Fragrance-releasing color-changing gel sphere, and preparation method therefor and use thereof

Abstract

A fragrance-releasing color-changing gel sphere, and a preparation method therefor and the use thereof. The fragrance-releasing color-changing gel sphere has a particle size of 3.2-3.6 mm, undergoes a color change along with changes in temperature, and is capable of releasing fragrance molecules.

Description

A fragrance-releasing color-changing gel ball, its preparation method and uses Technical Field

[0001] This invention patent belongs to the field of tobacco additives, specifically relating to aroma-releasing and color-changing gel spheres, their preparation method, and their application in cigarette filter rods. Background Technology

[0002] Photonic crystals, as structures composed of dielectric materials with varying dielectric constants arranged in a regular, periodic pattern in space, exhibit a unique physical property—the photonic bandgap. This bandgap characteristic can induce rich optical color effects depending on the wavelength of the incident light. Specifically, the periodic arrangement of two dielectric materials with different dielectric constants constructs a specific "photonic potential field," and once this arrangement is adjusted, the photonic crystal immediately exhibits the ability to change colors.

[0003] Traditional color-changing materials are limited in their application in sensitive fields such as cigarette products due to potential chemical pollution and toxicity issues. Furthermore, current optoelectronic industries, such as those using liquid crystal displays and LED screens, often require high energy consumption to achieve color conversion. Although patent CN2005100112192 reports a full-color colloidal photonic crystal film, its preparation method, and applications, this approach lacks a gel substrate support and relies on a light-triggered color-changing mechanism rather than a color change induced by temperature variations.

[0004] This invention is proposed for this purpose. Summary of the Invention

[0005] In view of this, the present invention discloses a fragrance-releasing color-changing gel ball and its preparation method. The fragrance-releasing color-changing gel ball of the present invention changes color with temperature and can release fragrance molecules. The preparation method of the fragrance-releasing color-changing gel ball of the present invention firstly sprays a photocurable resin film layer onto the surface of the fragrance-carrying composite ball, which serves as the basic support structure for the photonic crystal film layer, and also plays a role in secondary solidification of the fragrance-carrying composite ball, as well as the color-developing matrix of the photonic crystal film; then, a photonic crystal film is sprayed, and the photonic crystal particles arrange and aggregate to attach to the photocurable film through the "self-assembly" effect to form a photonic crystal film layer; finally, another photocurable resin film layer is coated on this surface, providing a solidified shell and an additional protective barrier layer for the fragrance-releasing color-changing gel ball. The photonic crystal film layer is located between the two photocurable resin film layers. The core-shell structure particles in the photonic crystal film layer can change color in response to temperature changes; at the same time, the fragrance-releasing color-changing gel ball itself also has the function of releasing fragrance according to temperature. The entire aroma-releasing color-changing gel ball is then implanted into a visual ternary filter rod with transparent splicing paper through a filter rod forming process. During cigarette smoking, users can not only observe the color change of the aroma-releasing color-changing gel ball as the temperature changes, but also experience the released aroma substances, thereby effectively supplementing and enhancing the sensory enjoyment of the smoke.

[0006] The technical solution of the present invention is as follows:

[0007] The first aspect of this invention discloses a fragrance-releasing color-changing gel ball with a particle size of 3.2-3.6 mm, which changes color with temperature and can release fragrance molecules.

[0008] Preferably, the fragrance-releasing color-changing gel sphere comprises a core, an intermediate layer, and an outer layer; wherein the core comprises a fragrance-carrying composite sphere and a composite sphere protective layer, the intermediate layer is a photonic crystal film layer, and the outer layer is a gel sphere protective layer; both the composite sphere protective layer and the gel sphere protective layer are photocurable resin film layers, and the thickness of the photocurable resin film layer is 20-35 μm.

[0009] Preferably, the photonic crystal film has a thickness of 20-35 μm and is formed by the aggregation of multiple core-shell structured particles. The particle size is 170-300 nm, and the thickness of the particle shell is 20-50 nm. The particles are monodisperse latex particles with a polydispersity index of no more than 0.005. The glass transition temperature of the core polymer of the particles is greater than that of the shell polymer. The arrangement and aggregation mode of the particles in the photonic crystal film and the gaps between the particles change with temperature.

[0010] The second aspect of this invention discloses a method for preparing the fragrance-releasing color-changing gel spheres, comprising the following steps:

[0011] (1) Preparation of fragrance-loaded composite balls;

[0012] (2) Preparation of the formulation colloid for photocurable resin film;

[0013] (3) Wrap the formulation of the photocurable resin film layer from step (2) onto the surface of the fragrance-carrying composite ball from step (1), and then irradiate it with near-ultraviolet light in a shaker to cure and shape the core.

[0014] (4) Prepare an emulsion with core-shell structured particles;

[0015] (5) Spray the emulsion with core-shell structured particles from step (4) onto the core surface obtained in step (3), and then let it stand at a certain temperature for a period of time to obtain the photonic crystal film layer.

[0016] (6) Spray the formulation colloid of the photocurable resin film layer from step (2) onto the surface of the photonic crystal film layer obtained in step (5), and then irradiate it with an ultraviolet point light source in a shaker for a period of time to obtain the fragrance-releasing color-changing gel ball.

[0017] Preferably, the preparation method of the fragrance-carrying composite ball in step (1) is as follows: plant extract, fragrance, solvent and fragrance-carrying material are mixed, and then dripped into a spherical mold with a diameter of 3.2-3.6 mm at a certain rate using a dropper, and refrigerated for a period of time to obtain the fragrance-carrying composite ball; wherein the solvent is preferably a 95% ethanol solution.

[0018] Preferably, the formulation of the photocurable resin film layer in step (2) includes: epoxy resin monomer, IBOA, HDDA, butyl acetate and photoinitiator; wherein the mass ratio of epoxy resin monomer, IBOA, HDDA and butyl acetate is 52.5:12.2:10.1:25.2; and the photoinitiator is (4-8)% of the polymer monomer mass.

[0019] Step (3) The method of coating the surface of the fragrance-carrying composite ball with the formulation colloid of the photocurable resin film is as follows: the fragrance-carrying composite ball is completely immersed in the formulation colloid of the photocurable resin film, the shaker speed is 100-200 rpm, the near ultraviolet light is 360-370 nm, and the irradiation time is 1-2 min.

[0020] Preferably, step (4) is the preparation step of the emulsion with core-shell structured particles as follows: monomer 1 and monomer 2 are mixed and dispersed in an aqueous solution containing pH buffer and emulsifier, stirred at 300-800 rpm and at 70-80°C, 1 / 2 of the total amount of initiator is added to start the reaction, 1 / 4 of the total amount of initiator is added after 2-5 hours, and the remaining initiator is added after 2-5 hours to obtain the emulsion with core-shell structured particles; wherein the glass transition temperature of monomer 1 is greater than that of monomer 2.

[0021] Preferably, the spraying in step (5) or step (6) is carried out by air spraying; the spraying parameters are: the air pump pressure is 0.49-0.55MPa, the distance between the spray gun nozzle and the surface of the core is 25-30cm, and the time for spraying each core is 4-5 seconds.

[0022] Preferably, the energy of the ultraviolet point source in step (6) is 32 mW / cm². 2 The irradiation time is 300s, and the shaking speed of the shaker is 100-200rpm.

[0023] The third aspect of the present invention discloses the use of the aroma-releasing color-changing gel ball in cigarette filter rods.

[0024] The beneficial effects of this invention are:

[0025] The fragrance-releasing color-changing gel spheres of the present invention have a particle size of 3.2-3.6 mm; the gel spheres change color with temperature and release fragrance molecules. The fragrance-releasing color-changing gel spheres of the present invention comprise a core, an intermediate layer, and an outer layer; wherein the core comprises a fragrance-carrying composite sphere and a composite sphere protective layer, the intermediate layer is a photonic crystal film layer, and the outer layer is a gel sphere protective layer; both the composite sphere protective layer and the gel sphere protective layer are photocurable resin film layers, and the thickness of the photocurable resin film layer is 20-35 μm. The photonic crystal film layer, with a thickness of 20-35 μm, is a film layer formed by the aggregation of multiple core-shell structured particles, the particle size being 170-300 nm, and the thickness of the particle shell being 20-50 nm; the particles are monodisperse latex particles with a polydispersity index not greater than 0.005, and the glass transition temperature of the core polymer of the particles is greater than the glass transition temperature of the shell polymer; the arrangement and aggregation mode of the particles in the photonic crystal film layer and the gaps between the particles change with temperature.

[0026] During cigarette smoking, after the third or fourth puff, the filter rod temperature can rise from 40-50℃ to 65-70℃, and after the fifth puff, it can rise to over 80℃. The aroma-releasing color-changing gel balls of this invention are used in cigarette filters. The aroma-carrying composite balls are solid gel systems composed of various natural biopolymers and polymers. As the temperature rises, they transform into gel particle systems with open cavities. At this time, when single or complex aroma-producing components are added, different aroma-producing factors enter the corresponding cavities. After all aroma-producing factors have entered the cavities, the temperature is immediately lowered to below 40-50℃, and the system gradually solidifies, the cavities close, and a dense layer forms on the surface, binding and storing the aroma-producing factors. During cigarette smoking, as the temperature slowly rises to above 40-50℃, the cavities gradually open, and the aroma-producing factors inside are slowly released.

[0027] The fragrance-releasing color-changing gel spheres of this invention are first shaped using photocurable epoxy resin, and then a colloidal photonic crystal film is prepared. This photonic crystal film consists of monodisperse core-shell structured microspheres with a polymer (such as polystyrene) as the core and a polymer (polyacrylate) as the shell, which has a lower glass transition temperature (Tg). The dispersion coefficient is less than 0.005, and the particle size range is 170-300 nm (as shown in Figures 1 and 5). The prepared colloid is sprayed onto the surface of the fragrance-carrying composite spheres. The photonic crystal particles spontaneously aggregate into a stable film with a certain regular geometric structure through the particle "self-assembly effect," that is, through the interaction of non-covalent bonds. The photonic crystal particles absorb a specific spectrum through a certain regular arrangement and exhibit a specific color. When heated, the thermal motion of the particles constituting the photonic crystal intensifies, and the arrangement and spacing between the particles also change, causing the material to expand anisotropically, resulting in a change in refractive index; thus, the appearance of the material changes color (as shown in Figure 6). Therefore, during cigarette smoking, the photonic crystal film layer will produce a color-changing effect as the temperature rises. To protect this photonic crystal film layer, the outermost layer of the aroma-releasing color-changing gel ball of the present invention also has a photocurable resin film layer for fixing and protection, in order to protect the aroma-carrying composite ball material and the photonic crystal film layer from damage during production and transportation.

[0028] However, the photocurable resin film (substrate is AESO) is not a completely sealed film. The epoxy resin is cross-linked through monofunctional and difunctional groups. The reactive diluents are isobornyl acrylate (IBOA) and 1,6-hexanediol diacrylate (HDDA). The monofunctional IBOA linearly links the epoxy resin, while the difunctional HDDA forms a network cross-linked structure (see Figure 3). This combination of linear and network cross-linking using both functional group diluents creates a dense barrier layer with certain nanoscale porosity between the outer layer of the gel and the outer layer of the photonic crystal color-changing film (Figure 4). Therefore, during cigarette smoking, as the temperature slowly rises, the aroma molecules melt through the flavor-carrying composite spheres and flow through the micropores of the cross-linked structure, thus entering the smoke to replenish the aroma. Therefore, as the temperature of the filter rod rises during cigarette smoking, the aroma-releasing color-changing gel ball of the present invention can both produce a color-changing effect and release aroma, providing smokers with a richer sensory experience. Attached Figure Description

[0029] Figure 1 is a schematic diagram of the fragrance-releasing color-changing gel ball of the present invention.

[0030] Figure 2 shows the mold for preparing the fragrance-carrying composite balls.

[0031] Figure 3 shows the formulation and curing reaction of the resin photocurable layer.

[0032] Figure 4 shows the fiber structure of the photocurable film.

[0033] Figure 5 is a schematic diagram of photonic crystal film polymerization.

[0034] Figure 6 shows the physical image and SEM image of the photonic crystal film.

[0035] Figure 7 shows the structure of a ternary visualized cavity filter rod with the fragrance-releasing color-changing gel spheres of the present invention. Detailed Implementation

[0036] The technical solution of the present invention will be further described below with reference to specific embodiments. It should be noted that the examples described below are only used to illustrate and explain the present invention in detail, and the application scope of the present invention is not limited by the conditions in the examples.

[0037] As shown in Figure 1, the fragrance-releasing color-changing gel spheres have a particle size of 3.2-3.6 mm. Their color changes with temperature, and they release fragrance molecules. The fragrance-releasing color-changing gel spheres include a core, an intermediate layer, and an outer layer. The core includes a fragrance-carrying composite sphere and a protective layer for the composite sphere. The intermediate layer is a photonic crystal film, and the outer layer is a gel sphere protective layer. Both the composite sphere protective layer and the gel sphere protective layer are photocurable resin films with a thickness of 20-35 μm. The photonic crystal film, also 20-35 μm thick, is formed by the aggregation of multiple core-shell structured particles. The particle size is 170-300 nm, and the shell thickness is 20-50 nm. The particles are monodisperse latex particles with a polydispersity index not greater than 0.005. The glass transition temperature of the core polymer is greater than that of the shell polymer. The arrangement and aggregation of particles in the photonic crystal film and the spacing between particles change with temperature.

[0038] The preparation method of the fragrance-releasing color-changing gel spheres of the present invention comprises the following steps:

[0039] Step 1, Preparation of Fragrance-Loaded Composite Balls: Weigh 20-50g of dried guava, lemon, and kiwi slices (with the seeds removed, baked, and in a weight ratio of 2:0.5:1.2). Add 70wt% ethanol at a material-to-liquid mass ratio of 1:5. Extract twice under reflux at 65℃ for 2 hours each time. Cool the extract to room temperature, filter through a 200-mesh filter cloth, and let it stand for 24 hours. Filter under vacuum and concentrate to obtain a fruit mixture extract.

[0040] A fragrance carrier was prepared by mixing polyethylene glycol, chitosan, sodium carboxymethyl cellulose, starch, pectin, sodium alginate, and β-cyclopaste in a mass ratio of 16:0.5:1:0.2:0.1:0.4:0.5. A fruit extract was then mixed with the fragrance carrier in a mass ratio of 1:5, followed by the addition of water in a mass ratio of 4:1. The mixture was magnetically stirred at 250 rpm to fully emulsify the extract. The emulsified product was then mixed with PEG1500 and PEG4000 in a mass ratio of 1:3 (PEG1500 and PEG4000 mass...). The mixture is prepared by mixing in a ratio of 1:4 and heating and stirring at 55-65℃ for 0.5-0.75 hours to ensure thorough mixing and uniformity, resulting in a thermotropic phase change composite colloid with a melting point of 45-55℃. Then, the fragrance and solvent are added at a magnetic stirring speed of 500 rpm and a temperature of 55-60℃. The solvent is preferably a mixture of propylene glycol fatty acid ester and caprylic / capric glyceride. The amounts added are: fragrance, propylene glycol fatty acid ester, and caprylic / capric glyceride, which account for 15%, 1%, and 1.5% of the weight of the composite colloid, respectively, to obtain the fragrance-loaded composite gel product.

[0041] The fragrance-loaded composite gel is prepared by dripping using a dropper. The dropper is a funnel-shaped mold or a dropper mold with a diameter of 3mm to 4mm. The dripping speed of the composite gel is controlled by manually adjusting the nozzle or the opening and closing of the tube. The gel is dripped into a spherical mold with a diameter of 3.2-3.6mm at a rate of 10s-15s per drop. Then, the spherical mold containing the fragrance-loaded composite gel is placed in a refrigerator at 0-4℃ for 1.5-2 hours to ensure that the finished product solidifies into a sphere without being destroyed. This yields the fragrance-loaded composite sphere.

[0042] Step 2: Preparation of the photocurable resin film formulation: Using disposable flat-bottomed centrifuge tubes as containers, add 52.5 wt% acrylated epoxidized soybean oil (AESO), 12.2 wt% IBOA, 10.1 wt% HDDA, and 25.2 wt% butyl acetate according to the mass that the centrifuge tubes can hold; mix evenly on a stirring table; add a photoinitiator, preferably Irgacure 184, at an amount of 6 wt% of the polymer monomer mass, and stir on a stirring table until the initiator is completely dissolved to obtain a photocurable epoxy resin colloid formulation;

[0043] Step 3: Curing and shaping to obtain the core; Take the fragrance-carrying composite ball prepared in Step 1 out of the mold, absorb the excess liquid on the surface of the fragrance-carrying composite ball with a paper towel, and then place the fragrance-carrying composite ball in a glass petri dish; Pour the photocurable epoxy resin colloid formula obtained in Step 2 into the above petri dish, ensuring that the fragrance-carrying composite ball is completely immersed in the formula colloid and completely wrapped by the formula colloid; Then, pick out the fragrance-carrying composite balls one by one from the glass petri dish and place them on a polytetrafluoroethylene plate, wipe off the excess resin deposited on the polytetrafluoroethylene plate, and place them in a shaker; Turn on the shaker and roll the fragrance-carrying composite ball in the polytetrafluoroethylene plate at maximum speed for nearly half a minute, and then turn on the LED lamp with a wavelength of 365nm and irradiate continuously for 90s; After the film layer is cured, a cured and shaped spherical core is obtained; The thickness of the photocurable resin film layer is about 50nm, which provides a smooth spherical surface for subsequent photonic crystal film adhesion.

[0044] Step 4: Preparation of an emulsion with core-shell structured particles; 10g styrene, 7g methylstyrene, 0.5g acrylic acid, 0.5g ethyl acrylate, 0.5g ammonium bicarbonate as pH buffer, and 4.2-9.0mg sodium dodecylmethylphenyl cyclate as emulsifier are dispersed in 100ml of deionized water; the mixture is magnetically stirred at 300-800rpm and heated to 70-80℃; 1g potassium persulfate is dissolved in 40ml of water and poured into the above solution for reaction. 5ml of water is added every 5 hours for three polymerization reactions. After the polymerization reaction is complete, particles with a high glass transition temperature (Tg) of polystyrene as the core and a low glass transition temperature (Tg) of polyacrylic acid as the shell are obtained; the particle size range is 170-300nm (see Figures 1 and 5), and the polydispersity index is not greater than 0.005; the preparation of the emulsion with core-shell structured particles in this step can refer to existing techniques;

[0045] Step 5: At room temperature, the emulsion mixture with core-shell structure particles obtained in Step 4 is mixed to prepare a 5wt% colloidal solution and placed in an air-driven spray gun. The solvent is 95% ethanol solution. Air spraying is used, with the following parameters: air pump pressure of 0.49-0.55 MPa, distance between the spray gun nozzle and the solidified core sphere of 25-30 cm, and spraying time for each core sphere of 4-5 seconds. After spraying, the core spheres are left to stand at 25-30℃ for 2-4 hours to allow the photonic crystal particles to "auto-assemble," that is, spontaneously aggregate into a stable, geometrically regular structure to form a film based on non-covalent bond interactions. During this period, it is necessary to ensure that there is no air flow around the spheres. The resulting spheres with photonic crystal film layers are shown in Figure 6.

[0046] Step 6: Spray the sphere with the photonic crystal film layer from step (5) with the formula colloid for the photocurable resin film layer from step (2), using the same spraying process as in step 5; after drying at room temperature, roll it over and spray the other side, using the same spraying process; repeat the spraying four times to ensure the entire sphere is completely covered without gaps; after spraying, irradiate it in a shaker with an EFOSlite 50W ultraviolet point light source, with a point light source energy of 32mW / cm². 2 The irradiation time was 300s, and the shaking speed was 100-200rpm; the fragrance-releasing color-changing gel spheres were obtained; as shown in Figure 1.

[0047] The obtained fragrance-releasing color-changing gel spheres are compounded with ternary cavity filter rods. Prepare the necessary auxiliary materials in advance, including popping beads, transparent forming paper, cellulose acetate base rods, and adhesive tape. The steps are as follows: load the materials onto the machine, debug and trial-produce according to the filter rod design specifications, and start collecting the produced filter rods once all product indicators meet the requirements; filter rod length (L) = L1 (first part of the filter rod) + L2 (visible transparent section) + L3 (second part of the filter rod) (as shown in Figure 7). To address the adhesion issue that occurs during the filter rod molding process, the process can be adjusted. By strictly controlling the glue line position (i.e., the glue line is 1mm away from the edge of the transparent forming paper), the hot melt adhesive will not seep out after cooling, preventing adhesion at the glue line. Control the packing quantity, such as packing one less row of filter rods to reduce compression between them; and reduce adhesion of the paper section by controlling the amount of sizing agent applied.

[0048] When smoking cigarettes with the aforementioned filter rod, the smoke exhibits a color change from blue-green to yellow-green and a refreshing, natural fruity aroma.

[0049] The fragrance-releasing color-changing gel spheres in this embodiment exhibit a color shift (Δλ) within a temperature range of 45-70℃. max =28±1nm), and at the same time, it exhibits a significant colorimetric response (ΔE*>1.5) within this temperature range, with a thermochromic response time of less than 5 seconds.

[0050] The above description is only used to detail the specific embodiments of the present invention, but the technical solutions proposed by the present invention are not limited to the above methods. All equivalent modifications and variations made by those skilled in the art to the technology proposed by the present invention without departing from the basic principles of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A fragrance-releasing, color-changing gel ball, characterized in that, Its particle size is 3.2-3.6 mm, and its color changes with temperature and it can release aroma molecules.

2. The fragrance-releasing color-changing gel ball according to claim 1, characterized in that, The fragrance-releasing color-changing gel sphere comprises a core, an intermediate layer, and an outer layer; wherein the core comprises a fragrance-carrying composite sphere and a composite sphere protective layer, the intermediate layer is a photonic crystal film layer, and the outer layer is a gel sphere protective layer; both the composite sphere protective layer and the gel sphere protective layer are photocurable resin film layers, and the thickness of the photocurable resin film layer is 20-35μm.

3. The fragrance-releasing color-changing gel ball according to claim 2, characterized in that, The photonic crystal film has a thickness of 20-35 μm and is formed by the aggregation of multiple core-shell structured particles. The particle size is 170-300 nm, and the thickness of the particle shell is 20-50 nm. The particles are monodisperse latex particles with a polydispersity index of no more than 0.

005. The glass transition temperature of the core polymer of the particles is greater than that of the shell polymer. The arrangement and aggregation mode of the particles in the photonic crystal film and the gaps between the particles change with temperature.

4. The method for preparing fragrance-releasing color-changing gel spheres according to any one of claims 1-3, characterized in that, Includes the following steps: (1) Preparation of fragrance-loaded composite balls; (2) Preparation of the formulation colloid for photocurable resin film; (3) Wrap the formulation of the photocurable resin film layer from step (2) onto the surface of the fragrance-carrying composite ball from step (1), and then irradiate it with near-ultraviolet light in a shaker to cure and shape the core. (4) Prepare an emulsion with core-shell structured particles; (5) Spray the emulsion with core-shell structured particles from step (4) onto the core surface obtained in step (3), and then let it stand at a certain temperature for a period of time to obtain the photonic crystal film layer. (6) Spray the formulation colloid of the photocurable resin film layer from step (2) onto the surface of the photonic crystal film layer obtained in step (5), and then irradiate it with an ultraviolet point light source in a shaker for a period of time to obtain the fragrance-releasing color-changing gel ball.

5. The preparation method according to claim 4, characterized in that, Step (1) The preparation method of the fragrance-carrying composite ball is as follows: mix the plant extract, fragrance, solvent and fragrance-carrying material, and then use a dropper to drip into a spherical mold with a diameter of 3.2-3.6 mm at a certain rate. After refrigeration for a period of time, the fragrance-carrying composite ball is obtained.

6. The preparation method according to claim 4, characterized in that, Step (2) The formulation of the photocurable resin film includes: epoxy resin monomer, IBOA, HDDA, butyl acetate and photoinitiator; wherein the mass ratio of epoxy resin monomer, IBOA, HDDA and butyl acetate is 52.5:12.2:10.1:25.2; the photoinitiator is (4-8)% of the polymer monomer mass; Step (3) The method of coating the surface of the fragrance-carrying composite ball with the formulation colloid of the photocurable resin film is as follows: the fragrance-carrying composite ball is completely immersed in the formulation colloid of the photocurable resin film, the shaker speed is 100-200 rpm, the near ultraviolet light is 360-370 nm, and the irradiation time is 1-2 min.

7. The preparation method according to claim 4, characterized in that, Step (4) The preparation steps of the emulsion with core-shell structured particles are as follows: Monomer 1 and monomer 2 are mixed and dispersed in an aqueous solution containing pH buffer and emulsifier. The mixture is stirred at 300-800 rpm and at 70-80°C. Half of the total amount of initiator is added to start the reaction. After 2-5 hours, half of the total amount of initiator is added. After 2-5 hours, the remaining initiator is added to obtain the emulsion with the core-shell structured particles. The glass transition temperature of monomer 1 is greater than that of monomer 2.

8. The preparation method according to claim 4, characterized in that, The spraying in step (5) or step (6) is performed by air spraying; The spraying parameters are as follows: air pump pressure is 0.49-0.55MPa, the distance between the spray gun nozzle and the core surface is 25-30cm, and the spraying time for each core is 4-5 seconds.

9. The preparation method according to claim 4, characterized in that, The energy of the ultraviolet point source in step (6) is 32 mW / cm². 2 The irradiation time is 300s, and the shaking speed of the shaker is 100-200rpm.

10. Use of the aroma-releasing color-changing gel ball according to any one of claims 1-3 in cigarette filter rods.

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