Essential oil microcapsule as well as preparation method and application thereof

Abstract

The invention relates to the technical field of essential oil microcapsules, and provides an essential oil microcapsule as well as a preparation method and application thereof. According to the preparation method, modified chitosan, tetraethyl orthosilicate, fluorosilane and essential oil are taken as main raw materials, and the chitosan / SiO2 composite microcapsule coated with the essential oil is prepared by adopting a single condensation-sol-gel method. The essential oil microcapsule provided by the invention has the property of slowly releasing the coated essential oil under the response of CO2 and the hydrophobic property, and can be used in fabric finishing.

Description

Technical Field

[0001] The present invention relates to the technical field of essential oil microcapsules, and in particular to an essential oil microcapsule and a preparation method and application thereof. Background Art

[0002] Recently, increasing attention has been focused on bio-based polymers such as chitosan, sodium alginate, and cellulose. With the increasing emphasis on green chemical textiles and the development of natural materials, the use of bio-based polymers as functional microcapsule shell materials is also gaining increasing attention. Therefore, the use of bio-based polymers as functional microcapsule shell materials is the most promising material for functional fabric finishing.

[0003] With the improvement of people's living standards, scented health-care textiles have attracted widespread attention. However, essential oils generally have poor thermal stability, are volatile, and are easily oxidized. If essential oils are directly applied to textiles, the fragrance not only lasts for a short time but also has poor water fastness. In addition, textiles also require additional properties, such as anti-fouling properties, UV protection, and electrical conductivity. Although chitosan is hydrophilic, the numerous amino and hydroxyl functional groups on the chitosan skeleton can be modified with other molecules to expand the application range of chitosan. By modifying chitosan, multifunctional microcapsules with a wider range of properties can be developed to meet the needs of different textile applications.

[0004] Currently, patent CN114150500A discloses a method for preparing aromatic cotton fiber textiles, which involves first preparing an impregnation solution composed of chitosan, an emulsifier, a penetrant, and plant essential oil microcapsules, then immersing cotton fibers in the impregnation solution, washing and drying, and then subjecting the cotton fibers to a textile process to obtain the aromatic cotton fiber textiles. Patent CN111764175A discloses a method for preparing textile fragrance microcapsules, which involves first mixing a liquid essential oil with an aliphatic isocyanate polymer to form a cross-linked fragrance oil polymer, and then encapsulating the cross-linked fragrance oil polymer with an acrylamide solution and acrylamidopropyltrimethylammonium chloride to form solid textile fragrance microcapsules. Although these textiles can achieve the effect of long-lasting fragrance release, the fragrance release is uncontrollable, the preparation process is complex and tedious, and the resulting textiles have a single function, which cannot meet different application requirements. Summary of the Invention

[0005] In view of the above technical problems, the object of the present invention is to provide an essential oil microcapsule and a preparation method and application thereof.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] A method for preparing essential oil microcapsules comprises the following steps:

[0008] 3-(6-amino-9H-purine-9-yl)-2-propylene is added to a chitosan acetic acid solution to carry out a modification reaction to obtain modified chitosan;

[0009] Tetraethyl orthosilicate, fluorosilane, a silane coupling agent, essential oil, an initiator, and an emulsifier are added to deionized water to form an oil-water emulsion;

[0010] The oil-water emulsion and the modified chitosan solution are mixed to carry out capsule-forming reaction to prepare chitosan / SiO2 composite microcapsules coated with essential oil, namely, essential oil microcapsules.

[0011] Furthermore, the mass concentration of chitosan in the chitosan acetic acid solution is 1% to 5%; the mass ratio of the 3-(6-amino-9H-purine-9-yl)-2-propylene to the chitosan is 3 to 5:10.

[0012] Furthermore, the mass ratio of the chitosan acetate solution to the tetraethyl orthosilicate is 1-10:0.1-1; the mass ratio of the tetraethyl orthosilicate, fluorosilane, silane coupling agent, essential oil, emulsifier and deionized water is 0.5-5:0.1-5:0.1-2:0.5-10:0.5-10:10-150.

[0013] Furthermore, the reaction temperature of the modification reaction is 75-85° C., and the reaction time is 9-11 hours.

[0014] Furthermore, the reaction temperature of the encapsulation reaction is 55-65° C., and the reaction time is 11-13 hours.

[0015] Furthermore, the essential oil is at least one of vanilla oil, carvacrol, thymol, lemon oil, peppermint oil, laurel oil, patchouli oil, geranium oil, perilla oil, jasmine oil or lavender oil.

[0016] Furthermore, the fluorosilane is at least one of tridecafluorooctyltrimethoxysilane, tridecafluoroalkylpropyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane or perfluorodecyldioxysilane.

[0017] Furthermore, the emulsifier is one or more of Triton X-100, dodecyl ammonium chloride, polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester, sodium dodecylbenzenesulfonate or sodium lauryl sulfate.

[0018] The present invention also provides an essential oil microcapsule, which is prepared by the above-mentioned preparation method of the essential oil microcapsule.

[0019] Compared with the prior art, the preparation method of essential oil microcapsules provided by the present invention first modifies chitosan with a CO2-responsive monomer 3-(6-amino-9H-purine-9-yl)-2-propylene, and then uses the modified chitosan, tetraethyl orthosilicate, fluorosilane, and essential oil as main raw materials to prepare chitosan / SiO2 composite microcapsules coated with essential oils by a single coagulation-sol-gel method. The obtained essential oil microcapsules use essential oils as the core material, and form CO2-responsive polymers (3-(6-amino-9H-purine-9-yl)-2-propylene and a silane coupling agent copolymerize on the surface of silica to form a CO2-responsive polymer) and fluorosilane hydrophobic chains on the surface of the essential oil microcapsules, giving the microcapsules the ability to slowly release the coated essential oils in response to CO2 and hydrophobic properties. The preparation method provided by the present invention is simple and environmentally friendly, and the materials used for the essential oil microcapsules have good biocompatibility, biodegradability, and non-toxicity, and have broad application prospects.

[0020] The present invention also provides the use of the essential oil microcapsules in fabric finishing, wherein the essential oil microcapsules are applied to the fabric by padding, dipping, coating or spraying.

[0021] Furthermore, the fabric includes woven fabric, knitted fabric or non-woven fabric.

[0022] The present invention also provides a fabric finishing liquid comprising the essential oil microcapsules.

[0023] The present invention also provides a fabric product, which is made from the fabric finished with the above fabric finishing liquid.

[0024] Furthermore, the fabric products include masks, nasal cotton swabs and face towels.

[0025] Essential oil microcapsules are applied to fabrics such as non-woven fabrics or viscose fibers to create fabrics with CO2-responsive, slow-release fragrance and antibacterial properties. Exhaled CO2 gas is used to induce the protonation and contraction of the amino groups of 3-(6-amino-9H-purin-9-yl)-2-propylene on the microcapsules, opening the pores in the microcapsule shell and releasing the essential oil from the inside to the outside. This ultimately achieves the CO2-controlled release of the essential oil. CO2-responsive essential oil slow-release microcapsules can further improve the utilization rate of the essential oil. Therefore, applying these CO2-responsive essential oil microcapsules to fabric products that come into close contact with the nose or face, such as masks, nasal cotton swabs, and face towels, could make them more widely applicable.

[0026] In addition, the present invention also provides a coating based on the essential oil microcapsules, comprising the following raw materials in parts by mass: 35 to 50 parts of the essential oil microcapsules and 45 to 65 parts of a water-based resin.

[0027] Furthermore, the water-based resin is one or more of water-based polysiloxane resin, water-based epoxy resin, water-based polyurethane, water-based fluorocarbon resin or water-based acrylic resin.

[0028] Furthermore, the preparation method of the coating comprises the following steps:

[0029] The essential oil microcapsules and water-based resin are mixed and stirred until uniformly dispersed to obtain a fabric coating. The fabric coating is applied to the surface of the fabric and dried at 40-100° C. for 20-60 minutes to obtain a fabric coating.

[0030] Furthermore, the coating further comprises the following raw materials in parts by mass: 0.1 to 5 parts of an auxiliary agent and 3 to 40 parts of deionized water.

[0031] Furthermore, the auxiliary agent is one or more of a softener, a leveling agent, an adhesion promoter or an antistatic agent.

[0032] The essential oil microcapsules provided by the present invention can be applied to fabric finishing. The essential oil microcapsules can be compounded with a variety of water-based resins and applied to the fabric surface in one step to form a fabric coating, which has the advantages of low cost, green and high efficiency. The fabric coating containing essential oil microcapsules can give the fabric the performance of long-term controllable sustained release of essential oils under CO2 response and superhydrophobicity. At the same time, the essential oil in the microcapsules and chitosan synergistically give the fabric excellent antibacterial properties. The coating can be applied to fabric products such as outdoor clothing, home textile fabrics, interior decorations, protective clothing, etc. As the CO2 concentration in the environment increases, the pores on the CO2-responsive essential oil microcapsule shells in the fabric coating gradually open, and the release rate of the essential oil increases. On the contrary, if the CO2 concentration decreases, the essential oil release rate decreases, and the effect of CO2-controlled release of essential oils can be achieved, achieving the effect of long-lasting release of fragrance and long-lasting antibacterial effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a scanning electron microscope (SEM) image of the essential oil microcapsules according to an embodiment of the present invention;

[0034] Figure 2 This is a scanning electron microscope (SEM) image of the fabric coating according to an embodiment of the present invention;

[0035] Figure 3 The water contact angle test results of the fabric coatings of the embodiments of the present invention and the comparative examples are shown;

[0036] Figure 4 The hydrophobicity test results of the fabric coating according to the embodiment of the present invention are shown below;

[0037] Figure 5 、 6 7 is the essential oil release curve of the fabric coating in the test example of the present invention;

[0038] Figure 8This is a diagram showing the antibacterial effect of the fabric coating in the test example of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0040] Example 1

[0041] A method for preparing essential oil microcapsules comprises the following steps:

[0042] (1) 1 g of chitosan was added to 50 mL of 1% acetic acid solution and ultrasonically treated at room temperature for 0.5 h until completely dissolved to obtain a chitosan acetic acid solution. 0.3 g of 3-(6-amino-9H-purine-9-yl)-2-propene was added dropwise under magnetic stirring, and the mixture was stirred at 80°C for 10 h at a stirring speed of 500 rpm to obtain a modified chitosan solution.

[0043] (2) 0.5 g of tetraethyl orthosilicate, 0.25 g of lemon oil, 0.2 g of tridecafluorooctyltrimethoxysilane, 0.1 g of silane coupling agent KH570, 0.1 g of azobisisobutyronitrile, and 0.1 g of Triton X-100 were added to 50 mL of deionized water and stirred under ultrasound for 30 minutes to form an oil-water emulsion;

[0044] (3) pouring the oil-water emulsion of step (2) into the chitosan solution modified in step (1), stirring at 650 rpm for 12 hours at 60° C. to obtain a chitosan / SiO2 composite microcapsule solution coated with essential oil, that is, an essential oil microcapsule solution.

[0045] The preparation method of the coating based on the essential oil microcapsules obtained above is as follows:

[0046] 50 parts of the obtained essential oil microcapsule solution (solid content 6 wt%) were mixed with 50 parts of an aqueous polysiloxane resin emulsion (solid content 60 wt%), and the mixture was mixed under mechanical stirring at 1000 rpm for 10 minutes until uniformly dispersed to obtain a fabric coating. The fabric coating was applied to the surface of the fabric by roller coating and dried at 50° C. for 30 minutes to obtain a fabric coating.

[0047] Example 2

[0048] A method for preparing essential oil microcapsules comprises the following steps:

[0049] (1) 1.2 g of chitosan was added to 50 mL of 1% acetic acid solution and ultrasonically treated at room temperature for 0.5 h until completely dissolved to obtain a chitosan acetic acid solution. 0.4 g of 3-(6-amino-9H-purine-9-yl)-2-propene was added dropwise under magnetic stirring, and the mixture was stirred at 85°C for 11 h at a stirring speed of 500 rpm to obtain a modified chitosan solution.

[0050] (2) 0.5 g of tetraethyl orthosilicate, 0.3 g of lavender oil, 0.25 g of tridecafluoroalkylpropyltrimethoxysilane, 0.15 g of silane coupling agent KH570, 0.5 g of azobisisobutyronitrile, and 0.2 g of sodium dodecylbenzenesulfonate were added to 50 mL of deionized water and stirred under ultrasound for 30 minutes to form an oil-water emulsion;

[0051] (3) pouring the oil-water emulsion of step (2) into the chitosan solution modified in step (1), stirring at 65° C. and 650 rpm for 11 hours to obtain a chitosan / SiO2 composite microcapsule solution coated with essential oil, that is, an essential oil microcapsule solution.

[0052] The preparation method of the coating based on the essential oil microcapsules obtained above is as follows:

[0053] 40 parts of the obtained essential oil microcapsule solution (solid content 6 wt%) were mixed with 60 parts of an aqueous epoxy resin emulsion (solid content 60 wt%), and the mixture was mixed under mechanical stirring at 1000 rpm for 10 minutes until uniformly dispersed to obtain a fabric coating. The fabric coating was applied to the surface of the fabric by roller coating and dried at 40° C. for 50 minutes to obtain a fabric coating.

[0054] Example 3

[0055] A method for preparing essential oil microcapsules comprises the following steps:

[0056] (1) 1.5 g of chitosan was added to 50 mL of 1% acetic acid solution and ultrasonically treated at room temperature for 0.5 h until completely dissolved to obtain a chitosan acetic acid solution. 0.45 g of 3-(6-amino-9H-purine-9-yl)-2-propene was added dropwise under magnetic stirring and stirred at 75°C for 11 h at a stirring speed of 500 rpm to obtain a modified chitosan solution.

[0057] (2) 0.75 g of tetraethyl orthosilicate, 0.35 g of peppermint oil, 0.25 g of heptadecafluorodecyltrimethoxysilane, 0.15 g of silane coupling agent KH570, 0.3 g of azobisisobutyronitrile, and 0.25 g of dodecylammonium chloride were added to 50 mL of deionized water and stirred under ultrasound for 30 minutes to form an oil-water emulsion;

[0058] (3) pouring the oil-water emulsion of step (2) into the chitosan solution modified in step (1), stirring at 55° C. and 650 rpm for 13 hours to obtain a chitosan / SiO2 composite microcapsule solution coated with essential oil, that is, obtaining an essential oil microcapsule solution.

[0059] The preparation method of the coating based on the essential oil microcapsules obtained above is as follows:

[0060] 35 parts of the obtained essential oil microcapsule solution (solid content 6 wt%) were mixed with 65 parts of an aqueous polysiloxane resin emulsion (solid content 60 wt%), and the mixture was mixed under mechanical stirring at 1000 rpm for 10 minutes until uniformly dispersed to obtain a fabric coating. The fabric coating was applied to the surface of the fabric by roller coating and dried at 60° C. for 25 minutes to obtain a fabric coating.

[0061] Example 4

[0062] A method for preparing essential oil microcapsules comprises the following steps:

[0063] (1) 2 g of chitosan was added to 50 mL of 1% acetic acid solution and ultrasonically treated at room temperature for 0.5 h until completely dissolved to obtain a chitosan acetic acid solution. 0.65 g of 3-(6-amino-9H-purine-9-yl)-2-propene was added dropwise under magnetic stirring, and the mixture was stirred at 80°C for 10 h at a stirring speed of 500 rpm to obtain a modified chitosan solution.

[0064] (2) 1 g of tetraethyl orthosilicate, 0.45 g of jasmine oil, 0.3 g of perfluorodecyldioxysilane, 0.2 g of silane coupling agent KH570, 0.2 g of azobisisobutyronitrile, and 0.3 g of sodium lauryl sulfate were added to 50 mL of deionized water and stirred under ultrasound for 30 minutes to form an oil-water emulsion;

[0065] (3) pouring the oil-water emulsion of step (2) into the chitosan solution modified in step (1), stirring at 650 rpm for 12 hours at 60° C. to obtain a chitosan / SiO2 composite microcapsule solution coated with essential oil, that is, an essential oil microcapsule solution.

[0066] The preparation method of the coating based on the essential oil microcapsules obtained above is as follows:

[0067] 45 parts of the obtained essential oil microcapsule solution (solid content 6 wt%) were mixed with 55 parts of an aqueous polyurethane emulsion (solid content 60 wt%), and the mixture was mixed under mechanical stirring at 1000 rpm for 10 minutes until uniformly dispersed to obtain a fabric coating. The fabric coating was applied to the surface of the fabric by roller coating and dried at 45° C. for 40 minutes to obtain a fabric coating.

[0068] Example 5

[0069] A method for preparing essential oil microcapsules comprises the following steps:

[0070] (1) 2.5 g of chitosan was added to 50 mL of 1% acetic acid solution and ultrasonically treated at room temperature for 0.5 h until completely dissolved to obtain a chitosan acetic acid solution. 1 g of 3-(6-amino-9H-purine-9-yl)-2-propene was added dropwise under magnetic stirring and stirred at 80°C for 10 h at a stirring speed of 500 rpm to obtain a modified chitosan solution.

[0071] (2) 1.25 g of tetraethyl orthosilicate, 0.5 g of vanilla oil, 0.35 g of tridecafluorooctyltrimethoxysilane, 0.25 g of silane coupling agent KH570, 0.4 g of azobisisobutyronitrile, and 0.35 g of sorbitan fatty acid ester were added to 50 mL of deionized water and stirred under ultrasound for 30 minutes to form an oil-water emulsion;

[0072] (3) pouring the oil-water emulsion of step (2) into the chitosan solution modified in step (1), stirring at 650 rpm for 12 hours at 60° C. to obtain a chitosan / SiO2 composite microcapsule solution coated with essential oil, that is, an essential oil microcapsule solution.

[0073] The preparation method of the coating based on the essential oil microcapsules obtained above is as follows:

[0074] 40 parts of the obtained essential oil microcapsule solution (solid content 6 wt%) were mixed with 60 parts of an aqueous acrylic resin emulsion (solid content 60 wt%), and the mixture was mixed under mechanical stirring at 1000 rpm for 10 minutes until uniformly dispersed to obtain a fabric coating. The fabric coating was applied to the surface of the fabric by roller coating and dried at 80° C. for 15 minutes to obtain a fabric coating.

[0075] In order to improve or enhance the performance of the coating, additives and deionized water can be added for preparation.

[0076] In addition, the essential oil microcapsules provided in Examples 1 to 5 of the present invention can be prepared into a fabric finishing liquid with conventional auxiliary materials using conventional methods, and the fabric finished with the finishing liquid can be made into products such as masks, nasal cotton swabs, and face towels.

[0077] Comparative Example 1

[0078] A method for preparing essential oil microcapsules comprises the following steps:

[0079] (1) Add 1 g of chitosan to 50 mL of 1% acetic acid solution and ultrasonicate at room temperature for 0.5 h until the chitosan is completely dissolved to obtain chitosan acetic acid solution;

[0080] (2) 0.3 g of 3-(6-amino-9H-purine-9-yl)-2-propene, 0.5 g of tetraethyl orthosilicate, 0.25 g of lemon oil, 0.2 g of tridecafluorooctyltrimethoxysilane, 0.1 g of silane coupling agent KH570, 0.1 g of azobisisobutyronitrile, and 0.1 g of Triton X-100 were added to 50 mL of deionized water and stirred under ultrasound for 30 minutes to form an oil-water emulsion;

[0081] (3) Pour the oil-water emulsion of step (2) into the chitosan solution of step (1), and stir at 650 rpm for 12 hours at 60° C. to obtain an essential oil microcapsule solution.

[0082] The preparation method of the coating based on the essential oil microcapsules obtained above is as follows:

[0083] 50 parts of the obtained essential oil microcapsule solution (solid content 6 wt%) were mixed with 50 parts of an aqueous polysiloxane resin emulsion (solid content 60 wt%), and the mixture was mixed under mechanical stirring at 1000 rpm for 10 minutes until uniformly dispersed to obtain a fabric coating. The fabric coating was applied to the surface of the fabric by roller coating and dried at 50° C. for 30 minutes to obtain a fabric coating.

[0084] Comparative Example 2

[0085] A method for preparing essential oil microcapsules comprises the following steps:

[0086] (1) 1 g of chitosan was added to 50 mL of 1% acetic acid solution and ultrasonically treated at room temperature for 0.5 h until completely dissolved to obtain a chitosan acetic acid solution. 0.3 g of 3-(6-amino-9H-purine-9-yl)-2-propene was added dropwise under magnetic stirring, and the mixture was stirred at 80°C for 10 h at a stirring speed of 500 rpm to obtain a modified chitosan solution.

[0087] (2) 0.25 g of lemon oil and 0.1 g of Triton X-100 were added to 50 mL of deionized water and stirred under ultrasound for 30 minutes to form an oil-water emulsion;

[0088] (3) Pour the oil-water emulsion of step (2) into the chitosan solution modified in step (1), and stir at 650 rpm for 4 hours at 60° C. to obtain a chitosan microcapsule solution; then add 0.5 g of tetraethyl orthosilicate, 0.2 g of tridecafluorooctyltrimethoxysilane, 0.1 g of silane coupling agent KH570 and 0.1 g of azobisisobutyronitrile, and continue the reaction for 8 hours to obtain essential oil microcapsules.

[0089] The preparation method of the coating based on the essential oil microcapsules obtained above is as follows:

[0090] 50 parts of the obtained essential oil microcapsule solution (solid content 6 wt%) were mixed with 50 parts of an aqueous polysiloxane resin emulsion (solid content 60 wt%), and the mixture was mixed under mechanical stirring at 1000 rpm for 10 minutes until uniformly dispersed to obtain a fabric coating. The fabric coating was applied to the surface of the fabric by roller coating and dried at 50° C. for 30 minutes to obtain a fabric coating.

[0091] Test Example 1

[0092] The essential oil microcapsules prepared in Example 1, the untreated fabric, and the fabric coating obtained in Example 1 were subjected to scanning electron microscopy.

[0093] like Figure 1 As shown, the morphology of the essential oil microcapsules prepared in Example 1 was observed by scanning electron microscopy, and the particle size of the microcapsules was 20 to 30 μm.

[0094] like Figure 2 As shown in Figures 2a and 2b, the surface of the untreated fabric is composed of a large number of cylindrical fibers with smooth surfaces. Figure 2 c and Figure 2 As shown in Figure d, the microstructure of the fabric coating obtained in Example 1, the coating covers the fabric surface in the form of a film, and is composed of a large number of microspheres with an average particle size of about 20 μm.

[0095] Test Example 2

[0096] The fabric coatings obtained in Example 1 and Comparative Examples 1 and 2 were tested for hydrophobicity.

[0097] The water contact angles of the fabric coating surfaces prepared in Example 1 and Comparative Examples 2 and 3 were 156.6°, 136.8°, and 140.7°, respectively. Figure 3 shown.

[0098] The surface contact angle of the fabric coating prepared in Example 1 was 156.6°, and the contact angles for tea, soy sauce, milk, acidic solution (pH=3) and alkaline solution (pH=10) were all above 150°. Figure 4 This shows that the fabric coating containing essential oil microcapsules provided by the embodiment of the present invention can achieve waterproof and antifouling effects.

[0099] Test Example 3

[0100] The essential oil sustained-release performance of the fabric coatings containing essential oil microcapsules obtained in Example 1 and Comparative Examples 1 and 2 was tested under different atmospheres using an ultraviolet spectrophotometer.

[0101] First, a certain amount of lemon oil was weighed and prepared into five different concentrations of lemon oil-cyclohexane solutions (25 mg / L, 50 mg / L, 100 mg / L, 200 mg / L, and 400 mg / L) using cyclohexane as the solvent. The absorbance of these five solutions within the wavelength range of 200-400 nm was measured using a UV-visible spectrophotometer, and a standard curve was plotted. The coated fabric containing the essential oil microcapsules was immersed in an appropriate amount of cyclohexane and aerated with CO2. The absorbance within the wavelength range of 200-400 nm was measured at 15-minute intervals. The values ​​were substituted into the standard curve equation to calculate the concentration, and then the amount of lemon oil released (%) was calculated.

[0102] As shown in Table 1 and Figure 5 、 6 、7(Among them, Figure 5 For Example 1; Figure 6 For comparative example 1; Figure 7 As shown in Comparative Example 2, the release efficiency of lemon oil from the fabric coating prepared in Example 1 varies under different atmospheres. The release rate of lemon oil is significantly increased under CO₂, while the release rate is lower under atmospheric conditions with lower CO₂ concentrations, achieving the effect of controlled CO₂ release. The release rates of essential oil from the fabric coating prepared in Comparative Example 1 are both low under CO₂ and atmospheric conditions, with no significant difference. Compared to Comparative Example 1, the release rates of essential oil from the fabric coating prepared in Comparative Example 2 are both improved under CO₂ and atmospheric conditions, but lower than the release rate of Example 1 under CO₂.

[0103] Table 1

[0104]

[0105] It can be seen from the above data that the essential oil microcapsules obtained in Example 1 have good compactness, good stability under normal atmospheric conditions, good CO2 responsiveness, and good controllable sustained release. Although the essential oil microcapsules obtained in Comparative Example 1 have good stability under normal atmospheric conditions, the CO2 response monomer has not been successfully connected to the microcapsule shell material, resulting in weak or no CO2 response. The essential oil microcapsules obtained in Comparative Example 2 have silica on the outer surface and gaps in the shell, resulting in poor stability and weak CO2 response. Compared with the comparative example, the essential oil microcapsules obtained in the embodiment of the present invention have good compactness, good stability, good CO2 responsiveness, and achieve the function of long-term CO2 controllable sustained release of essential oil.

[0106] Test Example 4

[0107] The antibacterial properties of the blank fabric and the coated fabric prepared in Example 1 were tested according to the test method in accordance with GB-T20944.3-2008 "Evaluation of Antibacterial Properties of Textiles Part 3: Oscillation Method". The specific method is as follows:

[0108] (1) Cut the blank fabric and the coated fabric prepared in Example 1 into approximately 5 mm x 5 mm pieces. Weigh 0.25 g of each piece and place it in a 100 mL conical flask. Weigh multiple pieces as needed for the experiment and sterilize them with ultraviolet light.

[0109] (2) Prepare bacterial inoculum (Escherichia coli and Staphylococcus aureus) and PBS buffer, and prepare nutrient agar plates.

[0110] (3) Preparation of bacterial suspension: Use a bacterial inoculation loop to take a colony from the cultured bacteria, place it in a conical flask containing bacterial inoculation solution, and place it in a shaker (temperature: 37°C, speed 130 r / min) for 24 hours.

[0111] (4) Dilution and separation: Use a UV spectrophotometer to test the bacterial concentration and dilute it with PBS buffer to control the bacterial concentration at around 0.4.

[0112] (5) When the concentration is appropriate, take 5 mL of bacterial solution and dilute it with PBS buffer for 10 min. 2 , transferred into a conical flask containing fabric, and placed in a shaker for 18 h (24 ° C, 150 r / min).

[0113] (6) After the specified time, 1 mL of bacterial solution was drawn from the conical flask in step (5) and diluted to an appropriate dilution factor with PBS buffer. 25 μL of the solution was transferred to sterilized agar plates and evenly coated. Finally, the plates were placed in a constant temperature cabinet at 37°C and cultured for 24 h. The number of bacteria was recorded.

[0114] (7) Calculate the results according to GB-T20944.3-2008 and obtain the antibacterial rate.

[0115] like Figure 8 As shown, the inhibition rates of the coated fabric prepared in Example 1 against Staphylococcus aureus and Escherichia coli were 98.3% and 95.7%, respectively, and the antibacterial performance was excellent.

[0116] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing essential oil microcapsules, characterized in that: The preparation method comprises the following steps: 3-(6-amino-9H-purine-9-yl)-2-propylene is added to a chitosan acetic acid solution to carry out a modification reaction to obtain modified chitosan; Tetraethyl orthosilicate, fluorosilane, a silane coupling agent, essential oil and an emulsifier are added to deionized water to form an oil-water emulsion; The oil-water emulsion and the modified chitosan solution are mixed to carry out capsule-forming reaction to prepare chitosan / SiO2 composite microcapsules coated with essential oil, namely, essential oil microcapsules.

2. The method for preparing essential oil microcapsules according to claim 1, wherein The mass concentration of chitosan in the chitosan acetic acid solution is 1% to 5%; the mass ratio of the 3-(6-amino-9H-purine-9-yl)-2-propylene to the chitosan is 3 to 5:

10.

3. The method for preparing essential oil microcapsules according to claim 2, wherein The mass ratio of the chitosan acetate solution to the tetraethyl orthosilicate is 1-10:0.1-1; the mass ratio of the tetraethyl orthosilicate, fluorosilane, silane coupling agent, essential oil, emulsifier and deionized water is 0.5-5:0.1-5:0.1-2:0.5-10:0.5-10:10-150.

4. The method for preparing essential oil microcapsules according to claim 1, wherein The reaction temperature of the modification reaction is 75-85° C., and the reaction time is 9-11 hours.

5. The method for preparing essential oil microcapsules according to claim 1, wherein The reaction temperature of the encapsulation reaction is 50-80° C., and the reaction time is 11-13 hours.

6. The method for preparing essential oil microcapsules according to claim 1, wherein The essential oil is at least one of vanilla oil, carvacrol, thymol, lemon oil, peppermint oil, laurel oil, patchouli oil, geranium oil, perilla oil, jasmine oil or lavender oil.

7. The method for preparing essential oil microcapsules according to claim 1, wherein The fluorosilane is at least one of tridecafluorooctyltrimethoxysilane, tridecafluoroalkylpropyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane or perfluorodecyldioxysilane.

8. The method for preparing essential oil microcapsules according to claim 1, wherein The emulsifier is one or more of Triton X-100, dodecyl ammonium chloride, polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester, sodium dodecylbenzenesulfonate or sodium lauryl sulfate.

9. An essential oil microcapsule, characterized in that: The essential oil microcapsules are prepared by the preparation method of any one of claims 1 to 8.

10. Use of the essential oil microcapsules according to claim 9 in fabric finishing, characterized in that: The essential oil microcapsules are arranged on the fabric by padding, dipping, coating or spraying.

11. The use according to claim 10, characterized in that The fabrics include woven fabrics, knitted fabrics or non-woven fabrics.

12. A fabric finishing liquid, characterized in that: The essential oil microcapsule according to claim 9.

13. A fabric product, characterized in that: The method is prepared from a fabric treated with the fabric finishing liquid according to claim 12.

14. The fabric article according to claim 13, wherein The fabric products include masks, cotton swabs for nasal cavity and face towels.

15. A coating based on the essential oil microcapsules according to claim 9, characterized in that: The invention comprises the following raw materials in parts by mass: 35 to 50 parts of the essential oil microcapsules and 45 to 65 parts of the water-based resin.

16. The coating according to claim 15, wherein The water-based resin is one or more of water-based polysiloxane resin, water-based epoxy resin, water-based polyurethane, water-based fluorocarbon resin or water-based acrylic resin.

17. The coating according to claim 16, wherein The preparation method comprises the following steps: The essential oil microcapsules and water-based resin are mixed and stirred until uniformly dispersed to obtain a fabric coating. The fabric coating is applied to the surface of the fabric and dried at 40-100° C. for 20-60 minutes to obtain a fabric coating.

18. The coating according to claim 17, wherein The invention also includes the following raw materials in parts by weight: 0.1 to 5 parts of auxiliary agent and 3 to 40 parts of deionized water.

19. The coating according to claim 18, wherein The auxiliary agent is one or more of a softener, a leveling agent, an adhesion promoter or an antistatic agent.

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