A non-densely packed photonic crystal structure color-producing fabric and its preparation method

Abstract

The present invention belongs to the field of textile structural coloration, and particularly relates to a non-densely packed photonic crystal structure color-forming fabric and its preparation method. The method comprises the following steps: S1 constructing an assembly working fluid, S2 applying the assembly working fluid and completing assembly: uniformly applying the assembly working fluid to the fabric surface, and assembling at a temperature of 50-80°C for 2-10 minutes. When the apparent moisture completely evaporates, the assembly is completed; S3 a water removal step, and S4 a brightening step. The brightening treatment process conditions are a temperature of 110-140°C and a time of 2-10 minutes. The present invention realizes the rapid and large-scale preparation of non-densely packed photonic crystal structure color-forming fabrics by constructing an assembly working fluid, applying the assembly working fluid to the fabric surface, and then performing a three-stage process of assembly, sufficient water removal, and brightening.

Description

Technical Field

[0001] The invention belongs to the field of textile structural coloration, and in particular relates to a non-densely packed photonic crystal structure coloration fabric and a preparation method thereof. Background Art

[0002] Photonic crystals are "crystalline" materials formed by the periodic arrangement of media with different refractive indices in space. In nature, objects such as chameleons, butterfly wings, peacock feathers, and opals all display the structural colors of photonic crystals. Photonic crystals can be divided into close-packed and non-packed photonic crystals based on the compactness of their stacking structure. Currently, the most commonly used method for textile biomimetic structural color generation is to construct close-packed photonic crystals by self-assembly of colloidal nanospheres on textile substrates. The process is simple, requires low equipment, and the assembly process is controllable. It is easy to obtain long-range regular and ordered structures, resulting in bright and beautiful structural colors. However, the practical application of close-packed photonic crystal structural color generation technology based on hard microspheres such as polystyrene (PS), polymethyl methacrylate (PMMA), and silicon oxide (SiO2) in the field of textile coloring faces two key challenges that need to be addressed: first, the low efficiency of nanosphere self-assembly. In the conventional self-assembly process of nanospheres, the assembly of elementary nanospheres needs to go through complex processes such as crystal nucleation and crystal growth, which makes it difficult to achieve large-scale and efficient construction of photonic crystals; secondly, the structural stability of photonic crystals is poor and it is difficult to balance optical properties.

[0003] In response to the above problems, replacing densely packed photonic crystals with non-densely packed photonic crystals is an effective solution. Unlike densely packed photonic crystals, non-densely packed photonic crystals refer to photonic crystal structures in which the assembly units are not densely packed but are regularly arranged in space. The structural advantage of non-densely packed photonic crystals is that there is a large space between the assembly units with a certain spacing, which can be used to introduce soft materials, thereby greatly improving the structural stability of the photonic crystals. At the same time, as the volume proportion of soft materials increases, the effective refractive index difference between the two media that constitute the photonic crystal will increase accordingly, thereby preparing photonic crystal materials with high brightness, high saturation and highly stable structure. At present, the preparation methods of non-densely packed photonic crystals are mainly special template methods and microsphere soft shell fusion methods. The template method is to first construct a densely packed photonic crystal array, use special means to etch it, increase the gaps between the microspheres, and then use a curable polymer to fill and solidify it to prepare a non-densely packed photonic crystal film. For example, Wu et al. from Dalian University of Technology used ZnS@SiO2 microspheres to construct a densely packed ordered photonic crystal structure as a "transition state". After the SiO2 shell was etched with HF, it was filled with polymer again. After curing, a non-densely packed photonic crystal structure constructed by ZnS microspheres and polymer was formed. (Wu Y, Wang Y, Zhang S, et al. Artificial Chameleon Skin with Super-Sensitive Thermal and Mechanochromic Response[J]. ACS Nano, 2021, 15(10): 15720-15729.) This type of special template method usually has complicated procedures and is difficult to prepare on a large scale, making it unsuitable for large-scale application of textile structural color. The microsphere soft-shell fusion method is currently the main method for large-scale preparation of non-close-packed photonic crystal films. This method requires extracting the three-layer microspheres of soft shell-transition layer-hard shell from the emulsion by demulsification to obtain a solid clay-like masterbatch, which is then extruded through a twin-screw extruder. The soft shell components are softened and melted under high temperature conditions, and then multiple oscillation shear-induced assembly is carried out to prepare non-close-packed photonic crystal materials with excellent optical properties.(Li H, Wu P, Zhao G, et al. Fabrication of industrial-level polymerphotonic crystal films at ambient temperature Based on uniform core / shell colloidal particles. J. Colloid. Interface. Sci. 2021, 584, 145-153.) However, the melt-shear assembly process is too complicated (demulsification to extract microspheres, high-temperature melting, multiple oscillation shearing, etc.), and the high temperature and hot pressing assembly conditions are usually difficult for textile substrates to withstand.

[0004] Therefore, it is of great significance to develop a non-densely packed photonic crystal that can be efficiently prepared on the surface of a textile substrate with both structural stability and high color saturation. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing a non-densely packed photonic crystal structured color-producing fabric. The method is simple and efficient, and can be implemented using conventional textile dyeing and finishing processing equipment and methods; the prepared non-densely packed photonic crystals are flexible and elastic, can adapt to flexible textile substrates, and have the ability to change color upon stretching, giving the textiles a sense of technology and fashion.

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

[0007] A method for preparing a non-close-packed photonic crystal structure color-producing fabric, the method comprising the following steps:

[0008] S1 construction assembly working solution

[0009] The assembly working solution comprises: based on 100% by weight of the assembly working solution, 15-40% of nano-microspheres with a hard core-soft shell structure, 2.0-6.0% of a high boiling point solvent, and the balance of water;

[0010] S2: Applying the assembly working liquid and completing the assembly: The assembly working liquid is evenly applied to the surface of the fabric, and the assembly is carried out at a temperature of 50-80°C for 2-10 minutes. When the apparent moisture is completely evaporated, the assembly is completed; S3: Dehydration process: The assembled photonic crystal structure color-forming fabric is placed in an oven for sufficient dehydration treatment to fully evaporate the moisture inside the photonic crystal and induce the microspheres to move toward a highly regularly arranged structure;

[0011] The process conditions for water removal treatment are temperature 90-100°C and time 1-5 minutes;

[0012] S4 brightening process: The photonic crystal structure color-forming fabric obtained by the water removal process is placed in a high-temperature oven for brightening treatment to further improve the regularity of the photonic crystal structure, thereby obtaining a non-densely packed photonic crystal structure color-forming fabric with bright colors and significant iridescent effect;

[0013] The process conditions of the brightening treatment are temperature 110-140°C and time 2-10 minutes.

[0014] This method can use intermittent processing or continuous processing equipment with three boxes of different temperatures to continuously complete steps S2-S4.

[0015] This method constructs an assembly working solution, applies it to the fabric surface, and then undergoes a three-stage process: assembly, thorough water removal, and brightening. This method enables the rapid, large-scale production of non-densely packed photonic crystal-structured color-producing fabrics. This method is simple and efficient, and can be implemented using conventional textile dyeing and finishing equipment and methods. The resulting photonic crystals exhibit both high structural stability (high color fastness) and high color saturation, resulting in a significant iridescent effect.

[0016] The present invention adopts a three-stage process of assembly-full water removal-brightening. The key point lies in the control of process parameters of gradual staged temperature increase. Among them, the first stage temperature is 50-80°C, in which the nano-microspheres self-assemble toward the face-centered cubic structure with the lowest system energy, and a certain degree of mutual micro-point bonding is generated between the soft monomer segments of the microsphere shell, which has the effect of enhancing the stability of the photonic crystal structure; the second stage temperature is 90-100°C, in order to further evaporate the small amount of water inside the photonic crystal, so as to enhance the overall regularity of the photonic crystal; the third stage temperature is 110-140°C, in order to melt the microsphere shell, so that the hard core part can move within the fused shell layer, and achieve the purpose of regular assembly.

[0017] Preferably, the fabric is polyester fabric, spandex fabric, polyester-spandex blended fabric, cotton fabric or polyester-cotton blended fabric; the fabric is a surface-modified fabric or an unmodified fabric with a smooth surface and a tight structure, and the fabric modification material is selected from polyacrylate, polyurethane, polydimethylsiloxane, ethylene oxide or PVC.

[0018] Preferably, the nanospheres of the hard core-soft shell structure have an inner core of highly cross-linked polystyrene (PS), polymethyl methacrylate (PMMA), polymethacrylic acid (PMAA), poly(styrene-methyl methacrylate) (P(St-MMA)) or poly(styrene-methacrylic acid) (P(St-MAA)), and a shell of soft and hard monomer copolymers of poly(butyl acrylate-methyl methacrylate) (P(MMA-BA)), poly(hydroxyethyl acrylate-hydroxyethyl methacrylate) (P(HEA-HEMA)) or poly(ethyl acrylate-methacrylic acid) (P(EA-MAA)).

[0019] The high boiling point solvent is selected from one or a mixture of glycerol, propylene glycol, formamide, ethylene glycol, fatty alcohol polyoxyethylene ether or fatty acid polyoxyethylene ester.

[0020] Preferably, the non-close-packed photonic crystal structure is a non-closely-packed skeleton structure (dispersed phase) constructed by a hard core, and a continuous phase embedded in the skeleton is formed by the fusion of soft shells, wherein the sum of the volume ratios of the hard core and the soft shell is 100%, and the proportion of the soft shell is 30-60%.

[0021] Preferably, the assembly working liquid is applied to the fabric by a doctor blade coating method, a spray coating method, a screen printing method or a digital printing method.

[0022] A non-densely packed photonic crystal structure color-producing fabric obtained by the preparation method of the present invention.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The method of the present invention breaks through the problems of the previous melt shear assembly method (emulsification extraction of microspheres, high temperature melting, multiple oscillation shearing, etc.) for preparing non-densely packed photonic crystals, which is complicated, energy-consuming, and not conducive to application on textiles. It realizes the rapid and large-scale preparation of non-densely packed photonic crystal structure color-producing fabrics. Specifically, soft shell-hard core nano-microspheres are used as assembly primitives, and a high boiling point solvent is introduced into the assembly working fluid to suppress the uneven force on the liquid surface caused by rapid evaporation of water, which is conducive to the crack-free assembly of non-densely packed photonic crystals. Then, conventional textile dyeing and finishing equipment (such as scraping, spraying, screening, digital printing, etc.) is used to apply the assembly working fluid to the surface of the textile substrate. After a three-stage process, non-densely packed photonic crystal structure color-producing fabrics are quickly and efficiently prepared on a large scale.

[0025] 2. Apply a three-stage process (assembly - sufficient water removal - brightening) to achieve the refined and controllable preparation of non-densely packed photonic crystal structure color-producing fabrics. During the assembly process, the nanospheres self-assemble towards the face-centered cubic structure with the lowest energy in the system. When the apparent water evaporates, the assembly of the nanospheres is apparently completed, and a certain mutual micro-point bonding effect is generated between the soft monomer segments of the microsphere shell, which enhances the stability of the photonic crystal structure and avoids cracking problems. During the water removal process, the small amount of water and high-boiling-point solvent present in the photonic crystal further evaporates, inducing fine-tuning of the core-shell nanospheres as a whole, compensating for the defects in the self-assembly process, and improving the overall structural regularity of the photonic crystal. During the brightening process, under the action of high temperature, the soft and hard molecular segments of the soft shell soften and present a certain molten state, and the hard cross-linked core is further adjusted within the continuous phase formed by the molten soft shell, forming a photonic crystal skeleton composed of regularly arranged hard cores, and the soft shell fills the space between the skeleton hard cores and fuses with each other to form a non-densely packed photonic crystal structure.

[0026] 3. The prepared non-dense-packed photonic crystal structure is flexible and adaptable to flexible textile substrates. It also exhibits the ability to change color upon stretching, giving textiles a sense of technology and fashion. Furthermore, the prepared non-dense-packed photonic crystal structure color-forming fabrics exhibit ultra-high structural stability (color fastness), significantly enhancing the practical application value of photonic crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a digital photograph of the assembly working solution constructed in Example 1;

[0028] Figure 2 is an optical photograph of the assembly working fluid constructed in Example 2;

[0029] Figure 3 is the reflectivity curve of the photonic crystal structure color-producing fabric prepared in Example 3;

[0030] Figure 4 This is a digital photo of the self-assembly process of the photonic crystal in Example 4;

[0031] Figure 5 is a SEM image of the non-close-packed photonic crystal structure color-producing fabric prepared in Example 5;

[0032] Figure 6 This is a digital photo of the photonic crystal structure color-producing fabric prepared in Example 6;

[0033] Figure 7 This is a digital photo of the photonic crystal structure color-producing fabric prepared in Example 7;

[0034] Figure 8This is a digital photograph of the photonic crystal structure color-producing fabric prepared in Example 8 in a stretched state;

[0035] Figure 9 This is an optical microscope photograph of the non-close-packed photonic crystal structure color-producing fabric prepared in Comparative Example 1;

[0036] Figure 10 are optical microscope photographs of the photonic crystal structure color-bearing fabrics prepared in Comparative Example 2, Comparative Example 3, and Example 6, wherein a, b, and c correspond to the photonic crystal structure color-bearing fabrics prepared in Comparative Example 2, Comparative Example 3, and Example 6, respectively;

[0037] Figure 11 These are optical microscope photos of the photonic crystal structure color-producing fabrics prepared in Comparative Example 4(a) and Example 6(b). DETAILED DESCRIPTION

[0038] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0039] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0040] The present invention will now be further described in conjunction with specific examples. The following examples are only intended to explain the present invention but do not limit the present invention. The test samples and test procedures used in the following examples include the following (if the specific experimental conditions are not specified in the examples, they are usually based on conventional conditions or the conditions recommended by the reagent company; the reagents, consumables, etc. used in the following examples, unless otherwise specified, can be obtained from commercial sources).

[0041] In the present invention, nano-microspheres with a hard core-soft shell structure are prepared according to the method described in the Chinese invention patents "A preparation method of flexible photonic crystal elementary nano-microspheres" (ZL201911112794.X, CN110804127B) and "A photonic crystal structure color-producing fabric and its preparation method" (ZL2020112313341, CN112323495B).

[0042] Example 1

[0043] A method for preparing a non-densely packed photonic crystal structure color-producing fabric, comprising the following steps:

[0044] (1) The composition of the assembly working solution is as follows: based on the weight of the assembly working solution as 100%, the assembly working solution contains 40% of 180 nm PS@P(MMA-BA) nanospheres, 2.0% of glycerol, and the balance of water;

[0045] (2) Applying an assembly working solution with a solid content of 40 wt% to the surface of the polyurethane surface-modified polyester fabric by a doctor blade method, and placing it at 60°C for 6 min. When the apparent water completely evaporates, the assembly is completed;

[0046] (3) The assembled photonic crystal structured chromogenic fabric was placed in a 90°C oven for 5 min to remove water, so that the water inside the photonic crystal was fully evaporated and the microspheres were induced to move toward a regularly arranged structure;

[0047] (4) The photonic crystal structure color-forming fabric that has undergone the dehydration process is placed in a 110°C oven for a 10-minute brightening process. This process can further improve the regularity of the photonic crystal structure and obtain a non-densely packed photonic crystal structure color-forming fabric with bright colors and iridescent effects.

[0048] Example 2

[0049] A method for preparing a non-densely packed photonic crystal structure color-producing fabric, comprising the following steps:

[0050] (1) The composition of the assembly working solution is as follows: based on the weight of the assembly working solution as 100%, the assembly working solution contains 40% of 200 nm PS@P(HEA-HEMA) nanospheres, 4.0% of glycerol, and the balance of water;

[0051] (2) Using a screen printing method, an assembly working solution with a solid content of 40 wt% was applied to the surface of a polydimethylsiloxane-modified polyester-cotton blended fabric, and the fabric was placed at 50°C for 10 min. When the apparent water completely evaporated, the assembly was completed;

[0052] (3) The assembled photonic crystal structured chromogenic fabric was placed in a 90°C oven for 2 min to remove water, so that the water inside the photonic crystal was fully evaporated and the microspheres were induced to move toward a regularly arranged structure;

[0053] (4) The photonic crystal structure color-forming fabric that has undergone the dehydration process is placed in a 120°C oven for 8 minutes of brightening process. This process can further improve the regularity of the photonic crystal structure and obtain a non-densely packed photonic crystal structure color-forming fabric with bright colors and iridescent effect.

[0054] Example 3

[0055] A method for preparing a non-densely packed photonic crystal structure color-producing fabric, comprising the following steps:

[0056] (1) The composition of the assembly working solution is as follows: based on the weight of the assembly working solution as 100%, the assembly working solution contains 15% of 280 nm PMMA@P(MMA-BA) nanospheres, 6.0% of formamide, and the balance of water;

[0057] (2) The assembly working solution with a solid content of 15 wt% was applied to the surface of the polyacrylate-modified spandex fabric using a digital printing method, and the fabric was placed at 50°C for 8 min. When the apparent water completely evaporated, the assembly was completed;

[0058] (3) The assembled photonic crystal structured chromogenic fabric was placed in an oven at 100°C for 1 min for dehydration treatment to fully evaporate the water inside the photonic crystal and induce the microspheres to move toward a regularly arranged structure;

[0059] (4) The photonic crystal structure color-forming fabric that has undergone the dehydration process is placed in a 130°C oven for a 6-minute brightening process. This process can further improve the regularity of the photonic crystal structure and obtain a non-densely packed photonic crystal structure color-forming fabric with bright colors and iridescent effects.

[0060] Example 4

[0061] A method for preparing a non-densely packed photonic crystal structure color-producing fabric, comprising the following steps:

[0062] (1) The assembly working solution is composed of: 30% of 260 nm PMAA@P(HEA-HEMA) nanospheres, 4.0% of fatty alcohol polyoxyethylene ether, and the balance of water, based on 100% by weight of the assembly working solution;

[0063] (2) The assembly working solution with a solid content of 30 wt% was applied to the surface of the ethylene oxide-modified cotton fabric by spraying, and the fabric was assembled at 70°C for 4 min. When the apparent water completely evaporated, the assembly was completed;

[0064] (3) The assembled photonic crystal structured chromogenic fabric was placed in an oven at 100°C for 5 min to remove water, so that the water inside the photonic crystal was fully evaporated and the microspheres were induced to move toward a regularly arranged structure;

[0065] (4) The photonic crystal structure color-forming fabric that has undergone the dehydration process is placed in a 130°C oven for a 4-minute brightening process. This process can further improve the regularity of the photonic crystal structure and obtain a non-densely packed photonic crystal structure color-forming fabric with bright colors and iridescent effect.

[0066] Example 5

[0067] A method for preparing a non-densely packed photonic crystal structure color-producing fabric, comprising the following steps:

[0068] (1) The assembly working solution is composed of: 40% of 300 nm P(St-MMA)@P(MMA-BA) nanospheres, 6.0% of fatty acid polyoxyethylene ester, and the balance of water, based on 100% by weight of the assembly working solution;

[0069] (2) A 40 wt% solid content assembly working solution was applied to the surface of the ethylene oxide surface-modified cotton fabric by spraying, and the fabric was placed at 80°C for 2 min. When the apparent water completely evaporated, the assembly was completed;

[0070] (3) The assembled photonic crystal structured chromogenic fabric was placed in an oven at 100°C for 4 minutes for dehydration treatment to fully evaporate the water inside the photonic crystal and induce the microspheres to move toward a regularly arranged structure;

[0071] (4) The photonic crystal structure color-forming fabric that has undergone the dehydration process is placed in a 140°C oven for a 2-minute brightening process. This process can further improve the regularity of the photonic crystal structure and obtain a non-densely packed photonic crystal structure color-forming fabric with bright colors and iridescent effect.

[0072] Example 6

[0073] A method for preparing a non-densely packed photonic crystal structure color-producing fabric, comprising the following steps:

[0074] (1) The assembly working solution is composed of: 30% of 270 nm PS@P(MMA-BA) nanospheres, 4.0% of glycerol, and the balance of water, based on 100% by weight of the assembly working solution;

[0075] (2) Applying an assembly working solution with a solid content of 30 wt% to the surface of a PVC-modified polyester / ammonia blended fabric by a doctor blade method, and placing the fabric under 80°C for assembly for 2 min. When the apparent water content is completely evaporated, the assembly is completed.

[0076] (3) The assembled photonic crystal structured chromogenic fabric was placed in a 95°C oven for 3 min to remove water, so that the water inside the photonic crystal was fully evaporated and the microspheres were induced to move toward a regularly arranged structure;

[0077] (4) The photonic crystal structure color-forming fabric that has undergone the dehydration process is placed in a 140°C oven for a 2-minute brightening process. This process can further improve the regularity of the photonic crystal structure and obtain a non-densely packed photonic crystal structure color-forming fabric with bright colors and iridescent effect.

[0078] Example 7

[0079] A method for preparing a non-densely packed photonic crystal structure color-producing fabric, comprising the following steps:

[0080] (1) The assembly working solution is composed of 20% of 200 nm PS@P(MMA-BA) nanospheres, 2.0% of propylene glycol, and the balance of water, based on 100% by weight of the assembly working solution;

[0081] (2) Applying an assembly working solution with a solid content of 20 wt% to the surface of a PVC-modified polyester / ammonia blended fabric by spraying, and placing the fabric at 60°C for assembly for 6 min. When the surface moisture completely evaporates, the assembly is completed;

[0082] (3) The assembled photonic crystal structured chromogenic fabric was placed in an oven at 100°C for 4 minutes for dehydration treatment to fully evaporate the water inside the photonic crystal and induce the microspheres to move toward a regularly arranged structure;

[0083] (4) The photonic crystal structure color-forming fabric that has undergone the dehydration process is placed in a 140°C oven for a 2-minute brightening process. This process can further improve the regularity of the photonic crystal structure and obtain a non-densely packed photonic crystal structure color-forming fabric with bright colors and iridescent effect.

[0084] Example 8

[0085] A method for preparing a non-densely packed photonic crystal structure color-producing fabric, comprising the following steps:

[0086] (1) The composition of the assembly working solution is as follows: based on the weight of the assembly working solution as 100%, the assembly working solution contains 40% of 295 nm PS@P(MMA-BA) nanospheres, 4.0% of glycerol, and the balance of water;

[0087] (2) Applying an assembly working solution with a solid content of 40 wt% to the surface of the polyester fabric by a doctor blade method, and placing it at 60°C for 6 min. When the apparent water completely evaporates, the assembly is completed;

[0088] (3) The assembled photonic crystal structured chromogenic fabric was placed in an oven at 100°C for 4 minutes for dehydration treatment to fully evaporate the water inside the photonic crystal and induce the microspheres to move toward a regularly arranged structure;

[0089] (4) The photonic crystal structure color-forming fabric that has undergone the dehydration process is placed in a 140°C oven for a 2-minute brightening process. This process can further improve the regularity of the photonic crystal structure and obtain a non-densely packed photonic crystal structure color-forming fabric with bright colors and iridescent effect.

[0090] Comparative Example 1

[0091] A method for preparing a non-densely packed photonic crystal structure color-producing fabric, comprising the following steps:

[0092] (1) The composition of the assembly working solution is as follows: based on the weight of the assembly working solution as 100%, 30% of 270 nm PS@P(MMA-BA) nanospheres and the balance of water to form the assembly working solution;

[0093] (2) Applying an assembly working solution with a solid content of 30 wt% to the surface of a PVC-modified polyester / ammonia blended fabric by a doctor blade method, and placing the fabric under 80°C for assembly for 2 min. When the apparent water content is completely evaporated, the assembly is completed.

[0094] (3) The assembled photonic crystal structure color-forming fabric was placed in a 95°C oven for 3 minutes for dehydration treatment to fully evaporate the water inside the photonic crystal and induce the microspheres to move toward a regularly arranged structure.

[0095] (4) The photonic crystal structure color-forming fabric that has undergone the dehydration process is placed in a 140°C oven for a 2-minute brightening process. This process can further improve the regularity of the photonic crystal structure and obtain a non-densely packed photonic crystal structure color-forming fabric with bright colors and iridescent effect.

[0096] Comparative Example 2

[0097] A method for preparing a non-densely packed photonic crystal structure color-producing fabric, comprising the following steps:

[0098] (1) The assembly working solution is composed of: 30% of 270 nm PS@P(MMA-BA) nanospheres, 4.0% of glycerol, and the balance of water, based on 100% by weight of the assembly working solution;

[0099] (2) The assembly working solution with a solid content of 30 wt% was applied to the surface of the PVC-modified polyester-ammonia blended fabric by a doctor blade method, and the fabric was assembled at 80°C for 2 min. When the surface moisture was completely evaporated, the assembly was completed.

[0100] Comparative Example 3

[0101] A method for preparing a non-densely packed photonic crystal structure color-producing fabric, comprising the following steps:

[0102] (1) The assembly working solution is composed of: 30% of 270 nm PS@P(MMA-BA) nanospheres, 4.0% of glycerol, and the balance of water, based on 100% by weight of the assembly working solution;

[0103] (2) Applying an assembly working solution with a solid content of 30 wt% to the surface of a PVC-modified polyester / ammonia blended fabric by a doctor blade method, and placing the fabric under 80°C for assembly for 2 min. When the apparent water content is completely evaporated, the assembly is completed.

[0104] (3) The assembled photonic crystal structure color-forming fabric was placed in a 95°C oven for 3 minutes for dehydration treatment to fully evaporate the water inside the photonic crystal and induce the microspheres to move toward a regularly arranged structure.

[0105] Comparative Example 4

[0106] A method for preparing a non-densely packed photonic crystal structure color-producing fabric, comprising the following steps:

[0107] (1) The assembly working solution is composed of: 30% of 270 nm PS@P(MMA-BA) nanospheres, 4.0% of glycerol, and the balance of water, based on 100% by weight of the assembly working solution;

[0108] (2) Applying an assembly working solution with a solid content of 30 wt% to the surface of a PVC-modified polyester / ammonia blended fabric by a doctor blade method, and placing the fabric under 80°C for assembly for 2 min. When the apparent water content is completely evaporated, the assembly is completed.

[0109] (3) The assembled photonic crystal structured chromogenic fabric was placed in a 95°C oven for 3 min to remove water, so that the water inside the photonic crystal was fully evaporated and the microspheres were induced to move toward a regularly arranged structure;

[0110] (4) The photonic crystal structure color-forming fabric that has undergone the dehydration process is placed in a 90°C oven for a 2-minute brightening process. This process can further improve the regularity of the photonic crystal structure and obtain a non-densely packed photonic crystal structure color-forming fabric with bright colors and iridescent effect.

[0111] The digital photo of the assembly working solution constructed in Example 1 is shown in Figure 1 The nanospheres in this system have a high volume share. Relying on the high negative charge on the surface of the microspheres themselves, they can be arranged into a regular liquid photonic crystal structure in the aqueous phase, showing structural color.

[0112] The optical photograph of the assembly working solution constructed in Example 2 is shown in Figure 2 The prepared liquid photonic crystal has a beautiful structural color effect and excellent dynamic recovery, and can quickly return to its initial color state under external disturbance.

[0113] The reflectivity curve of the photonic crystal structure color-producing fabric prepared in Example 3 is shown in FIG. Figure 3 As shown in the figure, the reflection peak is high and narrow, proving that its structural color has high brightness and saturation.

[0114] The self-assembly process of the photonic crystal in Example 4 is shown in FIG. Figure 4 , which can demonstrate the rapid preparation of photonic crystal structured chromogenic fabrics.

[0115] The SEM image of the photonic crystal structure color-producing fabric prepared in Example 5 is shown in Figure 5 As shown in the figure, the photonic crystals assembled by nanospheres have excellent structural regularity.

[0116] The photonic crystal structure color-producing fabric prepared in Example 6 is shown in FIG. Figure 6 The photonic crystal structure color-producing fabric prepared by the blade coating method has bright and uniform colors.

[0117] The photonic crystal structure color-producing fabric prepared in Example 7 is shown in FIG. Figure 7 The photonic crystal structure color-producing fabric prepared by spraying has bright and uniform colors.

[0118] The non-close-packed photonic crystal structure color-producing fabric prepared in Example 8 is shown in FIG. Figure 8 The prepared non-densely packed photonic crystal structured color-producing fabric has an obvious iridescent effect and excellent toughness, that is, high structural stability.

[0119] The optical photograph of the photonic crystal structure color-producing fabric prepared in Comparative Example 1 is shown in Figure 9 Compared with Example 6, in Comparative Example 1, no high-boiling-point solvent was added to the assembly working solution, which would cause the microspheres to assemble too quickly and produce larger cracks in the prepared non-close-packed photonic crystal structure color-forming fabric;

[0120] The optical photograph of the photonic crystal structure color-producing fabric prepared in Comparative Example 2 is shown in FIG. Figure 10 a. Compared with Example 6, Comparative Example 2 did not perform the water removal process and the brightening process. It can be seen that the color saturation and brightness of the prepared non-close-packed photonic crystal structure are very low;

[0121] The optical photograph of the photonic crystal structure color-producing fabric prepared in Comparative Example 3 is shown in Figure 10 b, compared with Example 6, Comparative Example 3 did not perform the brightening process, and it can be seen that the color of the non-close-packed photonic crystal structure color-producing fabric prepared is brighter than that of the fabric without the water removal process ( Figure 10 a) has high color brightness, but is better than the structural color-producing fabric ( Figure 10 c) low brightness;

[0122] The digital photo of the photonic crystal structure color-producing fabric prepared in Comparative Example 4 is shown in Figure 11 a. Compared with Example 6, the brightening process temperature of Comparative Example 4 is lower, and it can be seen that the color of the prepared non-close-packed photonic crystal structure color-producing fabric is Figure 11 b has a lower degree of improvement compared to the previous one.

[0123] In summary, the present invention achieves the rapid, large-scale production of color-producing fabrics with non-densely packed photonic crystal structures by constructing an assembly working solution, applying the assembly working solution to the fabric surface, and then undergoing a three-stage process: assembly, sufficient water removal, and brightening. This method is simple and efficient, and can be implemented using conventional textile dyeing and finishing equipment and methods. The constructed photonic crystals combine high structural stability (high color fastness) with high color saturation, exhibiting a significant iridescent effect, among other characteristics.

[0124] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. Reference can be made to the descriptions of the identical or similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and the relevant parts can be referred to the descriptions of the methods.

[0125] The above describes in detail the non-close-packed photonic crystal structure color-forming fabric and its preparation method provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above examples is intended only to facilitate understanding of the method and core concept of the present invention. It should be noted that those skilled in the art may make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a non-close-packed photonic crystal structure color-producing fabric, characterized in that The method comprises the following steps: S1 construction assembly working solution The assembly working solution comprises: based on 100% by weight of the assembly working solution, 15-40% of nano-microspheres with a hard core-soft shell structure, 2.0-6.0% of a high boiling point solvent, and the balance of water; S2: applying the assembly working liquid and completing the assembly: applying the assembly working liquid evenly to the surface of the fabric, and assembling at a temperature of 50-80°C for 2-10 minutes. When the apparent moisture is completely evaporated, the assembly is completed; S3 dehydration process: the assembled photonic crystal structure color-forming fabric is placed in an oven for full dehydration treatment, so that the water inside the photonic crystal is fully evaporated and the microspheres are induced to move toward a highly regular arrangement structure; The process conditions for water removal treatment are temperature 90-100°C and time 1-5 min; S4 brightening process: The photonic crystal structure color-forming fabric obtained by the water removal process is placed in a high-temperature oven for brightening treatment to further improve the regularity of the photonic crystal structure, thereby obtaining a non-densely packed photonic crystal structure color-forming fabric with bright colors and significant iridescent effect; The process conditions for brightening treatment are temperature 110-140℃, time 2-10 min; The hard-core-soft-shell nanospheres have an inner core of any one of highly cross-linked polystyrene (PS), polymethyl methacrylate (PMMA), polymethacrylic acid (PMAA), poly(styrene-methyl methacrylate) (P(St-MMA)), or poly(styrene-methacrylic acid) (P(St-MAA)), and a shell of any one of soft and hard monomer copolymers of poly(butyl acrylate-methyl methacrylate) (P(MMA-BA)), poly(hydroxyethyl acrylate-hydroxyethyl methacrylate) (P(HEA-HEMA)), or poly(ethyl acrylate-methacrylic acid) (P(EA-MAA)). The high boiling point solvent is selected from one or a mixture of glycerol, propylene glycol, formamide, ethylene glycol, fatty alcohol polyoxyethylene ether or fatty acid polyoxyethylene ester.

2. The preparation method according to claim 1, wherein: The fabric is polyester fabric, spandex fabric, polyester-spandex blended fabric, cotton fabric or polyester-cotton blended fabric; the fabric is a surface-modified fabric or an unmodified fabric with a smooth surface and a tight structure, and the fabric modification material is selected from polyacrylate, polyurethane, polydimethylsiloxane, ethylene oxide or PVC.

3. The preparation method according to claim 1, wherein: The non-close-packed photonic crystal structure is a non-closely-packed skeleton structure constructed by a hard core, and a continuous phase embedded in the skeleton is formed by the fusion of soft shells, wherein the sum of the volume ratios of the hard core and the soft shell is 100%, and the proportion of the soft shell is 30-60%.

4. The preparation method according to claim 1, wherein: The assembly working fluid is applied to the fabric by a doctor blade coating method, a spray coating method, a screen printing method or a digital printing method.

5. A non-close-packed photonic crystal structure color-producing fabric obtained by the preparation method according to claim 1.

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