Double-temperature-zone preserved fresh flower phase change material and preparation method thereof
By dehydrating, bleaching, and solvent-replacing fresh roses, and then combining them with polyethylene glycol and paraffin wax to form a dual-temperature zone preserved flower phase change material, the problem of temperature regulation in preserved flower products is solved, and the combination of dual-temperature zone phase change energy storage and ornamental value is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- KUNMING UNIV OF SCI & TECH
- Filing Date
- 2025-12-30
- Publication Date
- 2026-04-14
AI Technical Summary
Existing preserved flower products fail to effectively utilize their function of regulating indoor temperature, and existing phase change materials are mostly single-temperature zones, making it difficult to meet the thermal management needs under different temperature environments.
Fresh roses are dehydrated and bleached, then reacted in a mixed solution of polyethylene glycol/carmine red pigment/tert-butanol after solvent replacement with tert-butanol. After freeze-drying, phase change paraffin is loaded to form a dual-temperature zone preserved flower phase change material. Combining the phase change characteristics of polyethylene glycol and paraffin, dual-temperature zone phase change energy storage is achieved.
The prepared dual-temperature zone preserved flower phase change material stores heat through a phase change reaction within the range of 4-47.5℃, which significantly expands the application range of preserved flowers, giving them the functional value of regulating indoor temperature while maintaining their ornamental value.
Smart Images
Figure CN121848852A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of phase change material technology, and specifically relates to a dual-temperature zone immortal flower phase change material and its preparation method. Background Technology
[0002] With the improvement of living standards, preserved flowers, as a type of decorative item that can be preserved for a long time, are popular due to their bright colors, beautiful shapes, and resistance to wilting. Phase change materials can absorb or release a large amount of latent heat during the phase change process, thereby achieving temperature regulation and heat storage. Due to their excellent thermal regulation performance, they have been widely used in fields such as building energy conservation, textiles and clothing, and heat dissipation of electronic equipment.
[0003] Currently, research on preserved flowers mainly focuses on their ornamental value, such as preservation time and color changes. Few studies combine preserved flowers with functional materials to give them more practical functions. In particular, in terms of temperature regulation, existing preserved flower products hardly consider how to use preserved flowers to regulate indoor temperature, which greatly limits the application scope and value of preserved flowers. In addition, existing phase change materials are mostly based on a single temperature range, which makes it difficult to meet the thermal management needs under different temperature environments.
[0004] Therefore, how to organically combine preserved flowers with phase change materials to develop dual-temperature zone preserved flower phase change materials that have both ornamental value and temperature regulation function has become a technical problem that urgently needs to be solved. Summary of the Invention
[0005] To address the technical problems existing in the prior art, this invention provides a dual-temperature zone preserved flower phase change material and its preparation method, in order to solve the technical problem that the research on preserved flowers in the prior art mainly focuses on the ornamental value such as preservation time and color change, without studying the functional properties of preserved flowers such as regulating indoor temperature, which limits the application scope of preserved flowers.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a method for preparing a dual-temperature-zone immortal flower phase change material, comprising: Fresh roses are dehydrated and then bleached to obtain bleached roses. Solvent displacement was performed on bleached rose petals using tert-butanol to obtain tert-butanol-displaced bleached rose petals. Bleached rose petals replaced with tert-butanol were placed in a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol and allowed to react statically to obtain rose petals containing polyethylene glycol / carmine red pigment / tert-butanol. Rose petals containing polyethylene glycol / carmine / tert-butanol were freeze-dried to obtain polyethylene glycol / carmine / rose petal aerogel. Phase change paraffin material was loaded onto polyethylene glycol / carmine red pigment / rose aerogel using a vacuum adsorption method to obtain a dual-temperature zone preserved flower phase change material.
[0007] Furthermore, the fresh roses are dehydrated and then bleached to obtain bleached roses, as follows: Fresh rose petals are placed in a methanol / ethanol mixture, then citric acid is added, and the mixture is allowed to stand for a dehydration reaction. After the dehydration reaction, sodium hypochlorite or sodium chlorite is added, and the mixture is allowed to stand for a bleaching reaction to obtain bleached rose petals.
[0008] Furthermore, the process of solvent displacement of bleached rose petals using tert-butanol to obtain tert-butanol-substituted bleached rose petals is as follows: The bleached rose petals were immersed in tert-butanol for solvent replacement to obtain bleached rose petals after tert-butanol replacement; wherein the solid-liquid ratio of the bleached rose petals to tert-butanol was (0.5-1):(40-50).
[0009] Furthermore, the bleached rose petals, after being replaced with tert-butanol, were placed in a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol and allowed to react statically to obtain rose petals containing polyethylene glycol / carmine red pigment / tert-butanol, as follows: Polyethylene glycol, carmine red pigment and tert-butanol were mixed to obtain a polyethylene glycol / carmine red pigment / tert-butanol mixed solution; Bleached rose petals replaced with tert-butanol were placed in a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol and allowed to react to obtain rose petals containing polyethylene glycol / carmine red pigment / tert-butanol; wherein the mass ratio of bleached rose petals replaced with tert-butanol to the mixed solution of polyethylene glycol / carmine red pigment / tert-butanol was (0.5-1):(40-50).
[0010] Furthermore, in the polyethylene glycol / carmine red pigment / tert-butanol mixed solution, the mass ratio of polyethylene glycol, carmine red pigment and tert-butanol is (0.5-1):(0.01-0.05):(1-2).
[0011] Furthermore, in the process of freezing and freeze-drying rose petals containing polyethylene glycol / carmine / tert-butanol to obtain polyethylene glycol / carmine / rose aerogel, the freezing conditions are a refrigerator (-15℃), a cold well (-65℃), or liquid nitrogen (-196℃), and the freezing time is 10-60 min; the freeze-drying temperature is -10℃~20℃, and the freeze-drying time is 24-72 h.
[0012] Furthermore, the process of loading phase change paraffin material onto polyethylene glycol / carmine red pigment / rose aerogel using vacuum adsorption to obtain dual-temperature zone preserved flower phase change material is as follows: An oil-soluble rose red pigment was added to liquid paraffin to obtain a liquid paraffin containing rose red pigment; wherein the mass fraction of the oil-soluble rose red pigment in the liquid paraffin containing rose red pigment was 0.01%-0.1%; Polyethylene glycol / carmine pigment / rose aerogel was impregnated in liquid paraffin containing rose pigment and subjected to a vacuum reaction to obtain roses after vacuum adsorption reaction. The rose petals after vacuum adsorption reaction were dried to obtain a dual-temperature zone preserved flower phase change material.
[0013] Furthermore, polyethylene glycol / carmine pigment / rose aerogel is impregnated in liquid paraffin containing rose pigment and subjected to a vacuum reaction to obtain roses after vacuum adsorption reaction. The reaction temperature is 45-50℃ and the reaction time is 10-120min.
[0014] Furthermore, the roses after the vacuum adsorption reaction are dried to obtain dual-temperature zone preserved flower phase change materials. The drying temperature is 45-50℃ and the drying time is 12-36h.
[0015] The present invention also provides a dual-temperature zone preserved flower phase change material, which is prepared by the aforementioned method; wherein, the dual-temperature zone preserved flower phase change material can carry out a phase change reaction at 4-47.5℃ to store heat, with an energy storage range of 50-100J / g.
[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a method for preparing a dual-temperature-zone preserved flower phase change material. Polyethylene glycol (PEG), with low-temperature phase change characteristics, and paraffin wax, with high-temperature phase change characteristics, are used as phase change energy storage materials and loaded into preserved flowers. This achieves dual-temperature-zone phase change energy storage capability in the preserved flowers, enabling them to regulate indoor temperature and effectively expanding their application range. Simultaneously, it significantly increases the temperature range of the phase change energy storage of the dual-temperature-zone preserved flower phase change material. Specifically, fresh roses are dehydrated to remove some lignin and hemicellulose from the rose petals, forming roses with a cellulose skeleton structure. The bleached roses, after being replaced with tert-butanol, are placed in a mixed solution of PEG / carmine red pigment / tert-butanol for a static reaction. This encapsulates the PEG using the cellulose skeleton structure. Hydrogen bonds are formed between the hydroxyl groups of cellulose and PEG in the cellulose skeleton structure, increasing the bonding force between PEG and the cellulose skeleton structure. This allows the liquid PEG after the endothermic phase change to still be encapsulated within the structure of the preserved flower. Specifically, the method utilizes… tert-butanol was used to replace the solvent in bleached rose petals and dissolve polyethylene glycol. Tert-butanol generates capillary forces on the wall surface during freeze-drying, significantly enhancing the porosity of the rose aerogel. The highly porosity of the rose aerogel was then used to adsorb liquid paraffin under vacuum, effectively improving the phase change energy storage capacity of the preserved flowers by utilizing the aerogel's high porosity to adsorb a large amount of paraffin. Furthermore, the uniform pore structure of the rose aerogel was used to encapsulate the paraffin, effectively achieving high energy storage and high mechanical properties. Dual-temperature zone preserved flower phase change material: The dual-temperature zone preserved flower phase change material prepared in this invention can undergo a phase change reaction at 4-47.5℃ to store heat, playing a role in temperature regulation of the environment. Its energy storage range is 50-100J / g, which significantly expands the application range of preserved flowers, making them not only ornamental but also functionally valuable for regulating indoor temperature. In addition, the elongation at break of the dual-temperature zone preserved flower phase change material is 10.7%-22.5%, and the tensile strength is 116.0-865.7kPa.
[0017] The dual-temperature zone preserved flower phase change material provided by this invention possesses all the advantages of the above-mentioned dual-temperature zone preserved flower phase change material preparation method. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a cross-sectional SEM image of the dual-temperature-zone immortal flower phase change material prepared in Example 1; Figure 2 The image shows a surface SEM image of the dual-temperature-zone immortal flower phase change material prepared in Example 1. Figure 3 The image shows the DSC diagram of the dual-temperature zone immortal flower phase change material prepared in Example 1. Detailed Implementation
[0020] To make the technical problems solved by the present invention, the technical solutions, and the beneficial effects clearer, the following specific embodiments provide a further detailed description of the present invention. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.
[0021] Before describing the specific embodiments of this application, some of the technical terms involved in the embodiments of this application are explained as follows: Preserved fresh flowers, also known as preserved flowers or eco-flowers, are made through a series of complex processes such as dehydration, decolorization, dyeing, and drying. They retain the color, shape, and feel of fresh flowers, while offering a wider range of colors and a shelf life of 3-5 years or even longer.
[0022] Phase change materials (PCMs) are materials that regulate temperature by undergoing a phase change (such as solid-liquid or liquid-gas) at a certain temperature, absorbing or releasing latent heat to the outside world.
[0023] This invention provides a method for preparing a dual-temperature-zone preserved flower phase change material, comprising: dehydrating fresh roses and then bleaching them to obtain bleached roses; solvent-displacing the bleached roses with tert-butanol to obtain tert-butanol-displaced bleached roses; placing the tert-butanol-displaced bleached roses in a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol and allowing it to react statically to obtain roses containing polyethylene glycol / carmine red pigment / tert-butanol; freezing and freeze-drying the roses containing polyethylene glycol / carmine red pigment / tert-butanol to obtain polyethylene glycol / carmine red pigment / rose aerogel; and loading a phase change paraffin material onto the polyethylene glycol / carmine red pigment / rose aerogel by vacuum adsorption to obtain the dual-temperature-zone preserved flower phase change material.
[0024] Specifically, the preparation process includes the following steps: Step 1: Take fresh roses with stems of 3-5cm and place them in a methanol / ethanol mixture with a mass ratio of (0.5-1):(1-2). Then add citric acid and let it stand for 73-100 hours for dehydration reaction to obtain the mixed system after reaction. The mass ratio of fresh roses to methanol / ethanol mixture is (0.5-1):(40-50). The amount of citric acid added is 0.1%-0.4% of the mass of fresh roses.
[0025] Step 2: Add sodium hypochlorite solution or sodium chlorite solution to the mixture after the reaction in Step 1, and let it stand for bleaching reaction for 50-100 hours to obtain bleached roses; wherein, the mass of sodium hypochlorite solution or sodium chlorite solution added is 4%-10% of the mass of fresh roses, and the mass concentration of sodium hypochlorite solution or sodium chlorite solution is 20%-30%.
[0026] Step 3: Soak the bleached rose petals obtained in Step 2 in tert-butanol for solvent replacement, so as to use tert-butanol to replace methanol, ethanol, citric acid, sodium hypochlorite or sodium chlorite in the bleached rose petals, and obtain tert-butanol-replaced bleached rose petals; wherein, the solid-liquid ratio of bleached rose petals to tert-butanol is (0.5-1):(40-50); the replacement time is 5-10 hours, and the replacement is performed 1-5 times.
[0027] Step 4: Mix polyethylene glycol, carmine red pigment, and tert-butanol in a mass ratio of (0.5-1):(0.01-0.05):(1-2) and react at 30-40℃ for 10-60 min to obtain a polyethylene glycol / carmine red pigment / tert-butanol mixed solution; wherein, polyethylene glycol 400, polyethylene glycol 600, or polyethylene glycol 800 are used.
[0028] Step 5: Place the bleached rose petals replaced with tert-butanol in a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol, and let it stand for 4-48 hours to obtain rose petals containing polyethylene glycol / carmine red pigment / tert-butanol; wherein the mass ratio of the bleached rose petals replaced with tert-butanol to the mixed solution of polyethylene glycol / carmine red pigment / tert-butanol is (0.5-1):(40-50).
[0029] Step 6: Place the roses containing polyethylene glycol / carmine red pigment / tert-butanol in a refrigerator (-15℃), cold well (-65℃), or liquid nitrogen (-196℃) for 10-60 minutes to obtain frozen rose bodies.
[0030] Step 7: Place the frozen rose petals in a freeze dryer and freeze dry at -10℃ to 20℃ for 24-72 hours to obtain polyethylene glycol / carmine red pigment / rose aerogel.
[0031] Step 8: Heat solid paraffin to a liquid state at 45-50℃ to obtain liquid paraffin; wherein the solid paraffin is No. 40 paraffin or No. 45 paraffin; add oil-soluble rose red pigment to the solid paraffin to obtain liquid paraffin containing rose red pigment; wherein the amount of oil-soluble rose red pigment added is 0.01%-0.1% of the mass of the solid paraffin.
[0032] Step 9: Impregnate the polyethylene glycol / carmine red pigment / rose aerogel obtained in Step 7 into the liquid paraffin containing rose red pigment prepared in Step 8, and react under vacuum in a vacuum drying oven at 45-50℃ for 10-120 minutes to obtain the rose after vacuum adsorption reaction.
[0033] Step 10: Place the rose petals after vacuum adsorption reaction on a support and put them in an oven to dry at 45-50℃ for 12-36 hours to obtain dual-temperature zone preserved flower phase change material.
[0034] Preparation principle: In the above embodiments, fresh rose petals are reacted with a methanol / ethanol mixture and citric acid is added. The weak acidity of citric acid reduces the damage to the rose petals caused by the strong alkalinity of sodium hypochlorite or sodium chlorite during the bleaching process. Furthermore, the citrate ions chelate metal ions, reducing the binding of metal ions with anthocyanins and flavonoids in the rose petals, thereby improving the degree and efficiency of decolorization. Methanol is used as a dehydrating agent to effectively displace the water from the rose petals, improving the decolorization effect of the subsequent decolorizing agents, sodium hypochlorite or sodium chlorite. The rapid penetration of methanol also fixes the fibrous structure in the petals, preventing subsequent petal collapse. When bleaching with sodium hypochlorite or sodium chlorite, some lignin and hemicellulose in the rose petals are removed, resulting in rose petals with a cellulose skeleton structure. Then, tert-butanol is used to perform solvent replacement on the bleached rose petals to remove sodium hypochlorite or sodium chlorite, as well as low-molecular-weight lignin and hemicellulose, ensuring and improving the quality of the rose petals. The stability of the rose skeleton was assessed. Subsequently, bleached roses replaced with tert-butanol were placed in a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol to encapsulate the polyethylene glycol within the rose's cellulose skeleton structure. The encapsulation of polyethylene glycol within the cellulose skeleton structure utilizes hydrogen bonding between the hydroxyl groups of cellulose and polyethylene glycol, enhancing the binding force and ensuring that the liquid polyethylene glycol remains encapsulated within the preserved flower after the endothermic phase change. Next, tert-butanol was used as a solvent to dissolve the polyethylene glycol... Alcohol can prevent capillary forces during freeze-drying, increasing the porosity of rose aerogel. Roses containing polyethylene glycol / carmine / tert-butanol were freeze-dried, and phase change paraffin material was loaded onto the polyethylene glycol / carmine / rose aerogel using a vacuum adsorption method. This allowed the highly porous rose aerogel to adsorb liquid paraffin under vacuum, and the high porosity of the aerogel could be used to adsorb excess paraffin, effectively improving the phase change energy storage capacity of the preserved flower.
[0035] In this invention, carmine is added to a mixed solution of polyethylene glycol / carmine / tert-butanol to color bleached roses, giving them a vibrant rose-red color. Oil-soluble rose-red pigment is added to liquid paraffin to avoid reducing the rose-red color of the preserved flowers when only liquid paraffin is added, thus ensuring the color of the petals and enhancing the ornamental value of the preserved flower material.
[0036] In this invention, by introducing polyethylene glycol and utilizing the porous structure of rose aerogel to encapsulate paraffin, a dual-temperature-zone phase change energy storage capacity for preserved flowers is achieved, resulting in a dual-temperature-zone preserved flower phase change material with high energy storage and high mechanical properties. Experimental verification shows that the dual-temperature-zone preserved flower phase change material prepared in this invention can undergo a phase change reaction at 4-47.5℃ to store heat, playing a role in temperature regulation of the environment. Its energy storage range is 50-100 J / g, significantly expanding the application range of preserved flowers, making them not only ornamental but also functionally valuable for regulating indoor temperature. In addition, the elongation at break of the dual-temperature-zone preserved flower phase change material is 10.7%-22.5%, and the tensile strength is 116.0-865.7 kPa.
[0037] The following specific embodiments further explain the preparation method of the dual-temperature zone immortal flower phase change material provided by the present invention: Example 1 This embodiment 1 provides a method for preparing a dual-temperature-zone immortal flower phase change material, including the following steps: Step 1: Take fresh roses with 3cm stems and place them in a methanol / ethanol mixture with a mass ratio of 0.5:2. Then add citric acid and let it stand for 100 hours for dehydration reaction to obtain the mixed system after reaction. The mass ratio of fresh roses to methanol / ethanol mixture is 0.5:50. The amount of citric acid added is 0.2% of the mass of fresh roses.
[0038] Step 2: Add sodium hypochlorite solution to the mixture after the reaction in Step 1, and let it stand for 100 hours to obtain bleached roses; wherein, the mass of sodium hypochlorite solution added is 4% of the mass of fresh roses, and the mass concentration of sodium hypochlorite solution is 20%.
[0039] Step 3: Soak the bleached rose petals obtained in Step 2 in tert-butanol for solvent replacement, so as to use tert-butanol to replace methanol, ethanol, citric acid, sodium hypochlorite or sodium chlorite in the bleached rose petals, and obtain tert-butanol-replaced bleached rose petals; wherein, the solid-liquid ratio of bleached rose petals to tert-butanol is 0.5:50; the replacement time is 10 hours, and the replacement is performed 5 times.
[0040] Step 4: Mix polyethylene glycol 400, carmine red pigment, and tert-butanol in a mass ratio of 0.5:0.01:2 and react at 30°C for 60 min to obtain a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol.
[0041] Step 5: Place the bleached rose petals replaced with tert-butanol in a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol, and let it stand for 48 hours to obtain rose petals containing polyethylene glycol / carmine red pigment / tert-butanol; wherein the mass ratio of the bleached rose petals replaced with tert-butanol to the mixed solution of polyethylene glycol / carmine red pigment / tert-butanol is 1:40.
[0042] Step 6: Place the rose petals containing polyethylene glycol / carmine red pigment / tert-butanol in liquid nitrogen (-196℃) and freeze for 10 minutes to obtain the frozen rose petals.
[0043] Step 7: Place the frozen rose petals in a freeze dryer and freeze-dry at -10°C for 72 hours to obtain polyethylene glycol / carmine red pigment / rose aerogel.
[0044] Step 8: Heat solid No. 45 paraffin to a liquid state at 50°C to obtain liquid paraffin; add oil-soluble rose red pigment to the solid paraffin to obtain liquid paraffin containing rose red pigment; wherein, the amount of oil-soluble rose red pigment added is 0.01% of the mass of solid paraffin.
[0045] Step 9: Impregnate the polyethylene glycol / carmine red pigment / rose aerogel obtained in Step 7 into the liquid paraffin containing rose red pigment prepared in Step 8, and react at 50°C in a vacuum drying oven for 120 min to obtain the rose after vacuum adsorption reaction.
[0046] Step 10: Place the rose petals after vacuum adsorption reaction on a support and put them in an oven to dry at 50°C for 36 hours to obtain dual-temperature zone preserved flower phase change material.
[0047] Performance test results explanation: The performance of the dual-temperature-zone preserved flower phase change material prepared in Example 1 was tested. Specifically, the phase change temperature and enthalpy of the material were determined using a differential scanning calorimeter, and its elongation at break and tensile strength were measured using a universal tensile testing machine. The experimental results showed that the dual-temperature-zone preserved flower phase change material prepared in Example 1 can undergo a phase change reaction at 6-47.5℃ to store heat, thus playing a role in temperature regulation of the environment, with an energy storage capacity of 86 J / g. The elongation at break and tensile strength of the dual-temperature-zone preserved flower phase change material were tested. The results showed that the elongation at break was 15.3% and the tensile strength was 865.7 kPa, which can ensure the self-support of the preserved flower and prevent it from breaking easily under external force.
[0048] As attached Figure 1 As shown, attached Figure 1 The attached image shows a cross-sectional SEM image of the dual-temperature-zone immortal flower phase change material prepared in Example 1. Figure 1As can be seen, the phase change materials polyethylene glycol and paraffin are evenly distributed inside the preserved flower, adhering to the fibrous structure of the petals without obvious voids, and exhibiting good bonding performance.
[0049] As attached Figure 2 As shown, attached Figure 2 The attached image shows a surface SEM image of the dual-temperature-zone immortal flower phase change material prepared in Example 1. Figure 2 As can be seen, the phase change material is evenly dispersed in the cell cavity and can be effectively distributed on the cell wall structure, which is beneficial to the stability of the material during the phase change process.
[0050] As attached Figure 3 As shown, attached Figure 3 The attached figure shows the DSC diagram of the dual-temperature-zone immortal flower phase change material prepared in Example 1. Figure 3 As can be seen, the dual-temperature-zone preserved flower phase change material has obvious dual-temperature-zone peaks and distinct dual-temperature-zone phase change enthalpy change peak characteristics; among them, the low-temperature zone is the phase change temperature zone of paraffin material, and the high-temperature zone is the phase change temperature zone of polyethylene glycol material.
[0051] Example 2 This embodiment 2 provides a method for preparing a dual-temperature-zone immortal flower phase change material, including the following steps: Step 1: Take fresh roses with 5cm stems and place them in a methanol / ethanol mixture with a mass ratio of 1:1. Then add citric acid and let it stand for 73 hours for dehydration reaction to obtain the mixed system after reaction. The mass ratio of fresh roses to methanol / ethanol mixture is 1:40. The amount of citric acid added is 0.1% of the mass of fresh roses.
[0052] Step 2: Add sodium chlorite to the mixture after the reaction in Step 1, and let it stand for 50 hours to bleach the roses. The mass of sodium chlorite added is 10% of the mass of the fresh roses, and the mass concentration of the sodium hypochlorite solution is 30%.
[0053] Step 3: Soak the bleached rose petals obtained in Step 2 in tert-butanol for solvent replacement, so as to use tert-butanol to replace methanol, ethanol, citric acid, sodium hypochlorite or sodium chlorite in the bleached rose petals, and obtain tert-butanol-replaced bleached rose petals; wherein, the solid-liquid ratio of bleached rose petals to tert-butanol is 1:40; the replacement time is 5 hours, and the replacement is performed once.
[0054] Step 4: Mix polyethylene glycol 600, carmine red pigment and tert-butanol in a mass ratio of 1:0.05:1 and react at 40°C for 10 min to obtain a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol.
[0055] Step 5: Place the bleached rose petals replaced with tert-butanol into a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol, and let it stand for 4 hours to obtain rose petals containing polyethylene glycol / carmine red pigment / tert-butanol; wherein the mass ratio of the bleached rose petals replaced with tert-butanol to the mixed solution of polyethylene glycol / carmine red pigment / tert-butanol is 0.5:50.
[0056] Step 6: Place the rose petals containing polyethylene glycol / carmine red pigment / tert-butanol in a refrigerator (-15℃) and freeze for 60 minutes to obtain frozen rose petals.
[0057] Step 7: Place the frozen rose petals in a freeze dryer and freeze-dry at 20°C for 24 hours to obtain polyethylene glycol / carmine red pigment / rose aerogel.
[0058] Step 8: Heat solid No. 40 paraffin to a liquid state at 45°C to obtain liquid paraffin; add oil-soluble rose red pigment to the solid paraffin to obtain liquid paraffin containing rose red pigment; wherein, the amount of oil-soluble rose red pigment added is 0.1% of the mass of solid paraffin.
[0059] Step 9: Impregnate the polyethylene glycol / carmine red pigment / rose aerogel obtained in Step 7 into the liquid paraffin containing rose red pigment prepared in Step 8, and react under vacuum at 45°C in a vacuum drying oven for 10 minutes to obtain the rose after vacuum adsorption reaction.
[0060] Step 10: Place the rose petals after vacuum adsorption reaction on a support and put them in an oven to dry at 45°C for 12 hours to obtain a dual-temperature zone preserved flower phase change material.
[0061] Performance test results explanation: The performance of the dual-temperature-zone preserved flower phase change material prepared in Example 2 was tested. Specifically, the phase change temperature and enthalpy of the material were determined using a differential scanning calorimeter, and its elongation at break and tensile strength were measured using a universal tensile testing machine. The experimental results showed that the dual-temperature-zone preserved flower phase change material prepared in Example 2 can undergo a phase change reaction at 4-41.2℃ to store heat, thus playing a role in temperature regulation of the environment, with an energy storage capacity of 50 J / g. The elongation at break and tensile strength of the dual-temperature-zone preserved flower phase change material were tested. The results showed that the elongation at break was 22.5%, and the tensile strength was 116.0 kPa, which can ensure the self-support of the preserved flower and prevent it from breaking easily under external force.
[0062] Example 3 This embodiment 3 provides a method for preparing a dual-temperature-zone immortal flower phase change material, including the following steps: Step 1: Take fresh roses with 4cm stems and place them in a methanol / ethanol mixture with a mass ratio of 0.7:1.5. Then add citric acid and let it stand for 90 hours for dehydration reaction to obtain the mixed system after reaction. The mass ratio of fresh roses to methanol / ethanol mixture is 0.8:45. The amount of citric acid added is 0.4% of the mass of fresh roses.
[0063] Step 2: Add sodium hypochlorite solution to the mixture after the reaction in Step 1, and let it stand for 75 hours to carry out the bleaching reaction to obtain bleached roses; wherein, the mass of sodium hypochlorite solution added is 7% of the mass of fresh roses, and the mass concentration of sodium hypochlorite solution is 25%.
[0064] Step 3: Soak the bleached rose petals obtained in Step 2 in tert-butanol for solvent replacement, so as to use tert-butanol to replace methanol, ethanol, citric acid, sodium hypochlorite or sodium chlorite in the bleached rose petals, and obtain tert-butanol-replaced bleached rose petals; wherein, the solid-liquid ratio of bleached rose petals to tert-butanol is 0.7:45; the replacement time is 8 hours, and the replacement is performed 3 times.
[0065] Step 4: Mix polyethylene glycol 800, carmine red pigment, and tert-butanol in a mass ratio of 0.7:0.03:1.5 and react at 35°C for 30 minutes to obtain a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol.
[0066] Step 5: Place the bleached rose petals replaced with tert-butanol in a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol, and let it stand for 24 hours to obtain rose petals containing polyethylene glycol / carmine red pigment / tert-butanol; wherein the mass ratio of the bleached rose petals replaced with tert-butanol to the mixed solution of polyethylene glycol / carmine red pigment / tert-butanol is 0.7:45.
[0067] Step 6: Place the rose petals containing polyethylene glycol / carmine red pigment / tert-butanol in a cold well (-65℃) and freeze for 30 minutes to obtain the frozen rose petals.
[0068] Step 7: Place the frozen rose petals in a freeze dryer and freeze-dry at 0°C for 60 hours to obtain polyethylene glycol / carmine red pigment / rose aerogel.
[0069] Step 8: Heat solid No. 40 paraffin to liquid state at 47℃ to obtain liquid paraffin; add oil-soluble rose red pigment to solid paraffin to obtain liquid paraffin containing rose red pigment; wherein, the amount of oil-soluble rose red pigment added is 0.05% of the mass of solid paraffin.
[0070] Step 9: Impregnate the polyethylene glycol / carmine red pigment / rose aerogel obtained in Step 7 into the liquid paraffin containing rose red pigment prepared in Step 8, and react under vacuum at 47°C for 100 min in a vacuum drying oven to obtain the rose after vacuum adsorption reaction.
[0071] Step 10: Place the rose petals after vacuum adsorption reaction on a support and put them in an oven. Dry them at 48°C for 30 hours to obtain a dual-temperature zone preserved flower phase change material.
[0072] Performance test results explanation: Performance testing was conducted on the dual-temperature-zone preserved flower phase change material prepared in Example 3 above. Specifically, the phase change temperature and enthalpy of the material were determined using a differential scanning calorimeter, and its elongation at break and tensile strength were measured using a universal tensile testing machine. The experimental results showed that the dual-temperature-zone preserved flower phase change material prepared in Example 3 can undergo a phase change reaction at 4-47.5℃ to store heat, playing a role in temperature regulation of the environment, with an energy storage capacity of 100 J / g. The elongation at break and tensile strength of the dual-temperature-zone preserved flower phase change material were tested, and the results showed that the elongation at break was 10.7% and the tensile strength was 758.4 kPa, which can ensure the self-support of the preserved flower and is not easily broken under external force.
[0073] Example 4 This embodiment 4 provides a method for preparing a dual-temperature-zone immortal flower phase change material, including the following steps: Step 1: Take fresh roses with 4.5cm stems and place them in a methanol / ethanol mixture with a mass ratio of 0.6:1.1. Then add citric acid and let it stand for 80 hours for dehydration reaction to obtain the mixed system after reaction. The mass ratio of fresh roses to methanol / ethanol mixture is 0.65:42. The amount of citric acid added is 0.15% of the mass of fresh roses.
[0074] Step 2: Add sodium chlorite to the mixture after the reaction in Step 1, and let it stand for 55 hours to bleach the roses; wherein the mass of sodium chlorite solution added is 6% of the mass of fresh roses, and the mass concentration of sodium hypochlorite solution is 23%.
[0075] Step 3: Soak the bleached rose petals obtained in Step 2 in tert-butanol for solvent replacement, so as to use tert-butanol to replace methanol, ethanol, citric acid, sodium hypochlorite or sodium chlorite in the bleached rose petals, and obtain tert-butanol-replaced bleached rose petals; wherein, the solid-liquid ratio of bleached rose petals to tert-butanol is 0.6:44; the replacement time is 6 hours, and the replacement is performed twice.
[0076] Step 4: Mix polyethylene glycol 600, carmine red pigment and tert-butanol in a mass ratio of 0.8:0.02:1.3 and react at 36°C for 20 min to obtain a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol.
[0077] Step 5: Place the bleached rose petals replaced with tert-butanol into a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol, and let it stand for 12 hours to obtain rose petals containing polyethylene glycol / carmine red pigment / tert-butanol; wherein the mass ratio of the bleached rose petals replaced with tert-butanol to the mixed solution of polyethylene glycol / carmine red pigment / tert-butanol is 0.7:43.
[0078] Step 6: Place the rose petals containing polyethylene glycol / carmine red pigment / tert-butanol in a cold well (-65℃) and freeze for 15 minutes to obtain the frozen rose petals.
[0079] Step 7: Place the frozen rose petals in a freeze dryer and freeze-dry at 5°C for 70 hours to obtain polyethylene glycol / carmine red pigment / rose aerogel.
[0080] Step 8: Heat solid No. 40 paraffin to a liquid state at 47°C to obtain liquid paraffin; add oil-soluble rose red pigment to the solid paraffin to obtain liquid paraffin containing rose red pigment; wherein, the amount of oil-soluble rose red pigment added is 0.03% of the mass of solid paraffin.
[0081] Step 9: Impregnate the polyethylene glycol / carmine red pigment / rose aerogel obtained in Step 7 into the liquid paraffin containing rose red pigment prepared in Step 8, and react under vacuum at 49°C for 20 minutes in a vacuum drying oven to obtain the rose after vacuum adsorption reaction.
[0082] Step 10: Place the rose petals after vacuum adsorption reaction on a support and put them in an oven to dry at 46°C for 32 hours to obtain a dual-temperature zone preserved flower phase change material.
[0083] Performance test results explanation: The performance of the dual-temperature-zone preserved flower phase change material prepared in Example 4 was tested. Specifically, the phase change temperature and enthalpy of the material were determined using a differential scanning calorimeter, and its elongation at break and tensile strength were determined using a universal tensile testing machine. The experimental results showed that the dual-temperature-zone preserved flower phase change material prepared in Example 4 can undergo a phase change reaction at 4-40.5℃ to store heat, thus playing a role in temperature regulation of the environment, with an energy storage capacity of 74.4 J / g. The elongation at break and tensile strength of the dual-temperature-zone preserved flower phase change material were tested. The results showed that the elongation at break was 20.1% and the tensile strength was 237.8 kPa, which can ensure the self-support of the preserved flower and prevent it from breaking easily under external force.
[0084] The method for preparing dual-temperature-zone preserved flower phase change material of the present invention uses polyethylene glycol (PEG), which has low-temperature phase change characteristics, and paraffin wax, which has high-temperature phase change characteristics, as phase change energy storage materials and loads them into preserved flowers to achieve dual-temperature-zone phase change energy storage capacity of preserved flowers and significantly improve the temperature range of phase change energy storage. Specifically, fresh roses are dehydrated and then bleached. The bleached roses, after being replaced with tert-butanol, are placed in a mixed solution of PEG / carmine red pigment / tert-butanol and allowed to react statically. This utilizes the cellulose skeleton structure formed in the dehydrated roses to encapsulate the PEG, ensuring that the hydrated PEG remains encapsulated within the preserved flower even after heat absorption. Tert-butanol is used to replace the solvent in the bleached roses and dissolves the PEG as a solvent. Tert-butanol can be used to dissolve the PEG during freeze-drying. Capillary forces are generated, significantly enhancing the porosity of rose aerogel. The high porosity of the aerogel allows for the adsorption of large amounts of paraffin, effectively improving the phase change energy storage capacity of preserved flowers. Furthermore, the uniform pore structure of the rose aerogel effectively seals the paraffin, resulting in a dual-temperature-zone preserved flower phase change material with high energy storage and high mechanical properties. In this invention, by designing low-temperature phase change polyethylene glycol and high-temperature phase change paraffin as energy storage materials and loading them into preserved flowers, dual-temperature-zone phase change energy storage is achieved. This effectively expands the temperature range of phase change energy storage, enabling phase change reactions to store heat at 4-47.5℃, thus playing a role in environmental temperature regulation. The energy storage range is 50-100 J / g, effectively broadening the application range of preserved flowers and significantly increasing the temperature range of phase change energy storage in the dual-temperature-zone preserved flower phase change material.
[0085] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.
Claims
1. A method for preparing a dual-temperature-zone immortal flower phase change material, characterized in that, include: Fresh roses are dehydrated and then bleached to obtain bleached roses. Solvent displacement was performed on bleached rose petals using tert-butanol to obtain tert-butanol-displaced bleached rose petals. Bleached rose petals replaced with tert-butanol were placed in a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol and allowed to react statically to obtain rose petals containing polyethylene glycol / carmine red pigment / tert-butanol. Rose petals containing polyethylene glycol / carmine / tert-butanol were freeze-dried to obtain polyethylene glycol / carmine / rose petal aerogel. Phase change paraffin material was loaded onto polyethylene glycol / carmine red pigment / rose aerogel using a vacuum adsorption method to obtain a dual-temperature zone preserved flower phase change material.
2. The method for preparing a dual-temperature-zone immortal flower phase change material according to claim 1, characterized in that, The process of dehydrating fresh roses and then bleaching them to obtain bleached roses is as follows: Fresh rose petals are placed in a methanol / ethanol mixture, then citric acid is added, and the mixture is allowed to stand for a dehydration reaction. After the dehydration reaction, sodium hypochlorite or sodium chlorite is added, and the mixture is allowed to stand for a bleaching reaction to obtain bleached rose petals.
3. The method for preparing a dual-temperature-zone immortal flower phase change material according to claim 1, characterized in that, The process of solvent displacement of bleached rose petals using tert-butanol to obtain tert-butanol-substituted bleached rose petals is as follows: The bleached rose petals were immersed in tert-butanol for solvent replacement to obtain bleached rose petals after tert-butanol replacement; wherein the solid-liquid ratio of the bleached rose petals to tert-butanol was (0.5-1):(40-50).
4. The method for preparing a dual-temperature-zone immortal flower phase change material according to claim 1, characterized in that, The process of placing bleached rose petals, after being replaced with tert-butanol, in a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol and allowing it to react statically to obtain rose petals containing polyethylene glycol / carmine red pigment / tert-butanol is as follows: Polyethylene glycol, carmine red pigment and tert-butanol were mixed to obtain a polyethylene glycol / carmine red pigment / tert-butanol mixed solution; Bleached rose petals replaced with tert-butanol were placed in a mixed solution of polyethylene glycol / carmine red pigment / tert-butanol and allowed to react to obtain rose petals containing polyethylene glycol / carmine red pigment / tert-butanol; wherein the mass ratio of bleached rose petals replaced with tert-butanol to the mixed solution of polyethylene glycol / carmine red pigment / tert-butanol was (0.5-1):(40-50).
5. The method for preparing a dual-temperature-zone immortal flower phase change material according to claim 4, characterized in that, In the polyethylene glycol / carmine red pigment / tert-butanol mixed solution, the mass ratio of polyethylene glycol, carmine red pigment and tert-butanol is (0.5-1):(0.01-0.05):(1-2).
6. The method for preparing a dual-temperature-zone immortal flower phase change material according to claim 1, characterized in that, In the process of freezing and freeze-drying rose petals containing polyethylene glycol / carmine / tert-butanol to obtain polyethylene glycol / carmine / rose aerogel, the freezing conditions are refrigerator (-15℃), cold well (-65℃) or liquid nitrogen (-196℃), and the freezing time is 10-60 min; the freeze-drying temperature is -10℃~20℃, and the freeze-drying time is 24-72 h.
7. The method for preparing a dual-temperature-zone immortal flower phase change material according to claim 1, characterized in that, The process of loading phase change paraffin material onto polyethylene glycol / carmine red pigment / rose aerogel using vacuum adsorption to obtain dual-temperature zone preserved flower phase change material is as follows: An oil-soluble rose red pigment was added to liquid paraffin to obtain a liquid paraffin containing rose red pigment; wherein the mass fraction of the oil-soluble rose red pigment in the liquid paraffin containing rose red pigment was 0.01%-0.1%; Polyethylene glycol / carmine pigment / rose aerogel was impregnated in liquid paraffin containing rose pigment and subjected to a vacuum reaction to obtain roses after vacuum adsorption reaction. The rose petals after vacuum adsorption reaction were dried to obtain a dual-temperature zone preserved flower phase change material.
8. The method for preparing a dual-temperature-zone immortal flower phase change material according to claim 7, characterized in that, In the process of impregnating polyethylene glycol / carmine red pigment / rose aerogel in liquid paraffin containing rose red pigment and performing a vacuum reaction to obtain roses after vacuum adsorption reaction, the reaction temperature is 45-50℃ and the reaction time is 10-120min.
9. The method for preparing a dual-temperature-zone immortal flower phase change material according to claim 7, characterized in that, In the process of drying rose petals after vacuum adsorption reaction to obtain dual-temperature zone preserved flower phase change material, the drying temperature is 45-50℃ and the drying time is 12-36h.
10. A dual-temperature-zone immortal flower phase change material, characterized in that, The dual-temperature zone preserved flower phase change material is prepared by the preparation method of the dual-temperature zone preserved flower phase change material as described in any one of claims 1-9; wherein, the dual-temperature zone preserved flower phase change material can carry out a phase change reaction at 4-47.5℃ to store heat, and the energy storage range is 50-100J / g.