A photonic crystal structure color fiber and its preparation method

Abstract

This invention relates to a photonic crystal structured color fiber and its preparation method. The method includes the following steps: mixing SiO2 nanospheres, a black light absorber, and water to form a uniformly dispersed SiO2 colloidal dispersion; mixing the SiO2 colloidal dispersion with an oil-phase solution containing a lipophilic surfactant and stirring to form a water-in-oil emulsion droplet; placing the water-in-oil emulsion droplet in an oven to dry, allowing the nanospheres within the droplet to crystallize and assemble during solvent evaporation, forming a photonic crystal structured color pigment. The photonic crystal structured color pigment is then uniformly mixed with a thermoplastic polyurethane (TPU) solution at a specific mass ratio, and the mixture is used as a spinning solution, injected into a coagulation bath through a spinneret and collected. This invention uses a photonic crystal pigment prepared by an emulsion template method as an intermediate and co-spins it with a spinning solution to prepare brightly colored photonic crystal structured color fibers.

Description

Technical Field

[0001] This invention relates to the field of eco-friendly coloring technology for textile fibers, and in particular to a photonic crystal structure color fiber and its preparation method. Background Technology

[0002] Color is a crucial attribute of textile fibers. Conventional textile fiber coloring is primarily achieved through dyeing, with the color-generating principle mainly relying on the selective absorption of visible light by the dye. The resulting colors are typically called chemical colors or pigment colors. However, the dyeing process for textile fibers is often accompanied by high pollution and high energy consumption. Furthermore, the chromophores of dye molecules are prone to photochemical changes under prolonged light exposure, leading to color fading. Unlike pigment colors produced by dye molecules, some organisms in nature produce vibrant colors due to their unique periodic structures, which generate diffraction, interference, or scattering of light through physical optical processes. These are called physical colors or structural colors. Photonic crystals are currently the most studied type of structural color material. Their most fundamental characteristic is the presence of a photonic bandgap. Incident light within the bandgap is prevented from propagating within the photonic crystal and is selectively reflected, resulting in bright and vibrant structural colors. Using colloidal nanospheres as building blocks, colloidal self-assembly is an effective way to construct artificial photonic crystal structures. Constructing photonic crystal structures on textiles can impart bright and vibrant structural color effects, representing an emerging and important approach to achieving eco-friendly coloring of textiles.

[0003] Fibers are an important form of textile material. Currently, structural coloring of fibers mainly involves constructing physical color-generating structures on the surface of existing fibers. For example, in recent years, researchers both domestically and internationally have successively developed technologies for preparing structural color fibers, such as electrophoretic deposition (ACS Macro Letters 2.2(2013):116-120.)(CN103074757A), surface coating (Angewandte Chemie International Edition 54.12(2015):3630-3634.), and atomic deposition (ACS Nano 11.10(2017):10330-10336.). However, since these technologies all construct ordered physical color-generating structures on the fiber surface, they all face problems such as structural instability, low preparation efficiency, and complex processes. Therefore, developing a method for preparing photonic crystal structural color fibers with high structural stability is of great significance for promoting the development and practical application of photonic crystal structural color generation technology in the field of fiber coloring. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a photonic crystal structured color fiber and its preparation method. The preparation method of this invention first prepares SiO2 photonic crystal structured color pigment via a water-in-oil emulsion method, then disperses it in a certain proportion in thermoplastic polyurethane (TPU), and achieves continuous preparation of the photonic crystal structured color fiber through wet spinning.

[0005] The first objective of this invention is to provide a method for preparing photonic crystal structured color fibers, comprising the following steps:

[0006] (1) SiO2 colloidal dispersion was obtained by mixing SiO2 nanospheres, black light absorber and water;

[0007] (2) The SiO2 colloidal dispersion obtained in step (1) is mixed and emulsified with an oil phase solution containing a lipophilic surfactant to form water-in-oil emulsion droplets; the mixed solution includes a lipophilic surfactant and an oil phase solvent;

[0008] (3) The water-in-oil emulsion droplets obtained in step (2) are dried so that the SiO2 nanospheres in the droplets crystallize and assemble during the solvent evaporation process to form SiO2 photonic crystal structure pigment.

[0009] (4) Mix the SiO2 photonic crystal structure color pigment obtained in step (3) with TPU solution to obtain spinning solution, and spin to obtain photonic crystal structure color fiber.

[0010] In one embodiment of the present invention, in step (1), at least one or more of the following conditions are satisfied:

[0011] In the SiO2 colloidal dispersion, the mass fraction of SiO2 nanospheres is 50-70 wt%, the mass fraction of black light absorber is 0.1-1%, and the balance is deionized water;

[0012] The SiO2 nanospheres have a particle size of 200–350 nm and good sphericity.

[0013] The monodispersity index of the SiO2 nanospheres is less than 0.08.

[0014] The black light absorber is selected from one or more of nano carbon black, black dye, graphene, and carbon nanotubes.

[0015] In one embodiment of the present invention, the prime number black dye is selected from one or more of Reactive Black RHH, Reactive Black KN-B, Direct Black 168, Disperse Black S-3BL and Disperse Black eco300.

[0016] In one embodiment of the present invention, in step (1), the amount of SiO2 nanospheres is 50-70 wt%, the amount of black light absorber is 0.1-1%, and the remainder is water;

[0017] It also includes ultrasonic treatment of the resulting mixture.

[0018] In one embodiment of the present invention, in step (2), the lipophilic surfactant is selected from one or more of Span 80, Span 20, Tween 20 and Tween 60;

[0019] The solvent of the oil phase solution is selected from one or more of hexadecane, perfluorinated oil and dimethyl silicone oil; the amount of the lipophilic surfactant is 2 to 10 wt% relative to the amount of solvent in the oil phase solution.

[0020] In one embodiment of the present invention, in step (2), the volume ratio of the SiO2 colloidal dispersion to the solvent of the oil phase solution is 1:50-1:10.

[0021] In one embodiment of the present invention, in step (2), the mixing process is carried out by mechanical stirring at a speed of 60 to 300 rpm.

[0022] In one embodiment of the present invention, in step (3), the drying temperature is 40-80°C.

[0023] In one embodiment of the present invention, in step (4), the concentration of the TPU solution is 15-30 wt%.

[0024] In one embodiment of the present invention, in step (4), the mass ratio of SiO2 photonic crystal structure pigment to TPU solution is 1:20 to 1:5.

[0025] In one embodiment of the present invention, in step (4), after obtaining the spinning solution, it is injected into the coagulation bath through the spinneret to obtain photonic crystal structure color fiber.

[0026] The second objective of this invention is to provide a photonic crystal structure color fiber obtained by the above-described preparation method.

[0027] The method for preparing photonic crystal structured color fibers provided by this invention first assembles nanoscale colloidal microspheres into micron-scale photonic crystal pigments. Then, using the photonic crystal pigments as an intermediate, photonic crystal structured color fibers can be directly and continuously prepared via traditional wet spinning. This avoids the assembly and crystallization processes of colloidal nanospheres during fiber formation in traditional structural color fiber preparation methods (such as electrostatic self-assembly, surface coating, or atomic deposition). Simultaneously, because the color-generating structure is embedded within the polymer fiber, it endows the photonic crystal color-generating structure with high stability. This method solves the problems of difficult continuous preparation, long preparation time, and poor color fastness in structural color fiber preparation, and features simple operation, low cost, and continuous preparation capability.

[0028] The technical solution of the present invention has the following advantages over the prior art:

[0029] 1. This invention emulsifies colloidal microsphere droplets, allowing the microspheres to accumulate and assemble in an orderly manner within the droplets as the solvent evaporates, forming micron-sized photonic crystal pigments. By adjusting the size of the nanospheres, structural color pigments of different hues can be obtained (as the nanosphere particle size gradually increases from 200nm to 350nm, the hue of the resulting structural color pigment changes from short-wavelength purple to long-wavelength red). By introducing nano-carbon black into the assembly system, scattered light outside the photonic bandgap can be effectively absorbed, thereby effectively improving the color saturation of the pigment.

[0030] 2. This invention achieves continuous preparation of photonic crystal structured colored fibers by dispersing brightly colored photonic crystal pigments in TPU spinning solution and using wet spinning. This method is similar to the solution coloring method for conventional colored fiber preparation and has the advantages of simple operation and low cost.

[0031] 3. This invention greatly improves the stability of the photonic crystal color-generating structure on the fiber by embedding the assembled structure prepared by the emulsion template method inside the polymer fiber, so that the prepared structural color fiber has high color fastness. Attached Figure Description

[0032] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0033] Figure 1 These are optical photographs of the SiO2 structural color pigments prepared in Examples 1, 2, and 3 of this invention;

[0034] Figure 2 These are scanning electron microscope images of the SiO2 structural color pigment prepared in Example 1 of this invention;

[0035] Figure 3These are optical photographs of the three structural color spinning solutions prepared in Examples 4, 5, and 6 of this invention; wherein, (a) corresponds to Example 4, (b) corresponds to Example 5, and (c) corresponds to Example 6.

[0036] Figure 4 These are optical photographs of the three structural color fibers prepared in Examples 1, 2, and 3 of this invention; wherein, (a) corresponds to Example 1, (b) corresponds to Example 2, and (c) corresponds to Example 3;

[0037] Figure 5 These are the reflection spectra of the three structural color fibers prepared in Examples 4, 5, and 6 of this invention, wherein blue-violet corresponds to Example 4, green corresponds to Example 5, and red corresponds to Example 6. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0039] Example 1

[0040] This embodiment provides a photonic crystal structured color fiber and its preparation method. The specific steps of the method are as follows:

[0041] (1) SiO2 nanospheres with a particle size of 300 nm, carbon black nanoparticles and deionized water were ultrasonically mixed in proportion to obtain SiO2 colloidal dispersion; wherein the mass fraction of SiO2 nanospheres was 60 wt%, the mass fraction of carbon black nanoparticles was 0.5%, and the remainder was deionized water.

[0042] (2) Span 80 is added to hexadecane at a mass ratio of 5% to form the oil phase. The above SiO2 colloidal dispersion is added to the oil phase as the aqueous phase. Under the action of mechanical stirring, it is emulsified to form water-in-oil emulsion droplets, wherein the mass ratio of the aqueous phase to the oil phase is 1:30.

[0043] 3) The above water-in-oil emulsion droplets were dried in an oven at 50°C, allowing the SiO2 nanospheres within the dispersion droplets to crystallize and assemble during solvent evaporation, forming a SiO2 photonic crystal structured color pigment. The resulting SiO2 photonic crystal structured color pigment was characterized, and the results are shown in [Figure number missing]. Figure 1-2 .

[0044] (4) The above-mentioned structural color pigment was added to a 25 wt% solution of TPU DMF and mixed evenly by mechanical stirring. The mass ratio of the structural color pigment to the TPU solution was 1:15. This solution was then injected into the coagulation bath through the spinneret at a speed of 5 m / min and collected to obtain photonic crystal structural color fibers. The obtained photonic crystal structural color fibers were characterized, and the results are shown in […]. Figure 4 (a)

[0045] Example 2

[0046] This embodiment provides a photonic crystal structured color fiber and its preparation method. The specific steps of the method are as follows:

[0047] (1) SiO2 nanospheres with a particle size of 260 nm, active black RHH and deionized water were ultrasonically mixed in proportion to obtain SiO2 colloidal dispersion; wherein the mass fraction of SiO2 nanospheres was 60 wt%, the mass fraction of nano carbon black was 0.5%, and the remainder was deionized water.

[0048] (2) Span 80 is added to hexadecane at a mass ratio of 5% to form the oil phase. The above SiO2 colloidal dispersion is added to the oil phase as the aqueous phase. Under the action of mechanical stirring, it is emulsified to form water-in-oil emulsion droplets, wherein the mass ratio of aqueous phase to oil phase is 1:20.

[0049] (3) Same as Example 1

[0050] (4) The above-mentioned structural color pigment was added to a 25wt% solution of DMF in TPU and mixed evenly by mechanical stirring. The mass ratio of the structural color pigment to the TPU solution was 1:10. This solution was then injected into the coagulation bath through the spinneret at a speed of 5 m / min and collected to obtain photonic crystal structural color fibers. The obtained photonic crystal structural color fibers were characterized, and the results are shown in […]. Figure 4 (b)

[0051] Example 3

[0052] This embodiment provides a photonic crystal structured color fiber and its preparation method. The specific steps of the method are as follows:

[0053] (1) SiO2 nanospheres with a particle size of 210 nm, carbon black nanoparticles and deionized water were ultrasonically mixed in proportion to obtain a SiO2 colloidal dispersion; wherein the mass fraction of SiO2 nanospheres was 60 wt%, the mass fraction of carbon black nanoparticles was 0.5%, and the remainder was deionized water.

[0054] (2) Same as Example 1

[0055] (3) Same as Example 1

[0056] (4) The above-mentioned structural color pigment was added to a solution of N,N-dimethylformamide (DMF) in thermoplastic polyurethane (TPU) and mixed evenly by mechanical stirring. The mass ratio of the structural color pigment to the TPU solution was 1:5. This solution was then injected into the coagulation bath through the spinneret at a speed of 5 m / min and collected to obtain photonic crystal structural color fibers. The obtained photonic crystal structural color fibers were characterized, and the results are shown in […]. Figure 4 (c)

[0057] Example 4

[0058] This embodiment provides a photonic crystal structured color fiber and its preparation method. The specific steps of the method are as follows:

[0059] (1) SiO2 nanospheres with a particle size of 300 nm, Direct Black 168 and deionized water were ultrasonically mixed in proportion to obtain SiO2 colloidal dispersion; wherein the mass fraction of SiO2 nanospheres was 70 wt%, the mass fraction of nano carbon black was 0.8%, and the remainder was deionized water.

[0060] (2) Span 80 is added to the perfluorinated oil at a mass ratio of 88% to form the oil phase. The above-mentioned SiO2 colloidal dispersion is added to the oil phase as the water phase. Under the action of mechanical stirring, the mixture is emulsified to form water-in-oil emulsion droplets, wherein the mass ratio of the water phase to the oil phase is 1:20.

[0061] 3) The above water-in-oil emulsion droplets are placed in an oven at 40°C to dry, so that the SiO2 nanospheres in the dispersion droplets crystallize and assemble during the solvent evaporation process to form SiO2 photonic crystal structure pigment.

[0062] (4) The above-mentioned structural color pigment was added to a 15wt% solution of DMF in TPU and mixed evenly by mechanical stirring. The mass ratio of the structural color pigment to the TPU solution was 1:10. This solution was then injected into the coagulation bath through the spinneret at a speed of 5 m / min and collected to obtain photonic crystal structural color fibers. The obtained photonic crystal structural color fibers were characterized by reflectance spectroscopy. The results are shown in […]. Figure 5 .

[0063] Example 5

[0064] This embodiment provides a photonic crystal structured color fiber and its preparation method. The specific steps of the method are as follows:

[0065] (1) SiO2 nanospheres with a particle size of 260 nm, graphene and deionized water were ultrasonically mixed in proportion to obtain SiO2 colloidal dispersion; wherein the mass fraction of SiO2 nanospheres was 70 wt% and the mass fraction of nano carbon black was 0.8%.

[0066] (2) Tween 20 is added to dimethylsilane at a mass ratio of 8% to form an oil phase. The above SiO2 colloidal dispersion is added to the oil phase as an aqueous phase. Under the action of mechanical stirring, the mixture is emulsified to form water-in-oil emulsion droplets, wherein the mass ratio of aqueous phase to oil phase is 1:20.

[0067] 3) The above water-in-oil emulsion droplets are placed in an oven at 60°C to dry, so that the SiO2 nanospheres in the dispersion droplets crystallize and assemble during the solvent evaporation process to form SiO2 photonic crystal structure pigment.

[0068] (4) The above-mentioned structural color pigment was added to a 20wt% solution of DMF in TPU and mixed evenly by mechanical stirring, wherein the mass ratio of structural color pigment to TPU solution was 1:5; this solution was then injected into the coagulation bath through the spinneret at a speed of 5 m / min and collected to obtain photonic crystal structural color fibers. The obtained photonic crystal structural color fibers were characterized by reflectance spectroscopy, and the results are shown in […]. Figure 5 .

[0069] Example 6

[0070] This embodiment provides a photonic crystal structured color fiber and its preparation method. The specific steps of the method are as follows:

[0071] (1) SiO2 nanospheres with a particle size of 210 nm, carbon nanotubes and deionized water were ultrasonically mixed in proportion to obtain SiO2 colloidal dispersion; wherein the mass fraction of SiO2 nanospheres was 70 wt% and the mass fraction of nano carbon black was 0.8%.

[0072] (2) Tween 60 is added to hexadecane at a mass ratio of 8% to form the oil phase. The above SiO2 colloidal dispersion is added to the oil phase as the aqueous phase. Under the action of mechanical stirring, the mixture is emulsified to form water-in-oil emulsion droplets, wherein the mass ratio of the aqueous phase to the oil phase is 1:20.

[0073] 3) The above water-in-oil emulsion droplets are placed in an oven at 70°C to dry, so that the SiO2 nanospheres in the dispersion droplets crystallize and assemble during the solvent evaporation process to form SiO2 photonic crystal structure pigment.

[0074] (4) The above-mentioned structural color pigment was added to a 30wt% solution of DMF in TPU and mixed evenly by mechanical stirring. The mass ratio of structural color pigment to TPU solution was 1:20. This solution was then injected into the coagulation bath through the spinneret at a speed of 5 m / min and collected to obtain photonic crystal structural color fibers. The obtained photonic crystal structural color fibers were characterized by reflectance spectroscopy. The results are shown in […]. Figure 5 .

[0075] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a photonic crystal structured color fiber, characterized in that, Includes the following steps: (1) A SiO2 colloidal dispersion was obtained by mixing SiO2 nanospheres, a black light absorber and water; the particle size of the SiO2 nanospheres was 200~350 nm. (2) The SiO2 colloidal dispersion obtained in step (1) is mixed and emulsified with an oil phase solution containing a lipophilic surfactant to form water-in-oil emulsion droplets; (3) The water-in-oil emulsion droplets obtained in step (2) are dried so that the SiO2 nanospheres in the droplets crystallize and assemble during the solvent evaporation process to form SiO2 photonic crystal structure pigment. (4) Mix the SiO2 photonic crystal structure color pigment obtained in step (3) with TPU solution to obtain spinning solution, and wet spin to obtain photonic crystal structure color fiber.

2. The preparation method according to claim 1, characterized in that, In step (1), the SiO2 colloidal dispersion contains 50-70 wt% SiO2 nanospheres, 0.1-1% black light absorber, and the remainder is deionized water. The monodispersity index of the SiO2 nanospheres is less than 0.08; The black light absorber is selected from one or more of nano carbon black, black dye, graphene, and carbon nanotubes.

3. The preparation method according to claim 1, characterized in that, Step (1) also includes ultrasonic treatment of the mixture obtained after mixing.

4. The preparation method according to claim 1, characterized in that, In step (2), the lipophilic surfactant is selected from one or more of Span 80, Span 20, Tween 20 and Tween 60; The solvent for the oil phase solution is selected from one or more of hexadecane, perfluorinated oil, and dimethyl silicone oil; The amount of the lipophilic surfactant used is 2 to 10 wt% relative to the amount of solvent in the oil phase solution.

5. The preparation method according to claim 1, characterized in that, In step (2), the volume ratio of the SiO2 colloidal dispersion to the solvent in the oil phase solution is 1:50-1:

10.

6. The preparation method according to claim 1, characterized in that, In step (2), the mixing process is carried out by mechanical stirring at a speed of 60~300 rpm.

7. The preparation method according to claim 1, characterized in that, In step (3), the drying temperature is 40~80℃.

8. The preparation method according to claim 1, characterized in that, In step (4), the concentration of the TPU solution is 15~30wt%.

9. The preparation method according to claim 1, characterized in that, In step (4), the mass ratio of SiO2 photonic crystal structure pigment to TPU solution is 1:20~1:

5.

10. A photonic crystal structure color fiber, characterized in that, Obtained by any one of the preparation methods of claims 1-9.

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