A structural color textile with phase change temperature regulation performance, high color visibility and stability, and a preparation method thereof

Abstract

A structural color textile with high color visibility and stability and having phase change temperature regulation performance, and a preparation method thereof, belonging to the field of intelligent textiles. The textile is composed of a fabric substrate, an amorphous photonic structure on the substrate, and an aqueous polyurethane phase change material having phase change temperature regulation performance. In the present invention, the fabric substrate is pre-impregnated in the prepared aqueous polyurethane phase change material to enhance the adhesion between the fabric and the amorphous photonic structure. Monodisperse nano-microspheres are assembled on the pretreated fabric through an interface to form an amorphous photonic structure, generating a low-angle-dependent structural color. By regulating the particle size of the monodisperse nano-microspheres, multiple color outputs are achieved. The subsequently sprayed aqueous polyurethane phase change material forms a protective film on the surface of the amorphous photonic structure, and has excellent effects in washing and friction tests. The phase change performance of the aqueous polyurethane phase change material endows the fabric with phase change temperature regulation performance, and absorbs and releases heat during the phase change process to adapt to environmental changes.

Description

Technical Field

[0001] The present invention relates to a structural color textile with phase change temperature regulation performance, high color visibility and stability, and a preparation method thereof, belonging to the field of intelligent textiles. Background Art

[0002] Structural color is a bio-inspired phenomenon generated by the interaction between light and periodic micro-nano structures, including interference, diffraction or scattering, etc. Dyeing technologies represented by structural color have the advantages of high color saturation, environmental protection, and non-fading, etc., and are expected to replace traditional dyeing technologies. At present, highly ordered photonic crystals assembled by colloidal microspheres and amorphous photonic structures with short-range order and long-range disorder are the main ways to artificially construct structural colors. The amorphous photonic structure endows structural color with isotropy and does not change with the change of the observation angle, which is more in line with human visual perception. Therefore, the application of structural color in the field of intelligent textiles has received extensive attention from researchers. (References: Adv. Mater. 2013, 25 (37) :5314-5320; Angew. Chem. Int. Ed. 2018, 57 (10): 2544-2553;)

[0003] At present, it has been reported that monodisperse nano-microspheres are used to construct an angle-independent structural color on a fabric substrate, and the optical properties are adjusted by changing the geometric characteristics. For example, Li et al. used an atomization deposition process to co-assemble silica microspheres and polyvinyl alcohol on silk fabrics to prepare a structural color coating with bright colors. Although remarkable achievements have been made in the development of amorphous photonic structures in the field of textile dyeing, there are still unresolved challenges. On the one hand, incoherent scattering and background light interference significantly reduce the color saturation, making the color dull. On the other hand, monodisperse nano-microspheres usually have point-to-point contacts and lack strong interaction connections, so they are easily damaged by external forces. (References: RSC Adv. 2017, 7,8443-8452; Adv. Funct. Mater. 2021, 31 (19): 2010746;) Summary of the Invention

[0004] The object of the present invention is to provide a structural color textile with high color visibility and stability having phase change temperature regulation performance and a preparation method thereof. The present invention enhances the adhesion between the fabric and the amorphous photonic structure by pre-impregnating the fabric substrate in the prepared aqueous polyurethane phase change material. Monodisperse nanospheres are assembled on the pretreated fabric through interfacial assembly to form an amorphous photonic structure, generating angle-independent structural color. By regulating the particle size of the monodisperse nanospheres, multiple color outputs can be achieved. The subsequently sprayed aqueous polyurethane phase change material forms a protective film on the surface of the amorphous photonic structure, making the prepared structural color textile exhibit excellent flexibility and stability in bending, washing, and friction tests. In addition, the prepared aqueous polyurethane phase change material exhibits phase change characteristics at a temperature close to the human body temperature (36.5 °C), absorbing and releasing heat through phase change during heating and cooling tests, playing a role in body temperature regulation and saving energy.

[0005] This process is simple, rapid, green, and environmentally friendly. The prepared textile has high color visibility and structural stability, and can achieve human body temperature regulation in a hot and cold alternating environment, providing a new solution idea for the application field of intelligent textiles.

[0006] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0007] A preparation method of a structural color textile with high color visibility and stability having phase change temperature regulation performance, characterized in that: the textile sequentially includes a fabric substrate, an amorphous photonic structure on the substrate, and an aqueous polyurethane phase change material having phase change temperature regulation performance, and is characterized by including the following steps:

[0008] (1) Prepare a monodisperse nanosphere emulsion with uniform particle size;

[0009] (2) Prepare an aqueous polyurethane phase change material having phase change temperature regulation performance;

[0010] (3) Pre-impregnate the fabric substrate in the above-mentioned aqueous polyurethane phase change material, and after it is fully adsorbed, dry it for standby;

[0011] (4) Use the interfacial assembly method to assemble a 5% - 20% monodisperse nanosphere dispersion liquid on the fabric surface to obtain an amorphous photonic structure, and after drying, obtain a structural color fabric with bright colors;

[0012] (5) Compound the aqueous polyurethane phase change material in step (2) into an emulsion with a solid content of 1 - 5%, and spray it on the surface of the amorphous photonic structure in step (4), and dry it to form a transparent protective film on the surface of the amorphous photonic structure, obtaining a structural color textile with high color visibility and stability having phase change temperature regulation performance.

[0013] Further, in step (1), the monodisperse nano-microspheres include one of monodisperse silica microspheres, polystyrene microspheres, polymethyl methacrylate microspheres and polythiol resin microspheres, and the particle size of the monodisperse nano-microspheres is 150-350 nm.

[0014] The preparation of the monodisperse nano-microsphere emulsion with uniform particle size in step (1) of the present invention is a prior art in the field. The specific method of polythiol resin microspheres is disclosed in (Tang Bingtao, Li Feihu, Zhang Shufen. A kind of polythiol resin nano-microspheres and its preparation method and application: China, ZL201510776808.3 [P]. Patent category: invention patent, authorization date: August 21, 2017).

[0015] Further, the nano-microsphere emulsion is prepared by adding nano-microspheres to deionized water and compounding to a required concentration for sufficient dispersion, and concentrations of 5%, 10%, 15%, 20% etc. can be prepared.

[0016] Further, the aqueous polyurethane phase change material of the present invention is prepared by a prior art in the field. The present invention preferably prepares the aqueous polyurethane phase change material according to the following method: Add monomers to a 250 mL three-necked flask equipped with mechanical stirring and condensation device and stir at 50 °C for 30 min; on the basis of maintaining good airtightness of the device, add polyisocyanate in batches slowly; after 30 min, add hydrophilic chain extender, crosslinking agent and catalyst, and stir at 40 °C for 6 h to obtain a prepolymer; at the end of the reaction, add acetone and neutralizing agent to reduce the viscosity; add ice water for emulsification and stir vigorously for 30 min, and finally remove acetone by vacuum distillation at 45 °C.

[0017] In the technical solution of the present invention, the monomers of the aqueous polyurethane phase change material are polyethylene glycols with different molecular weights, and further preferably polyethylene glycol with a molecular weight of 2000.

[0018] In the technical solution of the present invention, the polyisocyanate of the aqueous polyurethane phase change material is diisocyanate, which is selected from one of diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), and hexamethylene diisocyanate (HDI).

[0019] Further, the diisocyanate is selected as isophorone diisocyanate (IPDI).

[0020] In the technical solution of the present invention, the hydrophilic chain extender of the aqueous polyurethane phase change material is one of 2,2-bis(hydroxymethyl)propionic acid and 2,2-bis(hydroxymethyl)butyric acid.

[0021] In the technical solution of the present invention, it is preferred that the crosslinking agent of the aqueous polyurethane phase change material is one of trimethylolpropane, phloroglucinol and glycerol.

[0022] In the technical solution of the present invention, it is preferred that the catalyst of the aqueous polyurethane phase change material is dibutyltin dilaurate (DBTDL).

[0023] In the technical solution of the present invention, it is preferred that the neutralizing agent of the aqueous polyurethane phase change material is triethylamine (TEA).

[0024] In the above technical solution, it is preferred that the dosage of acetone is 2-12 g, more preferably 2-8 g, and most preferably 6 g; the dosage of polyethylene glycol 2000 is preferably 2-8 g, more preferably 2-6 g, and most preferably 4 g; the dosage of isophorone diisocyanate is preferably 1-5 g, more preferably 1-3 g, and most preferably 2 g; the dosage of the hydrophilic chain extender 2,2-dimethylolpropionic acid is preferably 1-5 g, more preferably 1-2 g, and most preferably 1.2 g; the dosage of trimethylolpropane is preferably 0.5-3 g, more preferably 0.5-1.5 g, and most preferably 0.8 g; the dosage of triethylamine is preferably 0.5-4 g, more preferably 0.5-2 g, and most preferably 1 g; the dosage of deionized water is preferably 10-30 g, more preferably 10-20 g, and most preferably 15 g; the reduced pressure distillation is carried out using a rotary evaporator, and the temperature is preferably 45 °C.

[0025] Further, in step (4), the temperature for interfacial assembly of the monodisperse nano-microspheres on the fabric substrate is preferably 70-100 °C.

[0026] Further, in step (5), the aqueous polyurethane phase change material obtained in step (2) is formulated into an emulsion with a solid content of 1-5% (which can be 1%, 2%, 5%, etc.) and sprayed on the amorphous photonic structure to form a transparent protective film on the surface of the amorphous photonic structure layer. The drying temperature after spraying is preferably 70-100 °C.

[0027] A structural color textile with phase change temperature regulation performance, high color visibility and stability, is prepared according to the above preparation method;

[0028] Further, the fabric substrate is selected from one of natural fiber fabrics or synthetic fiber fabrics, and is selected from cotton fabrics, silk fabrics, polyester fabrics or nylon fabrics.

[0029] Further, the thickness of the amorphous photonic structure is adjusted by the dropping amount of the monodisperse nano-microsphere emulsion.

[0030] The structural color fabric is formed by monodisperse nano - microspheres aggregating on the fabric surface in a closely - packed amorphous photonic structure form. By adjusting the particle size of the monodisperse nano - microspheres, the preparation of structural color textiles with different colors is realized; through the effective combination of water - borne polyurethane phase - change materials and the amorphous photonic structure, the structural color fabric is endowed with excellent color visibility and stability; by utilizing the phase - change performance of the water - borne polyurethane phase - change material, the structural color fabric is given the function of temperature regulation to adapt to the change of environmental temperature.

[0031] The beneficial effects of the present invention are as follows: In this application, the monodisperse microspheres assembled at the interface of the structural color textile aggregate on the surface of the microspheres in a closely - packed form, presenting a short - range ordered and long - range disordered amorphous photonic structure. After spraying the water - borne polyurethane phase - change material, part of it penetrates into the internal amorphous photonic structure and fills the gaps between the microspheres, and the other part solidifies on its surface to form a protective film.

[0032] (1)The present invention realizes the multi - color output performance of the structural color textile by regulating the particle size of the monodisperse nano - microspheres; and the presented structural color does not change with the observation angle, showing low - angle correlation.

[0033] (2)The water - borne polyurethane phase - change material, as a binder, enhances the adhesion between the fabric and the amorphous photonic structure layer. The protective film formed by spraying on the amorphous photonic structure layer further enhances the structural stability, making the prepared structural color textile show excellent flexibility and stability in bending, washing, and friction tests.

[0034] (3)The prepared water - borne polyurethane phase - change material shows phase - change characteristics at a temperature close to the human body temperature (36.5 °C), enabling the prepared fabric to absorb and release heat through phase transformation during heating and cooling tests, playing a role in body temperature regulation. The phase - change performance of the water - borne polyurethane phase - change material endows the fabric with phase - change temperature - regulation performance, absorbing and releasing heat during the phase - change process to adapt to the change of the environment.

[0035] This method has the characteristics of simplicity, rapidity, low cost, and environmental friendliness. The prepared structural color textiles will provide new innovative ideas in the future field of intelligent textiles. Description of the Drawings

[0036] Figure 1 In (a), it is the scanning electron microscope (SEM) image of the amorphous photonic structure assembled by the monodisperse nano - microspheres described in Example 1, and in (b), it is the scanning electron microscope (SEM) image of the fabric after spraying the water - borne polyurethane phase - change material described in Example 1.

[0037] Figure 2 It is the digital photo image of the green structural color textile described in Example 1 at different angles.

[0038] Figure 3Reflectance spectra of the green structural color textile described in Example 1 at different angles.

[0039] Figure 4 Reflectance spectra of the green structural color textile described in Example 1 before and after spraying with the aqueous polyurethane phase change material.

[0040] Figure 5 In (a) are the reflectance spectra of the textile without spraying with the aqueous polyurethane phase change material in Comparative Example 1 before and after the friction test, and in (b) are the reflectance spectra of the green structural color textile described in Example 1 before and after the friction test.

[0041] Figure 6 In (a) is the temperature change curve of the structural color textile described in Example 1 during the heating process, and in (b) is the temperature change curve of the structural color textile described in Example 1 during the cooling process. Embodiment

[0042] The following non-limiting examples can enable those of ordinary skill in the art to more comprehensively understand the present invention, but do not limit the present invention in any way.

[0043] The test methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials, unless otherwise specified, can all be obtained commercially or can be prepared by conventional methods. Example

[0044] 1. Prepare a monodisperse polythiourethane resin microsphere emulsion with a particle size of 198 nm. The specific preparation method is as follows:

[0045] a. Weigh 20.0 g of solid sodium hydroxide particles and add them to a 250 mL three-necked flask equipped with a mechanical stirrer and a condenser. Then add 100 mL of deionized water and stir. After heating to 95 °C and fully dissolving, add 16 g of sublimed sulfur powder and react for 1 h under vigorous stirring conditions to obtain an orange sodium disulfide solution;

[0046] b. Add 1.5 g of Pluronic-F127, 70 mL of ethanol, and 180 mL of deionized water to a 500 mL three-necked flask, mix well under magnetic stirring, raise the reaction temperature to 82 °C, add 50 mL of the sodium disulfide solution prepared above, continue stirring for 10 min, add 6.25 g of 1,2,3-trichloropropane, and react for 6 hours. After the reaction is completed and cooled to room temperature, the obtained emulsion is centrifuged and washed 3 times with deionized water, and an appropriate amount of deionized water is added to prepare the required concentration for standby.

[0047] 2. Preparation of aqueous polyurethane phase change materials. The specific method is as follows: Add 4 g of polyethylene glycol with a molecular weight of 2000 to a 250 mL three-necked flask, and under the condition of 50 °C, mechanically stir for 30 min to make it melt. On the basis of maintaining good airtightness of the device, add IPDI (2.00 g) in batches and slowly, and make it react for 30 min. Add 1.2 g of hydrophilic chain extender 2,2-dimethylolpropionic acid, 0.8 g of trimethylolpropane and 3 drops of catalyst dibutyltin dilaurate, and stir at 40 °C for 6 h to obtain a prepolymer. At the end of the reaction, add 6 g of acetone and 1 g of triethylamine to reduce the viscosity. Add 15 g of ice water for emulsification and stir vigorously for 20 min. After the reaction ends, distill off acetone under reduced pressure at 45 °C.

[0048] 3. Wash the cotton fabric with washing powder and dry it in a drying oven. Immerse the cotton fabric substrate in the prepared aqueous polyurethane phase change materials in advance. After it is fully adsorbed, dry it in an oven at 70 °C for standby.

[0049] 4. Drop the polythiourethane resin microsphere emulsion with a solid content of 10% and a dosage of 56 μL / cm 2 onto a 2 cm * 2 cm glass plate placed on a 70 °C hot plate. When a bright structural color appears on the liquid surface of the emulsion, cover the washed 2 cm * 2 cm cotton fabric substrate on the liquid surface and perform interfacial assembly at 70 °C to obtain a fabric with a bright structural color.

[0050] 5. Spray the aqueous polyurethane phase change materials obtained in step (2) compounded into an emulsion with a solid content of 2% on the surface of the amorphous photonic structure in step (4), dry it at 70 °C, and form a transparent protective film on the surface of the amorphous photonic structure to obtain a structural color textile with high color visibility and stability and phase change temperature regulation performance.

[0051] In step (5) of Example 1, the aqueous polyurethane phase change materials were not sprayed, and the structural color presented by the obtained amorphous photonic structure was taken as the final structure.

[0052] Figure 1 Among them, (a) and (b) are respectively the scanning electron microscope pictures of the amorphous photonic structure assembled by monodisperse nanospheres in Example 1 and the scanning electron microscope pictures of the fabric after spraying the aqueous polyurethane phase change materials. It can be seen from the figure that the monodisperse microspheres assembled at the interface are aggregated on the surface of the microspheres in a closely packed form, presenting an amorphous photonic structure with short-range order and long-range disorder. After spraying the aqueous polyurethane phase change materials, part of them penetrates into the internal part of the amorphous photonic structure and fills the gaps between the microspheres, and the other part solidifies on its surface to form a protective film, thereby improving the stability.

[0053] Figure 2Digital photos of the structural color fabric formed by assembling monodisperse polythiol resin microspheres with a diameter of 198 nm at different viewing angles. It can be seen from the figure that the presented structural color does not change with the viewing angle, showing low-angle correlation.

[0054] Figure 3 Reflection spectra of the structural color fabric formed by assembling monodisperse polythiol resin microspheres with a diameter of 198 nm at different viewing angles, further confirming the structural color with low-angle correlation.

[0055] Figure 4 Reflection spectra of the green structural color textile in Example 1 before and after spraying the waterborne polyurethane phase change material. It can be seen from the figure that only a slight red shift appears in the structural color after spraying the waterborne polyurethane phase change material, and the intensity of the reflection peak does not change significantly.

[0056] Figure 5 (a) Reflection spectra of the green structural color textile without spraying the waterborne polyurethane phase change material in Comparative Example 1 before and after the friction test. The results show that the intensity of the spectral reflection peak decreases significantly before and after friction, which is due to the destruction of the amorphous photon structure layer during the friction process. Figure 5 (b) Reflection spectra of the green structural color textile described in Example 1 before and after the friction test. The results show that the color does not change significantly before and after friction, confirming that spraying the waterborne polyurethane phase change material further improves the structural stability.

[0057] Figure 6 (a) and (b) are the temperature change curves of the structural color textile described in Example 1 during the heating process and the cooling process. During the heating process, when the temperature is higher than the phase change temperature, due to the absorption and storage of abundant energy by the waterborne polyurethane phase change material during the phase change process, the temperature of the obtained textile is lower. On the contrary, during the cooling process, when the ambient temperature is lower than the phase change temperature, due to the release of energy by the waterborne polyurethane phase change material, the temperature of the obtained textile is higher.

[0058] In step (1) of Example 1, the temperature of 82 °C in the process of preparing the monodisperse polythiol resin microsphere emulsion was changed to 80 °C, 84 °C, and 86 °C, and monodisperse polythiol resin microspheres with diameters of 185, 211, and 230 nm were obtained. Other conditions were the same as those in Example 1. Purple, orange, and red structural color fabrics were obtained through interfacial assembly and subsequent spraying, with bright colors, good structural stability, and excellent phase change temperature regulation performance.

[0059] Replace the monodisperse polythiourethane resin microspheres in Example 1 with polystyrene microspheres, and adjust the dosage of the emulsifier to prepare polystyrene microspheres with different particle sizes (193, 240, 260, and 300 nm). Other conditions are the same as those in Example 1. Purple, green, orange, and red structural color fabrics are obtained through interfacial assembly and subsequent spraying. The structure has good stability and excellent phase change temperature regulation performance.

[0060] Replace the monodisperse polythiourethane resin microspheres in Example 1 with polymethyl methacrylate microspheres, and adjust the dosage of the emulsifier to prepare polymethyl methacrylate microspheres with different particle sizes (198, 245, 268, and 310 nm). Other conditions are the same as those in Example 1. Purple, green, orange, and red structural color fabrics are obtained through interfacial assembly and subsequent spraying. The structure has good stability and excellent phase change temperature regulation performance.

[0061] Replace the monodisperse polythiourethane resin microspheres in Example 1 with silica microspheres, and adjust the dosage of the seeds to prepare silica microspheres with different particle sizes (201, 252, 273, and 306 nm). Other conditions are the same as those in Example 1. Purple, green, orange, and red structural color fabrics are obtained through interfacial assembly and subsequent spraying. The structure has good stability and excellent phase change temperature regulation performance.

[0062] Replace the cotton fabric in Step 3 of Example 1 with silk fabric, polyester, and nylon. Other conditions are the same as those in Example 1. The obtained fabrics have bright colors, good structural stability, and excellent phase change temperature regulation performance.

Claims

1. A preparation method of a structural color textile with phase change temperature regulation performance, high color visibility and stability, characterized in that: The textile sequentially includes a fabric substrate, an amorphous photonic structure on the substrate, and an aqueous polyurethane phase change material with phase change temperature regulation performance, and is characterized in that it includes the following steps: (1) Prepare a monodisperse nano-microsphere emulsion with uniform particle size; (2) Prepare an aqueous polyurethane phase change material with phase change temperature regulation performance; Add monomers to a 250 mL three-necked flask connected with a mechanical stirring and condensation device, and stir at 50 °C for 30 min; on the basis of maintaining good airtightness of the device, add polyisocyanate in batches; after 30 min, add a hydrophilic chain extender, a crosslinking agent and a catalyst, and stir at 40 °C for 6 h to obtain a prepolymer; at the end of the reaction, add acetone and a neutralizing agent; add ice water for emulsification and stir for 30 min, and finally remove acetone by vacuum distillation at 45 °C; The monomer is polyethylene glycol; The polyisocyanate is a diisocyanate, selected from one of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate; The hydrophilic chain extender is one of 2,2-bis(hydroxymethyl)propionic acid and 2,2-bis(hydroxymethyl)butyric acid; The crosslinking agent is one of trimethylolpropane, phloroglucinol, and glycerol; The catalyst is dibutyltin dilaurate; The neutralizing agent is triethylamine; (3) Immerse the fabric substrate in the above-mentioned aqueous polyurethane phase change material in advance, and after it is fully adsorbed, dry it for standby; (4) Use the interfacial assembly method to assemble a 5%-20% monodisperse nano-microsphere emulsion on the fabric surface to obtain an amorphous photonic structure, and obtain a structural color fabric with bright color after drying; (5) Compound the aqueous polyurethane phase change material described in step (2) into an emulsion with a solid content of 1%-5%, and spray it on the surface of the amorphous photonic structure described in step (4), and dry it to form a transparent protective film on the surface of the amorphous photonic structure, and obtain a structural color textile with high color visibility and stability and phase change temperature regulation performance.

2. The preparation method according to claim 1, characterized in that: In step (1), the monodisperse nano-microspheres include one of monodisperse silica microspheres, polystyrene microspheres, polymethyl methacrylate microspheres, and polythiourethane microspheres, and the particle size of the monodisperse nano-microspheres is 150-350 nm.

3. The preparation method according to claim 1, wherein: In step (1), the solvent of the monodisperse nano-microsphere emulsion is water or ethanol.

4. The preparation method according to claim 1, characterized in that: In step (4), the interfacial assembly temperature of the monodisperse nano-microspheres on the fabric is 70-100 °C.

5. The preparation method according to claim 1, wherein: In step (5), a transparent protective film is formed on the surface of the amorphous photonic structure layer, and the drying temperature after spraying is 70-100 °C.

6. A structural color textile with phase change temperature regulation performance, high color visibility and stability, characterized in that: Obtained according to any one of claims 1-5.

7. The structural color textile according to claim 6, wherein: The fabric substrate is a natural fiber fabric or a synthetic fiber fabric.

8. The structural color textile according to claim 7, wherein: The fabric substrate is selected from cotton fabric, silk fabric, polyester fabric or nylon fabric.

9. The structural color textile according to claim 6, wherein; The thickness of the amorphous photonic structure is adjusted by changing the dropping amount of the monodisperse nano-microsphere emulsion.

10. The structural color textile according to claim 6, characterized in that: By adjusting the particle size of the monodisperse nano-microspheres, the preparation of structural color textiles with different colors is realized.

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