Self-regulating temperature and humidity double-effect desiccant and preparation method thereof

Abstract

This invention belongs to the field of desiccant technology, specifically relating to a self-regulating temperature and humidity dual-effect desiccant and its preparation method. The self-regulating temperature and humidity dual-effect desiccant has a core-shell structure, with a core consisting of a phase change microcapsule with a high enthalpy value and an outer shell consisting of a temperature-sensitive hydrogel loaded with hygroscopic salts. The core-shell structure is formed by adding the phase change microcapsules to a temperature-sensitive hydrogel prepolymer solution and then polymerizing in situ. This dual-effect desiccant can automatically switch its working mode according to changes in ambient temperature and humidity. It efficiently absorbs moisture and prevents dampness at low temperatures and high humidity, and automatically releases water and regenerates at high temperatures, achieving cooling through the latent heat of phase change, without requiring external energy or intervention. This invention combines intelligent response, dual temperature and humidity control, and green energy saving advantages. Its moisture absorption rate, temperature control delay, and cycle stability are far superior to traditional silica gel, with no risk of corrosion or leakage. It is suitable for temperature and humidity control in miniaturized high-efficiency electronic devices such as 5G communication and new energy vehicle battery packs.

Description

Technical Field

[0001] This invention belongs to the field of desiccant technology, specifically relating to a self-regulating temperature and humidity dual-effect desiccant and its preparation method. Background Technology

[0002] As electronic devices evolve towards higher energy efficiency, higher density, and miniaturization, such as 5G communication modules and new energy vehicle battery packs, the heat generated during operation increases dramatically, causing a sudden rise in the temperature of electronic components. Simultaneously, the humidity within the device's internal microenvironment may also increase. High temperature and high humidity environments can seriously threaten the safe operation of electronic components, potentially leading to short circuits or even irreparable damage such as fires.

[0003] Existing temperature and humidity control technologies have significant shortcomings. Single-mode temperature control, such as using heat-conducting sheets, heat pipes, or air cooling, cannot address humidity issues. Single-mode humidity control, such as placing desiccants like silica gel, montmorillonite, or calcium chloride inside electronic component housings, while absorbing moisture, does not provide cooling. Furthermore, halogen desiccants, once saturated with moisture, may release halogen ions that corrode the equipment. Traditional temperature and humidity control methods are fragmented, while the temperature and humidity of electronic devices change dynamically during operation. Therefore, current technologies cannot provide intelligent, coordinated, and efficient dual management of temperature and humidity within the equipment's internal environment. Simultaneously, as electronic products become increasingly miniaturized, traditional active cooling methods such as air or water cooling are difficult to apply due to size and energy consumption limitations.

[0004] Therefore, there is an urgent need to develop a self-regulating temperature and humidity dual-effect desiccant to overcome the technical shortcomings of existing temperature and humidity control materials and achieve the synergistic function of temperature control and drying of a single material. Summary of the Invention

[0005] The purpose of this invention is to provide a self-regulating temperature and humidity dual-effect desiccant that is highly efficient, energy-saving, intelligent, and provides stable temperature and humidity control, while simultaneously achieving both cooling and drying functions.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a self-regulating temperature and humidity dual-effect desiccant, which has a core-shell structure. The core is a phase change microcapsule with a high enthalpy value, and the outer shell is a temperature-sensitive hydrogel loaded with hygroscopic salts. The core-shell structure is formed by adding the phase change microcapsule to the temperature-sensitive hydrogel prepolymer solution and then polymerizing it in situ.

[0008] A self-regulating temperature and humidity dual-effect desiccant, the preparation method of which includes the following steps:

[0009] S1. Under nitrogen protection, the phase change microcapsules are added to the thermosensitive hydrogel prepolymer solution and stirred evenly to obtain liquid one.

[0010] S2. Heat the liquid to 60-75℃, add the initiator, react for 2-5 hours, then cool to room temperature, wash with deionized water 2-4 times, and dry to obtain the product.

[0011] Preferably, in step S1, the mass ratio of the thermosensitive hydrogel prepolymer to the phase change microcapsules is 100:(2-30).

[0012] The method for preparing the phase change microcapsules includes the following steps:

[0013] A1. Heating the phase change material to a liquid state yields a molten phase change material;

[0014] A2. Water and emulsifier are stirred evenly to obtain a continuous aqueous phase;

[0015] A3. Heat the continuous aqueous phase, add the molten phase change material, and stir to emulsify;

[0016] A4. After emulsification, add monomers and initiators for in-situ polymerization, wash, filter, and dry to obtain the final product.

[0017] Preferably, in step A1, the phase change material includes, but is not limited to, one or two of alkanes and paraffins.

[0018] Preferably, the alkane has the general formula The linear saturated alkane, wherein n is an integer from 14 to 30, preferably from 16 to 22.

[0019] Preferably, in step A1, the heating temperature is greater than or equal to the phase change point of the phase change material.

[0020] Preferably, in step A2, the emulsifier includes one or both of ionic and nonionic emulsifiers; more preferably, it is an ionic emulsifier and a nonionic emulsifier in a mass ratio of (1-3):1.

[0021] Preferably, the ionic emulsifier includes, but is not limited to, one or both of sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS).

[0022] Preferably, the nonionic emulsifier includes, but is not limited to, one or both of polyvinyl alcohol (PVA) and gum arabic.

[0023] Preferably, in step A2, the mass ratio of water to emulsifier is 100:(0.1-10).

[0024] Preferably, in step A2, the stirring speed is 200-600 rpm.

[0025] Preferably, in step A3, the heating temperature is 30-85℃, the stirring speed is 1000-5000 rpm, the emulsification temperature is 30-85℃, and the emulsification time is 10-30 min.

[0026] Preferably, the mass ratio of water to phase change material is 100:(2.5-25).

[0027] Preferably, in step A4, the monomer includes, but is not limited to, methyl methacrylate (MMA) monomer.

[0028] Preferably, in step A4, the initiator is one or both of potassium persulfate (KPS) and ammonium persulfate (APS); more preferably, it is potassium persulfate (KPS) and ammonium persulfate (APS) in a mass ratio of (0.8-1.2):1.

[0029] Preferably, the mass ratio of the phase change material to the MMA monomer is 100:(20-100).

[0030] Preferably, the mass ratio of the MMA monomer to the initiator is 10:(0.01-1).

[0031] Preferably, in step A4, the in-situ polymerization temperature is 65-85℃ and the polymerization time is 3-8h.

[0032] Preferably, in step A4, the specific steps of cleaning and filtration are as follows: vacuum filtration to obtain the microcapsule product; and washing the product alternately with deionized water 2-5 times.

[0033] Preferably, the vacuum degree of the vacuum filtration is -0.05-0.1 MPa, and the filtration continues until the filter cake no longer drips water.

[0034] Preferably, in step A4, the specific drying conditions are: temperature of 23-25℃, time of 48-72h, ventilation in a fume hood, and turning 3-5 times.

[0035] The preparation method of the temperature-sensitive hydrogel prepolymer includes the following steps:

[0036] B1. Heat the water and add sodium alginate (SA) to dissolve in the water to obtain the aqueous phase;

[0037] B2. After cooling the aqueous phase to room temperature, add N-isopropylacrylamide (NIPAM) monomer and stir thoroughly to obtain monomer liquid;

[0038] B3. Nitrogen gas is introduced into the monomer liquid, and crosslinking agent and hygroscopic salt are added. After stirring evenly, the mixture is reacted at room temperature for 1-2 hours to obtain the prepolymer liquid.

[0039] Preferably, in step B1, the water is heated to a temperature of 40-60°C.

[0040] Preferably, in step B2, the mass ratio of water to NIPAM monomer in the aqueous phase is 100:(0.5-3), and the mass ratio of NIPAM monomer to SA in the aqueous phase is 1:(0.3-1).

[0041] Preferably, in step B2, the stirring speed is 200-600 rpm and the stirring time is 10-30 min.

[0042] Preferably, in step B3, the crosslinking agent includes N,N'-methylenebisacrylamide (MBAA), and the mass ratio of NIPAM monomer to crosslinking agent is 10:(0.05-1).

[0043] Preferably, in step B3, the hygroscopic salt includes, but is not limited to, any one of lithium chloride, magnesium chloride, calcium chloride, activated carbon, and molecular sieve, and the mass ratio of NIPAM monomer to hygroscopic salt is 1:(0.1-10).

[0044] Preferably, in step S2, the initiator is one or both of potassium persulfate (KPS) and ammonium persulfate (APS).

[0045] Preferably, in step S2, the mass ratio of NIPAM monomer to initiator in the preparation method of the thermosensitive hydrogel prepolymer is 10:(0.05-1).

[0046] Preferably, in step S2, drying includes freeze drying or room temperature drying.

[0047] Preferably, the specific steps of the freeze-drying are as follows: pre-freezing the cleaned sample at -20℃ for 10-14 hours, and then vacuum drying it in a freeze dryer at -50℃ and below 10Pa for 45-50 hours.

[0048] Preferably, the specific conditions for room temperature drying are: temperature of 23-25℃, time of 48-72h, ventilation in a fume hood, and turning 3-5 times.

[0049] By utilizing the volume phase change temperature characteristics of PNIPAM to construct a temperature-sensitive hydrogel shell, a dual-effect desiccant can automatically switch between moisture absorption and temperature control modes based on ambient temperature without external intervention. The working principle of the dual-effect desiccant is as follows: Under low-temperature operation or high-humidity storage conditions, the hydrophilic expansion of the PNIPAM molecular chains causes the hydrogel network to swell and open its pores. With the synergistic effect of highly hygroscopic salts such as lithium chloride, it efficiently adsorbs and locks in water molecules from the environment, significantly reducing microenvironmental humidity and providing superior moisture-proof and anti-condensation effects. When the equipment generates heat and the temperature rises, the PNIPAM molecular chains undergo a hydrophilic-hydrophobic transition, causing the network to collapse hydrophobically and the pores to close, forcibly releasing most of the water stored in the moisture absorption mode. This achieves the gel's own "drying regeneration," preparing it for the next moisture absorption cycle, demonstrating that the desiccant prepared by this invention possesses excellent recyclability. Simultaneously, the inner phase change microcapsules absorb heat and undergo a solid-liquid transition, while the shell absorbs a large amount of heat energy to achieve temperature control, thus realizing intelligent passive switching between the two functions of drying and temperature control using a single material.

[0050] By constructing a core-shell structure with high-enthalpy phase change microcapsules as the core and a temperature-sensitive hydrogel that adsorbs hygroscopic salts as the outer shell, a dual-effect desiccant can be prepared, enabling a single material to simultaneously achieve the dual functions of intelligent temperature control and efficient dehumidification. This is because the core phase change material undergoes a solid-liquid phase transition when the temperature exceeds its melting point, not only absorbing a large amount of latent heat and acting as a temperature buffer, but also delaying the temperature rise, preventing short circuits or fire risks caused by sudden temperature increases, thus meeting the needs of electronic devices such as electronic components. The outer PNIPAM and SA interpenetrating network hydrogel, through temperature response, regulate the pore state to synergistically absorb or release moisture. The spatial coupling of the two allows the cooling and drying functions to be passively coordinated within a single material, eliminating the need for traditional independent temperature and humidity control systems. Furthermore, the polymer shell confines the solid-liquid transition of the phase change material within the phase change microcapsules, while the hydrogel network locks the deliquescent salt solution within the gel pores, ensuring a strong moisture absorption effect while avoiding the corrosion risk caused by direct contact with electronic components after moisture saturation of traditional halogen desiccants, thus ensuring the structural stability of the material during long-term cycling.

[0051] Integrating phase change thermal storage and temperature-sensitive moisture absorption into a single passive response material system achieves both temperature control and dehumidification simultaneously, resulting in green and energy-saving effects without external energy intervention. This is because the latent heat absorption of the phase change microcapsules and the temperature response of PNIPAM are both physically self-driven processes. The material directly utilizes the ambient heat generated during equipment operation to trigger the temperature-sensitive transition and desiccant regeneration, avoiding the additional energy losses associated with traditional air cooling, water cooling, or electric heating regeneration methods. This meets the demands of electronic devices for high energy efficiency, high density, and miniaturization. In other words, it eliminates the need for external energy intervention, reduces energy loss, and achieves both temperature control and green energy consumption requirements.

[0052] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0053] 1. This invention proposes a self-regulating temperature and humidity dual-effect desiccant that can automatically switch working modes according to changes in ambient temperature and humidity. It can efficiently absorb moisture and prevent dampness at low temperature and high humidity, and automatically release water and regenerate at high temperature, and achieve cooling through latent heat of phase change, without the need for external energy or intervention.

[0054] 2. Intelligent response: When the temperature and humidity of the environment change, the microcapsule phase change material and hygroscopic salt undergo corresponding changes, automatically adjusting the temperature or humidity of the object (e.g., cooling or absorbing moisture) without external intervention.

[0055] 3. Dual Functions: Combining "cooling" and "drying" functions. Cooling is achieved through the latent heat absorption of phase change microcapsules, while humidity is intelligently regulated through the switching effect of temperature-sensitive hydrogels and highly hygroscopic salts.

[0056] 4. Green and energy-saving: The entire working process requires no external energy input. It can achieve passive management of temperature and humidity by relying solely on the physical and chemical changes of the material itself, which greatly reduces energy consumption.

[0057] 5. The dual-effect desiccant prepared by this invention has the advantages of intelligent response, dual temperature and humidity control, and green energy saving. Its moisture absorption rate, temperature control delay and cycle stability are far superior to traditional silica gel. It has no risk of corrosion and leakage and is suitable for temperature and humidity control of miniaturized high-efficiency electronic devices such as 5G communication and new energy vehicle battery packs. Attached Figure Description

[0058] Figure 1 The diagram shows the structure of the self-regulating temperature and humidity dual-effect desiccant prepared according to the present invention before (left) and after (right) heat absorption. Detailed Implementation

[0059] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] Example 1

[0061] This embodiment provides a self-regulating temperature and humidity dual-effect desiccant, the preparation method of which includes the following steps:

[0062] S1. Under nitrogen protection, the phase change microcapsules are added to the thermosensitive hydrogel prepolymer solution and stirred evenly to obtain liquid one.

[0063] S2. Heat the liquid to 60°C, add the initiator, react for 4 hours, then cool to room temperature, wash three times with deionized water, and dry to obtain the final product.

[0064] In step S1, the mass ratio of the thermosensitive hydrogel prepolymer to the phase change microcapsules is 100:3.79.

[0065] The preparation method of the phase change microcapsules includes the following steps:

[0066] A1. Heating the phase change material to a liquid state yields a molten phase change material;

[0067] A2. Water and emulsifier are stirred evenly to obtain a continuous aqueous phase;

[0068] A3. Heat the continuous aqueous phase, add the molten phase change material, and stir to emulsify;

[0069] A4. After emulsification, add monomers and initiators for in-situ polymerization, wash, filter, and dry to obtain the final product.

[0070] In step A1, the phase change material is an alkane.

[0071] The alkane has the general formula The linear saturated alkane, wherein n is 18, i.e., the alkane is octadecane, and the phase transition temperature is 28°C.

[0072] In step A1, the heating temperature is 35°C.

[0073] In step A2, the emulsifier is an ionic emulsifier and a nonionic emulsifier, with a mass ratio of 2:1.

[0074] The ionic emulsifier is sodium dodecyl sulfate (SDS).

[0075] The nonionic emulsifier is polyvinyl alcohol (PVA).

[0076] In step A2, the mass ratio of water to emulsifier is 100:3.

[0077] In step A2, the stirring speed is 400 rpm.

[0078] In step A3, the heating temperature is 50°C, the stirring speed is 1500 rpm, the emulsification temperature is 50°C, and the emulsification time is 20 min.

[0079] The mass ratio of water to phase change material is 100:10.

[0080] In step A4, the monomer is methyl methacrylate (MMA) monomer.

[0081] In step A4, the initiator is potassium persulfate (KPS) and ammonium persulfate (APS) in a mass ratio of 1:1.

[0082] The mass ratio of the phase change material to MMA monomer is 100:50.

[0083] The mass ratio of the MMA monomer to the initiator is 10:0.4.

[0084] In step A4, the in-situ polymerization temperature is 80℃ and the polymerization time is 4h.

[0085] In step A4, the specific steps of cleaning and filtration are as follows: vacuum filtration to obtain microcapsule products; washing the products alternately with deionized water 4 times.

[0086] The vacuum degree of the vacuum filtration is -0.1MPa, and filtration continues until the filter cake no longer drips water.

[0087] In step A4, the specific drying conditions are: temperature of 25°C, time of 72 hours, ventilation in a fume hood, and turning 4 times.

[0088] The preparation method of the temperature-sensitive hydrogel prepolymer solution includes the following steps:

[0089] B1. Heat the water and add sodium alginate (SA) to dissolve it in the water to obtain the aqueous phase;

[0090] B2. After cooling the aqueous phase to room temperature, add N-isopropylacrylamide (NIPAM) monomer and stir thoroughly to obtain monomer liquid;

[0091] B3. Nitrogen gas is introduced into the monomer liquid, and crosslinking agent and hygroscopic salt are added. After stirring evenly, the mixture is reacted at room temperature for 1.5 hours to obtain the prepolymer liquid.

[0092] In step B1, the water is heated to a temperature of 50°C.

[0093] In step B2, the mass ratio of water to NIPAM monomer in the aqueous phase is 100:1.6, and the mass ratio of NIPAM monomer to SA in the aqueous phase is 1:0.625.

[0094] In step B2, the stirring speed is 400 rpm and the stirring time is 30 min.

[0095] In step B3, the crosslinking agent is N,N'-methylenebisacrylamide (MBAA), and the mass ratio of NIPAM monomer to crosslinking agent is 10:0.25.

[0096] In step B3, the hygroscopic salt is lithium chloride, and the mass ratio of NIPAM monomer to hygroscopic salt is 1:1.875.

[0097] In step S2, the initiator is ammonium persulfate (APS).

[0098] In step S2, the mass ratio of NIPAM monomer to initiator in the preparation method of the thermosensitive hydrogel prepolymer is 10:0.375.

[0099] In step S2, the drying is performed at room temperature.

[0100] The specific conditions for room temperature drying are: temperature 25℃, time 72h, ventilation in a fume hood, and turning 5 times.

[0101] Example 2

[0102] This embodiment provides a self-regulating temperature and humidity dual-effect desiccant. The specific implementation method is the same as in Embodiment 1, except that:

[0103] S1. Under nitrogen protection, the phase change microcapsules are added to the thermosensitive hydrogel prepolymer solution and stirred evenly to obtain liquid one.

[0104] S2. Heat the liquid to 60°C, add the initiator, react for 4 hours, then cool to room temperature, wash three times with deionized water, and dry to obtain the final product.

[0105] In step S1, the mass ratio of the thermosensitive hydrogel prepolymer to the phase change microcapsules is 100:3.72. In step A2, the emulsifier is an ionic emulsifier and a nonionic emulsifier, with a mass ratio of 5:3.

[0106] The ionic emulsifier is sodium dodecyl sulfate (SDS).

[0107] The nonionic emulsifier is polyvinyl alcohol (PVA).

[0108] In step A2, the mass ratio of water to emulsifier is 100:2.

[0109] In step A2, the stirring speed is 400 rpm.

[0110] In step A3, the heating temperature is 50°C, the stirring speed is 1500 rpm, the emulsification temperature is 50°C, and the emulsification time is 10 min.

[0111] The mass ratio of water to phase change material is 100:7.5.

[0112] The mass ratio of the phase change material to MMA monomer is 15:8.

[0113] The mass ratio of the MMA monomer to the initiator is 10:0.4.

[0114] In step A4, the in-situ polymerization temperature is 80°C and the polymerization time is 5 hours.

[0115] In step A4, the specific steps of cleaning and filtration are as follows: vacuum filtration to obtain microcapsule products; and washing the products alternately with deionized water three times.

[0116] The vacuum degree of the vacuum filtration is -0.1MPa, and filtration continues until the filter cake no longer drips water.

[0117] In step A4, the specific drying conditions are: temperature of 25°C, time of 72 hours, ventilation in a fume hood, and turning 4 times.

[0118] The preparation method of the temperature-sensitive hydrogel prepolymer solution includes the following steps:

[0119] B1. Heat the water and add sodium alginate (SA) to dissolve it in the water to obtain the aqueous phase;

[0120] B2. After cooling the aqueous phase to room temperature, add N-isopropylacrylamide (NIPAM) monomer and stir thoroughly to obtain monomer liquid;

[0121] B3. Nitrogen gas is introduced into the monomer liquid, and crosslinking agent and hygroscopic salt are added. After stirring evenly, the mixture is reacted at room temperature for 1.5 hours to obtain the prepolymer liquid.

[0122] In step B2, the mass ratio of water to NIPAM monomer in the aqueous phase is 100:2, and the mass ratio of NIPAM monomer to SA in the aqueous phase is 1:0.75.

[0123] In step B2, the stirring speed is 400 rpm and the stirring time is 30 min.

[0124] In step B3, the hygroscopic salt is lithium chloride, and the mass ratio of NIPAM monomer to hygroscopic salt is 1:2.

[0125] In step S2, the mass ratio of NIPAM monomer to initiator in the preparation method of the thermosensitive hydrogel prepolymer is 10:0.3.

[0126] In step S2, the drying is performed at room temperature.

[0127] The specific conditions for room temperature drying are: temperature 25℃, time 72h, ventilation in a fume hood, and turning 5 times.

[0128] Comparative Example 1

[0129] The only difference between this comparative example and Example 1 is:

[0130] B2. After cooling the aqueous phase to room temperature, add acrylamide (AM) monomer and stir thoroughly to obtain monomer liquid.

[0131] Comparative Example 2

[0132] The only difference between this comparative example and Example 1 is:

[0133] In step B3, the hygroscopic salt is silica gel with a particle size of 200-425 mesh, sourced from Shanghai Maclean Reagent Co., Ltd.

[0134] Comparative Example 3

[0135] S1. Under nitrogen protection, the phase change material is added to the thermosensitive hydrogel prepolymer solution and stirred evenly to obtain liquid one;

[0136] The mass ratio of the phase change material to the N-isopropylacrylamide (NIPAM) monomer in step B2 is 10:1.6.

[0137] Performance testing

[0138] Moisture absorption rate test: 5g of desiccant was taken from each example and comparative example, and the moisture absorption rate was tested after 7 days of moisture absorption at 35°C and 95%RH.

[0139] Moisture absorption rate =

[0140] In the formula: The initial dry weight of the sample is in grams. The mass of the sample after it has absorbed moisture is expressed in grams (g).

[0141] Temperature rise effect test: Take 5g of desiccant for each example and comparative example, set the oven temperature to 80℃, put in the desiccant, and test the time required for the desiccant to rise from room temperature 25℃ to 50℃.

[0142] Formula for calculating high-temperature moisture release rate:

[0143] W0 represents the initial dry weight of the sample (g); W1 represents the mass (g) after 7 days of initial moisture absorption; and W2 represents the mass (g) after regeneration treatment (dehumidification in a 45℃ oven for 3 hours). High-temperature moisture release rate characterizes the proportion of moisture released by the material under high-temperature triggering relative to its total absorbed moisture.

[0144] Formula for calculating moisture absorption and regeneration rate:

[0145] In the formula: Initial dry weight (g); : Mass (g) after 7 days of initial moisture absorption; Mass (g) after regeneration treatment (dehumidification in a 45℃ oven for 3 hours); Mass (g) after secondary saturation moisture absorption (7 days of re-moistening after regeneration treatment).

[0146] Formula for calculating the moisture regeneration rate after 10 cycles:

[0147] In the formula: Initial dry weight of the sample (g); : Sample mass (g) 7 days after initial moisture absorption; : Sample mass (g) after the 10th regeneration treatment; : Sample mass (g) after the 10th re-hygroscopic treatment.

[0148] All performance test results are shown in Table 1, and compared with commercially available traditional silica gel desiccants.

[0149] Table 1 Group Moisture absorption rate / % Temperature rise time / min High temperature moisture release rate / % Moisture absorption regeneration rate / % 10-cycle moisture absorption regeneration rate / % Example 1 80% Less than 25 minutes 72% 70% 70% Example 2 85% Less than 25 minutes 71% 71% 70% Comparative Example 1 85% Less than 25 minutes 15% 8% 8% Comparative Example 2 15% Less than 25 minutes 10% 5% 3% Comparative Example 3 80% less than 10 minutes 71% 70% 68% Traditional silica gel desiccant 35% less than 10 minutes <5% <5% <5%

[0150] As shown in Table 1, the self-regulating temperature and humidity dual-effect desiccants prepared in Examples 1 and 2 exhibit high moisture absorption rate, slow temperature rise, and excellent cycle stability after 7 days. In Comparative Example 1, the NIPAM monomer was replaced with the AM monomer; in Comparative Example 2, the lithium chloride drying body was replaced with silica gel; and in Comparative Example 3, the phase change material was not microencapsulated and was directly blended with the temperature-sensitive hydrogel prepolymer. All properties of the resulting desiccants decreased.

[0151] Therefore, this invention proposes a self-regulating temperature and humidity dual-effect desiccant that combines the advantages of intelligent response, dual temperature and humidity control, and green energy saving. Its moisture absorption rate, temperature control delay, and cycle stability are far superior to traditional silica gel, and it has no risk of corrosion or leakage. It is suitable for temperature and humidity control of miniaturized high-efficiency electronic devices such as 5G communication and new energy vehicle battery packs.

[0152] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A self-regulating temperature and humidity adjusting double-effect desiccant, characterized by, It has a core-shell structure, with the core being a phase change microcapsule with a high enthalpy value and the outer shell being a thermosensitive hydrogel loaded with hygroscopic salts; the core-shell structure is formed by adding the phase change microcapsule into the thermosensitive hydrogel prepolymer solution and then polymerizing it in situ.

2. A method of preparing a self-regulating temperature and humidity double-effect desiccant according to claim 1, characterized by, Includes the following steps: S1. Under nitrogen protection, the phase change microcapsules are added to the thermosensitive hydrogel prepolymer solution and stirred evenly to obtain liquid one. S2. Heat the liquid to 60-75℃, add the initiator, react for 2-5 hours, then cool to room temperature, wash with deionized water 2-4 times, and dry to obtain the product.

3. The method of claim 2, wherein the self-regulating temperature and humidity double- effect desiccant is prepared by the steps of: In step S1, the mass ratio of the thermosensitive hydrogel prepolymer to the phase change microcapsules is 100:(2-30). ​ 4. The method of claim 2, wherein the self-regulating temperature and humidity dual- effect desiccant is prepared by the steps of: The method for preparing the phase change microcapsules includes the following steps: ​ A1. Heating the phase change material to a liquid state yields a molten phase change material; A2. Water and emulsifier are stirred evenly to obtain a continuous aqueous phase; A3. Heat the continuous aqueous phase, add the molten phase change material, and stir to emulsify; A4. After emulsification, add monomers and initiators for in-situ polymerization, wash, filter, and dry to obtain the final product.

5. The method for preparing the self-regulating temperature and humidity dual-effect desiccant according to claim 4, characterized in that, In step A1, the phase change material includes, but is not limited to, one or two of alkanes and paraffin.

6. The method for preparing the self-regulating temperature and humidity dual-effect desiccant according to claim 5, characterized in that, The alkane has the general formula Straight-chain saturated alkanes, where n is an integer from 14 to 30.

7. The method for preparing the self-regulating temperature and humidity dual-effect desiccant according to claim 2, characterized in that, The preparation method of the temperature-sensitive hydrogel prepolymer includes the following steps: B1. Heat the water and add sodium alginate to dissolve in the water to obtain the aqueous phase; B2. After cooling the aqueous phase to room temperature, add N-isopropylacrylamide monomer and stir thoroughly to obtain monomer liquid; B3. Nitrogen gas is introduced into the monomer liquid, and crosslinking agent and hygroscopic salt are added. After stirring evenly, the mixture is reacted at room temperature for 1-2 hours to obtain the prepolymer liquid.

8. The method for preparing the self-regulating temperature and humidity dual-effect desiccant according to claim 7, characterized in that, In step B2, the mass ratio of water to N-isopropylacrylamide monomer in the aqueous phase is 100:(0.5-3), and the mass ratio of N-isopropylacrylamide monomer to sodium alginate in the aqueous phase is 1:(0.3-1).

9. The method for preparing the self-regulating temperature and humidity dual-effect desiccant according to claim 7, characterized in that, In step B3, the crosslinking agent includes N,N'-methylenebisacrylamide, and the mass ratio of N-isopropylacrylamide monomer to crosslinking agent is 10:(0.05-1).

10. The method for preparing the self-regulating temperature and humidity dual-effect desiccant according to claim 7, characterized in that, In step B3, the hygroscopic salt includes, but is not limited to, any one of lithium chloride, magnesium chloride, calcium chloride, activated carbon, and molecular sieve, and the mass ratio of N-isopropylacrylamide monomer to hygroscopic salt is 1:(0.1-10).

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