An electrically heated liquid formulation for air purification and its method of preparation and use
Patent Information
- Application Number
- CN202611093228.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-22
- Publication Date
- 2026-10-09
AI Technical Summary
[0006]为了克服现有空气净化电热液体制剂存在的活性组分负载能力有限、持续释放性能较差、植物精油易挥发损失、储存稳定性不足以及空气净化效率难以长期保持技术问题，本发明的目的在于提供一种用于空气净化的电热液体制剂及其制备方法和应用
本发明采用KH550对介孔二氧化硅进行氨基化改性，通过硅烷偶联剂与介孔二氧化硅表面羟基发生缩合反应，在介孔二氧化硅表面引入稳定的氨基活性基团，不仅提高了介孔二氧化硅表面的有机相亲和性，而且增加了活性吸附位点，使其对植物精油等活性组分具有更高的负载能力。相比未经改性的介孔二氧化硅，氨基化改性后的介孔二氧化硅能够利用其丰富的介孔结构及表面氨基与植物精油分子之间形成氢键、偶极相互作用等多重作用力，减少植物精油在储存及电热使用过程中的快速挥发和损失，提高植物精油在载体表面的负载稳定性和缓释性能，从而实现活性组分持续、均匀释放，提高空气净化效率及持续净化能力。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of air purification materials technology, and in particular to an electrothermal liquid preparation for air purification, its preparation method, and its application. Background Technology
[0002] With the improvement of residents' living standards and the increasing awareness of indoor environmental health, air purification products have been widely used in enclosed spaces such as homes, offices, hotels, and public transportation. Among them, liquid air purification formulations that operate through electrothermal evaporation have become an important product form in the air purification field due to their advantages such as stable evaporation, ease of use, and long-lasting effect. These products typically use an electric heating device to continuously heat the liquid formulation, causing its active components to slowly evaporate into the air, thereby achieving the purpose of removing odors, improving air quality, and reducing the concentration of volatile organic compounds (VOCs).
[0003] Currently, most existing electrothermal air purification liquid formulations are composed of plant essential oils, fragrances, alcohol solvents, and surfactants. Their active components primarily rely on natural evaporation to achieve air purification. Because volatile active components such as plant essential oils have low boiling points, they are prone to excessively rapid evaporation and short-lived release during electrothermal processes. Furthermore, localized heating can easily lead to the decomposition of active components, reducing air purification efficiency. In addition, the dispersion stability of active components in traditional liquid systems is poor, making them susceptible to stratification, precipitation, or evaporation loss during long-term storage, affecting the product's storage stability and lifespan.
[0004] To address these issues, some studies have attempted to introduce porous materials such as activated carbon, molecular sieves, and mesoporous silica as adsorption carriers to improve the loading capacity and sustained-release performance of active components like plant essential oils. Mesoporous silica, in particular, is widely used in adsorption, sustained-release, and air purification due to its large specific surface area, uniform pore size, good chemical stability, and excellent biocompatibility. However, unmodified mesoporous silica has a limited number of active sites, resulting in weak interactions with organic components like plant essential oils. This can easily lead to low loading efficiency, poor sustained-release effects, and uneven release of active components during long-term use.
[0005] Furthermore, while existing air purification liquid formulations employ various additives to improve system stability, their utilization of the active sites on the adsorbent carrier surface remains insufficient, making it difficult to simultaneously achieve high-efficiency loading of plant essential oils, sustained release, and long-term storage stability. Therefore, developing an air purification electrothermal liquid formulation with high active component loading capacity, good sustained-release performance, and storage stability is of great significance for improving air purification efficiency, extending product lifespan, and enhancing overall performance. Summary of the Invention
[0006] To overcome the technical problems of existing air-purifying electrothermal liquid formulations, such as limited loading capacity of active components, poor sustained release performance, easy volatilization and loss of plant essential oils, insufficient storage stability, and difficulty in maintaining air purification efficiency over a long period, the present invention aims to provide an electrothermal liquid formulation for air purification, its preparation method, and its application. This invention uses KH550 aminated mesoporous silica as a high specific surface area adsorption and sustained-release carrier. KH550 is used to aminate the surface of the mesoporous silica, improving its surface active sites and loading capacity for plant essential oils. A stable electrothermal liquid system is constructed by combining components such as β-cyclodextrin, polyvinylpyrrolidone, propylene glycol, glycerol, polyethylene glycol 400, Tween 80, and disodium EDTA. This allows the plant essential oils to achieve stable dispersion and sustained release under electrothermal conditions, thereby obtaining an electrothermal liquid formulation that combines air purification performance, sustained release performance, and storage stability. This invention utilizes the synergistic effect of KH550 aminated modified mesoporous silica and a sustained-release stabilizing system to improve the loading capacity and sustained release performance of plant essential oils, enhance air purification efficiency and system storage stability, and extend the effective use time of electrothermal liquid formulations.
[0007] The objective of this invention can be achieved through the following technical solutions: An electrothermal liquid formulation for air purification comprises the following raw materials in parts by weight: 8-30 parts of KH550 aminated mesoporous silica; 0.5-8 parts of plant essential oil; 2-10 parts of β-cyclodextrin; 0.5-5 parts of polyvinylpyrrolidone; 15-40 parts of propylene glycol; 5-20 parts of glycerol; 2-12 parts of polyethylene glycol 400; 0.5-5 parts of Tween 80; 0.05-1 part of disodium ethylenediaminetetraacetate; and 40-120 parts of deionized water. The KH550 aminated mesoporous silica is obtained by surface aminated modification of mesoporous silica with γ-aminopropyltriethoxysilane.
[0008] Optionally, the KH550 aminated modified mesoporous silica comprises the following raw materials in parts by weight: 100 parts mesoporous silica; 5-15 parts γ-aminopropyltriethoxysilane (KH550); 100-180 parts anhydrous ethanol; 40-80 parts deionized water; and 0.5-3 parts glacial acetic acid.
[0009] Optionally, the preparation method of KH550 aminated modified mesoporous silica includes the following steps: (1) Add mesoporous silica to a mixed solvent consisting of anhydrous ethanol and deionized water, stir and disperse evenly, then add glacial acetic acid to adjust the pH of the system, and continue stirring to obtain a mesoporous silica dispersion. (2) Add γ-aminopropyltriethoxysilane to the mesoporous silica dispersion and carry out silanization reaction under stirring conditions to make KH550 condense with the hydroxyl groups on the surface of mesoporous silica to obtain an aminated modified mesoporous silica suspension. (3) The aminated modified mesoporous silica suspension is subjected to solid-liquid separation, and is washed with anhydrous ethanol and deionized water in sequence, dried and pulverized to obtain the KH550 aminated modified mesoporous silica.
[0010] Optionally, the reaction conditions in step (1) are a stirring speed of 300-600 rpm, a dispersion time of 20-40 min, and the pH of the system is adjusted to 4.5-5.5 using glacial acetic acid.
[0011] Optionally, the reaction conditions in step (2) are a reaction temperature of 60-80℃, a stirring speed of 400-700rpm, and a reaction time of 3-6h.
[0012] Optionally, the reaction conditions in step (3) are as follows: wash with anhydrous ethanol 2 to 4 times, then wash with deionized water 2 to 3 times, then dry at 80 to 100°C for 6 to 10 hours, pulverize and pass through a 200 to 400 mesh sieve to obtain the KH550 aminated modified mesoporous silica.
[0013] Optionally, a method for preparing an electrothermal liquid formulation for air purification includes the following steps: S1. Weigh out propylene glycol, glycerin, polyethylene glycol 400 and polyvinylpyrrolidone according to the weight parts, add them to the reaction vessel, stir and mix evenly to fully dissolve the polyvinylpyrrolidone and obtain a homogeneous base solution. S2, add KH550 aminated mesoporous silica and β-cyclodextrin to the base solution, continue stirring and dispersing to ensure that KH550 aminated mesoporous silica is uniformly dispersed in the system and that the plant essential oil is fully adsorbed into the sustained-release system formed by KH550 aminated mesoporous silica and β-cyclodextrin. Then add the plant essential oil, Tween 80 and disodium ethylenediaminetetraacetate, and continue stirring and mixing until uniform. S3. Add deionized water to the mixture and continue stirring until the system is uniform and stable. After standing to remove bubbles and filtering, the electrothermal liquid preparation for air purification is obtained.
[0014] Optionally, the reaction conditions in step S1 are: a stirring temperature of 30–50°C, a stirring speed of 300–500 rpm, and a stirring time of 20–40 min.
[0015] Optionally, the reaction conditions for step S2 are as follows: after adding KH550 aminated modified mesoporous silica, the dispersion speed is 500-800 rpm and the dispersion time is 20-40 min; after adding plant essential oil, Tween 80 and disodium EDTA, the mixture is stirred at 30-45°C for 30-60 min.
[0016] Optionally, the reaction conditions for step S3 are as follows: after adding deionized water, stir at 25-35°C for 20-40 minutes, let stand to degas for 20-60 minutes, and then filter through a 300-500 mesh filter to obtain the electrothermal liquid preparation for air purification.
[0017] The beneficial effects of this invention are: This invention employs KH550 to aminate mesoporous silica. A condensation reaction occurs between a silane coupling agent and the hydroxyl groups on the surface of the mesoporous silica, introducing stable amino active groups onto the silica surface. This not only improves the organic affinity of the mesoporous silica surface but also increases the number of active adsorption sites, resulting in a higher loading capacity for active components such as plant essential oils. Compared to unmodified mesoporous silica, the aminated mesoporous silica can utilize its rich mesoporous structure and the multiple forces formed between its surface amino groups and plant essential oil molecules, such as hydrogen bonds and dipole interactions. This reduces the rapid volatilization and loss of plant essential oils during storage and electrothermal use, improving the loading stability and sustained-release performance of plant essential oils on the carrier surface. This achieves continuous and uniform release of active components, improving air purification efficiency and sustained purification capability.
[0018] This invention constructs a synergistic sustained-release stabilizing system by co-constructing KH550 aminated modified mesoporous silica with β-cyclodextrin and polyvinylpyrrolidone. β-cyclodextrin can further encapsulate some plant essential oil molecules through cavity inclusion, slowing their release rate. Polyvinylpyrrolidone improves the dispersion stability of the system, reduces the aggregation and sedimentation of modified mesoporous silica particles, and allows the plant essential oils to be more uniformly loaded into the modified mesoporous silica and liquid system. The synergistic effect of these components enables the electrothermal liquid formulation to maintain a relatively stable evaporation rate during heating, avoiding the problems of excessively rapid evaporation in the early stages and insufficient evaporation in the later stages of traditional electrothermal liquids, effectively extending the continuous use time of the product.
[0019] This invention employs a composite solvent system composed of propylene glycol, glycerin, and polyethylene glycol 400. This system ensures good solubility of plant essential oils while improving the viscosity and moisturizing properties of the liquid system, reducing rapid solvent loss during electrothermal evaporation. Tween 80 further improves the compatibility between plant essential oils and the aqueous phase, while disodium EDTA can complex metal ion impurities in the system, reducing the impact of metal ions on the stability of plant essential oils and other active components, thereby further improving the storage and long-term stability of the formulation. Through the synergistic effect of the above components, the air-purifying electrothermal liquid formulation prepared by this invention has a high plant essential oil loading capacity, excellent sustained release performance, good storage stability, and high air purification efficiency, effectively improving the overall performance and service life of the product. Attached Figure Description
[0020] The invention will now be further described with reference to the accompanying drawings.
[0021] Figure 1 This is a comparison chart of the air purification efficiency test results for samples with different ratios. Detailed Implementation
[0022] The present invention will be further described below with reference to specific embodiments. However, the present invention is not limited to the following embodiments. Equivalent adjustments made without departing from the spirit and essence of the present invention should also be considered to fall within the protection scope of the present invention.
[0023] Example 1: The purpose of this example is to verify that when each component is in the lower limit ratio within the scope of the claims and the reaction conditions are lower, the prepared air-purifying electrothermal liquid formulation still has good dispersion stability, plant essential oil loading capacity and air purification performance.
[0024] Preparation of S1, KH550 aminated modified mesoporous silica 100 parts of mesoporous silica were weighed and added to a mixed solvent consisting of 100 parts of anhydrous ethanol and 40 parts of deionized water. The mixture was stirred and dispersed at 300 rpm for 20 min. Then, 0.5 parts of glacial acetic acid were added to adjust the pH of the system to 4.5. The mixture was stirred until it was evenly dispersed to obtain a mesoporous silica dispersion. Subsequently, 5 parts of γ-aminopropyltriethoxysilane (KH550) were added, and the mixture was heated to 60 °C and reacted at 400 rpm for 3 h to allow KH550 to be fully hydrolyzed and to undergo a condensation reaction with the hydroxyl groups on the surface of the mesoporous silica, resulting in an aminated modified mesoporous silica suspension. The obtained suspension was subjected to solid-liquid separation, washed twice with anhydrous ethanol, and then washed twice with deionized water. The suspension was dried at 80 °C for 6 h, pulverized, and passed through a 200-mesh sieve to obtain KH550 aminated modified mesoporous silica. S2, Preparation of electrothermal liquid preparations Weigh out 15 parts of propylene glycol, 5 parts of glycerol, 2 parts of polyethylene glycol 400 and 0.5 parts of polyvinylpyrrolidone and add them to a reaction vessel. Stir at 30°C and 300 rpm for 20 min to fully dissolve the polyvinylpyrrolidone and obtain a homogeneous basic solution. Then add 8 parts of KH550 aminated modified mesoporous silica and 2 parts of β-cyclodextrin and disperse at 500 rpm for 20 min to uniformly disperse the modified mesoporous silica and form a plant essential oil sustained-release carrier. Then add 0.5 parts of plant essential oil, 0.5 parts of Tween 80 and 0.05 parts of disodium EDTA and continue stirring at 30°C for 30 min to fully mix all components. S3, Finished Product Preparation Add 40 parts of deionized water to the mixture obtained in step S2, and continue stirring at 25°C for 20 minutes to make the system uniform and stable. Then let it stand for 20 minutes to remove bubbles, and filter it through a 300-mesh filter to obtain the electrothermal liquid preparation for air purification.
[0025] Example 2: The purpose of this example is to verify the synergistic effect of KH550 aminated modified mesoporous silica with plant essential oils, β-cyclodextrin and polyvinylpyrrolidone on improving air purification efficiency, continuous release performance, storage stability and plant essential oil loading capacity when each component adopts the intermediate ratio within the scope of the claims and appropriate reaction conditions are adopted.
[0026] Preparation of S1, KH550 aminated modified mesoporous silica 100 parts of mesoporous silica were weighed and added to a mixed solvent consisting of 140 parts of anhydrous ethanol and 60 parts of deionized water. The mixture was stirred and dispersed at 450 rpm for 30 min. Then, 1.5 parts of glacial acetic acid were added to adjust the pH of the system to 4.8. The mixture was stirred until homogeneous to obtain a mesoporous silica dispersion. Subsequently, 10 parts of γ-aminopropyltriethoxysilane (KH550) were added, and the mixture was heated to 70 °C and reacted at 550 rpm for 4 h to allow KH550 to be fully hydrolyzed and uniformly grafted onto the surface of the mesoporous silica, resulting in an aminated modified mesoporous silica suspension. The obtained suspension was subjected to solid-liquid separation, washed three times with anhydrous ethanol, and then washed twice with deionized water. The suspension was dried at 90 °C for 8 h, pulverized, and passed through a 300-mesh sieve to obtain KH550 aminated modified mesoporous silica. S2, Preparation of electrothermal liquid preparations Weigh 28 parts of propylene glycol, 12 parts of glycerol, 4007 parts of polyethylene glycol, and 2.5 parts of polyvinylpyrrolidone and add them to a reaction vessel. Stir at 40℃ and 400 rpm for 30 min to fully dissolve the polyvinylpyrrolidone and form a homogeneous basic solution. Then add 19 parts of KH550 aminated modified mesoporous silica and 6 parts of β-cyclodextrin and disperse at 650 rpm for 30 min to uniformly disperse the modified mesoporous silica in the system and improve the loading capacity of plant essential oils. Then add 4 parts of plant essential oils, 2.5 parts of Tween 80, and 0.5 parts of disodium EDTA and continue stirring at 40℃ for 45 min to fully adsorb the plant essential oils into the synergistic sustained-release system formed by KH550 aminated modified mesoporous silica and β-cyclodextrin. S3, Finished Product Preparation Add 80 parts of deionized water to the mixture obtained in step S2, and continue stirring at 30°C for 30 minutes to form a uniform and stable liquid system. Then let it stand for 40 minutes to remove bubbles, and filter it through a 400-mesh filter to obtain an electrothermal liquid preparation for air purification.
[0027] Example 3: The purpose of this example is to verify that when each component is in the upper limit ratio within the scope of the claims and higher reaction conditions are used, the prepared air-purifying electrothermal liquid formulation can still maintain good plant essential oil loading capacity, continuous release performance and system stability, and to further investigate the effect of higher active component addition on air purification performance.
[0028] Preparation of S1, KH550 aminated modified mesoporous silica 100 parts of mesoporous silica were weighed and added to a mixed solvent consisting of 180 parts of anhydrous ethanol and 80 parts of deionized water. The mixture was stirred and dispersed at 600 rpm for 40 min. Then, 3 parts of glacial acetic acid were added to adjust the pH of the system to 5.5. The mixture was stirred until homogeneous to obtain a mesoporous silica dispersion. Subsequently, 15 parts of γ-aminopropyltriethoxysilane (KH550) were added, and the mixture was heated to 80℃ and reacted at 700 rpm for 6 h to allow KH550 to be fully hydrolyzed and undergo a condensation reaction with the hydroxyl groups on the surface of the mesoporous silica, forming aminated modified mesoporous silica with a high grafting density. The resulting suspension was subjected to solid-liquid separation, washed 4 times with anhydrous ethanol, and then washed 3 times with deionized water. The suspension was dried at 100℃ for 10 h, pulverized, and passed through a 400-mesh sieve to obtain KH550 aminated modified mesoporous silica. S2, Preparation of electrothermal liquid preparations Weigh out 40 parts of propylene glycol, 20 parts of glycerol, 12 parts of polyethylene glycol 400, and 5 parts of polyvinylpyrrolidone and add them to a reaction vessel. Stir at 50°C and 500 rpm for 40 min to fully dissolve the polyvinylpyrrolidone and form a homogeneous basic solution. Then add 30 parts of KH550 aminated modified mesoporous silica and 10 parts of β-cyclodextrin and disperse at 800 rpm for 40 min to ensure that the modified mesoporous silica is uniformly dispersed in the liquid system and fully exerts its adsorption and loading effect. Then add 8 parts of plant essential oil, 5 parts of Tween 80, and 1 part of disodium EDTA and continue stirring at 45°C for 60 min to ensure that the plant essential oil is fully adsorbed into the synergistic sustained-release system constructed by KH550 aminated modified mesoporous silica and β-cyclodextrin, while forming a stable and uniform dispersion system under the action of Tween 80 and polyvinylpyrrolidone. S3, Finished Product Preparation Add 120 parts of deionized water to the mixture obtained in step S2, and continue stirring at 35°C for 40 minutes to form a uniform and stable liquid system. Then let it stand for 60 minutes to remove bubbles, and filter it through a 500-mesh filter to obtain an electrothermal liquid preparation for air purification.
[0029] Comparative Example 1: The purpose of this comparative example is to verify the effect of using unmodified mesoporous silica instead of KH550 aminated mesoporous silica on the loading capacity of plant essential oils, air purification efficiency, continuous release performance and storage stability.
[0030] S1, Preparation of mesoporous silica Weigh 100 parts of mesoporous silica, dry it in a 90℃ forced-air drying oven for 8 hours, pulverize it and pass it through a 300-mesh sieve for later use; S2, Preparation of electrothermal liquid preparations Weigh 28 parts of propylene glycol, 12 parts of glycerol, 4007 parts of polyethylene glycol, and 2.5 parts of polyvinylpyrrolidone and add them to a reaction vessel. Stir at 40°C and 400 rpm for 30 min to fully dissolve the polyvinylpyrrolidone and form a homogeneous basic solution. Then add 19 parts of unmodified mesoporous silica and 6 parts of β-cyclodextrin and disperse at 650 rpm for 30 min. Then add 4 parts of plant essential oil, 2.5 parts of Tween 80, and 0.5 parts of disodium ethylenediaminetetraacetate and continue stirring at 40°C for 45 min to ensure that all components are fully mixed. S3, Finished Product Preparation Add 80 parts of deionized water to the mixture obtained in step S2, and continue stirring at 30°C for 30 minutes to form a uniform and stable liquid system. Then let it stand for 40 minutes to remove bubbles, and filter it through a 400-mesh filter to obtain an electrothermal liquid preparation for air purification.
[0031] Comparative Example 2: The purpose of this comparative example is to verify the effects of removing β-cyclodextrin and using only KH550 aminated modified mesoporous silica as the adsorbent carrier for plant essential oils on air purification efficiency, continuous release performance, storage stability and plant essential oil loading capacity.
[0032] Preparation of S1, KH550 aminated modified mesoporous silica 100 parts of mesoporous silica were weighed and added to a mixed solvent consisting of 140 parts of anhydrous ethanol and 60 parts of deionized water. The mixture was stirred and dispersed at 450 rpm for 30 min. Then, 1.5 parts of glacial acetic acid were added to adjust the pH of the system to 4.8. The mixture was stirred until homogeneous to obtain a mesoporous silica dispersion. Subsequently, 10 parts of γ-aminopropyltriethoxysilane (KH550) were added, and the mixture was heated to 70 °C and reacted at 550 rpm for 4 h to allow KH550 to be fully hydrolyzed and uniformly grafted onto the surface of the mesoporous silica, resulting in an aminated modified mesoporous silica suspension. The obtained suspension was subjected to solid-liquid separation, washed three times with anhydrous ethanol, and then washed twice with deionized water. The suspension was dried at 90 °C for 8 h, pulverized, and passed through a 300-mesh sieve to obtain KH550 aminated modified mesoporous silica. S2, Preparation of electrothermal liquid preparations Weigh 28 parts of propylene glycol, 12 parts of glycerol, 4007 parts of polyethylene glycol, and 2.5 parts of polyvinylpyrrolidone and add them to a reaction vessel. Stir at 40°C and 400 rpm for 30 min to fully dissolve the polyvinylpyrrolidone and form a homogeneous basic solution. Then add 19 parts of KH550 aminated mesoporous silica and disperse at 650 rpm for 30 min. Then add 4 parts of plant essential oil, 2.5 parts of Tween 80, and 0.5 parts of disodium EDTA and continue stirring at 40°C for 45 min to fully adsorb the plant essential oil onto the surface of KH550 aminated mesoporous silica. S3, Finished Product Preparation Add 86 parts of deionized water to the mixture obtained in step S2, and continue stirring at 30°C for 30 minutes to form a uniform and stable liquid system. Then let it stand for 40 minutes to remove bubbles, and filter it through a 400-mesh filter to obtain an electrothermal liquid preparation for air purification.
[0033] Performance testing: 1. Air purification efficiency test The air-purifying electrothermal liquid formulations prepared in Examples 1-3 and Comparative Examples 1-2 were added to electrothermal evaporators of the same specifications, with 30 mL of sample added to each group. The mixtures were then heated to 30 mL. 3The test was conducted in a sealed environmental chamber with the ambient temperature controlled at 25±2℃ and the relative humidity controlled at 50±5%. A certain concentration of mixed formaldehyde and TVOC pollutants was released into the chamber to maintain a consistent initial concentration. The electric heating evaporator was run continuously for 4 hours, and the changes in formaldehyde and TVOC concentrations within the chamber were measured at 0h, 2h, and 4h. Air purification efficiency was used as the evaluation index. Each group was tested in triplicate, and the average value was taken.
[0034] 2. Continuous Performance Testing The air-purifying electrothermal liquid formulations prepared in Examples 1-3 and Comparative Examples 1-2 were added to electrothermal evaporators of the same specifications, with 30 mL of sample added to each group. The devices were continuously powered on at a constant temperature of 25±2℃, and the mass change of the samples was measured every 24 hours. Simultaneously, the concentration of characteristic components of plant essential oils in the air was determined using gas chromatography. The tests were conducted continuously for 30 days. The cumulative release rate of plant essential oils and the stability of their later release were used as evaluation indicators. Each group was tested in triplicate, and the average value was taken.
[0035] 3. Storage stability test The air-purifying electrothermal liquid preparations obtained in Examples 1-3 and Comparative Examples 1-2 were respectively placed in sealed glass bottles and placed in a constant temperature chamber at 54±1℃ for 14 days. After that, they were restored to room temperature, and the presence of stratification, sedimentation, precipitation and turbidity in each group of samples was observed. At the same time, the retention rate of plant essential oil content before and after storage was measured, and the samples were centrifuged at 4000rpm for 30min using a high-speed centrifuge to observe the sedimentation. The sedimentation rate and the retention rate of plant essential oil were used as evaluation indicators of storage stability. Each group was tested in parallel 3 times and the average value was taken.
[0036] 4. Plant essential oil load capacity test Weigh out the same mass of the adsorbents used in Examples 1-3 and Comparative Examples 1-2, add equal amounts of plant essential oils to each, and adsorb for 24 hours under the same temperature and stirring conditions. Filter to remove unadsorbed plant essential oils, and determine the content of remaining plant essential oils in the filtrate by gas chromatography. Calculate the plant essential oil loading capacity of each carrier based on the change in plant essential oil content before and after adsorption. Use the plant essential oil loading capacity (mg / g) as the evaluation index. Perform three parallel tests for each group and take the average value.
[0037] Table 1. Performance test results of the examples and comparative examples.
[0038] According to Table 1 and Figure 1The air-purifying electrothermal liquid formulations prepared in Examples 1-3 are superior to Comparative Examples 1 and 2 in terms of air purification efficiency, continuous release time, plant essential oil retention rate, and plant essential oil loading. Among them, Example 2 achieved the best performance in all aspects, indicating that using appropriate formulation ratios and reaction conditions can fully leverage the synergistic effect between KH550 aminated modified mesoporous silica, β-cyclodextrin, and polyvinylpyrrolidone, thereby significantly improving the overall performance of the air-purifying electrothermal liquid formulation.
[0039] As can be seen from Example 2 compared with Comparative Example 1, when other components, formulation ratios, and preparation processes remain the same, simply replacing the KH550 aminated mesoporous silica with unmodified mesoporous silica resulted in a decrease in air purification efficiency from 94.3% to 81.9%, a shortening of the continuous release time from 35.6 days to 21.2 days, a decrease in plant essential oil retention rate from 96.8% to 84.5%, and a decrease in plant essential oil loading from 226.9 mg / g to 132.8 mg / g. This indicates that the unmodified mesoporous silica has fewer surface active sites and weaker interaction with plant essential oils, leading to a significant decrease in plant essential oil loading capacity and sustained-release capacity. However, after KH550 amination modification, abundant amino active groups are introduced onto the surface of the mesoporous silica, improving the adsorption and binding capacity of plant essential oil molecules on the material surface. This allows the plant essential oils to be more stably loaded in the mesoporous structure, thereby significantly improving air purification efficiency, continuous release performance, and storage stability.
[0040] As can be seen from Example 2 compared with Comparative Example 2, when KH550 aminated modified mesoporous silica and its preparation process remain unchanged, the air purification efficiency decreased from 94.3% to 86.8% after only β-cyclodextrin was removed, the continuous release time decreased from 35.6 days to 24.7 days, the plant essential oil retention rate decreased from 96.8% to 89.3%, and the plant essential oil loading decreased from 226.9 mg / g to 171.6 mg / g. This indicates that although KH550 aminated modified mesoporous silica can improve the adsorption loading capacity of plant essential oils, the lack of β-cyclodextrin inclusion effect leads to a faster release rate of plant essential oils and a decrease in the sustained release effect, resulting in a significant reduction in continuous release performance and air purification effect. This further proves that there is a significant synergistic sustained release effect between KH550 aminated modified mesoporous silica and β-cyclodextrin.
[0041] The test results of Examples 1, 2, and 3 further demonstrate that when each component is formulated within the lower, median, and upper limits of the claims, good overall performance can be obtained. Example 2, using an intermediate ratio and suitable reaction conditions, allows for a more coordinated matching relationship between the components. In Example 1, the relatively low KH550 grafting amount and plant essential oil loading limit the adsorption sites and sustained-release capacity, resulting in slightly lower performance than Example 2. Although Example 3 increased the KH550 grafting amount and plant essential oil addition, the excessively high grafting density and active component content can easily obscure some mesoporous channels, increasing the diffusion resistance of the plant essential oil. Therefore, the air purification efficiency, continuous release performance, and plant essential oil retention rate are slightly lower than in Example 2, but still significantly better than Example 1 and the comparative examples.
[0042] In summary, this invention uses KH550 to aminate mesoporous silica and combines it with β-cyclodextrin, polyvinylpyrrolidone, and a composite solvent system to construct an air-purifying electrothermal liquid formulation. The components exhibit a good synergistic effect, significantly improving the loading capacity and retention rate of plant essential oils, effectively extending the continuous release time of the plant essential oils, and enhancing air purification efficiency and system storage stability. Example 2, prepared using an intermediate ratio and suitable process conditions, demonstrates the best overall performance, fully verifying the effectiveness and superiority of the technical solution of this invention.
Claims
1. An electrothermal liquid preparation for air purification, characterized in that, The raw materials include the following parts by weight: 8-30 parts of KH550 aminated modified mesoporous silica; 0.5-8 parts of plant essential oil; 2-10 parts of β-cyclodextrin; 0.5-5 parts of polyvinylpyrrolidone; 15-40 parts of propylene glycol; and 5-20 parts of glycerin. Polyethylene glycol 400 2-12 parts; Tween 80 0.5-5 parts; disodium ethylenediaminetetraacetate 0.05-1 part; deionized water 40-120 parts; the KH550 aminated modified mesoporous silica is obtained by surface aminated modification of mesoporous silica with γ-aminopropyltriethoxysilane.
2. The electrothermal liquid preparation for air purification according to claim 1, characterized in that, The KH550 aminated modified mesoporous silica comprises the following raw materials in parts by weight: 100 parts mesoporous silica; 5-15 parts γ-aminopropyltriethoxysilane (KH550); 100-180 parts anhydrous ethanol; 40-80 parts deionized water; and 0.5-3 parts glacial acetic acid.
3. An electrothermal liquid preparation for air purification according to claim 1 or 2, characterized in that, The preparation method of the KH550 aminated modified mesoporous silica includes the following steps: (1) Add mesoporous silica to a mixed solvent consisting of anhydrous ethanol and deionized water, stir and disperse evenly, then add glacial acetic acid to adjust the pH of the system, and continue stirring to obtain a mesoporous silica dispersion. (2) Add γ-aminopropyltriethoxysilane to the mesoporous silica dispersion and carry out silanization reaction under stirring conditions to make KH550 condense with the hydroxyl groups on the surface of mesoporous silica to obtain an aminated modified mesoporous silica suspension. (3) The aminated modified mesoporous silica suspension is subjected to solid-liquid separation, and is washed with anhydrous ethanol and deionized water in sequence, dried and pulverized to obtain the KH550 aminated modified mesoporous silica.
4. The electrothermal liquid preparation for air purification according to claim 3, characterized in that, The reaction conditions for step (1) are a stirring speed of 300-600 rpm, a dispersion time of 20-40 min, and the pH of the system is adjusted to 4.5-5.5 using glacial acetic acid.
5. The electrothermal liquid preparation for air purification according to claim 3, characterized in that, The reaction conditions for step (2) are a reaction temperature of 60-80℃, a stirring speed of 400-700rpm, and a reaction time of 3-6h.
6. The electrothermal liquid preparation for air purification according to claim 3, characterized in that, The reaction conditions for step (3) are as follows: wash with anhydrous ethanol 2 to 4 times, then wash with deionized water 2 to 3 times, then dry at 80 to 100°C for 6 to 10 hours, pulverize and pass through a 200 to 400 mesh sieve to obtain the KH550 aminated modified mesoporous silica.
7. A method for preparing an electrothermal liquid formulation for air purification, characterized in that, The preparation method includes the following steps: S1. Weigh out propylene glycol, glycerin, polyethylene glycol 400 and polyvinylpyrrolidone according to the weight parts, add them to the reaction vessel, stir and mix evenly to fully dissolve the polyvinylpyrrolidone and obtain a homogeneous base solution. S2, add KH550 aminated mesoporous silica and β-cyclodextrin to the base solution, continue stirring and dispersing to ensure that KH550 aminated mesoporous silica is uniformly dispersed in the system and that the plant essential oil is fully adsorbed into the sustained-release system formed by KH550 aminated mesoporous silica and β-cyclodextrin. Then add the plant essential oil, Tween 80 and disodium ethylenediaminetetraacetate, and continue stirring and mixing until uniform. S3. Add deionized water to the mixture and continue stirring until the system is uniform and stable. After standing to remove bubbles and filtering, the electrothermal liquid preparation for air purification is obtained.
8. The method for preparing an electrothermal liquid preparation for air purification according to claim 7, characterized in that, The reaction conditions for step S1 are: stirring temperature of 30-50℃, stirring speed of 300-500rpm, and stirring time of 20-40min.
9. A method for preparing an electrothermal liquid preparation for air purification according to claim 7, characterized in that, The reaction conditions for step S2 are as follows: after adding KH550 aminated modified mesoporous silica, the dispersion speed is 500-800 rpm and the dispersion time is 20-40 min; after adding plant essential oil, Tween 80 and disodium EDTA, the mixture is stirred at 30-45℃ for 30-60 min.
10. A method for preparing an electrothermal liquid formulation for air purification according to claim 7, characterized in that, The reaction conditions for step S3 are as follows: after adding deionized water, stir at 25-35°C for 20-40 minutes, let stand to degas for 20-60 minutes, and then filter through a 300-500 mesh filter to obtain the electrothermal liquid preparation for air purification.