Biomass-based moisture-sensitive repair recyclable fluorescent tunable microcapsules and methods of making the same

Abstract

The application discloses a biomass-based moisture-sensitive repair recyclable fluorescent adjustable microcapsule and a preparation method thereof. Specifically, the biomass glue microcapsule coated with polyurea is prepared by taking isocyanate compounds and amino compounds as shell material raw materials and taking biomass glue as core material. Compared with the existing microcapsules, the prepared microcapsules not only have different fluorescent properties and moisture-sensitive self-repair behaviors, but also have core material recyclable behaviors.

Description

Technical Field

[0001] This invention belongs to the field of functional polymer microcapsules, specifically relating to a biomass-based moisture-sensitive remediation recyclable fluorescently tunable microcapsule and its preparation method. Background Technology

[0002] Natural biomass adhesives are made from natural biomass. These adhesives not only possess excellent bonding properties but also offer significant environmental advantages due to their renewable resource origin. Compared to traditional petroleum-based adhesives, natural biomass adhesives generate less pollution during production and use, are biodegradable, and help alleviate environmental pressure. However, these natural biomass adhesives are often susceptible to physical factors (high temperature, violent vibration, etc.) and chemical factors (acids and alkalis), leading to the breakage of primary structures (such as peptide bond breakage) and secondary bonds (such as hydrogen bonds and disulfide bonds) between protein molecules. This causes the natural conformation to transform into a disordered extended structure, resulting in the loss of biological activity and adhesive properties, often limiting their application. Therefore, effectively protecting natural biomass adhesives and preventing their denaturation is of particular significance for their application. Furthermore, protein-based adhesives are highly sensitive to moisture, requiring specific storage conditions. Interestingly, protein-based adhesives contain aromatic amino acids, which give them certain fluorescent properties. However, this fluorescence is quenched by adhesive aggregation. Therefore, preventing aggregation is crucial for effectively maintaining the fluorescent behavior of the adhesive. Thus, researching protein-based biomass adhesives to obtain multifunctional materials is of particular significance. Summary of the Invention

[0003] Given the current advantages of protein biomass adhesives in terms of structure and performance, but also their poor environmental resistance during application, this invention proposes to prepare microcapsules using protein biomass adhesives as the core. On the one hand, the capsule wall protects the core from environmental influences; on the other hand, the microcapsule size is controlled, utilizing the small size effect of the microcapsules to achieve the fluorescence effect of the protein biomass adhesive, thereby obtaining a biomass-based, moisture-sensitive, recyclable, fluorescently tunable microcapsule for remediation and its preparation method.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A method for preparing biomass-based moisture-sensitive remediation recyclable fluorescent tunable microcapsules includes the following steps: mixing dehydrated biomass powder, surfactant and isocyanate compound, then adding emulsifier and amine compound, and reacting to obtain a microcapsule suspension; the microcapsule suspension is washed, filtered and dried to obtain biomass-based moisture-sensitive remediation recyclable fluorescent tunable microcapsules; the mass ratio of dehydrated biomass powder, surfactant, isocyanate compound, emulsifier and amine compound is (1.0~2.0):(0.01~0.05):(1.0~2.0):(0.05~0.5):(0.2~1).

[0006] In this invention, the biomass adhesive powder is a hydrophilic protein adhesive powder; the isocyanate compound is one or more of aliphatic isocyanates and aromatic isocyanates; the amine compound is a water-soluble polyethylene polyamine; the surfactant is a polyoxyethylene ether nonionic surfactant; and the emulsifier is polyvinyl alcohol.

[0007] Furthermore, the biomass gelatin powder is one or more of fish swim bladder gelatin powder, gelatin powder, prickly pear gum powder, gum arabic powder, and carrageenan powder; the isocyanate compound is one or more of isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, and lysine diisocyanate; the amine compound is one or more of diethylenetriamine, triethylenetetraamine, and tetraethylenepentamine; and the surfactant is one or two of octylphenol polyoxyethylene ether and nonylphenol polyoxyethylene ether.

[0008] This invention involves soaking biomass gum powder in a dehydrating agent, then filtering and vacuum drying at room temperature to obtain dehydrated and dried biomass gum powder.

[0009] In this invention, the reaction is carried out at room temperature (15-25℃) for 5-20 hours.

[0010] In this invention, drying is performed by air drying at room temperature (15-25℃).

[0011] This invention discloses the application of the aforementioned biomass-based moisture-sensitive, recyclable, fluorescently tunable microcapsules in the preparation of functional materials. Specifically, the functional materials include one or more of the following: luminescent materials, recyclable materials, moisture-sensitive materials, self-healing materials, intelligent fluorescent anti-counterfeiting materials, ultraviolet-transmitting materials, and coating materials.

[0012] This invention discloses a functional material whose raw materials include the above-mentioned biomass-based moisture-sensitive repair recyclable fluorescent tunable microcapsules.

[0013] Compared with existing fluorescent microcapsules, the beneficial effects achieved by the present invention are as follows: the core of the microcapsules prepared by the present invention is made of biomass, the microcapsules can emit ultraviolet and blue light based on different excitation wavelengths, have significant tunable fluorescence behavior, and have recyclable and moisture-sensitive self-healing properties, which can be used for intelligent anti-counterfeiting, "transmitting" ultraviolet light and coating repair. Attached Figure Description

[0014] Figure 1 This is an optical microscope image of the sample from Example 1.

[0015] Figure 2 The Fourier transform infrared (FTIR) spectra of the sample, shell material particles, and core material particles in Example 1 are shown.

[0016] Figure 3 The images show the UV absorption spectra of the sample, shell material particles, and core material particles from Example 1.

[0017] Figure 4 Images are taken under 365nm UV light, where (a) is the sample of Example 1, (b) is the core material particles, (c) is the shell material particles, (d) is the bulk core material and (e) is the bulk shell material.

[0018] Figure 5 The images are photographs taken under fluorescent and 365°C ultraviolet light, where (a) shows the epoxy coating and (b) shows the epoxy coating with the sample from Example 1.

[0019] Figure 6 This is a photograph of the moisture-sensitive self-healing behavior of the sample in Example 1 in an epoxy coating.

[0020] Figure 7 The image shows the FTIR spectrum of the core material of the sample from Example 1 in the epoxy coating after recycling.

[0021] Figure 8 This is an optical microscope image of the sample from Example 2.

[0022] Figure 9 This is an image of the sample from Example 2 under 365nm ultraviolet light irradiation.

[0023] Figure 10 This is an optical microscope image of the sample from Example 3.

[0024] Figure 11 This is an image of the sample from Example 3 under 365nm ultraviolet light irradiation.

[0025] Figure 12 This is an optical microscope image of the sample from Example 4.

[0026] Figure 13 This is an image of the sample from Example 4 under 365nm ultraviolet light irradiation.

[0027] Figure 14 This is an optical microscope image of the sample from Example 5.

[0028] Figure 15 This is an image of the sample from Example 5 under 365nm ultraviolet light irradiation. Detailed Implementation

[0029] This invention involves immersing biomass gum powder in a dehydrating solvent to remove water, filtering off the solvent, and then vacuum drying at room temperature (25°C) to obtain dry biomass gum powder. Then, at room temperature (15-25°C), the dehydrated biomass gum powder, surfactant, and isocyanate compound are mixed and stirred for 1-10 minutes. An emulsifier solution is then added, and the mixture is stirred for 1-10 minutes before adding an amine compound. The mixture is stirred and reacted at room temperature for 10-16 hours to obtain a polyurea-coated biomass gum microcapsule suspension. After washing, filtration, and air drying at room temperature, microcapsule powder is obtained, which is a biomass-based, moisture-sensitive, recyclable, fluorescently tunable microcapsule for remediation. The mass ratio of dehydrated biomass gum powder, surfactant, isocyanate compound, emulsifier, and amine compound is (1.0-2.0):(0.01-0.05):(1.0-2.0):(0.05-0.5):(0.2-1).

[0030] In this invention, the dehydrating solvent is one or more of ethanol, acetone and glycerol, and the mass ratio of biomass gum powder to dehydrating solvent is 1: (5-100).

[0031] In this invention, the biomass adhesive is a hydrophilic protein adhesive, such as one or a mixture of fish glue, gelatin, prickly pear gum, gum arabic, and carrageenan.

[0032] In this invention, the isocyanate compound is an aliphatic and aromatic isocyanate, such as one or more of isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, and lysine diisocyanate.

[0033] In this invention, the surfactant is a polyoxyethylene ether nonionic surfactant, such as octylphenol polyoxyethylene ether (OPEO) and nonylphenol polyoxyethylene ether (NPEO).

[0034] In this invention, the emulsifier is a water-soluble polyvinyl alcohol of different molecular weights; the emulsifier solution is a polyvinyl alcohol aqueous solution with a mass concentration of 0.1-3%, and the mass of the emulsifier solution is 5-15 times the mass of the biomass rubber powder.

[0035] In this invention, the amine organic compounds are water-soluble polyethylene polyamines, such as diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

[0036] The microcapsules prepared by this invention can emit ultraviolet and blue light, and also have recyclable and moisture-sensitive self-healing properties, which can be used for fluorescent smart anti-counterfeiting, "transmitting" ultraviolet light and coating repair.

[0037] The following specific experiments illustrate the technological advancements of this invention. The raw materials used are existing products, and the specific preparation operations and performance tests follow conventional techniques. Unless otherwise specified, magnetic stirring was employed at a speed of 600 rpm / min. In the following experiments: the biomass adhesive was fish glue (commercially available in block form, pulverized into powder before use); the diisocyanate compound was isophorone diisocyanate (IPDI); the polyethylene polyamine was tetraethylenepentamine (TEPA); the surfactant was nonylphenol polyoxyethylene ether (NP-9); and the emulsifier solution was a 1% (w / w) aqueous solution of polyvinyl alcohol (PVA, molecular weight 79245.95).

[0038] Example 1

[0039] (1) The biomass glue powder fish maw glue (particle size 30μm, D90) was soaked in the dehydrating solvent acetone for 30 minutes, then the solvent was filtered and then dried under vacuum at room temperature to obtain dried biomass glue powder, wherein the mass ratio of biomass glue powder to dehydrating agent was 1:50.

[0040] (2) At room temperature (25℃), 10g of dried fish maw glue powder after dehydration in step (1), 0.35g of surfactant nonylphenol polyoxyethylene ether (NP-9) and 13g of isophorone diisocyanate (IPDI) were mixed and stirred for 2min. Then, 100ml of polyvinyl alcohol aqueous solution (concentration of 1wt%) was added and stirred for another 2min. Then, 5g of tetraethylenepentamine (TEPA) was added and stirred at room temperature for 12h to obtain a microcapsule suspension. The suspension was washed with water 5 times and filtered and then dried at room temperature to obtain microcapsule powder. Polyurea was used as the shell material and biomass glue was used as the core material. The mass ratio of dried biomass glue powder (fish maw glue), diisocyanate compound (IPDI), surfactant nonylphenol polyoxyethylene ether (NP-9), emulsifier polyvinyl alcohol and amine (tetraethylenepentamine) was 1:1.3:0.035:0.1:0.5. The core content of the synthesized microcapsules was about 34% and the shell content was about 66%. The shell material content in the microcapsules was analyzed by grinding 5g of dried microcapsule powder for 5 minutes, soaking it in 50g of water for 2 hours, filtering it, and then drying the solid filter residue under vacuum at 50℃ for 6 hours. The percentage of the shell material content in the microcapsules was determined by the mass of the shell material.

[0041] Comparative Example 1-1

[0042] Referring to Example 1, the difference is that biomass glue powder fish bladder glue is used directly, i.e. dehydration is omitted, but the rest is the same, and microcapsule powder is prepared. The prepared microcapsules are obviously aggregated and the capsule walls are not dense, which causes most of the capsule core to dissolve in water during the microcapsule synthesis process, resulting in a significant decrease in the capsule core coverage rate and a capsule core content of only 11%.

[0043] Comparative Examples 1-2

[0044] (1) Dry biomass gum powder was obtained according to Example 1;

[0045] (2) At room temperature (25°C), 10g of dried fish maw gelatin powder after dehydration in step (1) and 0.35g of surfactant nonylphenol polyoxyethylene ether (NP-9) were mixed and stirred for 2 minutes. Then, 100ml of polyvinyl alcohol aqueous solution (concentration of 1wt%) was added and stirred for another 2 minutes. Then, 13g of isophorone diisocyanate (IPDI) was added and stirred for another 2 minutes. Then, 5g of tetraethylenepentamine (TEPA) was added and stirred at room temperature for 12 hours to obtain a microcapsule suspension. The suspension was washed with water 5 times and filtered and then dried at room temperature to obtain microcapsule powder, wherein the core content was 5%.

[0046] Compared to Comparative Examples 1-1 and 1-2, the microcapsules prepared by the method in Example 1 have a significantly higher core-encapsulation content, which can effectively prevent biomass from dissolving in water.

[0047] Figure 1 Here is an optical microscope image of the sample from Example 1. Figure 1 As can be seen, the synthesized microcapsules have a spherical structure with a particle size of approximately 10-50 μm.

[0048] Figure 2 The Fourier transform infrared (FTIR) spectra of the sample of Example 1, shell material particles, and core material particles reveal that the sample of Example 1 clearly contains shell material particles at 2260 cm⁻¹. -1 1557 cm -1 1473cm -1 1303 cm -1 ) and core material (1237 cm) -1 1075 cm -1 The sample from Example 1 contains characteristic absorption peaks of both the core and shell materials, such as -OH / NH (3321 cm⁻¹). -1 ), CH (3301-2811cm) -1 ), 2363-2331cm -1 C=O (1635cm) -1 ). Figure 3The images show the UV absorption spectra of the sample from Example 1, the shell particles, and the core particles. It can be observed that the sample from Example 1 exhibits significant absorption in the 240-339 nm range, corresponding to the absorption of the core material; while the weak absorption in the 370-450 nm range corresponds to the absorption of the shell material. These results suggest that the microcapsules were successfully prepared.

[0049] Table 1 presents the performance data of the Example 1 sample, core particles, and shell particles, as well as the self-healing efficiency of the epoxy coating and the core material recovery rate. As shown in Table 1, the Example 1 sample can emit blue light (maximum fluorescence intensity wavelength 410 nm) and ultraviolet light (maximum fluorescence intensity wavelength 352 nm); the core particles emit blue light (maximum fluorescence intensity wavelengths 430 / 470 nm); and the shell particles emit blue light (maximum fluorescence intensity wavelengths 440 / 473 nm). Comparing the fluorescence performance of the core and shell particles, the Example 1 sample powder not only produces blue fluorescence (410 nm) but also generates new ultraviolet light (352 nm) based on ultraviolet absorption. This suggests that the Example 1 sample possesses potential fluorescent anti-counterfeiting and ultraviolet "transmission" functions.

[0050] Figure 4 These are images of the Example 1 sample, shell particles, core particles, bulk shell material, and bulk core material under 365nm UV light irradiation. Under 365nm UV light irradiation, the Example 1 sample, core particles, and shell particle powder all exhibit blue fluorescence. Figure 4 (a), (b), and (c)), but for bulk core and shell materials, the fluorescence performance is significantly reduced. Figure 4 (d) and (e)).

[0051] Figure 5 It is an epoxy coating ( Figure 5 (a) and the epoxy coating of the sample from Example 1 (a) Figure 5 (b) Photographs under fluorescent and 365°C UV light. The sample of Example 1 was embedded in an epoxy coating, which imparts fluorescent properties to the coating.

[0052] Figure 6 These are photographs of the moisture-sensitive self-healing behavior of the sample in Example 1 within an epoxy coating. When scratches appear on the coating surface, water is sprayed onto the surface, and after 2 hours at room temperature, the scratches show significant healing. Figure 6 The healing efficiency can reach 92%.

[0053] Figure 7 This is the FTIR spectrum of the core material of the sample in Example 1 of the epoxy coating after recovery. The FTIR spectrum of the recovered core material is basically consistent with the FTIR spectrum of the initial core material fish maw glue powder, confirming that the recovered core material product is fish maw glue, and the recovery rate of the core material is 93%.

[0054] Table 1: Performance data of sample, core material particles and shell material particles in Example 1, as well as self-healing efficiency of epoxy coating and core material recovery rate.

[0055]

[0056] illustrate:

[0057] a: Shell particles: The preparation method of shell particles is based on the microcapsule preparation process of Example 1. Shell particle powder can be obtained by omitting the biomass gum powder.

[0058] b: Core material particles: The core material particles used in the analysis and testing process are the dehydrated biomass gum powder in step (1) of Example 1.

[0059] c: Preparation of epoxy coating: Mix 20g of epoxy resin E-51 and 8g of polyetheramine D230 and stir for 5min. Then add 4.2g of microcapsules (i.e., 15% of the mass of the epoxy resin system) and stir for 5min. Cure at room temperature for 24h. To compare the self-healing experiment, core particles (mass: microcapsule mass × core content) and shell particles (mass: microcapsule mass × shell content) can be added separately to prepare epoxy coatings containing core particles and epoxy coatings containing shell particles.

[0060] d: Self-healing efficiency is defined as follows: a sample is embedded in an epoxy coating. When a scratch occurs on the coating surface, a layer of water is sprayed onto the scratch. After standing for 2 hours, the percentage of the width of the healed scratch on the coating surface relative to the width of the initial scratch is calculated. The initial scratch on the coating surface is made using a blade with a thickness of 0.28 mm and a scratch depth of 0.5 mm.

[0061] e: Core material recovery rate is defined as follows: 15g of epoxy coating is mechanically crushed for 5 minutes, soaked in 50g of water for 2 hours, filtered and the filter residue is washed 5 times. The collected filtrate is then dried to obtain the recovered core material. The core material recovery rate is calculated as: [Recovered core material mass / (microcapsule mass × core content)] × 100%.

[0062] f: Bulk Shell Material: The bulk shell material was prepared based on the same mass ratio of isocyanate compound and amine substance used in the synthesis of microcapsules in the examples. The specific process is as follows: At room temperature (25°C), 13g of isophorone diisocyanate (IPDI) was added to 5g of tetraethylenepentamine (TEPA), and the mixture was stirred at room temperature for 12 hours to obtain the bulk shell material.

[0063] g: Bulk core material: The bulk core material is prepared by agglomerated samples of dehydrated and dried biomass gum powder after being left at room temperature (70% humidity) for 6 hours to absorb moisture.

[0064] Example 2

[0065] (1) The biomass glue powder fish maw glue (particle size 25μm, D90) was soaked in the dehydrating solvent acetone for 25 minutes, then the solvent was filtered and then dried under vacuum at room temperature to obtain dried biomass glue powder, wherein the mass ratio of biomass glue powder to dehydrating agent was 1:50.

[0066] (2) At room temperature (25℃), 10g of fish maw gelatin powder dehydrated in step (1), 0.35g of surfactant nonylphenol polyoxyethylene ether (NP-9) and 13g of isophorone diisocyanate (IPDI) were mixed and stirred for 2min. Then, 100ml of polyvinyl alcohol aqueous solution (concentration of 1wt%) was added and stirred for another 2min. Then, 4.5g of tetraethylenepentamine (TEPA) was added and stirred at room temperature for 12h to obtain a microcapsule suspension. After washing and filtration 5 times, the microcapsule powder was dried at room temperature and characterized. The mass ratio of dried biomass gelatin powder (fish maw gelatin), diisocyanate compound (IPDI), surfactant nonylphenol polyoxyethylene ether (NP-9), emulsifier polyvinyl alcohol and amine (tetraethylenepentamine) was 1:1.3:0.035:0.1:0.45.

[0067] Figure 8 The image shown is an optical microscope image of the sample from Example 2. It can be seen that the synthesized microcapsules have a spherical structure with a particle size between 5 and 100 μm.

[0068] Figure 9 This is an image of the sample from Example 2 under 365nm ultraviolet light. Under 365nm ultraviolet light, the sample from Example 2 produces blue fluorescence.

[0069] The sample in Example 2 can emit blue light (maximum fluorescence intensity wavelength of 411nm, excitation wavelength of 365nm) and ultraviolet light (maximum fluorescence intensity wavelength of 303nm, excitation wavelength of 280nm). It can not only produce blue fluorescence, but also generate new ultraviolet light, which has obvious application potential in the preparation of fluorescent anti-counterfeiting and "transmission" ultraviolet materials.

[0070] Following the method of Example 1, the sample of Example 2 was embedded in an epoxy coating (the mass percentage of the microcapsule sample relative to the epoxy resin system was 15%), and the scratch healing efficiency was 95%. In contrast, the repair efficiency of individual core particles was very low, at 20%, and the repair efficiency of individual shell particles was even lower. The core material recovery rate of the sample of Example 2 was 93%.

[0071] Example 3

[0072] (1) Referring to Example 2, dried biomass gum powder was obtained;

[0073] (2) At room temperature (25℃), 10g of dehydrated fish maw gelatin powder from step (1), 0.35g of surfactant nonylphenol polyoxyethylene ether (NP-9), and 13g of isophorone diisocyanate (IPDI) were mixed and stirred for 2min. Then, 100ml of polyvinyl alcohol aqueous solution (concentration of 1wt%) was added, and stirring was continued for 2min. Then, 4g of tetraethylenepentamine (TEPA) was added. After stirring and reacting at room temperature for 12h, a microcapsule suspension was obtained. After washing and filtration 5 times, the microcapsule powder was obtained by air drying at room temperature and then characterized. The mass ratio of biomass gelatin powder (fish maw gelatin), diisocyanate compound (IPDI), surfactant nonylphenol polyoxyethylene ether (NP-9), emulsifier polyvinyl alcohol, and amine substance (tetraethylenepentamine) was 1:1.3:0.035:0.1:0.4.

[0074] Figure 10 The image shown is an optical microscope image of the sample from Example 3. The synthesized microcapsules have a spherical structure and a particle size between 10 and 60 μm.

[0075] The sample in Example 3 can emit blue light (maximum fluorescence intensity wavelength of 410nm, excitation wavelength of 365nm) and ultraviolet light (maximum fluorescence intensity wavelength of 302nm, excitation wavelength of 280nm). It can produce not only blue fluorescence but also ultraviolet light, which has obvious application potential in the preparation of fluorescent anti-counterfeiting and ultraviolet "transmission" materials.

[0076] Figure 11 This is an image of the sample from Example 3 under 365nm ultraviolet light. Under 365nm ultraviolet light, the powder of the sample from Example 3 can produce blue fluorescence.

[0077] Referring to Example 1, the sample of Example 3 was embedded in an epoxy coating (the mass percentage of the microcapsule sample relative to the epoxy resin system was 15%), and the scratch healing efficiency was 96%. In contrast, the repair efficiency of individual core particles or shell particles was very low. The core material recovery rate of the sample of Example 3 was 94%.

[0078] Example 4

[0079] (1) The biomass glue powder fish maw glue (particle size 45μm, D90) was soaked in the dehydrating solvent ethanol for 40 minutes, and then the solvent was removed by vacuum drying at room temperature to obtain dry biomass glue powder, wherein the mass ratio of biomass glue powder to dehydrating agent was 1:100.

[0080] (2) At room temperature (25℃), 10g of dehydrated fish maw gelatin powder from step (1), 0.3g of surfactant nonylphenol polyoxyethylene ether (NP-9), and 13g of isophorone diisocyanate (IPDI) were mixed and stirred for 4min. Then, 100ml of polyvinyl alcohol aqueous solution (concentration of 1wt%) was added, and stirring was continued for 4min. Then, 5g of tetraethylenepentamine (TEPA) was added. After stirring and reacting at room temperature for 12h, a microcapsule suspension was obtained. After washing and filtration 5 times, the microcapsule powder was obtained by air drying at room temperature and then characterized. The mass ratio of biomass gelatin powder (fish maw gelatin), diisocyanate compound (IPDI), surfactant nonylphenol polyoxyethylene ether (NP-9), emulsifier polyvinyl alcohol, and amine substance (tetraethylenepentamine) was 1:1.3:0.03:0.1:0.5.

[0081] Figure 12 The image shown is an optical microscope image of the sample from Example 4. The synthesized microcapsules have a spherical structure and a particle size between 10 and 90 μm.

[0082] The sample powder in Example 4 can emit blue light (maximum fluorescence intensity wavelength of 409nm, excitation wavelength of 365nm) and ultraviolet light (maximum fluorescence intensity wavelength of 302nm, excitation wavelength of 280nm). It can produce not only blue fluorescence but also ultraviolet light, and has obvious application potential in the preparation of fluorescent anti-counterfeiting and ultraviolet "transmission" materials.

[0083] Figure 13 This is an image of the sample powder from Example 4 under 365nm ultraviolet light. Under 365nm ultraviolet light, the sample powder from Example 4 produces blue fluorescence.

[0084] Referring to Example 1, the sample of Example 4 was embedded in an epoxy coating (the mass percentage of the microcapsule sample relative to the epoxy resin system was 15%), and the scratch healing efficiency was 95%. The core material recovery rate of the sample of Example 4 was 94%.

[0085] Example 5

[0086] (1) The biomass glue powder fish maw glue (particle size 35μm, D90) was soaked in the dehydrating solvent ethanol for 35 minutes, the solvent was removed by suction filtration, and then dried under vacuum at room temperature to obtain dried biomass glue powder, wherein the mass ratio of biomass glue powder to dehydrating agent was 1:100.

[0087] (2) At room temperature (25℃), 10g of dehydrated fish maw gelatin powder from step (1), 0.25g of surfactant nonylphenol polyoxyethylene ether (NP-9), and 10g of isophorone diisocyanate (IPDI) were mixed and stirred for 4min. Then, 100ml of polyvinyl alcohol aqueous solution (concentration of 1wt%) was added, and stirring was continued for 10min. Then, 4g of tetraethylenepentamine (TEPA) was added. After stirring and reacting at room temperature for 16h, a microcapsule suspension was obtained. After washing and filtration 5 times, the microcapsule powder was obtained by air drying at room temperature and then characterized. The mass ratio of biomass gelatin powder (fish maw gelatin), diisocyanate compound (IPDI), surfactant nonylphenol polyoxyethylene ether (NP-9), emulsifier polyvinyl alcohol, and amine substance (tetraethylenepentamine) was 1:1:0.025:0.1:0.4.

[0088] Figure 14 The image shown is an optical microscope image of the sample from Example 5. The synthesized microcapsules have a spherical structure and a particle size between 10 and 70 μm.

[0089] The sample powder in Example 5 can emit blue light (maximum fluorescence intensity wavelength of 414nm, excitation wavelength of 365nm) and ultraviolet light (maximum fluorescence intensity wavelength of 303nm, excitation wavelength of 280nm). It can produce not only blue fluorescence but also ultraviolet light, and has obvious application potential in the preparation of fluorescent anti-counterfeiting and ultraviolet "transmission" materials.

[0090] Figure 15 This is an image of the sample powder from Example 5 under 365nm ultraviolet light. Under 365nm ultraviolet light, the sample powder from Example 5 exhibits blue fluorescence.

[0091] Referring to Example 1, the sample of Example 5 was embedded in an epoxy coating (the mass percentage of the microcapsule sample relative to the epoxy resin was 15%), and the scratch healing efficiency was 96%. The core material recovery rate of the sample of Example 5 was 93%.

[0092] This invention involves immersing biomass gum powder in a dehydrating agent to remove the solvent, followed by filtration to obtain dried biomass gum powder. This dehydrated biomass gum powder, surfactant, and isocyanate compound are then mixed and stirred. An emulsifier solution is added, followed by an amine compound. The mixture is stirred and reacted at room temperature to obtain a polyurea-coated biomass gum microcapsule suspension. After washing, filtration, and air-drying at room temperature, the microcapsule powder is obtained. The prepared microcapsules emit ultraviolet and blue light and possess recyclable and moisture-sensitive self-healing properties, making them suitable for intelligent fluorescent anti-counterfeiting, "transmitting" ultraviolet light, and coating repair.

Claims

1. A process for the preparation of a biomass-based, moisture-sensitive, repairable, recyclable, fluorescently tunable microcapsule, characterized in that, The method comprises the following steps: The biomass glue powder is soaked in a dehydrating solvent, and then filtered, dried at room temperature, and dehydrated biomass glue powder is obtained; The dehydrated biomass glue powder, a surfactant, and an isocyanate compound are mixed, and then an emulsifier and an amine compound are added, and a microcapsule suspension is obtained by reaction; The microcapsule suspension is washed, filtered, and dried to obtain a biomass-based moisture-sensitive repair recyclable fluorescent adjustable microcapsule; The mass ratio of the dehydrated biomass glue powder, the surfactant, the isocyanate compound, the emulsifier, and the amine compound is (1.0-2.0):(0.01-0.05):(1.0-2.0):(0.05-0.5):(0.2-1); the biomass glue powder is fish swim bladder glue powder; the dehydrating solvent is one or more of ethanol and acetone; and the amine compound is a water-soluble polyethylene polyamine.

2. The process for the preparation of biomass-based, moisture-sensitive, repairable, recyclable, fluorescently tunable microcapsules according to claim 1, characterized in that, The isocyanate compound is one or more of aliphatic isocyanate and aromatic isocyanate; the surfactant is a polyoxyethylene ether nonionic surfactant; the emulsifier is polyvinyl alcohol; and the amine compound is one or more of diethylene triamine, triethylene tetramine, and tetraethylene pentaamine.

3. The method for preparing biomass-based wet-sensitive remediation recyclable fluorescently tunable microcapsules according to claim 2, characterized in that, The isocyanate compound is one or more of isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenyl methane diisocyanate, dicyclohexyl methane diisocyanate, and lysine diisocyanate; and the surfactant is one or both of octylphenol polyoxyethylene ether and nonylphenol polyoxyethylene ether.

4. The method for preparing biomass-based wet-sensitive remediation recyclable fluorescently tunable microcapsules according to claim 1, characterized in that, The reaction is a room temperature reaction for 5-20 hours.

5. The method for preparing biomass-based moisture-sensitive remediation recyclable fluorescently tunable microcapsules according to claim 1, characterized in that, The drying is air drying at room temperature.

6. A biomass-based moisture-sensitive repair recyclable fluorescent adjustable microcapsule prepared by the method of claim 1.

7. The use of the biomass-based moisture-sensitive repair recyclable fluorescent adjustable microcapsule of claim 6 in the preparation of a functional material.

8. Use according to claim 7, characterized in that, The functional material comprises one or more of a light-emitting material, a recyclable material, a moisture-sensitive material, a self-repairing material, an intelligent anti-counterfeiting material, a UV-transmitting material, and a coating material.

9. A functional material, wherein the raw material for the preparation of the functional material comprises the biomass-based moisture-sensitive repair recyclable fluorescent adjustable microcapsule of claim 6.

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