Photo-thermal phase change energy storage composite fabric as well as preparation method and application thereof

Abstract

The invention relates to the technical field of photo-thermal and phase change energy storage application, in particular to a preparation method of a photo-thermal phase change energy storage composite fabric, a photo-thermal phase change microcapsule with a full-wave band photo-thermal conversion function is prepared through effective combination of a photo-thermal conversion material polypyrrole and a phase change microcapsule, and collaboration of photo-thermal conversion and energy storage is achieved; and then a flexible fiber fabric is used as a substrate material, the photo-thermal phase change microcapsules are implanted into the surface of the fabric through an electrostatic flocking technology, the photo-thermal phase change energy storage composite fabric is prepared, and good solar energy absorption, conversion and storage can be achieved. The photo-thermal phase change energy storage composite fabric has excellent photo-thermal performance and energy storage potential, the preparation process is simple, large-scale production can be achieved, and the photo-thermal phase change energy storage composite fabric has huge application potential in the fields of energy, environment, medical treatment, personal heat management and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of photothermal and phase change energy storage application, and specifically to a photothermal phase change energy storage composite fabric and a preparation method and application thereof. Background Art

[0002] With the continuous development of human society, the energy crisis is becoming increasingly serious and has become a global problem that threatens human survival and development. Solar energy, as a renewable clean energy, is the most abundant and readily available energy on the earth's surface. At present, the main ways to utilize solar energy include solar power generation, photothermal conversion, and photochemical utilization. Among them, photothermal conversion technology absorbs solar radiation and converts it into thermal energy for utilization, and has important value in the fields of solar energy utilization and thermal management. However, photothermal conversion technology is limited by the intermittent and instability of solar energy illumination. In practical applications, continuous photothermal conversion cannot be achieved, which greatly reduces the efficiency of solar energy utilization.

[0003] Phase change thermal storage materials (PCMs) can achieve high-density storage and on-demand release of energy through the absorption and release of latent heat during phase change. Phase change materials can be used to collect and store solar energy, so the development of photothermal phase change composite materials with photothermal conversion and thermal energy storage functions is considered to be one of the most promising technologies to overcome the intermittent nature of sunlight and improve the efficiency of solar energy utilization.

[0004] In order to improve practicality, the Chinese patent document announcement number is: CN114369447A, which discloses a multi-level porous carbon-based photothermal phase change material. First, the zinc-metal organic framework is treated by a controllable carbonization method to prepare a zinc oxide / multi-level porous carbon composite; then the zinc oxide / multi-level porous carbon composite is immersed in a phase change material solution, stirred, impregnated, and dried to obtain a photothermal phase change composite material. This invention utilizes the synergistic effect of a three-dimensional hierarchical porous carbon matrix and ZnO particles to significantly improve the thermal conductivity and photothermal conversion capacity of the phase change material, and can quickly convert solar energy into thermal energy and store it in the phase change material. The conversion efficiency can reach 93.14%, and to a certain extent, it realizes efficient photothermal conversion, rapid heat storage / release, and dynamic temperature control functions. However, this technical solution still has shortcomings. Due to the rigid structure, the material cannot meet the needs of flexible wear, which restricts its application scenarios. The Chinese patent document announcement number is: CN118422374B, which discloses an intelligent heat storage and temperature regulation fabric based on ethylene carbon phase change fiber, which has high stability and multifunctional adjustment, can realize light-heat conversion and light-heat-electric conversion, and can be used to achieve human thermal management under extreme environmental conditions. However, the preparation method of this scheme is relatively complicated and requires a variety of processing methods and finishing methods to prepare it. It can be seen that the development of a photothermal phase change fabric with flexible integration and functional expansion, at the same time, the material meets the photothermal conversion performance and heat storage and temperature regulation functions, the preparation process is simple, and the photothermal phase change composite material technology solution that can be realized in large-scale production and multi-field applications is of great significance. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a photothermal phase change energy storage composite fabric and a preparation method and application thereof, with the aim of integrating photothermal conversion and phase change energy storage technology, solving the intermittent problem of sunlight and realizing efficient utilization of solar energy. At the same time, the prepared photothermal phase change energy storage composite fabric meets the practical application requirements of being flexible and wearable, having excellent photothermal conversion performance and heat storage and temperature regulation functions, and having a simple preparation process, and can realize large-scale production.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a photothermal phase change energy storage composite fabric, wherein the composite fabric comprises a base fabric layer, an adhesive layer and a photothermal phase change energy storage layer from top to bottom; The photothermal phase change energy storage layer is a photothermal phase change microcapsule flocked onto the surface of the fabric by an electrostatic flocking method, and the photothermal phase change microcapsule can synergistically play the role of photothermal conversion and phase change energy storage; The adhesive layer is an adhesive used to bond the photothermal phase change microcapsules to the fabric; The substrate is fabric, which is flexible and wearable, has good physical and mechanical properties, and is easy to store and transport, which is beneficial to improving the practicality of the product and expanding the application scenarios.

[0007] Preferably, the method for preparing the photothermal phase change microcapsules comprises the following steps: S1. The phase change microcapsules and the structure inducing agent are added to water and stirred thoroughly to obtain a phase change microcapsule dispersion; S2. Add pyrrole to the phase change microcapsule dispersion and adjust the pH value. After sufficient stirring, add the oxidant solution dropwise and stir the mixture at 0-4°C for 4-8 h to obtain a photothermal phase change microcapsule suspension. Wash and filter the suspension with ethanol and water several times. The filter cake is vacuum dried to obtain polypyrrole-modified photothermal phase change microcapsules.

[0008] Preferably, the photothermal phase change microcapsule comprises an inner core and an outer shell, the inner core is a phase change material, the outer shell is a polymer wall material, the phase change temperature of the phase change material is 28 to 60° C., and the particle size of the photothermal phase change microcapsule is 5 to 70 μm.

[0009] Preferably, the phase change material is at least one of straight-chain alkane compounds, straight-chain alkane halides and fatty acid compounds; the polymer wall material is at least one of polyethylene, polypropylene, melamine-formaldehyde, polymethyl methacrylate, toluene diisocyanate, melamine resin or polyurea.

[0010] Preferably, in step S1, the structure inducer is any one or a combination of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate, and sodium dioctyl succinate sulfonate, and the added amount of the structure inducer is 40% to 80% of the mass of the phase change microcapsules.

[0011] Preferably, in the step S2, the photothermal phase change microcapsules are obtained on the surface of the phase change microcapsules of 5 to 70 μm by the oxidative self-polymerization reaction of pyrrole, the amount of pyrrole used is 10% to 30% of the mass of the phase change microcapsules, the stirring speed is 300 to 450 rpm, and the pH value of the dispersion is 3 to 4.

[0012] A method for preparing a photothermal phase change energy storage composite fabric comprises the following steps: S1. Pre-treat the base fabric, remove surface grease and impurities, iron and finish, and then apply a certain thickness of adhesive on its surface; S2. In a flocking box, place a certain mass of photothermal phase change microcapsules on the lower plate, fix the obtained adhesive-coated fabric on the upper plate, and connect it to the ground wire. When powered on, the photothermal phase change microcapsules on the lower plate are polarized under the action of the electrostatic field and evenly implanted on the surface of the adhesive-coated fabric fixed on the upper plate. The flocking density is 0.1-0.8 g / cm 2 ; S3. Place the fabric in an oven for drying to firmly compound the photothermal phase change microcapsules with the fabric to obtain a photothermal phase change energy storage composite fabric.

[0013] Preferably, in step S1, the base fabric is at least one of cotton fabric, polyester-cotton fabric, recycled fiber fabric, linen fiber fabric, wool fabric, and non-woven fabric, the adhesive is any one of acrylic adhesive, hydroxymethyl fiber adhesive, polyurethane adhesive, and silicone resin adhesive, and the thickness of the adhesive coated on the fabric surface is 0.1 to 0.2 mm.

[0014] Preferably, in the step S2, the electrostatic voltage of the electrostatic field is 20-50 kV, the distance between the upper and lower plates is 8-16 cm, and the flocking time is 5-20 s; in the step S3, the drying temperature in the oven is 50-80°C.

[0015] The present invention provides a photothermal phase change energy storage composite fabric and a preparation method and application thereof. It has the following beneficial effects: The polypyrrole particles deposited on the surface of the microcapsules of the present invention have excellent light-to-heat conversion performance, and can efficiently convert solar energy into required heat energy, so that the composite fabric has excellent light absorption performance.

[0016] The present invention can achieve the purpose of continuous energy supply by storing energy and releasing heat through the phase change process through photothermal phase change microcapsules. Under strong sunlight, the photothermal phase change microcapsules convert solar energy into thermal energy, part of which is used for practical application and the other part is used for phase change energy storage; when the sunlight is relatively weak, the phase change material releases heat to ensure continuous heat energy output, solving the problem of mismatch between supply and demand of sunlight and intermittentness, and can store excess heat to achieve efficient utilization of solar energy and temperature regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of preparing a photothermal phase change energy storage composite fabric by an electrostatic flocking method according to the present invention; Figure 2 The SEM images of the composite fabric of Example 2 of the present invention, wherein (a) is a phase change microcapsule; (b) and (c) are the photothermal phase change microcapsules and local enlarged images, respectively; (d) and (e) are the photothermal phase change energy storage layer and local enlarged images of the photothermal phase change energy storage composite fabric; (f) is an interface cross-sectional view of the photothermal phase change energy storage composite fabric; Figure 3 A schematic diagram of the light absorption rate of the photothermal phase change energy storage composite fabric prepared in Example 2 of the present invention; Figure 4 This is an infrared thermal imaging image of the photothermal phase change energy storage composite fabric prepared in Example 2 of the present invention; Figure 5 Schematic diagram of mass loss of the photothermal phase change energy storage composite fabric and the base fabric prepared in Example 2 of the present invention during the photo-steam conversion test process; Figure 6The temperature rise curves of the photothermal phase change energy storage composite fabric and the photothermal fabric without phase change material under light and the cooling curves after turning off the light prepared in Example 2 of the present invention; Figure 7 This is a diagram of the evaporation rate and evaporation mass loss of the photothermal phase change energy storage composite fabric and the photothermal fabric without phase change material prepared in Example 2 of the present invention during the process of turning on the light for 50 minutes and turning off the light for 50 minutes; Figure 8 The DSC curve diagram of the photothermal phase change energy storage composite fabric prepared in Example 3 of the present invention and the infrared thermal imaging schematic diagram of its temperature regulation during wearing. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0019] The embodiment of the present invention provides a photothermal phase change energy storage composite fabric, wherein the composite fabric comprises a base fabric layer, an adhesive layer and a photothermal phase change energy storage layer from top to bottom; The photothermal phase change energy storage layer is a photothermal phase change microcapsule flocked onto the surface of the fabric by an electrostatic flocking method. The photothermal phase change microcapsule can synergistically play the role of photothermal conversion and phase change energy storage, and has a significant effect on regulating the balance between supply and demand of sunlight. The adhesive layer is an adhesive, which is used to bond the photothermal phase change microcapsules to the fabric to ensure that the photothermal phase change microcapsules are firmly attached to the fabric surface; The base fabric is a hydrophilic fabric. The fabric-based material has low cost, high scalability, and potential for large-scale industrial application. At the same time, the flexible material has good physical and mechanical properties and is easy to store and transport, which is conducive to improving the practicality of the product and expanding the application scenarios.

[0020] The photothermal phase change energy storage composite fabric has excellent photothermal conversion performance and a simple preparation process, and can be mass-produced and applied in multiple fields. At the same time, the fabric is composited with phase change materials to store the energy converted from solar energy as latent heat, which is expected to achieve energy supply and demand matching and temperature regulation during solar energy conversion. Example

[0021] The embodiment of the present invention provides a method for preparing a photothermal phase change energy storage composite fabric, comprising the following steps: S1. adding phase change microcapsules and sodium dodecylbenzene sulfonate into water, stirring thoroughly to obtain a phase change microcapsule dispersion, wherein the phase change material of the phase change microcapsules is a linear alkane compound, the phase change temperature is 45°C, the microcapsule wall material is a melamine resin, and the amount of sodium dodecylbenzene sulfonate added is 60% of the phase change microcapsules; S2. Add pyrrole to the phase change microcapsule dispersion, the mass ratio of pyrrole to phase change microcapsule is 1:4, and adjust the pH value, add the oxidant solution dropwise after sufficient stirring, and stir the reaction at 0°C for 6 hours to obtain a photothermal phase change microcapsule suspension, the stirring speed is 400 rpm, and then wash and filter with ethanol and water several times, and the obtained filter cake is vacuum dried to obtain polypyrrole modified photothermal phase change microcapsules; S3. The cotton fabric is pretreated to remove surface grease and impurities, and ironed and finished, and then a 0.15 mm thick adhesive is applied to its surface; S4. In a flocking box, place a certain mass of photothermal phase change microcapsules on the lower plate, fix the obtained cotton fabric coated with adhesive on the upper plate, and connect it to the ground wire. When powered on, the photothermal phase change microcapsules on the lower plate are polarized under the action of the electrostatic field and evenly implanted on the surface of the fabric coated with adhesive fixed on the upper plate. The voltage is 35kv, the distance between the upper and lower plates is 7cm, the flocking time is 10s, and the flocking density is 0.41g / cm 2 ; S5. Place the fabric in an oven and dry it at 50°C to firmly compound the photothermal phase change microcapsules with the fabric to obtain a photothermal phase change energy storage composite fabric.

[0022] Figure 1 Schematic diagram of preparing photothermal phase change energy storage composite fabric by electrostatic flocking method. The prepared photothermal phase change microcapsules move directionally along the electric field in the high-voltage electrostatic field and are finally implanted on the fabric surface of the upper electrode to form a photothermal phase change energy storage layer. Figure 2 The SEM images are shown in Figure 1, where (a) is a phase change microcapsule; (b) and (c) are photothermal phase change microcapsules and local magnified images, respectively; (d) and (e) are photothermal phase change energy storage layers and local magnified images of photothermal phase change energy storage composite fabrics; (f) is an interface cross-sectional view of the photothermal phase change energy storage composite fabric, as shown in Figure 1. Figure 2 As shown in the figure, polypyrrole nanoparticles are oxidized and deposited on the surface of phase change microcapsules. The photothermal phase change microcapsules are evenly implanted on the surface of the base fabric to form a rough surface. The flocking density of the photothermal microcapsules is 0.41g / cm 2 ; Figure 3 is a line graph of the light absorption rate of the photothermal phase change energy storage composite fabric, such as Figure 3 As shown, the light absorption rate of the photothermal phase change energy storage composite fabric reaches an average light absorption rate of 93.4% at a wavelength of 250-2500nm; Figure 4This is the infrared thermal imaging image of the photothermal phase change energy storage composite fabric, such as Figure 4 As shown, the photothermal phase change energy storage composite fabric has excellent photothermal conversion performance, and the steady-state temperature during actual evaporation is 52.9°C, showing a rapid photothermal response. Figure 5 The comparison chart of mass loss of photothermal phase change energy storage composite fabric and base fabric during photo-steam conversion test is shown in Figure 2. Figure 5 As shown in the figure, the photothermal phase change energy storage composite fabric and the base fabric were placed in a pure water solution for photo-vapor conversion test. The test time was 1800s. The test results showed that the mass of pure water continued to decrease with time, and the mass loss of the photothermal phase change energy storage composite fabric was more obvious. The evaporation rate of pure water was calculated to be 1.92kg·m -2 ·h -1 ; Figure 6 The heating curves of the photothermal phase change energy storage composite fabric and the photothermal fabric without phase change material under light and the cooling curves after turning off the light are shown in Figure 2. Figure 6 As shown, the steady-state temperatures of the photothermal fabric (without phase change material) and the photothermal phase change energy storage composite fabric after illumination are similar, while the photothermal phase change energy storage composite fabric shows a temperature hysteresis during the heating and cooling process, which is related to the phase transition process of melting and crystallization of the phase change material. This proves that under sunlight, the photothermal phase change energy storage composite fabric can absorb a large amount of solar thermal energy, and release the stored heat through reversible phase change under the condition of no sunlight, which can play a role in coordinating the balance of solar energy supply and demand and temperature regulation. Figure 7 Schematic diagram of the evaporation rate and evaporation mass loss of the photothermal phase change energy storage composite fabric and the photothermal fabric without phase change material during the process of turning on the light for 50 minutes and turning off the light for 50 minutes. Figure 7 As shown in the figure, the effect of thermal energy storage and release of photothermal phase change energy storage composite fabric on evaporation performance was investigated. During the continuous evaporation experiment under one-fold light intensity and in a dark environment, it was found that under one-fold light intensity, the evaporation rate of the photothermal fabric (without phase change material) was slightly higher than that of the photothermal phase change energy storage composite fabric. However, the evaporation rate of the photothermal fabric (without phase change material) dropped rapidly in a dark environment. In contrast, thanks to the heat release of the phase change material, the evaporation rate of the photothermal phase change energy storage composite fabric evaporator can still maintain a relatively high evaporation rate in the absence of sunlight. After the test process, the evaporation mass of the evaporator based on the photothermal phase change energy storage composite fabric was 7.6% higher than that of the photothermal fabric without phase change material. Example

[0023] The embodiment of the present invention provides a method for preparing a photothermal phase change energy storage composite fabric, comprising the following steps: S1. adding phase change microcapsules and sodium dodecyl sulfate into water, and stirring thoroughly to obtain a phase change microcapsule dispersion, wherein the phase change material of the phase change microcapsules is a straight-chain alkane compound, the phase change temperature is 45°C, the microcapsule wall material is polyurea, and the amount of sodium dodecyl sulfate added is 70% of the phase change microcapsules; S2. Pyrrole was added to the phase change microcapsule dispersion, the mass ratio of pyrrole to phase change microcapsule was 3:7, and the pH value was adjusted. After sufficient stirring, the oxidant solution was added dropwise, and the reaction was stirred at 4°C for 8 hours to obtain a photothermal phase change microcapsule suspension. The stirring speed was 350 rpm, and then the suspension was washed and filtered with ethanol and water for multiple times. The filter cake was vacuum dried to obtain polypyrrole-modified photothermal phase change microcapsules. S3. The cotton fabric is pretreated to remove surface grease and impurities, and ironed and finished, and then a 0.15 mm thick adhesive is applied to its surface; S4. In a flocking box, place a certain mass of photothermal phase change microcapsules on the lower plate, fix the obtained cotton fabric coated with adhesive on the upper plate, and connect it to the ground wire. When powered on, the photothermal phase change microcapsules on the lower plate are polarized under the action of the electrostatic field and evenly implanted on the surface of the fabric coated with adhesive fixed on the upper plate. The voltage is 40kv, the distance between the upper and lower plates is 8cm, the flocking time is 15s, and the flocking density is 0.5g / cm 2 ; S5. Place the fabric in an oven and dry it at 50°C to firmly compound the photothermal phase change microcapsules with the fabric to obtain a photothermal phase change energy storage composite fabric.

[0024] The light absorption rate of the photothermal phase change energy storage composite fabric is 94.5%. When applied to the field of interface evaporation, the steady-state temperature of the evaporation process is 53.5°C under one solar intensity. The evaporation rates in pure water and 3.5wt% NaCl aqueous solution are 2.02kg·m -2 ·h -1 and 1.82 kg·m -2 ·h -1 .also Figure 8 DSC curve of photothermal phase change energy storage composite fabric ( Figure 8 a) and infrared thermal imaging diagram of temperature regulation during consumption ( Figure 8 b), such as Figure 8 As shown in a, it can be seen from the figure that the melting temperature of the heat storage and temperature regulation fabric is 44.1℃, the crystallization temperature is 29.6℃, the melting enthalpy is 25.6 J / g, and the crystallization enthalpy is 25.9 J / g, indicating that the fabric has heat storage performance. In addition, the practical application value of the photothermal phase change energy storage composite fabric in human body latent heat storage and temperature regulation is evaluated, such as Figure 8As shown in Figure b, it can be seen from the figure that the temperature of ordinary fabrics without phase change materials rises rapidly in a high temperature environment, and the temperature fluctuates violently, which cannot fully meet the requirements of human comfort. In contrast, the temperature of the photothermal phase change energy storage composite fabric rises slowly, and the temperature change is relatively stable, which can better meet the requirements of human comfort. Example

[0025] The embodiment of the present invention provides a method for preparing a photothermal phase change energy storage composite fabric, comprising the following steps: S1. adding phase change microcapsules and sodium dioctyl succinate sulfonate to water, stirring thoroughly to obtain a phase change microcapsule dispersion, wherein the phase change material of the phase change microcapsules is a fatty acid compound, the phase change temperature is 50°C, the microcapsule wall material is polymethyl methacrylate, and the addition amount of sodium dioctyl succinate sulfonate is 60% of the phase change microcapsules; S2. Add pyrrole to the phase change microcapsule dispersion, the mass ratio of pyrrole to phase change microcapsule is 1:3, and adjust the pH value. After sufficient stirring, add the oxidant solution dropwise, and stir the reaction at 4°C for 6 hours to obtain a photothermal phase change microcapsule suspension. The stirring speed is 450 rpm, and then wash and filter with ethanol and water several times. The obtained filter cake is vacuum dried to obtain polypyrrole-modified photothermal phase change microcapsules; S3. The cotton fabric is pretreated to remove surface grease and impurities, and ironed and finished, and then a 0.12 mm thick adhesive is applied to its surface; S4. In a flocking box, place a certain mass of photothermal phase change microcapsules on the lower plate, fix the obtained cotton fabric coated with adhesive on the upper plate, and connect it to the ground wire. When powered on, the photothermal phase change microcapsules on the lower plate are polarized under the action of the electrostatic field and evenly implanted on the surface of the fabric coated with adhesive fixed on the upper plate. The voltage is 45kv, the distance between the upper and lower plates is 7cm, the flocking time is 12s, and the flocking density is 0.43g / cm 2 ; S5. Place the fabric in an oven and dry it at 50°C to firmly compound the photothermal phase change microcapsules with the fabric to obtain a photothermal phase change energy storage composite fabric.

[0026] The light absorption rate of the photothermal phase change fabric is 92.5%. When applied to the field of interface evaporation, the steady-state temperature of the evaporation process is 51.5°C under one solar intensity. The evaporation rates in pure water and 3.5wt% NaCl aqueous solution are 1.89kg·m -2 ·h -1 and 1.78 kg·m -2 ·h -1 . Example

[0027] The embodiment of the present invention provides a method for preparing a photothermal phase change energy storage composite fabric, comprising the following steps: S1. adding phase change microcapsules and sodium dodecylbenzene sulfonate into water, stirring thoroughly to obtain a phase change microcapsule dispersion, wherein the phase change material of the phase change microcapsules is a linear alkane compound, the phase change temperature is 28°C, the microcapsule wall material is melamine-formaldehyde, and the addition amount of sodium dodecylbenzene sulfonate is 50% of the phase change microcapsules; S2. Add pyrrole to the phase change microcapsule dispersion, the mass ratio of pyrrole to phase change microcapsule is 1:4, and adjust the pH value. After sufficient stirring, add the oxidant solution dropwise, and stir the reaction at 4°C for 4 hours to obtain a photothermal phase change microcapsule suspension. The stirring speed is 400 rpm, and then wash and filter with ethanol and water several times. The obtained filter cake is vacuum dried to obtain polypyrrole-modified photothermal phase change microcapsules; S3. The cotton fabric is pretreated to remove surface grease and impurities, and ironed and finished, and then a 0.16 mm thick adhesive is applied to its surface; S4. In a flocking box, place a certain mass of photothermal phase change microcapsules on the lower plate, fix the obtained cotton fabric coated with adhesive on the upper plate, and connect it to the ground wire. When powered on, the photothermal phase change microcapsules on the lower plate are polarized under the action of the electrostatic field and evenly implanted on the surface of the fabric coated with adhesive fixed on the upper plate. The voltage is 30kv, the distance between the upper and lower plates is 8cm, the flocking time is 16s, and the flocking density is 0.34g / cm 2 ; S5. Place the fabric in an oven and dry it at 50°C to firmly compound the photothermal phase change microcapsules with the fabric to obtain a photothermal phase change energy storage composite fabric.

[0028] The light absorption rate of the photothermal phase change fabric is 92.1%. When applied to the field of interface evaporation, the steady-state temperature of the evaporation process is 50.5°C under one solar intensity. The evaporation rates in pure water and 3.5wt% NaCl aqueous solution are 1.85kg·m -2 ·h -1 and 1.72 kg·m -2 ·h -1 .

[0029] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A photothermal phase change energy storage composite fabric, characterized in that: The composite fabric comprises a base fabric layer, an adhesive layer and a photothermal phase change energy storage layer from top to bottom; The photothermal phase change energy storage layer is a photothermal phase change microcapsule flocked onto the surface of the fabric by an electrostatic flocking method, and the photothermal phase change microcapsule can synergistically play the role of photothermal conversion and phase change energy storage; The adhesive layer is an adhesive used to bond the photothermal phase change microcapsules to the fabric; The substrate is fabric, which is flexible and wearable, has good physical and mechanical properties, and is easy to store and transport, which is beneficial to improving the practicality of the product and expanding the application scenarios.

2. The photothermal phase change energy storage composite fabric according to claim 1, characterized in that: The preparation method of the photothermal phase change microcapsules comprises the following steps: S1. The phase change microcapsules and the structure inducing agent are added to water and stirred thoroughly to obtain a phase change microcapsule dispersion; S2. Add pyrrole to the phase change microcapsule dispersion and adjust the pH value. After sufficient stirring, add the oxidant solution dropwise and stir the mixture at 0-4°C for 4-8 h to obtain a photothermal phase change microcapsule suspension. Wash and filter the suspension with ethanol and water several times. The filter cake is vacuum dried to obtain polypyrrole-modified photothermal phase change microcapsules.

3. The photothermal phase change energy storage composite fabric according to claim 2, characterized in that: The photothermal phase-change microcapsule comprises an inner core and an outer shell, wherein the inner core is a phase-change material and the outer shell is a polymer wall material. The phase-change temperature of the phase-change material is 28-60° C. and the particle size of the photothermal phase-change microcapsule is 5-70 μm.

4. The photothermal phase change energy storage composite fabric according to claim 3, characterized in that: The phase change material is at least one of linear alkane compounds, linear alkane halides and fatty acid compounds; the polymer wall material is at least one of polyethylene, polypropylene, melamine-formaldehyde, polymethyl methacrylate, toluene diisocyanate, melamine resin or polyurea.

5. The photothermal phase change energy storage composite fabric according to claim 2, characterized in that: In the step S1, the structure inducer is any one or a combination of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate, and sodium dioctyl succinate sulfonate, and the added amount of the structure inducer is 40% to 80% of the mass of the phase change microcapsule.

6. The photothermal phase change energy storage composite fabric according to claim 1, characterized in that: In the step S2, the photothermal phase change microcapsules are obtained on the surface of the phase change microcapsules of 5 to 70 μm by the oxidative self-polymerization reaction of pyrrole, the amount of pyrrole used is 10% to 30% of the mass of the phase change microcapsules, the stirring speed is 300 to 450 rpm, and the pH value of the dispersion is 3 to 4.

7. The method for preparing a photothermal phase change energy storage composite fabric according to claim 1, characterized in that: The following steps are involved: S1. Pre-treat the base fabric, remove surface grease and impurities, iron and finish, and then apply a certain thickness of adhesive on its surface; S2. In a flocking box, place a certain mass of photothermal phase change microcapsules on the lower plate, fix the obtained adhesive-coated fabric on the upper plate, and connect it to the ground wire. When powered on, the photothermal phase change microcapsules on the lower plate are polarized under the action of the electrostatic field and evenly implanted on the surface of the adhesive-coated fabric fixed on the upper plate. The flocking density is 0.1-0.8 g / cm 2 ; S3. Place the fabric in an oven for drying to firmly compound the photothermal phase change microcapsules with the fabric to obtain a photothermal phase change energy storage composite fabric.

8. The photothermal phase change energy storage composite fabric and the preparation method thereof according to claim 7, characterized in that: In step S1, the base fabric is at least one of cotton fabric, polyester-cotton fabric, recycled fiber fabric, linen fiber fabric, wool fabric, and non-woven fabric; the adhesive is any one of acrylic adhesive, hydroxymethyl fiber adhesive, polyurethane adhesive, and silicone resin adhesive; and the thickness of the adhesive coated on the surface of the fabric is 0.1 to 0.2 mm.

9. The photothermal phase change energy storage composite fabric and its preparation method and application according to claim 7, characterized in that: In the step S2, the electrostatic voltage of the electrostatic field is 20-50 kV, the distance between the upper and lower plates is 8-16 cm, and the flocking time is 5-20 s; in the step S3, the drying temperature in the oven is 50-80°C.

10. Application of the photothermal phase change energy storage composite fabric according to claim 1 in photothermal interface evaporation, intelligent temperature regulating textiles, medical rehabilitation, and building home furnishings.

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