Temperature / humidity-sensitive photovoltaic power generation fiber membrane as well as preparation method and application thereof

Abstract

The invention provides a temperature-sensitive and humidity-sensitive photovoltaic power generation fiber membrane and a preparation method and application thereof, and belongs to the field of energy conversion and sensor devices, the temperature-sensitive and humidity-sensitive photovoltaic power generation fiber membrane comprises a temperature-sensitive and humidity-sensitive conductive fiber membrane and an asymmetric structure color film layer attached to the temperature-sensitive and humidity-sensitive conductive fiber membrane; the temperature / humidity-sensitive conductive fiber membrane is a fabric comprising a conductive polymer, moisture absorption salt and a temperature-sensitive precursor, the asymmetric structure color film layer comprises at least one of trimethyl aluminum, titanium tetrachloride and diethyl zinc; the temperature / humidity sensitive conductive fiber film is black, and the asymmetric structural color film layer is in structural color. The fiber membrane disclosed by the invention can efficiently convert temperature and humidity energy in the environment into electric energy for supplying power to small-sized electronic equipment or a sensor. Compared with a traditional energy collecting device, the energy collecting device has higher energy conversion efficiency and stability, the energy obtaining way is greatly widened, and brand new possibility is brought to energy utilization.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy conversion and sensor-like devices, in particular to a temperature / humidity sensitive water-powered power generation fiber film and a preparation method and application thereof. BACKGROUND

[0002] Unlike traditional large-scale hydroelectric power generation, moisture power generation focuses on the interaction between water molecules and functional materials at the micro level, and uses the physical and chemical properties of the material surface to realize the conversion of electrical energy. In different ecological environments, moisture power generation faces many environmental self-adaptation problems. From the high humidity and high temperature environment of tropical rainforests to the low humidity and extreme temperature difference environment of desert areas, and to the high humidity and salt-rich air environment of coastal areas, moisture power generation is challenged. In the high temperature and high humidity of tropical rainforests, too high humidity may cause the power generation device to absorb too much water, affecting the charge transmission inside the material, and the continuous high temperature will accelerate the aging of the material and reduce the stability of the device. In the desert area, the humidity is extremely low, and the amount of water vapor available for power generation is scarce, making it difficult to maintain stable power generation efficiency. The salt in the air in the coastal area can also corrode the power generation device and damage its power generation performance. With the development of the smart wearable device market, the demand for adaptive energy is increasingly urgent. However, the current moisture power generation technology still faces many challenges on the road to practical application. In addition to the above-mentioned ecological environment problems, the power generation efficiency of moisture power generation devices is generally low, and there is a significant gap in output power and energy conversion efficiency compared with traditional energy, making it difficult to meet the energy consumption needs of smart wearable devices and other applications. At the same time, the materials and device structures used for moisture power generation need to be optimized. The existing materials have limited moisture absorption and charge conversion capabilities, and new types of nanomaterials and unique device structures need to be continuously explored to enhance the interaction between water molecules and materials and improve power generation performance. SUMMARY

[0003] In view of the technical problems in the background art, the present application provides a temperature / humidity sensitive water-powered power generation fiber film and a preparation method and application thereof, aiming to solve the technical problems of poor environmental self-adaptation, unstable power generation efficiency, low output power and energy conversion efficiency of existing moisture power generation.

[0004] In a first aspect, the embodiments of the present application provide a temperature / humidity sensitive water-powered power generation fiber film, comprising a temperature / humidity sensitive conductive fiber film and an asymmetric structural color thin film layer attached to the temperature / humidity sensitive conductive fiber film; The temperature / humidity sensitive conductive fiber film is a fabric comprising a conductive polymer, a hygroscopic salt and a temperature-sensitive precursor; The asymmetric structural color thin film layer comprises at least one of trimethylaluminum, titanium tetrachloride and diethyl zinc; The conductive fiber film with temperature / humidity sensitivity is black, and the asymmetric structural color thin film layer is structural color.

[0005] In some embodiments, the asymmetric structural color thin film layer accounts for 1 / 3 to 2 / 3 of the surface area of the conductive fiber film.

[0006] In some embodiments, the thickness of the asymmetric structural color thin film layer is 45-120 nm, and the thickness of the conductive fiber film with temperature / humidity sensitivity is 30-80 μm.

[0007] In the second aspect, the embodiments of the present application provide a preparation method of a water-voltaic power generation fiber film with temperature / humidity sensitivity, which comprises the following steps: S1, dispersing a conductive polymer and a dispersant in an organic oxidizing agent to obtain a conductive polymer dispersion liquid, electrospinning the conductive polymer dispersion liquid, and drying to obtain a conductive fiber film blank; S2, soaking the conductive fiber film blank in a hygroscopic salt dispersion liquid to perform an adsorption reaction, and then cleaning and drying after the reaction to obtain a humidity-sensitive conductive fiber film; S3, dispersing a temperature-sensitive precursor in water to obtain a temperature-sensitive precursor dispersion liquid, placing the humidity-sensitive conductive fiber film in the temperature-sensitive precursor dispersion liquid, adding an initiator and a catalyst, stirring and reacting, and then cleaning and drying after the reaction to obtain a conductive fiber film with temperature / humidity sensitivity; S4, ALD deposition on the surface of the conductive fiber film with temperature / humidity sensitivity to obtain a water-voltaic power generation fiber film with temperature / humidity sensitivity.

[0008] In some embodiments, the conductive polymer comprises at least one of carbon nanotubes, conductive carbon black, graphene, and MXene.

[0009] In some embodiments, the dispersant comprises at least one of polyethylene oxide, sodium hexametaphosphate, and polyacrylamide.

[0010] In some embodiments, the organic oxidizing agent comprises at least one of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0011] In some embodiments, the hygroscopic salt comprises at least one of lithium chloride, calcium chloride, and iron chloride.

[0012] In some embodiments, the temperature-sensitive precursor comprises at least one of 2-4 g of N-isopropyl acrylamide and N-vinyl caprolactam.

[0013] In some embodiments, the initiator comprises at least one of ammonium sulfite, sodium persulfate, and potassium persulfate.

[0014] In some embodiments, the catalyst comprises at least one of N,N,N',N'-tetramethyl ethylenediamine and triethylamine.

[0015] In some embodiments, the ALD-deposited precursor A comprises at least one of trimethylaluminum, titanium tetrachloride, diethylzinc, and the ALD-deposited precursor B comprises at least one of deionized water, ozone, ammonia, and hydrazine.

[0016] In some embodiments, the electrospinning voltage is 15-20 kV, the propelling speed is 0.5-1 mL / h, and the receiving distance is 15-20 cm.

[0017] In some embodiments, the adsorption reaction time in step S2 is 1-2 h. The stirring reaction time in step S3 is 3-5 h, and the reaction temperature is 60-70℃.

[0018] In some embodiments, the ALD deposition step in step S4 comprises: placing the temperature / humidity-sensitive and conductive fiber membrane into the reaction cavity of the ALD device, closing the reaction cavity door and vacuumizing to 1×10 -6 ~1×10 -8 Torr, setting the deposition temperature to 80-150℃, and performing 100-300 deposition cycles; each deposition cycle comprises: pulse injection of precursor A, pulse 0.05-0.2 s, nitrogen purging 5-15 s, pulse injection of precursor B, pulse 0.05-0.2 s, and nitrogen purging 5-15 s.

[0019] In a third aspect, the embodiments of the present application provide an application of the temperature / humidity-sensitive and conductive fiber membrane in the field of intelligent wearable devices.

[0020] Compared with the prior art, the present application has the following advantages: 1. High energy conversion efficiency: the fiber membrane of the present application can efficiently convert the temperature and humidity energy in the environment into electrical energy to power small electronic devices or sensors. Compared with traditional energy harvesting devices, it has higher energy conversion efficiency and stability, greatly widening the way of energy acquisition and bringing new possibilities for energy utilization.

[0021] The water-vapor power generation fiber membrane of the present application significantly improves the energy conversion efficiency and environmental stability through its ingenious composite structure design: (1) Enhancing moisture capture and ion gradient formation to improve energy conversion efficiency: Hygroscopic salt-loaded conductive network: conductive polymers (carbon nanotubes, etc.) provide a highly conductive skeleton and a large specific surface area. Hygroscopic salt (such as LiCl) is directly loaded on the fiber or in the network pores, providing strong hygroscopic dissociation capacity and maximizing the ion source.

[0022] Asymmetric structure design: First, color and photothermal difference: the exposed temperature / humidity sensitive and conductive fiber film area is black with high absorbance, and the covered asymmetric structural color film layer (ALD deposited Al2O3 / TiO2 / ZnO, etc.) presents structural color (specific wavelength reflection, lower absorbance than black).

[0023] Photothermal effect driven: under light (ambient light or simulated sunlight), the black area absorbs more light energy and converts it into heat energy, causing a significant temperature rise. This leads to faster evaporation of water in the black area, which reduces the relative humidity (or water content) in the vicinity of the black area, while the structural color covered area evaporates slowly, with relatively high humidity (or relatively more water content). This asymmetric distribution of water content spontaneously forms a more significant humidity gradient inside the fiber film, driving a stronger ion concentration gradient (high ion concentration in high humidity area, low ion concentration in low humidity area). This self-enhanced humidity gradient induced by photothermal effect is the core mechanism to greatly improve the efficiency of water-powered electricity generation.

[0024] Geometric asymmetry strengthens the gradient: the structural color layer only covers 1 / 3-2 / 3 of the surface area, and this physical asymmetry itself helps to form a natural humidity / ion concentration difference on both sides of the film, and the photothermal effect further amplifies this difference.

[0025] (2) Optimize ion transport path, improve energy conversion efficiency and stability: Add conductive polymers to the fiber film to form a conductive polymer network, providing a continuous electron transport path to ensure that the potential energy generated by internal charge separation is effectively converted into current.

[0026] In-situ polymerization in the fiber film forms a temperature-sensitive polymer network. At low temperature (<LCST), the temperature-sensitive polymer network is in a swollen state, providing open hydrophilic channels that facilitate the rapid diffusion of hydrated ions generated by the dissociation of hygroscopic salt, improving power generation efficiency. At high temperature (>LCST) or extreme humidity: the temperature-sensitive polymer network is in a contracted state, limiting the excessive infiltration of water molecules and the disordered diffusion of ions, preventing the over-dilution or loss of electrolyte, which helps to maintain the stability of power generation capacity and the integrity of material structure. This dynamic adjustment mechanism enables the fiber film to adapt to a wider range of environmental temperature and humidity.

[0027] (3) Improve material stability and durability: Compact protective layer by ALD deposition: The asymmetric structural color thin film layer (such as Al2O3, TiO2) formed on the surface of the conductive fiber membrane by atomic layer deposition (ALD) is an extremely compact, uniform (thickness controllable at 45-120 nm), and chemically stable thin film. Anti-environmental erosion (salt spray, corrosion): This thin film protects the internal conductive polymer, hygroscopic salt, and temperature-sensitive polymer network like a suit of armor, preventing direct contact and corrosion of the core functional materials by salt (coastal environment), pollutants, oxygen, and other substances in the air. It significantly improves the long-term stability in harsh environments (such as high-salt coastal areas). The compact asymmetric structural color thin film layer effectively blocks the possible deliquescence loss of hygroscopic salt under extremely high humidity, maintaining its hygroscopic dissociation ability stable. And the asymmetric structural color thin film layer can provide certain mechanical support to enhance the overall strength of the fiber membrane.

[0028] Buffering effect of temperature-sensitive polymers: As mentioned earlier, the shrinkage of temperature-sensitive polymers at high temperatures or low humidity can reduce the surface area of the material exposed to adverse environments and water loss, providing some protection.

[0029] (4) Multifunctional synergy and integration: Photo-thermal-evaporation-water-voltaic-temperature synergy: The light-thermal effect caused by structural color difference drives asymmetric evaporation, strengthening water-voltaic power generation; temperature-sensitive polymers simultaneously realize temperature sensing and ion channel regulation; conductive network ensures charge collection; asymmetric structural color thin film layer provides protection. Each component and function is highly synergistic, collectively improving energy capture and conversion efficiency.

[0030] Environmental self-adaptation: The temperature- and humidity-sensitive properties enable the fiber membrane to sense environmental changes (sensing function), and its internal physicochemical responses (swelling / shrinking, ion concentration / diffusion rate changes) themselves constitute a self-adaptive adjustment mechanism to environmental fluctuations (such as sudden changes in temperature and humidity), helping to maintain output and material stability in dynamic environments.

[0031] 2. Accurate sensing: Relying on high sensitivity to temperature and humidity, the fiber membrane can accurately sense changes in environmental temperature and humidity in real time and quickly convert them into electrical signals, achieving precise monitoring of environmental temperature and humidity. Its monitoring accuracy surpasses existing temperature-sensitive resistors, humidity-sensitive resistors, and other sensors, providing more reliable data support for environmental monitoring and making environmental data acquisition more accurate and timely.

[0032] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the specific embodiments of the present application can be implemented in accordance with the content of the specification, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the present application, the drawings used in the present application will be briefly introduced as follows. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0034] Figure 1 The temperature / humidity-sensitive water power generation fiber film structure diagram prepared for example 1 of the present application.

[0035] Figure 2 The V-t diagram and I-t diagram of the temperature / humidity-sensitive water power generation fiber film prepared for examples 1-3 and comparative example 1 of the present application were measured at the same temperature and humidity (40℃, 60%RH).

[0036] Figure 3 The conductivity diagram of the temperature / humidity-sensitive water power generation fiber film prepared for examples 1-3 and comparative example 1 of the present application was measured at the same temperature and humidity (40℃, 60%RH).

[0037] Figure 4 The temperature curve diagram of the temperature / humidity-sensitive water power generation fiber film prepared for examples 1-3 and comparative example 1 of the present application was measured at the same humidity (60%RH).

[0038] Figure 5 The absorption spectrum diagram of the temperature / humidity-sensitive water power generation fiber film prepared for examples 1-3 and comparative example 1 of the present application.

[0039] Figure 6 The temperature sensitivity test diagram of the temperature / humidity-sensitive water power generation fiber film prepared for examples 1-3 and comparative example 1 of the present application.

[0040] Figure 7 The swelling rate change diagram of the temperature / humidity-sensitive water power generation fiber film prepared for comparative example 1 of the present application.

[0041] Legend: 1, temperature / humidity-sensitive conductive fiber film; 2, asymmetric structural color film layer. DETAILED DESCRIPTION

[0042] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the use of the terms "including," "comprising," "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

[0044] In view of the above problems existing in the prior art, the present application aims to provide a temperature / humidity sensitive water-powered power generation fiber film and its preparation method and application, which belongs to the field of energy conversion and sensor devices. The fiber film has unique energy conversion and sensing properties. From the perspective of energy conversion, it can efficiently convert the temperature / humidity energy in the environment into electrical energy as an energy collection and conversion device, providing continuous power supply for small electronic devices or sensors. The principle is similar to the use of water vapor energy in the environment by a moisture power generation device. From the perspective of sensing function, it is also a sensor device with excellent performance. It can accurately sense the change of environmental temperature / humidity in real time and quickly convert it into an easily detected electrical signal. Like common sensors such as temperature-sensitive resistors and humidity-sensitive resistors, it reflects the environmental state through changes in its own electrical properties. Moreover, the fiber film of the present application innovatively integrates temperature sensitivity, humidity sensitivity, and power generation functions into one, which is a multifunctional integrated device that can simultaneously realize energy acquisition and environmental monitoring and other functions, providing more comprehensive and efficient support for intelligent devices and systems, greatly expanding its application scenarios and practical value.

[0045] In a first aspect, the embodiments of the present application provide a temperature / humidity sensitive water-powered power generation fiber film, as shown in Figure 1 The temperature / humidity sensitive conductive fiber film 1 and the asymmetric structural color film layer 2 attached to the temperature / humidity sensitive conductive fiber film 1 are provided. The temperature / humidity sensitive conductive fiber film 1 is black, and the asymmetric structural color film layer 2 is a structural color with different light absorbance from black. The "asymmetry" in the asymmetric structural color film layer refers to the fact that the structural color of the asymmetric structural color film layer is different from the color of the black temperature / humidity sensitive conductive fiber film and the electrochemical properties are different.

[0046] In the technical solution of the present application, the temperature / humidity sensitive water-powered power generation fiber film converts environmental temperature and humidity changes into electrical signals (voltage / current) mainly through the synergistic effect of two mechanisms: moisture-driven ion diffusion (water-powered effect) and temperature-driven phase change / ion migration. The unique structural design greatly enhances and utilizes these two effects.

[0047] The wet-sensitive driving mechanism (water-volting effect) as the core power generation principle, its basis is that the core substrate of the fiber membrane is a conductive polymer network (such as carbon nanotubes, graphene) containing hygroscopic salt (such as LiCl, CaCl2, FeCl3), when the ambient humidity increases, the hygroscopic salt strongly adsorbs water molecules in the air through hydrophilicity, the adsorbed water molecules will cause the salt to dissociate (for example, LiCl → Li + + Cl - ), a large number of movable anions and cations are generated, and the adsorption and dissociation of water molecules do not occur uniformly inside the fiber membrane, due to the differences in the structure of the membrane (such as fiber pores, component distribution) and environmental conditions (such as humidity distribution), an ion concentration gradient will be formed inside the fiber membrane, especially between the asymmetric structure color film layer covered area (1 / 3-2 / 3 surface area) and the uncovered area (bare black conductive fiber membrane area), there may be significant differences in hydrophilicity, hygroscopic rate, and ion diffusion capacity, which further strengthens the asymmetry of the concentration gradient; under the driving of the concentration gradient, the anions and cations (such as Li + and Cl - ) generated by dissociation will spontaneously diffuse from the high concentration area to the low concentration area, however, due to the different mobility (diffusion speed) of anions and cations, usually cations (such as Li + , H + ) migrate faster than anions (such as Cl - ), this difference in mobility leads to the separation of electric charge in space, one end accumulates positive charge (area with more cations), the other end accumulates negative charge (area with more anions), thus a diffusion potential is generated between the two ends of the fiber membrane, when connecting the two ends of the fiber membrane with a wire and forming a loop, this diffusion potential will drive electrons to flow in the external circuit, forming an electric current, completing the process of converting environmental humidity (water molecule kinetic energy and chemical potential energy) into electrical energy, and the higher the humidity, the greater the amount of hygroscopicity, the stronger the ion concentration gradient, the greater the voltage / current generated, when the humidity decreases, the process is reversible, but the power generation effect is weakened or reversed.

[0048] The basis of the temperature-sensitive driving mechanism is the network formed after the introduction of a temperature-sensitive polymer (such as PNIPAM) into the fiber membrane as a precursor reaction. The temperature-sensitive polymer (such as PNIPAM) has a lower critical solution temperature (LCST, about 32 °C). When the temperature is lower than the LCST, the polymer chains are hydrophilic, the network swells, absorbs a large amount of water, and forms open ion channels (hydrated state). When the temperature is higher than the LCST, the polymer chains are hydrophobic, the network undergoes a drastic contraction (phase transition), expels the internal water, and the ion channels close or become narrow (dehydrated state); this phase transition and swelling / shrinking's influence on the electrical signal is reflected in two aspects. On the one hand, it affects the hydrovoltaic effect. That is, temperature regulates the moisture absorption ability of the fiber membrane and the size / connectivity of the ion channels by affecting the swelling / shrinking state of the temperature-sensitive polymer. At low temperatures (<LCST), a high degree of swelling brings strong moisture absorption ability (strong humidity sensitivity response), and the open ion channels also facilitate ion diffusion, thus enhancing hydrovoltaic power generation. At high temperatures (>LCST), a low degree of swelling leads to weak moisture absorption ability (weak humidity sensitivity response), and the closed ion channels hinder ion diffusion, thereby inhibiting hydrovoltaic power generation. On the other hand, it directly generates changes in the electrical signal (sensing). The drastic swelling / shrinking of the polymer network causes a significant change in the contact state or conductive path between the conductive polymer networks (such as carbon nanotubes). At low temperatures (<LCST), swelling may increase the distance between conductive particles, resulting in an increase in resistance. At high temperatures (>LCST), contraction squeezes the conductive particles closer together, resulting in a decrease in resistance. This sudden change in resistance (especially when approaching the LCST) itself is a strong temperature sensing signal. Monitoring the resistance value can accurately reflect the environmental temperature change. At the same time, temperature change also indirectly affects the output of hydrovoltaic power generation by influencing the moisture absorption amount and ion mobility (temperature increase usually accelerates ion migration).

[0049] In summary, the hydrovoltaic power generation fiber membrane with both temperature and humidity sensitivity uses the dissociation of hygroscopic salts to generate an ion gradient (hydrovoltaic effect) as the main power generation mechanism. On the one hand, the temperature-sensitive polymer network regulates the moisture absorption ability and ion channels (affecting the power generation efficiency) through swelling / shrinking. On the other hand, the sudden change in the resistance of the conductive network caused by its phase transition provides a direct temperature sensing signal. The changes in environmental temperature and humidity ultimately manifest as measurable changes in voltage, current, or resistance by affecting physical and chemical parameters such as ion concentration, diffusion rate, and conductive network structure.

[0050] Secondly, the embodiments of the present application provide a preparation method for a hydrovoltaic power generation fiber membrane with both temperature and humidity sensitivity, including the following steps: S1, preparing conductive fiber membrane: 0.5-1.0 g of conductive polymer is added to 100-200 mL of organic oxidant containing one or more of 5-10 g of polyethylene oxide, sodium hexametaphosphate, and polyacrylamide. Polyethylene oxide, sodium hexametaphosphate, and polyacrylamide are dispersants that can prevent the agglomeration of conductive polymers and improve the uniformity of the spinning solution; the organic oxidant has a dual function, first as a solvent to dissolve the dispersant and conductive polymer, and second as a dopant to oxidize the conductive polymer to increase the carrier concentration.

[0051] Stir at 400-600 r / min for 8-12 h, then perform ultrasonic dispersion for 2-4 h to obtain a uniform conductive polymer dispersion. Then, the conductive polymer dispersion is loaded into a syringe with a 21G needle, the electrospinning voltage is set to 15-20 kV, the push speed is 0.5-1 mL / h, and the receiving distance is 15-20 cm. Then, the obtained conductive fiber membrane is collected on an aluminum foil and placed in a vacuum drying oven at 55-60°C for 8-12 h to remove the residual solvent, obtaining a conductive fiber membrane blank.

[0052] Polyethylene oxide, sodium hexametaphosphate, and polyacrylamide are dispersants that can prevent the agglomeration of conductive polymers and improve the uniformity of the spinning solution.

[0053] S2, then 1-3 g of hygroscopic salt is weighed and added to 50 mL of deionized water, stirred and dissolved to obtain a hygroscopic salt dispersion. The dried conductive fiber membrane blank is soaked in the hygroscopic salt dispersion at room temperature for 1-2 hours, then taken out and rinsed with deionized water for 3-5 times, and then dried in a vacuum drying oven at 50-60°C for 5-6 hours. The obtained hygroscopic conductive fiber membrane can be obtained after taking out.

[0054] S3, preparing the temperature / humidity sensitive conductive fiber film: take 2-4 g of one or more of N-isopropyl acrylamide, N-vinyl caprolactam, and add them to 50 mL of deionized water, stir to dissolve to obtain a temperature sensitive precursor dispersion, and set aside. At the same time, take 0.05-0.1 mL of one or more of N,N,N',N'-tetramethyl ethylenediamine, triethylamine as a catalyst solution, and set aside. Then, take 0.1-0.3 g of one or more of ammonium sulfite, sodium persulfate, potassium persulfate, add them to 10 mL of deionized water, stir to dissolve to obtain an initiator solution. Then, place the humidity sensitive conductive fiber film into a three-necked flask containing the temperature sensitive precursor dispersion, under the protection of nitrogen, heat the reaction system to 60-70°C, and stir uniformly. Then add the initiator solution and the catalyst solution, continue to react for 3-5 hours. After the reaction is completed, take out the humidity sensitive conductive fiber film, rinse it with deionized water for 5-8 times to remove unreacted monomers and impurities, and then dry it in a vacuum drying oven at 55-60°C for 6-8 hours. After taking it out, the temperature / humidity sensitive conductive fiber film is obtained.

[0055] Under the action of the initiator and the catalyst, the temperature sensitive precursor dispersion undergoes free radical polymerization to form a temperature sensitive polymer network, which is attached to the humidity sensitive conductive fiber film by in-situ polymerization to form the temperature / humidity sensitive conductive fiber film. The finished temperature sensitive polymer has a large molecular weight and is difficult to penetrate into the humidity sensitive conductive fiber film, resulting in low bonding strength. By in-situ polymerization, the temperature sensitive polymer forms an interpenetrating network that penetrates through the humidity sensitive conductive fiber film, enhancing the mechanical stability.

[0056] S4, preparing an asymmetric structural color film layer: place the temperature / humidity sensitive conductive fiber film prepared in step S3 into the reaction chamber of the ALD device, ensure that the sample is placed flat, close the reaction chamber door and vacuumize to a base vacuum degree of 1x10 -6 ~ 1x10 -8 Torr. Set the deposition temperature to 80-150°C, and after the temperature is stable, start the deposition cycle. One deposition cycle includes: precursor (A) pulse for 0.05-0.2 s, nitrogen purge for 5-15 s, precursor (B) pulse for 0.05-0.2 s, nitrogen purge for 5-15 s. Set the number of deposition cycles to 100-300, and the entire deposition process is 1-3 hours. After the deposition is completed, cool the reaction chamber to room temperature and take out the sample. The temperature / humidity sensitive water-powered generation fiber film is obtained.

[0057] In some embodiments, the conductive polymer includes at least one of carbon nanotubes, conductive carbon black, graphene, MXene, and preferably carbon nanotubes.

[0058] In some embodiments, the organic oxidizing agent comprises at least one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone.

[0059] In some embodiments, the hygroscopic salt comprises at least one of lithium chloride, calcium chloride, iron chloride, preferably lithium chloride.

[0060] In the technical solution of the embodiments of the present application, the hygroscopic salt adsorbs environmental moisture through deliquescence, forms an ion gradient, and the dissolved Li + / Cl - The directional diffusion generates an ion current (I-t curve) and cooperates with the conductive polymer to improve the humidity-sensitive response speed (swelling rate 80% within 20 min). Figure 2 Figure 7

[0061] The use of the hydrolysis-resistant lithium chloride as the hygroscopic salt can avoid Fe 3+ hydrolysis corrosion; and the use of the carbon nanotube as the conductive substrate can improve the corrosion resistance of the fiber membrane.

[0062] In some embodiments, the ALD-deposited precursor A comprises at least one of trimethylaluminum, titanium tetrachloride, diethyl zinc, preferably trimethylaluminum; and the ALD-deposited precursor B comprises at least one of deionized water, ozone, ammonia, hydrazine, preferably deionized water.

[0063] In a third aspect, the embodiments of the present application provide an application of the temperature / humidity-sensitive water-powered generation fiber membrane in the field of intelligent wearable devices.

[0064] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are used to explain the present application, and cannot be understood as a limitation of the present application. If a specific technology or condition is not specified in the embodiments, the technology or condition described in the literature in the art or according to the product manual is used. If the reagent or instrument is not specified by the manufacturer, it is a conventional product that can be obtained from the market.

[0065] I. Preparation method Embodiment 1 A preparation method of a temperature / humidity-sensitive water-powered generation fiber membrane comprises the following steps: ​​(1) Preparation of conductive fiber membrane: 0.5 g of carbon nanotubes was added to a 100 mL solution of N,N-dimethylformamide containing 5 g of polyethylene oxide, stirred at a speed of 400 r / min for 8 h, and then subjected to ultrasonic dispersion for 2 h to obtain a uniformly dispersed solution. Next, the dispersion solution was loaded into a syringe with a 21G needle, an electrostatic spinning voltage of 15 kV was set, the pushing speed was 0.5 mL / h, the receiving distance was 15 cm, and the fiber membrane was collected on an aluminum foil. The fiber membrane was placed in a vacuum drying oven and dried at 55°C for 8 h to remove the residual solvent. Then, 1 g of lithium chloride was weighed and added to 50 mL of deionized water to stir and dissolve, and the dried conductive fiber membrane was soaked therein, soaked at room temperature for 1 h, taken out and washed with deionized water for 3 times, and then dried in a vacuum drying oven at 50°C for 5 h to obtain a humidity-sensitive conductive fiber membrane.

[0066] (2) Preparation of a conductive fiber membrane with both temperature and humidity sensitivity: 2 g of N-isopropyl acrylamide was weighed and added to 50 mL of deionized water to stir and dissolve to obtain a temperature-sensitive precursor dispersion solution, which was placed for standby use. 0.05 g of N,N,N',N'-tetramethyl ethylenediamine was weighed as a catalyst solution and placed for standby use. 0.1 g of ammonium sulfite was weighed and added to 10 mL of deionized water to stir and dissolve to obtain an initiator solution. The conductive fiber membrane blank was placed in a three-necked flask containing the temperature-sensitive precursor dispersion solution, and was heated to 60°C under nitrogen protection and stirred uniformly, and the initiator and catalyst solutions were added, and the reaction was continued for 3 h. After the reaction was completed, the humidity-sensitive conductive fiber membrane was taken out, washed with deionized water for 5 times, and dried in a vacuum drying oven at 55°C for 6 h to obtain a conductive fiber membrane with both temperature and humidity sensitivity.

[0067] (3) Preparation of an asymmetric structural color thin film layer: the conductive fiber membrane with both temperature and humidity sensitivity was placed in the reaction chamber of the ALD device, ensuring that the sample was placed flat, the reaction chamber door was closed and vacuumed to a base vacuum degree of 1×10 -6 Torr. The deposition temperature was set to 100°C, and after the temperature was stabilized, the deposition cycle was started. One deposition cycle included: trimethylaluminum pulse for 0.05 s, nitrogen purge for 15 s, deionized water pulse for 0.05 s, and nitrogen purge for 15 s. The number of deposition cycles was set to 450. After the deposition was completed, the sample was taken out after the reaction chamber was cooled to room temperature, at which time the thickness of the thin film was about 45 nm, and the surface of the fiber membrane showed a golden color. Finally, a water-voltaic fiber membrane with both temperature and humidity sensitivity was prepared, which was recorded as "golden fiber membrane".

[0068] Example 2 The preparation method of this example is the same as that of Example 1, the only difference is that in the preparation of the asymmetric structural color film layer in step (3) of this example, the number of deposition cycles is set to 800 times. After deposition, the reaction chamber is cooled to room temperature, and the sample is taken out. At this time, the thickness of the film is about 80 nm, and the surface of the conductive fiber membrane presents a purple color. Finally, a temperature / humidity sensitive water power generation fiber membrane is prepared. Denoted as "purple fiber membrane".

[0069] Example 3 The preparation method of this example is the same as that of Example 1, the only difference is that in the preparation of the asymmetric structural color film layer in step (3) of this example, the number of deposition cycles is set to 1300 times. After deposition, the reaction chamber is cooled to room temperature, and the sample is taken out. At this time, the thickness of the film is about 120 nm, and the surface of the conductive fiber membrane presents a green color. Finally, a temperature / humidity sensitive water power generation fiber membrane is prepared. Denoted as "green fiber membrane".

[0070] Comparative Example 1 The preparation method of this example is the same as that of Example 1, the only difference is that in the preparation of the asymmetric structural color film layer in step (3) of this example, the number of deposition cycles is set to 1300 times. After deposition, the reaction chamber is cooled to room temperature, and the sample is taken out. At this time, the thickness of the film is about 120 nm, and the surface of the conductive fiber membrane presents a green color. Finally, a temperature / humidity sensitive water power generation fiber membrane is prepared. Denoted as "green fiber membrane".

[0071] II. Test method 1. Electrical signal change test: Measured by electrochemical workstation (CHI660E). The positive and negative electrodes are connected to the two ends of the cotton fabric in the power generator device, respectively. After 1 min, the data is recorded after the voltage / current is stable. The environmental temperature is 30-40℃ and the relative humidity is 56-62% when measuring the voltage.

[0072] 2. Conductive performance test: The conductivity of different positions on the surface of the sample is measured using a four-probe tester to evaluate the uniformity and conductive performance of the poly-conductive polymer.

[0073] 3. Thermocouple test: A k-type thermocouple sensor is placed at the bottom of the temperature / humidity sensitive water power generation fiber membrane for testing the temperature of the temperature / humidity sensitive water power generation fiber membrane. A two-channel temperature recorder (TA612C) is used to record the real-time temperature. A xenon lamp (CELHXF300, Education Au-light) is provided 30 cm above the power generator device to simulate sunlight, which is vertically irradiated on the surface of the conductive fiber membrane with an intensity of 1 kW / m 2In order to shield the influence of heat convection, a layer of polyethylene film is covered on the water-voltaic power generation fiber film with temperature / humidity sensitivity. The relative humidity of the environment is 56-62% when measuring the temperature.

[0074] 4. Solar radiation absorption test: The sample is scanned for 2 min by using the integral sphere UV-visible spectrophotometer (UV-3600plus), and the scanning step is 2 nm.

[0075] 5. Temperature-sensitive performance test: The water-voltaic power generation fiber film with temperature / humidity sensitivity is placed in a constant temperature and humidity incubator, the temperature is changed, the resistance of the water-voltaic power generation fiber film with temperature / humidity sensitivity is observed with the change of the temperature, and the response temperature range and response time are recorded.

[0076] 6. Swelling rate test: The mass change rate of the sample is calculated in an environment with a relative humidity of 30%-80%.

[0077] III. Analysis of test results of each embodiment and comparative example Figure 2 The V-t graph and I-t graph of the water-voltaic power generation fiber film with temperature / humidity sensitivity prepared in examples 1-3 and comparative example 1 are measured at the same temperature and humidity (40℃, 60%RH). It can be seen that the output of examples 1-3 (with structural color layer) is obviously higher than that of comparative example 1 (without structural color layer), which proves the importance of asymmetric structure design for enhancing the water-voltaic effect. The purple fiber film (example 2) shows the best output performance.

[0078] Figure 3 The conductivity graph of the water-voltaic power generation fiber film with temperature / humidity sensitivity prepared in examples 1-3 and comparative example 1 is measured at the same temperature and humidity (40℃, 60%RH). It can be seen that the water-voltaic power generation fiber film with temperature / humidity sensitivity prepared in the application has a higher and stable conductivity even in the case of temperature change, which proves the effectiveness of the conductive network and ion transmission path.

[0079] Figure 4 The temperature curve graph of the water-voltaic power generation fiber film with temperature / humidity sensitivity prepared in examples 1-3 and comparative example 1 is measured at the same humidity (60%RH), which shows the temperature change of different fiber films at the same humidity. It can be seen that: the asymmetric structural color (black and purple) in the prepared ("purple fiber film") water-voltaic power generation fiber film with temperature / humidity sensitivity in example 1 has a larger temperature difference than other asymmetric structural colors (black and gold), asymmetric structural colors (black and green), and the asymmetric effect of photothermal evaporation is better.

[0080] Figure 5The absorption spectrum of the temperature / humidity-sensitive water-powered generation fiber film prepared in the present application examples 1-3 and comparative example 1 is shown. It can be seen that the temperature / humidity-sensitive conductive fiber film (black) has an absorbance of nearly 92% in the wavelength range of 0.5-2.5 μm, and different color structural colors in the structural color film layer have different absorbance in the wavelength range of 0.5-2.5 μm (absorbance size: black > green > gold > purple), proving that the temperature / humidity-sensitive water-powered generation fiber film prepared in the present application can be applied to various different scenes and has wide application.

[0081] Figure 6 The temperature sensitivity test diagram of the temperature / humidity-sensitive water-powered generation fiber film prepared in the present application examples 1-3 and comparative example 1 is shown. The change of the fiber film resistance with temperature (temperature sensitivity test) is shown. It can be seen that the resistance of the fiber film changes abruptly at about 30℃, which is direct evidence of the significant change of the conductive network structure caused by the phase change of the temperature-sensitive polymer and is the basis of temperature sensing; on the other hand, it further affects the power output of the fiber film, indicating that the fiber film has good temperature sensitivity.

[0082] Figure 7 The swelling rate change diagram of the temperature / humidity-sensitive water-powered generation fiber film prepared in the present application comparative example 1 is shown. It can be seen that the swelling rate can be changed by 30%-80% within 0-20 min, indicating that the fiber film has good humidity sensitivity.

[0083] The temperature / humidity-sensitive water-powered generation fiber film of the present application realizes efficient temperature and humidity energy collection and conversion through the multifunctional conductive fiber film matrix composed of conductive polymer / absorbing salt / temperature-sensitive polymer, combined with the surface light-heat asymmetric ALD structural color film layer. The core lies in the asymmetric evaporation driven by light-heat effect, which spontaneously strengthens the ion concentration gradient required for humidity water-powered generation, greatly improving the efficiency; at the same time, the ALD protective layer significantly enhances the environmental tolerance, and the dynamic regulation of the temperature-sensitive polymer optimizes the ion transport path and provides self-adaptive buffer. This multi-component, multifunctional, multi-mechanism synergistic advanced structure design makes it surpass the traditional single-mechanism humidity generator in energy conversion efficiency and environmental stability, and provides an innovative solution for the self-powering and sensing of intelligent wearable devices.

[0084] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and embodiments having the same technical idea and playing the same role and effect within the scope of the technical solutions of the present application are all included in the technical scope of the present application. In addition, within the scope of the main idea of the present application, various modifications that can be thought of by those skilled in the art, and other ways constructed by combining part of the components in the embodiments are also included in the scope of the present application.

Claims

1. A temperature / humidity sensitive and water-driven power generation fiber film, characterized by, The asymmetric structural color film layer is deposited on the surface of the temperature / humidity sensitive conductive fiber membrane by ALD. The temperature / humidity sensitive conductive fiber membrane comprises a conductive polymer, a hygroscopic salt and a temperature sensitive precursor. The asymmetric structural color film layer comprises at least one of trimethylaluminum, titanium tetrachloride and diethyl zinc. The temperature / humidity sensitive conductive fiber membrane is black, and the asymmetric structural color film layer is structural color.

2. The temperature / humidity sensitive and water-driven power generating fiber film according to claim 1, characterized by, The asymmetric structural color film layer accounts for 1 / 3 to 2 / 3 of the surface area of the conductive fiber membrane.

3. The temperature / humidity sensitive and water-driven power generating fiber film according to claim 1, characterized in that, The thickness of the asymmetric structural color film layer is 45-120 nm, and the thickness of the temperature / humidity sensitive conductive fiber membrane is 30-80 μm.

4. A method for preparing the temperature / humidity sensitive and water-driven power generating fiber film according to claims 1 to 3, characterized by, The method comprises the following steps: S1, dispersing a conductive polymer and a dispersing agent in an organic oxidizing agent to obtain a conductive polymer dispersion liquid, and electrospinning the conductive polymer dispersion liquid to obtain a conductive fiber membrane blank after drying; S2, soaking the conductive fiber membrane blank in a hygroscopic salt dispersion liquid to perform an adsorption reaction, and then cleaning and drying after the reaction to obtain a humidity sensitive conductive fiber membrane; S3, dispersing a temperature sensitive precursor in water to obtain a temperature sensitive precursor dispersion liquid, and placing the humidity sensitive conductive fiber membrane in the temperature sensitive precursor dispersion liquid, adding an initiator and a catalyst, and stirring and reacting, and then cleaning and drying after the reaction to obtain a temperature / humidity sensitive conductive fiber membrane; S4, performing ALD deposition on the surface of the temperature / humidity sensitive conductive fiber membrane to obtain a temperature / humidity sensitive water power generation fiber membrane.

5. The method for preparing a water-based photovoltaic fiber membrane with both temperature and humidity sensitivity according to claim 4, characterized in that, The conductive polymer comprises at least one of carbon nanotubes, conductive carbon black, graphene and MXene; and / or, The dispersing agent comprises at least one of polyethylene oxide, sodium hexametaphosphate and polyacrylamide; and / or, The organic oxidizing agent comprises at least one of N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone; and / or, The hygroscopic salt comprises at least one of lithium chloride, calcium chloride and iron chloride; and / or, The temperature sensitive precursor comprises at least one of 2-4 g of N-isopropyl acrylamide and N-vinyl caprolactam; and / or, The initiator comprises at least one of ammonium sulfite, sodium persulfate and potassium persulfate; and / or, The catalyst comprises at least one of N,N,N',N'-tetramethyl ethylenediamine and triethylamine.

6. The method for preparing a water-based photovoltaic fiber membrane with both temperature and humidity sensitivity according to claim 4, characterized in that, The precursor A for ALD deposition comprises at least one of trimethylaluminum, titanium tetrachloride and diethyl zinc, and the precursor B for ALD deposition comprises at least one of deionized water, ozone, ammonia and hydrazine.

7. The method for preparing a water-based photovoltaic fiber membrane with both temperature and humidity sensitivity according to claim 4, characterized in that, The voltage of the electrospinning is 15-20 kV, the advancing speed is 0.5-1 mL / h, and the receiving distance is 15-20 cm.

8. The method for preparing a water-based photovoltaic fiber membrane with both temperature and humidity sensitivity according to claim 4, characterized in that, The adsorption reaction time in step S2 is 1-2 h; The stirring reaction time in step S3 is 3-5 h, and the reaction temperature is 60-70℃.

9. The method for preparing a water-based photovoltaic fiber membrane with both temperature and humidity sensitivity according to claim 6, characterized in that, The ALD deposition step in step S4 includes: placing the temperature / humidity sensitive and conductive fiber film into the reaction cavity of the ALD device, closing the reaction cavity door and vacuumizing to 1x10 -6 ~1x10 -8 Torr, setting the deposition temperature to 80-150 DEG C, and performing 450-1300 deposition cycles; each deposition cycle includes: pulse injection of precursor A, pulse 0.05-0.2 s, nitrogen purging 5-15 s, pulse injection of precursor B, pulse 0.05-0.2 s, and nitrogen purging 5-15 s.

10. Application of the temperature / humidity sensitive water power generation fiber membrane according to claims 1-3 in the field of intelligent wearable devices.

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