Intelligent color-changing greenhouse with temperature and humidity dual response and preparation method of intelligent color-changing greenhouse

Abstract

The invention discloses an intelligent color-changing greenhouse with temperature and humidity dual response and a preparation method of the intelligent color-changing greenhouse. The greenhouse is formed by combining novel temperature and humidity dual-response hydrogel, a humidity sensor, a humidifier and a supporting assembly, integrates passive heat insulation and cooling and active humidification and light transmission, and can achieve self-adaptive color change and light insulation according to the outdoor sunlight intensity; meanwhile, the humidity can be actively improved, the light inlet amount is increased, and plants in the greenhouse fully perform photosynthesis. The color of the gel can be adjusted in real time according to the temperature and humidity of the environment, and the gel becomes opaque from transparent when the temperature is high and the humidity is low at noon in the daytime, so that too strong illumination is reduced, and excessive heat is prevented from entering the greenhouse; the gel absorbs moisture and becomes transparent when the temperature is low and the humidity is high in the daytime, morning and evening, environment self-adaption cyclic utilization of the greenhouse is achieved, external energy input is not needed, and energy consumption is greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of stimulus-responsive hydrogel technology, specifically relating to an intelligent color-changing greenhouse with dual temperature and humidity responses and its preparation method. Background Technology

[0002] Traditional greenhouses rely mainly on external energy sources or devices for temperature control and insulation, which has drawbacks such as high energy consumption and large carbon emissions. Therefore, with the development of technology, modern greenhouses that can intelligently adjust light control, achieve dual-response regulation of temperature and humidity, and have energy-saving technology have important practical significance.

[0003] Stimulus-responsive hydrogels are currently a hot research topic. When external environmental conditions such as light, heat, humidity, electricity, magnetism, force, pH, or chemical conditions change, the internal network structure and intermolecular interactions of these hydrogels alter, resulting in changes in their physical or chemical properties, such as color, shape, volume, viscosity, toughness, or mechanical strength. Although there is considerable research on smart color-changing hydrogels, some problems remain. For example, most smart color-changing hydrogels only respond to a single stimulus and require sealed use, failing to adapt to complex environments and exhibiting significant functional limitations, thus failing to meet user needs (Adv. Funct. Mater. 2022, 32, 2109597). To achieve smart color-changing hydrogels that adapt to complex environments, they need to be adaptable to both temperature and humidity. Achieving this dual temperature and humidity stimulus response requires preparing corresponding materials using multiple different polymers, a complex and costly process that significantly limits their application.

[0004] Therefore, it is of great significance to develop a modern solar greenhouse with intelligent color-changing function that responds to both temperature and humidity, and can also have passive and synergistic cooling and active control of light transmittance. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an intelligent color-changing greenhouse with dual temperature and humidity response and its preparation method.

[0006] The objective of this invention is achieved through the following technical solutions.

[0007] A smart color-changing greenhouse with dual temperature and humidity response includes a greenhouse light-transmitting layer, a temperature and humidity dual-response color-changing layer, a support component, an indoor bracket, a humidifier, and a humidity sensor; wherein the humidifier and humidity sensor are supported inside the greenhouse by the indoor bracket.

[0008] The humidifier and humidity sensor use mobile power sources such as batteries. At the same time, the greenhouse monitors the ambient humidity in real time through the humidity sensor and actively turns the humidifier on or off to adjust the ambient humidity according to the user's needs.

[0009] Furthermore, the supporting components include, but are not limited to, metal frames, reinforced concrete frames, wooden frames, brick and mortar frames, etc. Furthermore, the temperature and humidity dual-response color-changing layer is a temperature and humidity dual-response hydrogel; the components of the temperature and humidity dual-response hydrogel include: acrylic monomer, alkaloid, crosslinking agent, organic solvent, photoinitiator, and deionized water.

[0010] Furthermore, the greenhouse light-transmitting layer and the temperature and humidity dual-response color-changing layer are attached together; Furthermore, the greenhouse light-transmitting layer is a transparent plastic film or transparent glass, including but not limited to polyvinyl chloride greenhouse film, polyethylene greenhouse film, and transparent glass.

[0011] This invention also provides a method for preparing an intelligent color-changing greenhouse with dual temperature and humidity responses, comprising the following steps: (1) Building a greenhouse: First, build the greenhouse using the support components, then connect the humidifier, humidity sensor and indoor bracket and support it inside the greenhouse; (2) Preparation of temperature and humidity responsive hydrogel: Add monomer, alkaloid, crosslinking agent and organic solvent to deionized water and stir until the solution is clear and transparent to obtain a mixture and pass inert gas into it. Then add photoinitiator and stir until the solution is clear and transparent to obtain a reaction solution. Pour the reaction solution into a mold for ultrasonic treatment and then initiate polymerization under ultraviolet light to obtain a temperature and humidity responsive hydrogel. (3) Assemble a smart color-changing greenhouse with dual temperature and humidity response: attach the temperature and humidity dual-response hydrogel obtained in step (2) to the inner side of the greenhouse light-transmitting layer and cover it on the outside of the support component, thereby preparing a smart color-changing greenhouse with dual temperature and humidity response.

[0012] Further, in step (2), the monomer is acrylic acid or methacrylic acid; the mass of acrylic acid added is 80% to 350% of the mass of the added deionized water.

[0013] Further, in step (2), the alkaloid is betaine; the mass of betaine added is 80% to 120% of the mass of the added deionized water.

[0014] Further, in step (2), the organic solvent is any one of polyethylene glycol with an average molecular weight of 600, 800, or 1000; the mass of the added organic solvent is 140% to 560% of the mass of the added deionized water.

[0015] Further, in step (2), the crosslinking agent is N,N'-methylenebispropionamide or polyethylene glycol diacrylate; the amount of crosslinking agent added is 0.1% to 0.5% of the amount of monomer.

[0016] Further, in step (2), the photoinitiator is any one of 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone or α-ketoglutaric acid, and the mass of the photoinitiator added is 0.1% to 0.5% of the total mass of the monomer.

[0017] Furthermore, in step (2), the inert gas is either nitrogen or argon.

[0018] Further, in step (2), the mold is either a polytetrafluoroethylene groove mold with a transparent cover plate or a mold assembled by sandwiching a washer between two glass plates, with a thickness of 1mm to 3mm.

[0019] Further, in step (2), the wavelength of the ultraviolet light is 320~365 nm, the power is 80~120 W, the irradiation time is 0.5~3 h, and the temperature of the polymerization reaction is 0~40 ℃.

[0020] Compared with the prior art, the present invention has the following advantages and technical effects: 1. The intelligent color-changing greenhouse prepared by this invention combines thermochromic heat insulation and cooling with hygrochromic humidification and light transmission functions. Its operating mode is as follows: (1) Temperature-responsive color change: Based on the thermochromic properties of the hydrogel with dual temperature and humidity response, when the greenhouse is exposed to sunlight, the temperature gradually increases and the gel gradually changes from a transparent state to a white opaque state. The stronger the light, the higher the temperature and the deeper the white opacity. When the sunlight stops, the temperature decreases and the gel gradually returns from a white opaque state to the initial transparent state, thereby achieving the protective measures of heat insulation and cooling in the greenhouse, while achieving the effect of environmental protection and energy saving.

[0021] (2) Humidity-responsive color change: Based on the humidification characteristics of the hydrogel with dual temperature and humidity response, when the greenhouse is in a low humidity environment with a relative humidity of less than 50%, the gel gradually changes from a transparent state to a white opaque state; when the relative humidity is higher than 50%, the gel gradually returns from a white opaque state to a transparent state, thereby achieving heat insulation and protection measures in the greenhouse when the humidity is low. At the same time, when more sunlight is needed to enter the greenhouse, the ambient humidity can be actively increased by a humidifier to maintain the stable transparent state of the gel and achieve the function of actively regulating the light transmittance.

[0022] (3) Temperature and humidity dual-response synergistic color change: Based on the two working mechanisms (1) and (2) above, they can generate a synergistic cooling effect. When the greenhouse is in a low humidity and high temperature environment during the day, the gel can quickly change from a transparent state to a white opaque state, blocking external heat and achieving a rapid response heat insulation and cooling effect. At night, in a high humidity and low temperature environment, the gel can gradually return to moisture absorption and transparency, achieving the effect of temperature regulation and recycling.

[0023] 2. The intelligent color-changing greenhouse with dual temperature and humidity response prepared by this invention has excellent heat insulation performance. The temperature and humidity dual-response hydrogel provided by this invention has significant blocking properties for visible light. Through thermal phase change, the visible light blocking rate of the hydrogel can reach more than 99%, thereby effectively preventing heat input.

[0024] 3. The temperature and humidity responsive hydrogel prepared by this invention has excellent transparency-phase transition repeatability and can still maintain a stable effect after 500 transparency-phase transition cycles.

[0025] 4. The intelligent color-changing greenhouse with dual temperature and humidity response prepared by the present invention has environmental adaptability and usage stability. It can actively absorb moisture and become transparent at night and change phase during the day to provide insulation and cooling. Under long-term high temperature and low humidity conditions, its solar blocking rate does not decrease significantly.

[0026] 5. The temperature and humidity responsive hydrogel of the present invention is prepared by direct polymerization at room temperature under ultraviolet light using a "one-pot method". The process is simple and easy to promote industrialization.

[0027] 6. The temperature and humidity responsive hydrogel of this invention exhibits volume stability, maintaining stable interfacial contact during phase transitions and preserving its volume during these transitions, thus preventing volume shrinkage during long-term use. This provides a favorable foundation for its bonding with transparent layers of various shapes.

[0028] 7. The temperature and humidity responsive hydrogel of the present invention has excellent flexibility and adhesion. It can be cut into any shape according to the application scenario and easily adapt to the greenhouse light-transmitting layer. It can be used to bond transparent layers of various shapes and materials.

[0029] 8. The intelligent color-changing greenhouse prepared by this invention combines the advantages of excellent passive synergistic cooling and active control of light transmittance in its structural design. In summer, when sunlight is intense, the temperature is high and humidity is low. The dual temperature and humidity response allows for faster color change and heat insulation through two synergistic responses, while ensuring superior heat insulation performance. When sunlight is needed, a humidity sensor can monitor real-time humidity and actively activate a humidifier to increase ambient humidity, thereby maintaining high transmittance of the gel and achieving active control.

[0030] 9. The temperature and humidity dual-response hydrogel of the present invention is the core component for realizing the temperature and humidity dual-response function of intelligent color-changing greenhouse. In addition to having dual-response function, it can also be effectively combined with the active humidification and color-changing layer of the greenhouse to effectively manage the greenhouse synchronously with light, heat and humidity and adapt to the environment. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of an intelligent color-changing greenhouse structure with dual temperature and humidity responses, provided as an embodiment of the present invention.

[0032] Figure 2 A photograph showing the change in transparency of the temperature and humidity-responsive hydrogel prepared in Example 1 as a function of humidity.

[0033] Figure 3 A photograph showing the change in transparency of the temperature and humidity-responsive hydrogel prepared in Example 1 as a function of temperature.

[0034] Figure 4 The image shows the 550 nm visible light transmittance of the temperature and humidity dual-responsive hydrogel prepared in Example 1 as a function of humidity.

[0035] Figure 5 The image shows the 550 nm visible light transmittance of the temperature and humidity dual-responsive hydrogel prepared in Example 1 as a function of temperature.

[0036] Figure 6 The graph shows the temperature variation of the intelligent color-changing greenhouse with dual temperature and humidity response prepared in Example 1 as a function of xenon lamp irradiation time.

[0037] Figure 7 The spectrum of 550 nm visible light transmittance as a function of humidity for the colorless and transparent hydrogels prepared in Comparative Examples 1, 2 and 3.

[0038] Figure 8 The spectrum shows the 550 nm visible light transmittance of the colorless and transparent hydrogels prepared in Comparative Examples 1, 2 and 3 as a function of temperature. Detailed Implementation

[0039] The following embodiments further illustrate the specific implementation of the present invention, but the implementation and protection of the present invention are not limited thereto. It should be noted that any processes not specifically described below are those that can be implemented or understood by those skilled in the art based on existing technology. Reagents or instruments whose manufacturers are not specified are considered to be conventional products that can be purchased commercially.

[0040] The present invention will be further described below with reference to the embodiments. The visible light transmittance and other properties of the hydrogels obtained in the embodiments were measured using the methods disclosed in ACS Appl. Mater. Interfaces 2024, 16, 21013-21023. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0041] like Figure 1 As shown, the present invention provides an intelligent color-changing greenhouse with dual temperature and humidity response, including a greenhouse light-transmitting layer 1, a temperature and humidity dual-response color-changing layer 2, a support component 3, an indoor bracket 4, a humidifier 5, and a humidity sensor 6; wherein, the humidifier 5 and the humidity sensor 6 are supported inside the greenhouse by the indoor bracket 4. Furthermore, the support component 3 includes, but is not limited to, a metal frame, a reinforced concrete frame, a wooden frame, a brick and mortar frame, etc. Furthermore, the temperature and humidity dual-response color-changing layer 2 is a temperature and humidity dual-response hydrogel; Furthermore, the greenhouse light-transmitting layer 1 and the temperature and humidity dual-response color-changing layer 2 are attached together; Furthermore, the greenhouse light-transmitting layer 1 is a transparent plastic film or transparent glass, including but not limited to polyvinyl chloride greenhouse film, polyethylene greenhouse film, and transparent glass.

[0042] Example 1 At room temperature, 8g of acrylic acid, 10g of deionized water, 8g of betaine, 14g of PEG600, and 0.017g of N,N'-methylenebisacrylamide were added to a glass bottle. The mixture was stirred for 10 min until the solids were completely dissolved, resulting in a clear and transparent solution. Nitrogen gas was then introduced to remove oxygen from the solution. Finally, 0.018g of 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone was added, and the mixture was stirred until the solution was clear and transparent, yielding the reaction solution. The reaction solution was then injected into a mold with a thickness of 1mm, consisting of two glass plates with a gasket sandwiched between them. The mold was sonicated for 5 min to remove air bubbles. Finally, the glass mold was placed under an 80 W, 320 nm UV lamp for 0.5 h to initiate polymerization at 0℃, resulting in a temperature and humidity responsive hydrogel.

[0043] Figure 2 A photograph showing the change in transparency of the temperature- and humidity-responsive hydrogel prepared in Example 1 as a function of humidity. Figure 2 It is evident that, under room temperature conditions, when the gel is stored in an environment with decreasing humidity from high to low, the gel changes from a colorless and transparent state to a white phase transition state, and the transparency gradually decreases. This indicates that the gel can change its transparency and achieve the function of color-changing, heat insulation, and cooling by changing the ambient humidity.

[0044] Figure 3 A photograph showing the change in transparency of the temperature- and humidity-responsive hydrogel prepared in Example 1 as a function of temperature. Figure 3 It can be seen that, under sealed conditions, when the gel is heated on the heating platform, the gel changes from a colorless and transparent state to a white phase transition state, and the transparency gradually decreases. This indicates that the gel can change its transparency and achieve the function of color-changing heat insulation and cooling by changing the ambient temperature.

[0045] Figure 4 The image shows the 550 nm visible light transmittance of the temperature and humidity-responsive hydrogel prepared in Example 1 as a function of humidity. Figure 4 As can be seen, the transmittance of the hydrogel at a wavelength of 550 nm changes with humidity. When the relative humidity is below 50%, the transmittance of the hydrogel at a wavelength of 550 nm is very low, and it appears to be opaque. In the opaque state, the hydrogel can effectively reduce the exchange of light and heat between the inside and outside of the greenhouse, achieving the effect of heat insulation and cooling. However, when the relative humidity is above 50%, the transmittance of the hydrogel at a wavelength of 550 nm gradually increases, and it appears to be transparent, which can effectively facilitate the exchange of light and heat between the inside and outside of the container, achieving the effect of light and heat collection.

[0046] Figure 5 The image shows the 550 nm visible light transmittance as a function of temperature for the temperature and humidity-responsive hydrogel prepared in Example 1. Figure 5 As can be seen, the transmittance of the hydrogel at a wavelength of 550nm changes with temperature. The transmittance of the hydrogel is very low, close to 0, in the temperature range of 50-60℃, and it is opaque. In the opaque state, the hydrogel can effectively reduce the exchange of light and heat between the inside and outside of the greenhouse, achieving the effect of heat insulation and cooling. In the temperature range of 10-30℃, the transmittance of the hydrogel is higher than 80%, and it is transparent, which can effectively facilitate the exchange of light and heat between the inside and outside of the container, achieving the effect of light and heat collection.

[0047] The temperature and humidity dual-response hydrogel prepared in Example 1 was attached to the inner side of the greenhouse light-transmitting layer and covered the outer side of the greenhouse built by the support components. Then, the humidifier, humidity sensor and indoor bracket were connected and supported inside the greenhouse, thereby preparing an intelligent color-changing greenhouse with temperature and humidity dual response. Figure 6This is a graph showing the temperature change of the intelligent color-changing greenhouse with dual temperature and humidity response prepared in Example 1 as a function of simulated solar xenon lamp irradiation time. The experiment shows that after 30 minutes of daylight, the temperature of the intelligent color-changing greenhouse with dual temperature and humidity response is 33.4℃, while the temperature of a conventional greenhouse reaches 40.5℃, representing a temperature drop of 7.1℃. During daylight exposure, the temperature and humidity-responsive hydrogel gradually changes from transparent and colorless to white. Real-time observation of the humidity sensor reading shows a relative humidity of 33% inside the greenhouse. By turning on the humidifier to increase the relative humidity to 60%, the gel becomes transparent, effectively facilitating light and heat exchange between the greenhouse interior and the outside environment, achieving the desired light and heat transmission. This intelligent color-changing greenhouse achieves excellent passive synergistic cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in multiple fields such as food display cases, plant greenhouses, intelligent building windows, and sunrooms.

[0048] Example 2 At room temperature, 8g of acrylic acid, 10g of deionized water, 8g of betaine, 14g of PEG600, and 0.017g of N,N'-methylenebisacrylamide were added to a glass bottle. The mixture was stirred for 10 min until the solids were completely dissolved, resulting in a clear and transparent solution. Nitrogen gas was then introduced to remove oxygen from the solution. Finally, 0.036g of 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone was added, and the mixture was stirred until the solution was clear and transparent, yielding the reaction solution. The reaction solution was then injected into a mold with a thickness of 1mm, consisting of two glass plates with a gasket sandwiched between them. The mold was sonicated for 5 min to remove air bubbles. Finally, the mold was placed under an 80 W, 320 nm UV lamp for 0.5 h to initiate polymerization at 0℃, resulting in a temperature and humidity responsive hydrogel.

[0049] The temperature and humidity dual-responsive hydrogel prepared in Example 2 was attached to the inner side of the greenhouse's light-transmitting layer and then covered the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse, thus creating a smart color-changing greenhouse with dual temperature and humidity responses. Experiments showed that after 30 minutes of daylight, the temperature in the smart color-changing greenhouse was 34.4℃, while the temperature in a typical greenhouse reached 40.1℃, representing a temperature drop of 5.7℃. During daylight exposure, the temperature and humidity dual-responsive hydrogel gradually changed from transparent and colorless to white. Real-time observation of the humidity sensor reading showed a relative humidity of 25% inside the greenhouse. By turning on the humidifier and increasing the relative humidity to 74%, the gel became transparent, effectively facilitating light and heat exchange between the greenhouse interior and exterior, achieving the desired light and heat transmission. This smart color-changing greenhouse achieves excellent passive cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in various fields such as food display cases, plant greenhouses, smart building windows, and sunrooms.

[0050] Example 3 At room temperature, 8g of methacrylic acid, 10g of deionized water, 8g of betaine, 14g of PEG600, and 0.064g of polyethylene glycol diacrylate were added to a glass bottle. The mixture was stirred for 10 min until the solids were completely dissolved, resulting in a clear and transparent solution. Nitrogen gas was then introduced to remove oxygen from the solution. Finally, 0.055g of 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone was added, and the mixture was stirred until the solution was clear and transparent, yielding the reaction solution. The reaction solution was then injected into a mold with a thickness of 1mm, consisting of two glass plates with a gasket sandwiched between them. The mold was sonicated for 5 min to remove air bubbles. Finally, the mold was placed under an 80 W, 320 nm UV lamp for 0.5 h to initiate polymerization at 0℃, resulting in a temperature and humidity responsive hydrogel.

[0051] The temperature and humidity dual-responsive hydrogel prepared in Example 3 was attached to the inner side of the greenhouse's light-transmitting layer and then covered the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse, thus creating a smart color-changing greenhouse with dual temperature and humidity responses. Experiments showed that after 30 minutes of daylight, the temperature of the smart color-changing greenhouse was 33.7℃, while the temperature of a conventional greenhouse reached 40.2℃, representing a temperature drop of 6.5℃. During daylight exposure, the temperature and humidity dual-responsive hydrogel gradually changed from transparent and colorless to white. Real-time observation of the humidity sensor reading showed a relative humidity of 32% inside the greenhouse. By turning on the humidifier and increasing the relative humidity to 72%, the gel became transparent, effectively facilitating light and heat exchange between the greenhouse interior and exterior, achieving the desired light and heat transmission. This smart color-changing greenhouse achieves excellent passive cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in various fields such as food display cases, plant greenhouses, smart building windows, and sunrooms.

[0052] Example 4 At room temperature, 10g of acrylic acid, 10g of deionized water, 8g of betaine, 14g of PEG600, and 0.064g of N,N'-methylenebisacrylamide were added to a glass bottle. The mixture was stirred for 10 min until the solids were completely dissolved, resulting in a clear and transparent solution. Nitrogen gas was then introduced to remove oxygen from the solution. Finally, 0.091g of 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone was added, and the mixture was stirred until the solution was clear and transparent, yielding the reaction solution. The reaction solution was then injected into a mold with a thickness of 1mm, consisting of two glass plates with a gasket sandwiched between them. The mold was sonicated for 5 min to remove air bubbles. Finally, the glass mold was placed under an 80 W, 320 nm UV lamp for 0.5 h to initiate polymerization at a reaction temperature of 10℃, resulting in a temperature and humidity responsive hydrogel.

[0053] The temperature and humidity dual-responsive hydrogel prepared in Example 4 was attached to the inner side of the greenhouse's light-transmitting layer and then covered the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse, thus creating a smart color-changing greenhouse with dual temperature and humidity responses. Experiments showed that after 30 minutes of daylight, the temperature in the smart color-changing greenhouse was 35.5°C, while the temperature in a typical greenhouse reached 40.5°C, representing a temperature drop of 5°C. During daylight exposure, the temperature and humidity dual-responsive hydrogel gradually changed from transparent and colorless to white. Real-time observation of the humidity sensor reading showed a relative humidity of 27% inside the greenhouse. By turning on the humidifier and increasing the relative humidity to 63%, the gel became transparent, effectively facilitating light and heat exchange between the greenhouse interior and exterior, achieving the desired light and heat transmission. This smart color-changing greenhouse achieves excellent passive cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in various fields such as food display cases, plant greenhouses, smart windows in buildings, and sunrooms.

[0054] Example 5 At room temperature, 10g of acrylic acid, 10g of deionized water, 8g of betaine, 28g of PEG800, and 0.064g of N,N'-methylenebisacrylamide were added to a glass bottle. The mixture was stirred for 10 min until the solids were completely dissolved, resulting in a clear and transparent solution. Nitrogen gas was then introduced to remove oxygen from the solution. Finally, 0.114g of 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone was added, and the mixture was stirred until the solution was clear and transparent, yielding the reaction solution. The reaction solution was then injected into a mold with a thickness of 1mm, consisting of two glass plates with a gasket sandwiched between them. The mold was sonicated for 5 min to remove air bubbles. Finally, the glass mold was placed under an 80 W, 320 nm UV lamp for 1 h to initiate polymerization at a reaction temperature of 10℃, resulting in a temperature and humidity responsive hydrogel.

[0055] The temperature and humidity dual-responsive hydrogel prepared in Example 5 was attached to the inner side of the greenhouse's light-transmitting layer and then covered the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse, thus creating a smart color-changing greenhouse with dual temperature and humidity responses. Experiments showed that after 30 minutes of daylight, the temperature in the smart color-changing greenhouse was 34.4°C, while the temperature in a typical greenhouse reached 40.4°C, representing a temperature drop of 6°C. During daylight exposure, the temperature and humidity dual-responsive hydrogel gradually changed from transparent and colorless to white. Real-time observation of the humidity sensor reading showed a relative humidity of 33% inside the greenhouse. By turning on the humidifier and increasing the relative humidity to 63%, the gel became transparent, effectively facilitating light and heat exchange between the greenhouse interior and exterior, achieving the desired light and heat transmission. This smart color-changing greenhouse combines excellent passive cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in various fields such as food display cases, plant greenhouses, smart windows in buildings, and sunrooms.

[0056] Example 6 At room temperature, 10g of methacrylic acid, 8g of deionized water, 10g of betaine, 28g of PEG800, and 0.24g of polyethylene glycol diacrylate were added to a glass bottle. The mixture was stirred for 10 min until the solids were completely dissolved, resulting in a clear and transparent solution. Nitrogen gas was then introduced to remove oxygen from the solution. Finally, 0.023g of 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone was added, and the mixture was stirred until the solution was clear and transparent, yielding the reaction solution. The reaction solution was then injected into a mold with a thickness of 2mm, consisting of two glass plates with a gasket sandwiched between them. The mold was sonicated for 5 min to remove air bubbles. Finally, the glass mold was placed under a 100 W, 320 nm UV lamp for 1 h to initiate polymerization at a reaction temperature of 10℃, resulting in a temperature and humidity responsive hydrogel.

[0057] The temperature and humidity dual-responsive hydrogel prepared in Example 6 was attached to the inner side of the greenhouse's light-transmitting layer and then covered the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse, thus creating a smart color-changing greenhouse with dual temperature and humidity responses. Experiments showed that after 30 minutes of daylight, the temperature of the smart color-changing greenhouse was 33.4°C, while the temperature of a conventional greenhouse reached 40.4°C, representing a temperature drop of 7°C. During daylight exposure, the temperature and humidity dual-responsive hydrogel gradually changed from transparent and colorless to white. Real-time observation of the humidity sensor reading showed a relative humidity of 21% inside the greenhouse. By turning on the humidifier and increasing the relative humidity to 69%, the gel became transparent, effectively facilitating light and heat exchange between the greenhouse interior and exterior, achieving the desired light and heat transmission. This smart color-changing greenhouse achieves excellent passive cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in various fields such as food display cases, plant greenhouses, smart building windows, and sunrooms.

[0058] Example 7 At room temperature, 15g of acrylic acid, 10g of deionized water, 10g of betaine, 28g of PEG800, and 0.16g of N,N'-methylenebisacrylamide were added to a glass bottle. The mixture was stirred for 10 min until the solids were completely dissolved, resulting in a clear and transparent solution. Nitrogen gas was then introduced to remove oxygen from the solution. Finally, 0.068g of 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone was added, and the mixture was stirred until the solution was clear and transparent, yielding the reaction solution. The reaction solution was then injected into a mold with a thickness of 2mm, consisting of two glass plates with a gasket sandwiched between them. The mold was sonicated for 5 min to remove air bubbles. Finally, the glass mold was placed under a 100 W, 320 nm UV lamp for 1 h to initiate polymerization at a reaction temperature of 20℃, resulting in a temperature and humidity responsive hydrogel.

[0059] The temperature and humidity dual-responsive hydrogel prepared in Example 7 was attached to the inner side of the greenhouse's light-transmitting layer and then covered the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse, thus creating a smart color-changing greenhouse with dual temperature and humidity responses. Experiments showed that after 30 minutes of daylight, the temperature in the smart color-changing greenhouse was 32.5°C, while the temperature in a typical greenhouse reached 39.1°C, representing a temperature drop of 6.6°C. During daylight exposure, the temperature and humidity dual-responsive hydrogel gradually changed from transparent and colorless to white. Real-time observation of the humidity sensor reading showed a relative humidity of 22% inside the greenhouse. By turning on the humidifier and increasing the relative humidity to 63%, the gel became transparent, effectively facilitating light and heat exchange between the greenhouse interior and exterior, achieving the desired light and heat transmission. This smart color-changing greenhouse achieves excellent passive cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in various fields such as food display cases, plant greenhouses, smart building windows, and sunrooms.

[0060] Example 8 At room temperature, 15g of acrylic acid, 10g of deionized water, 10g of betaine, 28g of PEG800, and 0.16g of N,N'-methylenebisacrylamide were added to a glass bottle. The mixture was stirred for 10 minutes until the solids were completely dissolved, resulting in a clear and transparent solution. Argon gas was then introduced to remove oxygen from the solution. Finally, 0.091g of α-ketoglutaric acid was added, and the mixture was stirred until the solution became clear and transparent, yielding the reaction solution. The reaction solution was then injected into a 2mm thick polytetrafluoroethylene grooved mold with a transparent cover and sonicated for 5 minutes to remove air bubbles. Finally, the glass mold was placed under a 100W, 365nm UV lamp for 1 hour to initiate polymerization at a reaction temperature of 20℃, resulting in a temperature and humidity responsive hydrogel.

[0061] The temperature and humidity dual-responsive hydrogel prepared in Example 8 was attached to the inner side of the greenhouse's light-transmitting layer and then covered the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse, thus creating a smart color-changing greenhouse with dual temperature and humidity responses. Experiments showed that after 30 minutes of daylight, the temperature in the smart color-changing greenhouse was 33.6°C, while the temperature in a typical greenhouse reached 40.4°C, representing a temperature drop of 6.8°C. During daylight exposure, the temperature and humidity dual-responsive hydrogel gradually changed from transparent and colorless to white. Real-time observation of the humidity sensor reading showed a relative humidity of 40% inside the greenhouse. By turning on the humidifier and increasing the relative humidity to 69%, the gel became transparent, effectively facilitating light and heat exchange between the greenhouse interior and exterior, achieving the desired light and heat transmission. This smart color-changing greenhouse achieves excellent passive cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in various fields such as food display cases, plant greenhouses, smart windows in buildings, and sunrooms.

[0062] Example 9 At room temperature, 15g of methacrylic acid, 10g of deionized water, 10g of betaine, 42g of PEG1000, and 0.599g of polyethylene glycol diacrylate were added to a glass bottle. The mixture was stirred for 10 minutes until the solids were completely dissolved, resulting in a clear and transparent solution. Argon gas was then introduced to remove oxygen from the solution. Finally, 0.122g of α-ketoglutaric acid was added, and the mixture was stirred until the solution became clear and transparent, yielding the reaction solution. The reaction solution was then injected into a 2mm thick polytetrafluoroethylene grooved mold with a transparent cover and sonicated for 5 minutes to remove air bubbles. Finally, the glass mold was placed under a 100W, 365nm UV lamp for 2 hours to initiate polymerization at a reaction temperature of 20℃, resulting in a temperature and humidity responsive hydrogel.

[0063] The temperature and humidity dual-responsive hydrogel prepared in Example 9 was attached to the inner side of the greenhouse's light-transmitting layer and then covered the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse, thus creating a smart color-changing greenhouse with dual temperature and humidity responses. Experiments showed that after 30 minutes of daylight, the temperature in the smart color-changing greenhouse was 33.1°C, while the temperature in a typical greenhouse reached 39.7°C, representing a temperature drop of 6.6°C. During daylight exposure, the temperature and humidity dual-responsive hydrogel gradually changed from transparent and colorless to white. Real-time observation of the humidity sensor reading showed a relative humidity of 32% inside the greenhouse. By turning on the humidifier and increasing the relative humidity to 76%, the gel became transparent, effectively facilitating light and heat exchange between the greenhouse interior and exterior, achieving the desired light and heat transmission. This smart color-changing greenhouse combines excellent passive cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in various fields such as food display cases, plant greenhouses, smart building windows, and sunrooms.

[0064] Example 10 At room temperature, 25g of acrylic acid, 10g of deionized water, 10g of betaine, 42g of PEG1000, and 0.053g of N,N'-methylenebisacrylamide were added to a glass bottle. The mixture was stirred for 10 min until the solids were completely dissolved, resulting in a clear and transparent solution. Argon gas was then introduced to remove oxygen from the solution. Finally, 0.253g of α-ketoglutaric acid was added, and the mixture was stirred until the solution became clear and transparent, yielding the reaction solution. The reaction solution was then injected into a 2mm thick polytetrafluoroethylene grooved mold with a transparent cover and sonicated for 5 min to remove air bubbles. Finally, the glass mold was placed under a 100W, 365nm UV lamp for 2 h to initiate polymerization at a reaction temperature of 30℃, resulting in a temperature and humidity responsive hydrogel.

[0065] The temperature and humidity dual-responsive hydrogel prepared in Example 10 was attached to the inner side of the greenhouse's light-transmitting layer and then covered the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse, thus creating a smart color-changing greenhouse with dual temperature and humidity responses. Experiments showed that after 30 minutes of daylight, the temperature in the smart color-changing greenhouse was 34.5°C, while the temperature in a typical greenhouse reached 40.4°C, representing a temperature drop of 5.9°C. During daylight exposure, the temperature and humidity dual-responsive hydrogel gradually changed from transparent and colorless to white. Real-time observation of the humidity sensor reading showed a relative humidity of 37% inside the greenhouse. By turning on the humidifier and increasing the relative humidity to 71%, the gel became transparent, effectively facilitating light and heat exchange between the greenhouse interior and exterior, achieving the desired light and heat transmission. This smart color-changing greenhouse achieves excellent passive cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in various fields such as food display cases, plant greenhouses, smart building windows, and sunrooms.

[0066] Example 11 At room temperature, 25g of acrylic acid, 10g of deionized water, 12g of betaine, 42g of PEG1000, and 0.053g of N,N'-methylenebisacrylamide were added to a glass bottle. The mixture was stirred for 10 minutes until the solids were completely dissolved, resulting in a clear and transparent solution. Argon gas was then introduced to remove oxygen from the solution. Finally, 0.051g of α-ketoglutaric acid was added, and the mixture was stirred until the solution became clear and transparent, yielding the reaction solution. The reaction solution was then injected into a 3mm thick polytetrafluoroethylene grooved mold with a transparent cover and sonicated for 5 minutes to remove air bubbles. Finally, the glass mold was placed under a 120W, 365nm UV lamp for 2 hours to initiate polymerization at a reaction temperature of 30℃, resulting in a temperature and humidity responsive hydrogel.

[0067] The temperature and humidity dual-responsive hydrogel prepared in Example 11 was attached to the inner side of the greenhouse's light-transmitting layer and then covered the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse, thus creating a smart color-changing greenhouse with dual temperature and humidity responses. Experiments showed that after 30 minutes of daylight, the temperature in the smart color-changing greenhouse was 33.7°C, while the temperature in a typical greenhouse reached 38.4°C, representing a temperature drop of 4.7°C. During daylight exposure, the temperature and humidity dual-responsive hydrogel gradually changed from transparent and colorless to white. Real-time observation of the humidity sensor reading showed a relative humidity of 27% inside the greenhouse. By turning on the humidifier to increase the relative humidity to 65%, the gel became transparent, effectively facilitating light and heat exchange between the greenhouse interior and exterior, achieving the desired light and heat transmission. This smart color-changing greenhouse achieves excellent passive cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in various fields such as food display cases, plant greenhouses, smart building windows, and sunrooms.

[0068] Example 12 At room temperature, 25g of methacrylic acid, 10g of deionized water, 12g of betaine, 42g of PEG1000, and 0.2g of polyethylene glycol diacrylate were added to a glass bottle. The mixture was stirred for 10 minutes until the solids were completely dissolved, resulting in a clear and transparent solution. Argon gas was then introduced to remove oxygen from the solution. Finally, 0.101g of α-ketoglutaric acid was added, and the mixture was stirred until the solution became clear and transparent, yielding the reaction solution. The reaction solution was then injected into a 3mm thick polytetrafluoroethylene grooved mold with a transparent cover and sonicated for 5 minutes to remove air bubbles. Finally, the glass mold was placed under a 120W 365nm UV lamp for 2 hours to initiate polymerization at a reaction temperature of 30℃, resulting in a temperature and humidity responsive hydrogel.

[0069] The temperature and humidity dual-responsive hydrogel prepared in Example 12 was attached to the inner side of the greenhouse's light-transmitting layer and then covered the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and supported inside the greenhouse, thus creating a smart color-changing greenhouse with dual temperature and humidity responses. Experiments showed that after 30 minutes of daylight, the temperature of the smart color-changing greenhouse was 33.1°C, while the temperature of a conventional greenhouse reached 39.4°C, representing a temperature drop of 6.3°C. During daylight exposure, the temperature and humidity dual-responsive hydrogel gradually changed from transparent and colorless to white. Real-time observation of the humidity sensor reading showed a relative humidity of 25% inside the greenhouse. By turning on the humidifier and increasing the relative humidity to 61%, the gel became transparent, effectively facilitating light and heat exchange between the greenhouse interior and exterior, achieving the desired light and heat transmission. This smart color-changing greenhouse achieves excellent passive cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in various fields such as food display cases, plant greenhouses, smart windows in buildings, and sunrooms.

[0070] Example 13 At room temperature, 35g of acrylic acid, 10g of deionized water, 12g of betaine, 56g of PEG600, and 0.374g of N,N'-methylenebisacrylamide were added to a glass bottle and stirred for 10 min until the solids were completely dissolved, resulting in a clear and transparent mixture. Argon gas was then introduced to remove oxygen from the mixture. Finally, 0.213g of α-ketoglutaric acid was added, and the mixture was stirred until the solution became clear and transparent, yielding the reaction solution. The reaction solution was then injected into a 3mm thick polytetrafluoroethylene grooved mold with a transparent cover and sonicated for 5 min to remove air bubbles. Finally, the mold was placed under a 120 W 365 nm UV lamp for 3 h to initiate polymerization at a reaction temperature of 40℃, resulting in a temperature and humidity responsive hydrogel.

[0071] The temperature and humidity dual-responsive hydrogel prepared in Example 13 was attached to the inner side of the greenhouse's light-transmitting layer and then covered the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse, thus creating a smart color-changing greenhouse with dual temperature and humidity responses. Experiments showed that after 30 minutes of daylight, the temperature of the smart color-changing greenhouse was 31.4°C, while the temperature of a typical greenhouse reached 37.4°C, representing a temperature drop of 6°C. During daylight exposure, the temperature and humidity dual-responsive hydrogel gradually changed from transparent and colorless to white. Real-time observation of the humidity sensor reading showed a relative humidity of 33% inside the greenhouse. By turning on the humidifier and increasing the relative humidity to 74%, the gel became transparent, effectively facilitating light and heat exchange between the greenhouse interior and exterior, achieving the desired light and heat transmission. This smart color-changing greenhouse achieves excellent passive cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in various fields such as food display cases, plant greenhouses, smart building windows, and sunrooms.

[0072] Example 14 At room temperature, 35g of acrylic acid, 10g of deionized water, 12g of betaine, 56g of PEG800, and 0.374g of N,N'-methylenebisacrylamide were added to a glass bottle and stirred for 10 min until the solids were completely dissolved to obtain a clear and transparent mixture. Argon gas was then introduced to remove oxygen from the mixture. Finally, 0.284g of α-ketoglutaric acid was added, and the mixture was stirred until the solution became clear and transparent, yielding the reaction solution. The resulting reaction solution was then injected into a 3mm thick polytetrafluoroethylene grooved mold with a transparent cover and sonicated for 5 min to remove air bubbles. Finally, the mold was placed under a 120 W 365nm UV lamp for 3 h to initiate polymerization at a reaction temperature of 40℃, resulting in a temperature and humidity responsive hydrogel.

[0073] The temperature and humidity dual-responsive hydrogel prepared in Example 14 was attached to the inner side of the greenhouse's light-transmitting layer and then covered the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse, thus creating a smart color-changing greenhouse with dual temperature and humidity responses. Experiments showed that after 30 minutes of daylight, the temperature of the smart color-changing greenhouse was 34.2°C, while the temperature of a conventional greenhouse reached 38.4°C, representing a temperature drop of 4.2°C. During daylight exposure, the temperature and humidity dual-responsive hydrogel gradually changed from transparent and colorless to white. Real-time observation of the humidity sensor reading showed a relative humidity of 20% inside the greenhouse. By turning on the humidifier to increase the relative humidity to 60%, the gel became transparent, effectively facilitating light and heat exchange between the greenhouse interior and exterior, achieving the desired light and heat transmission. This smart color-changing greenhouse achieves excellent passive cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in various fields such as food display cases, plant greenhouses, smart building windows, and sunrooms.

[0074] Example 15 At room temperature, 35g of methacrylic acid, 10g of deionized water, 12g of betaine, 56g of PEG1000, and 1.398g of polyethylene glycol diacrylate were added to a glass bottle. The mixture was stirred for 10 minutes until the solids were completely dissolved, resulting in a clear and transparent solution. Argon gas was then introduced to remove oxygen from the solution. Finally, 0.355g of α-ketoglutaric acid was added, and the mixture was stirred until the solution became clear and transparent, yielding the reaction solution. The reaction solution was then injected into a 3mm thick polytetrafluoroethylene grooved mold with a transparent cover and sonicated for 5 minutes to remove air bubbles. Finally, the mold was placed under a 120W 365nm UV lamp for 3 hours to initiate polymerization at a reaction temperature of 40℃, resulting in a temperature and humidity responsive hydrogel.

[0075] The temperature and humidity dual-responsive hydrogel prepared in Example 15 was attached to the inner side of the greenhouse's light-transmitting layer and then covered the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse, thus creating a smart color-changing greenhouse with dual temperature and humidity responses. Experiments showed that after 30 minutes of daylight, the temperature in the smart color-changing greenhouse was 32.8°C, while the temperature in a typical greenhouse reached 37.4°C, representing a temperature drop of 4.6°C. During daylight exposure, the temperature and humidity dual-responsive hydrogel gradually changed from transparent and colorless to white. Real-time observation of the humidity sensor reading showed a relative humidity of 33% inside the greenhouse. By turning on the humidifier and increasing the relative humidity to 65%, the gel became transparent, effectively facilitating light and heat exchange between the greenhouse interior and exterior, achieving the desired light and heat transmission. This smart color-changing greenhouse achieves excellent passive cooling and active light transmittance control in its structural design, fully demonstrating its potential application value in various fields such as food display cases, plant greenhouses, smart building windows, and sunrooms.

[0076] Comparative Example 1 At room temperature, 10g of acrylic acid, 10g of deionized water, 10g of betaine, and 0.021g of N,N'-methylenebisacrylamide were added to a glass bottle. The mixture was stirred for 10 min until the solids were completely dissolved, resulting in a clear and transparent solution. Nitrogen gas was then introduced to remove oxygen from the solution. Finally, 0.023g of 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone was added, and the mixture was stirred until the solution was clear and transparent, yielding the reaction solution. The reaction solution was then injected into a mold with a thickness of 1mm, consisting of two glass plates with a gasket sandwiched between them. The mold was sonicated for 5 min to remove air bubbles. Finally, the mold was placed under a 100 W, 320 nm UV lamp for 0.5 h to initiate polymerization at a reaction temperature of 0℃, resulting in a non-responsive, transparent hydrogel.

[0077] The hydrogel prepared in Comparative Example 1 is a non-responsive transparent hydrogel, with no temperature or humidity response. Figure 7 The image shows the 550 nm visible light transmittance of the non-responsive transparent hydrogel prepared in Comparative Example 1 as a function of humidity. Figure 8 The spectrum of the 550 nm visible light transmittance of the non-responsive transparent hydrogel prepared for Comparative Example 1 as a function of temperature.

[0078] The non-responsive transparent hydrogel prepared in Comparative Example 1 was attached to the inner side of the greenhouse's light-transmitting layer and then placed over the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse. The resulting greenhouse, after 30 minutes of daylight exposure, had a temperature of 38.8°C, while a typical greenhouse had a temperature of 39.2°C, indicating that it failed to provide insulation and cooling. The gel remained transparent throughout. Real-time observation of the humidity sensor showed a relative humidity of 31% inside the greenhouse. Increasing the relative humidity to 68% by turning on the humidifier did not result in a significant change in the gel's appearance, demonstrating a lack of intelligent color-changing functionality. This indicates that without the addition of polyethylene glycol, a smart color-changing greenhouse with dual temperature and humidity responses cannot be obtained, and the multi-functional integration of passive synergistic cooling and active control of light transmittance cannot be achieved.

[0079] Comparative Example 2 At room temperature, 10g of methacrylic acid, 10g of deionized water, 56g of PEG1000, and 0.021g of N,N'-methylenebisacrylamide were added to a glass bottle. The mixture was stirred for 10 min until the solids were completely dissolved, resulting in a clear and transparent solution. Nitrogen gas was then introduced to remove oxygen from the solution. Finally, 0.023g of 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone was added, and the mixture was stirred until the solution was clear and transparent, yielding the reaction solution. The reaction solution was then injected into a mold with a thickness of 1mm, consisting of two glass plates with a gasket sandwiched between them. The mold was sonicated for 5 min to remove air bubbles. Finally, the mold was placed under a 100 W, 320 nm UV lamp for 0.5 h to initiate polymerization at a reaction temperature of 0℃, resulting in a non-responsive, transparent hydrogel.

[0080] The hydrogel prepared in Comparative Example 2 is a non-responsive transparent hydrogel, with no temperature or humidity response. Figure 7 The image shows the 550 nm visible light transmittance of the non-responsive transparent hydrogel prepared in Comparative Example 2 as a function of humidity. Figure 8 The spectrum of the 550 nm visible light transmittance of the non-responsive transparent hydrogel prepared for Comparative Example 2 as a function of temperature.

[0081] The non-responsive transparent hydrogel prepared in Comparative Example 2 was attached to the inner side of the greenhouse's light-transmitting layer and then placed over the outer side of the greenhouse, which was constructed using supporting components. A humidifier, humidity sensor, and indoor support were then connected and placed inside the greenhouse. The resulting greenhouse, after 30 minutes of daylight exposure, had a temperature of 38.7°C, while a typical greenhouse had a temperature of 39.1°C, indicating that it failed to provide insulation and cooling. The gel remained transparent throughout. Real-time observation of the humidity sensor showed a relative humidity of 28% inside the greenhouse. Increasing the relative humidity to 69% by turning on the humidifier did not result in a significant change in the gel's appearance, demonstrating a lack of intelligent color-changing functionality. This indicates that without the addition of betaine, a smart color-changing greenhouse with dual temperature and humidity responses cannot be obtained, and the multi-functional integration of passive synergistic cooling and active control of light transmittance cannot be achieved.

[0082] Comparative Example 3 At room temperature, 10g of acrylic acid, 10g of deionized water, 10g of betaine, 56g of PEG2000, and 0.021g of N,N'-methylenebisacrylamide were added to a glass bottle. The mixture was stirred for 10 min until the solids were completely dissolved, resulting in a clear and transparent solution. Nitrogen gas was then introduced to remove oxygen from the solution. Finally, 0.023g of 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone was added, and the mixture was stirred until the solution was clear and transparent, yielding the reaction solution. The reaction solution was then injected into a mold with a thickness of 1mm, consisting of two glass plates with a gasket sandwiched between them. The mold was sonicated for 5 min to remove air bubbles. Finally, the mold was placed under a 100 W, 320 nm UV lamp for 0.5 h to initiate polymerization at a reaction temperature of 0℃, resulting in a non-responsive, transparent hydrogel.

[0083] The hydrogel prepared in Comparative Example 3 is a non-responsive transparent hydrogel, with no temperature or humidity response. Figure 7 The image shows the 550 nm visible light transmittance of the non-responsive transparent hydrogel prepared in Comparative Example 3 as a function of humidity. Figure 8 The spectrum of the 550 nm visible light transmittance of the non-responsive transparent hydrogel prepared for Comparative Example 3 as a function of temperature.

[0084] The gel remained in a white phase-change state throughout. Real-time observation of the humidity sensor showed a relative humidity of 33% inside the greenhouse. When the relative humidity was increased to 68% by turning on the humidifier, the gel showed no significant change and did not possess intelligent color-changing functionality. This indicates that the molecular weight of PEG2000 is too large to obtain an intelligent color-changing greenhouse with dual responses to temperature and humidity, and it is impossible to achieve multi-functional integration of passive synergistic cooling and active control of light transmittance.

Claims

1. A smart color-changing greenhouse with temperature and humidity dual response, characterized in that, The greenhouse comprises a greenhouse light-transmitting layer (1), a temperature and humidity double-response color-changing layer (2), a support assembly (3), an indoor support (4), a humidifier (5), and a humidity sensor (6). The humidifier (4) and the humidity sensor (5) are supported in the greenhouse through the indoor support (4). The support assembly (3) is a metal frame, a reinforced concrete frame, a wooden frame, or a brick frame. The temperature and humidity double-response color-changing layer (2) is a temperature and humidity double-response hydrogel. The temperature and humidity double-response color-changing layer (2) is attached to the greenhouse light-transmitting layer (1). The greenhouse light-transmitting layer (1) is a transparent plastic film or transparent glass, including a polyvinyl chloride film, a polyethylene film, or transparent glass.

2. The smart variable color greenhouse with temperature and humidity dual response according to claim 1, characterized in that, The temperature and humidity double-response hydrogel comprises acrylic acid monomers, alkaloids, a crosslinking agent, an organic solvent, a photoinitiator, and deionized water.

3. The method for preparing the smart variable color greenhouse with temperature and humidity double response according to claim 1 or 2, characterized in that, The method comprises the following steps: (1) Building a greenhouse: first, build a greenhouse with a support assembly, then connect the humidifier, the humidity sensor, and the indoor support and support them inside the greenhouse. (2) Preparing a temperature and humidity double-response hydrogel: add monomers, alkaloids, a crosslinking agent, and an organic solvent to deionized water and stir until the solution is clear and transparent to obtain a mixed solution, then introduce inert gas into the mixed solution, add a photoinitiator, and stir until the solution is clear and transparent to obtain a reaction solution, pour the reaction solution into a mold, perform ultrasonic treatment, then initiate polymerization under ultraviolet light to obtain a temperature and humidity double-response hydrogel. (3) Assembling a temperature and humidity double-response intelligent color-changing greenhouse: attach the temperature and humidity double-response hydrogel obtained in step (2) to the inside of the greenhouse light-transmitting layer and cover it on the outside of the support assembly to obtain a temperature and humidity double-response intelligent color-changing greenhouse.

4. The preparation method of the smart variable color greenhouse with temperature and humidity double response according to claim 3, characterized in that, In step (2), the monomers are acrylic acid or methacrylic acid; the mass of the added acrylic acid is 80% to 350% of the mass of the added deionized water.

5. The method for preparing the smart variable color greenhouse with temperature and humidity double response according to claim 3, characterized in that, In step (2), the alkaloids are betaine; the mass of the added betaine is 80% to 120% of the mass of the added deionized water.

6. The method for preparing the smart variable color greenhouse with temperature and humidity double response according to claim 3, characterized in that, In step (2), the organic solvent is any one of polyethylene glycol with an average molecular weight of 600, 800, or 1000; the mass of the added organic solvent is 140% to 560% of the mass of the added deionized water.

7. The method for preparing the smart variable color greenhouse with temperature and humidity double response according to claim 3, characterized in that, In step (2), the crosslinking agent is N,N'-methylene bisacrylamide or polyethylene glycol diacrylate; the amount of the added crosslinking agent is 0.1% to 0.5% of the amount of the monomers.

8. The method for preparing the smart variable color greenhouse with temperature and humidity double response according to claim 3, characterized in that, In step (2), the photoinitiator is any one of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone or α-ketoglutaric acid; the mass of the added photoinitiator is 0.1% to 0.5% of the total mass of the monomers.

9. The preparation method of the smart variable color greenhouse with temperature and humidity double response according to claim 3, characterized in that, In step (2), the mold is any one of a polytetrafluoroethylene groove mold with a transparent cover plate or a mold assembled from two glass plates sandwiching a gasket with a thickness of 1 to 3 mm.

10. The method for preparing the smart variable color greenhouse with temperature and humidity double response according to claim 3, characterized in that, In step (2), the wavelength of the ultraviolet light is 320 to 365 nm, the power is 80 to 120 W, the ultraviolet light irradiation time is 0.5 to 3 h, and the polymerization reaction temperature is 0 to 40 ℃.

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