syringe and expel it outward at a rate of 12 mm / s to obtain a linear sample; Step 1.3: Immerse the linear sample in methanol and perform water extraction with methanol for 3 hours, then dry it at 80°C to obtain phase change micelle fibers used as a phase change energy storage layer; Step 2.1: The phase change micelle fibers are impregnated in a polyethylene glycol solution for 48 hours, and then dried at 80°C for 24 hours to obtain self-supporting phase change micelle fibers. The polyethylene glycol solution is a solution of polyethylene glycol dissolved in ethanol, and the mass fraction of polyethylene glycol in the solution is 3%. Step 2.2: The self-supporting phase change micelle fiber is impregnated in a tin quantum dot dispersion for 24 hours, and then dried at 80°C for 24 hours to obtain a core-shell structured phase change fiber. The tin quantum dot dispersion is a dispersion of tin quantum dots in ethanol, and the mass fraction of tin quantum dots in the dispersion is 10%. Step 2.3: The core-shell structured phase change fiber is impregnated in a collagen nanofiber dispersion for 12 hours, and then dried at 75°C for 24 hours to obtain a self-healing material for phase change temperature control. The collagen nanofiber dispersion is a dispersion of collagen nanofibers in ethanol, and the mass fraction of collagen nanofibers in the dispersion is 10%.

[0054] Specifically, the preparation process for the tin quantum dots used in Examples 1 to 7 is as follows: 2g of tin powder is placed in a high-energy ball mill and ball milled. The ultrasonic power is 0.55kw and the ball milling speed is 300 revolutions per minute. After ball milling for 72 hours, tin quantum dots are obtained.

[0055] It should be noted that, please refer to Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8Corresponding sequentially to the self-healing materials for phase change temperature control prepared in Examples 1-7, it can be seen that the self-healing materials in the corresponding examples all have a dense microstructure. The phase change micelle fibers have abundant surface functional groups and nanoscale surface roughness, providing ideal interface conditions for the subsequent introduction of polyethylene glycol and adsorption of tin quantum dots. Polyethylene glycol constrains and shapes the phase change micelle fibers through its multiple non-covalent hydrogen bonds and the van der Waals forces formed. The huge specific surface area and numerous surface defects of tin quantum dots are conducive to increasing the external contact area of ​​the phase change micelle fibers, forming a highly dense and stable protective structure, and also providing ideal interface conditions for the stable filling and attachment of collagen nanofibers. By performing corresponding wet and dry state switching processes on the collagen nanofibers, the material has a strong damage self-repair capability. The four hierarchical structures work together to form a multi-level, self-assembled, and self-healing stable composite structure integrating functions such as phase change energy storage, fiber shaping, confined stabilization, and defect self-repair.

[0056] It should be understood that, for Examples 1 to 7, the tensile strength of the self-healing materials prepared in each example was measured using an electronic universal testing machine, the phase transition enthalpy of the self-healing materials prepared in each example was measured using a DSC differential scanning calorimeter, the mass retention rate of the self-healing materials prepared in each example was measured using a weighing method, and the strength retention rate and latent heat retention rate after self-healing were also measured. The specific measurement results are shown in Table 1. Based on the micro-dense structure design, the self-healing materials prepared for use in phase change temperature-controlled clothing exhibit excellent performance. They not only possess high mechanical strength and high assembly stability, meeting the high structural stability requirements of phase change temperature control, but also demonstrate high latent heat of phase change, achieving excellent temperature control effects. After 200 heating and cooling cycles within the range of 0℃ to 100℃, the tensile strength, latent heat of phase change, and mass retention rate remain essentially unchanged, demonstrating good structural stability.

[0057]

[0058] The foregoing description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of other embodiments of this disclosure upon considering the specification and the disclosure of practical truth. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described in this disclosure. The specification and embodiments are considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

Claims

1. A self-healing material for phase change temperature control, characterized in that, The self-healing material comprises, from the inside out, a phase change energy storage layer, a shaping and constraint layer, a physical protection layer, and a self-healing outer shell layer. The shaping and constraint layer is bonded to the outer surface of the phase change energy storage layer through non-covalent bonding. The physical protection layer is bonded to the outer surface of the shaping and constraint layer through adsorption. The self-healing outer shell layer is bonded to the outer surface of the physical protection layer through a wet-dry method.

2. The self-healing material for phase change temperature control according to claim 1, characterized in that, The phase change energy storage layer is made of amphiphilic phase change material, surfactant and water, the shaping and confinement layer is polyethylene glycol, the physical protection layer is tin quantum dots, and the self-healing outer shell layer is collagen nanofiber.

3. The self-healing material for phase change temperature control according to claim 2, characterized in that, Based on the total mass of the amphiphilic phase change material, surfactant, and water, the mass fraction of the amphiphilic phase change material is 10-20%, the mass fraction of the surfactant is 1-5%, and the remainder is water.

4. The self-healing material for phase change temperature control according to claim 2 or 3, characterized in that, The amphiphilic phase change material is one of hexadecyl alcohol, octadecyl alcohol, hexadecanoic acid, octadecanoic acid, hexadecylamine, and octadecylamine.

5. The self-healing material for phase change temperature control according to claim 2 or 3, characterized in that, The surfactant is one of sodium carboxymethyl cellulose, cationic guar gum, or sodium polyacrylate.

6. A method for preparing a self-healing material for phase change temperature control as described in any one of claims 2 to 5, characterized in that, Includes the following steps: Step 1: Mix the amphiphilic phase change material, surfactant, and water to form a mixed solution, and then shape and dry the mixed solution to obtain phase change micelle fibers used as a phase change energy storage layer; Step 2: The phase change micelle fibers are sequentially impregnated in polyethylene glycol solution, tin quantum dot dispersion, and collagen nanofiber dispersion, and dried each time they are impregnated to obtain a self-healing material for phase change temperature control.

7. The method for preparing a self-healing material for phase change temperature control according to claim 6, characterized in that, In step 1, the specific process for obtaining the phase change micelle fibers is as follows: Step 1.1: Mix the amphiphilic phase change material, surfactant, and water at 25°C to form a mixed solution; Step 1.2: Place the mixed solution in a syringe and expel it outward at a rate of 1-20 mm / s to obtain a linear sample; Step 1.3: Immerse the linear sample in methanol and perform water extraction with methanol for 3 hours, then dry at 80°C to obtain phase change micelle fibers.

8. The method for preparing a self-healing material for phase change temperature control according to claim 6, characterized in that, In step 2, the specific process for obtaining the self-healing material is as follows: Step 2.1: The phase change micelle fibers are impregnated in a polyethylene glycol solution for 48 hours, and then dried at 80°C for 24 hours. Step 2.2: The phase change micelle fibers treated in step 2.1 are immersed in a tin quantum dot dispersion for 24 hours, and then dried at 80°C for 24 hours. Step 2.3: The phase change micelle fibers treated in step 2.2 are immersed in collagen nanofiber dispersion for 12 hours, and then dried at 70-95°C for 24 hours to obtain a self-healing material for phase change temperature control.

9. The method for preparing a self-healing material for phase change temperature control according to claim 6 or 8, characterized in that, In step 2, the polyethylene glycol solution contains 1-5% polyethylene glycol by mass, the tin quantum dot dispersion contains 1-10% tin quantum dots by mass, and the collagen nanofiber dispersion contains 1-10% collagen nanofibers by mass.

10. The method for preparing a self-healing material for phase change temperature control according to claim 9, characterized in that, In step 2, the polyethylene glycol solution is a solution of polyethylene glycol dissolved in ethanol, the tin quantum dot dispersion is a dispersion of tin quantum dots dispersed in ethanol, and the collagen nanofiber dispersion is a dispersion of collagen nanofibers dispersed in ethanol.

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