A structural color pattern with a visual three-dimensional effect and its preparation method

Abstract

This invention discloses a structural color pattern with a visually three-dimensional effect and its preparation method, comprising the following steps: dispersing two or more monodisperse PS nanospheres with different particle sizes in water to obtain two or more nanosphere dispersions; attaching a mask with a partitioned hollow structure to a substrate surface; spraying the two or more nanosphere dispersions onto the corresponding hollow areas of the mask according to a preset pattern and partition design; after drying, the nanospheres in each partition on the substrate surface spontaneously and orderly assemble to form a photonic crystal coating, thereby obtaining a structural color pattern with a visually three-dimensional effect. Before spraying the coating, this invention uses a mask to partition the target substrate, designs the color to be represented in each partition, and, based on artistic principles, ensures that the combination of each color partition after spraying reflects one or more of the perspective effect, light and shadow effect, and occlusion relationship required for a three-dimensional effect in a planar image, thus achieving a three-dimensional visual effect for the structural color pattern.

Description

Technical Field

[0001] This invention relates to the field of photonic crystal patterning technology, specifically to a structural color pattern with a visual three-dimensional effect and its preparation method. Background Technology

[0002] Structural color refers to the selective reflection of light through the interaction between light and the microstructure of a material. This reflection is perceived by the human eye, forming a psychological response and being recognized as a color related to the wavelength of light. The physical principle behind this is that photonic crystals, composed of nanostructures of materials with different dielectric constants arranged periodically, possess photonic band gaps and can diffract light. Compared to traditional chemical dyeing, photonic crystal structural color is environmentally friendly and has become a new trend in research and technological improvement related to color, coatings, fibers, and fabrics.

[0003] The preparation of colored products using structural color materials and technologies mainly focuses on: 1) improving color purity and saturation; 2) enhancing color uniformity over a wide range, i.e., eliminating color difference; and 3) utilizing the angle dependence of photonic crystals to achieve the display of color changes dependent on angle, such as in anti-counterfeiting applications. In the application of colors and patterns, differentiated display effects are also a technological pursuit, such as the application of three-dimensional effects in planar patterns. This type of application is extremely common in mature chemically dyed products, but it has not been reported in research and technical reports related to structural colors. Achieving the visual three-dimensionality of planar patterns involves using changes in color and lines within planar space to create a psychological response that conforms to human experience and cognition, visually reflecting a three-dimensional spatial displacement perception.

[0004] In this technical field, from a raw material perspective, the materials used to create visual three-dimensional effects through planar patterns or coatings are mainly traditional chemical dyes or carbon materials; from a technical perspective, there are currently no patterns or coatings specifically designed to create three-dimensional effects for artificial structural color materials. Currently, the main methods for preparing patterned structural colors are inkjet printing and spraying.

[0005] Inkjet printing of photonic crystals is one of the effective ways to industrialize photonic crystal structural colors, and it is environmentally friendly, energy-saving, and easy to operate. Researchers have already explored ink composition and its influencing factors, proposing various solutions to improve color effects and enhance structural stability. Inkjet printing of photonic crystal structural colors has profound application prospects in printing, textiles, information technology, electronics, and medical fields. However, from a technical perspective, current common inkjet printing equipment is geared towards printer inks, which are molecular-level dispersion systems with good dispersibility and no sedimentation. Photonic crystal dispersions, on the other hand, have relatively poor dispersion stability, and their rheological properties are not well matched to current common inkjet printing equipment, making it difficult to achieve multi-head, multi-color printing.

[0006] The spray coating method involves adding a colloidal suspension to a spray gun, maintaining a certain distance between the spray gun and the fabric surface, and then using a high-pressure pump to atomize the suspension. Due to the jetting action, the solvent in the suspension evaporates rapidly, allowing the colloidal particles to quickly form a low-angle-dependent amorphous photonic crystal structure on the fabric surface. This method significantly shortens the assembly time of microspheres on the fabric surface. Currently, most methods for preparing structural color coatings focus on spray coating, but these methods generally aim for overall coating, pursuing uniformity and stability within a certain area.

[0007] In summary, one of the main drawbacks of inkjet printing is that the faster evaporation rate at the edges and the "coffee ring" effect caused by the ink gathering through capillary action result in different shades of color in areas where the pattern should be the same, and it is difficult to achieve multi-head multi-color printing. The overall coating of the spraying method cannot create visual errors through line and color contrast. Currently common structural color patterns have no color partitioning or the partitioning lacks contrast design, resulting in no visual three-dimensional effect.

[0008] Therefore, combining structural color preparation technology with the design of planar patterns to achieve three-dimensional effects (perspective, light and shadow layout, color difference adjustment, occlusion relationship) creates a new method for preparing structural color patterns with visual three-dimensional effects. This not only promotes the application of structural colors but also provides an environmentally friendly improvement solution for the application of three-dimensional effects in planar patterns. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a structural color pattern with a visual three-dimensional effect and its preparation method. Before spraying the coating, the target substrate is divided into sections using a mask, and the color to be reflected in each section is designed. Based on art principles, the combination of each color section after spraying reflects one or more of the perspective effect, light and shadow effect, and occlusion relationship required for the three-dimensional effect of the planar image, so that the structural color pattern achieves a three-dimensional visual effect.

[0010] To address the aforementioned technical problems, this invention provides a method for preparing a structural color pattern with a visual three-dimensional effect, comprising the following steps:

[0011] S1. Disperse two or more monodisperse PS nanospheres with different particle sizes in water to obtain two or more nanosphere dispersions.

[0012] S2. A photomask with a partitioned, hollowed-out structure is attached to the substrate surface. According to a preset pattern and partition design, two or more nanosphere dispersions are sprayed onto the corresponding hollowed-out areas of the photomask. After drying, the nanospheres in each partition on the substrate surface spontaneously and orderly assemble to form a photonic crystal coating, resulting in a structural color pattern with a visually three-dimensional effect. Specifically, the visually three-dimensional effect is achieved based on the principles of artistic perspective, shadow construction, color partitioning, and color matching.

[0013] This invention utilizes the cutout positions of a mask to achieve partitioning, and uses the mask partitioning to achieve the deposition of different structural colors in different areas; the reasonable setting of structural color partitions enables different partitions to achieve artistic perspective effects, light and shadow intensity effects, and occlusion effects in terms of color and lines, so that the structural color pattern presents a visual three-dimensional effect, which is more vivid and realistic.

[0014] Furthermore, the PS nanospheres have a particle size of 180-260 nm and a PDI < 0.05.

[0015] Furthermore, the concentration of the nanosphere dispersion is 6-10 wt%.

[0016] Furthermore, the preparation method of the PS nanospheres is as follows:

[0017] Styrene (St), acrylic acid (AA), and water were mixed and heated. Potassium persulfate (KPS) and sodium dodecyl sulfate (SDS) were then added to react and obtain the PS microspheres.

[0018] Furthermore, the volume ratio of styrene to acrylic acid is (15-25):1; the mass ratio of potassium persulfate to sodium dodecyl sulfate is (6-8):1.

[0019] Furthermore, the volume-to-mass ratio of styrene to potassium persulfate is 20 mL: (0.1-0.2) g. Different sizes of PS microspheres were prepared by adjusting the amounts of St, KPS, and SDS to achieve different structural colors.

[0020] Furthermore, the heat treatment involves heating to 90-110°C.

[0021] Furthermore, the spraying conditions are: spray gun pressure 0.15-0.3 MPa.

[0022] Furthermore, the drying condition is room temperature.

[0023] Furthermore, the substrate is one of paper, fabric, plastic, metal, ceramic, or wood.

[0024] The beneficial effects of this invention are:

[0025] This invention utilizes the cutouts in a mask to create partitions, and uses these partitions to achieve the deposition of different structural colors in different areas. By setting up structural color partitions, different partitions can achieve artistic perspective effects, light and shadow effects, and occlusion effects in terms of color and lines, making the structural color patterns present a visual three-dimensional effect that is more vivid and realistic. On the one hand, it serves as a color coating that distinguishes structural colors from chemical dyes; on the other hand, the differentiated pattern construction expands and enriches the practical application scenarios of structural colors.

[0026] This invention employs a simple spraying technique, which is easy and safe to operate. By using a hollowed-out partition in the mask, it avoids multi-head printing as is common in inkjet printing, thus reducing reliance on equipment and lowering costs. Attached Figure Description

[0027] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a photograph of a structural color pattern with a visual three-dimensional effect obtained in Embodiment 1 of the present invention;

[0029] Figure 2 This is a photograph of a structural color pattern with a visual three-dimensional effect obtained in Embodiment 1 of the present invention;

[0030] Figure 3 This is a photograph of a structural color pattern with a visual three-dimensional effect obtained in Embodiment 1 of the present invention;

[0031] Figure 4 This is a photograph of a structural color pattern with a visual three-dimensional effect obtained in Embodiment 1 of the present invention;

[0032] Figure 5 This is a photograph of a structural color pattern with a visual three-dimensional effect obtained in Embodiment 2 of the present invention;

[0033] Figure 6 This is a multi-point perspective schematic diagram of the structural color pattern with a visual three-dimensional effect obtained in Embodiment 2 of the present invention;

[0034] Figure 7 This is a photograph of the planar pattern obtained in Comparative Example 1 of the present invention. Detailed Implementation

[0035] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] This embodiment relates to a method for preparing a structural color pattern with a visual three-dimensional effect, comprising the following steps:

[0037] S1. Disperse two or more monodisperse PS nanospheres with different particle sizes in water to obtain two or more nanosphere dispersions.

[0038] S2. A photomask with a partitioned, hollowed-out structure is attached to the substrate surface. According to a preset pattern and partition design, two or more nanosphere dispersions are sprayed onto the corresponding hollowed-out areas of the photomask. After drying, the nanospheres in each partition on the substrate surface spontaneously and orderly assemble to form a photonic crystal coating, resulting in a structural color pattern with a visually three-dimensional effect. Specifically, the visually three-dimensional effect is achieved based on the principles of artistic perspective, shadow construction, color partitioning, and color matching.

[0039] This embodiment utilizes the cutout positions of the mask to achieve partitioning, and uses the mask partitioning to achieve the deposition of different structural colors in different areas; the reasonable setting of structural color partitions enables different partitions to achieve artistic perspective effects, light and shadow intensity effects, and occlusion effects in terms of color and lines, so that the structural color pattern presents a visual three-dimensional effect, which is more vivid and realistic.

[0040] In a preferred embodiment, the PS nanospheres have a particle size of 180-260 nm and a PDI < 0.05. The concentration of the nanosphere dispersion is 6-10 wt%.

[0041] In a preferred embodiment, the PS nanospheres are prepared by mixing styrene (St), acrylic acid (AA), and water, heating the mixture, and then adding potassium persulfate (KPS) and sodium dodecyl sulfate (SDS) to react and obtain the PS nanospheres. Preferably, the volume ratio of styrene to acrylic acid is (15-25):1; the mass ratio of potassium persulfate to sodium dodecyl sulfate is (6-8):1; and the volume-to-mass ratio of styrene to potassium persulfate is 20 mL: (0.1-0.2) g. PS nanospheres of different sizes can be prepared by adjusting the amounts of St, KPS, and SDS to exhibit different structural colors.

[0042] In a preferred embodiment, the heat treatment is performed at 90-110°C; the spraying conditions are: spray gun pressure 0.15-0.3 MPa; and the drying conditions are at room temperature.

[0043] In a preferred embodiment, the substrate is one of paper, fabric, plastic, metal, ceramic, or wood.

[0044] Example 1

[0045] This embodiment relates to a method for preparing a structural color pattern with a visual three-dimensional effect, comprising the following steps:

[0046] (1) Preparation of 180 nm PS microspheres (used to prepare blue photonic crystal coating):

[0047] 20 mL of styrene and 1.0 mL of acrylic acid were placed in a three-necked flask, and 100 mL of pure water was added. The oil bath temperature was controlled at 100 °C, and the mixture was mechanically stirred at 280 r / min for 10 min. Then, 0.15 g of potassium persulfate and 0.02 g of sodium dodecyl sulfate were added, and the mixture was stirred continuously for two hours to obtain the product. The product was washed four times by centrifugation with alcohol and pure water. Finally, the product was dried to obtain PS microspheres with a particle size of 180 nm (PDI < 0.05) powder for later use.

[0048] (2) Preparation of 200 nm PS microspheres (for preparing green photonic crystal coating):

[0049] 20 mL of styrene and 1.0 mL of acrylic acid were placed in a three-necked flask, and 100 mL of pure water was added. The oil bath temperature was controlled at 100 ℃, and the mixture was mechanically stirred at 280 r / min for 10 min. Then, 0.12 g of potassium persulfate and 0.02 g of sodium dodecyl sulfate were added, and the mixture was stirred continuously for two hours to obtain the product. The product was washed four times by centrifugation with alcohol and pure water. Finally, the product was dried to obtain PS microspheres with a particle size of 200 nm (PDI < 0.05) powder for later use.

[0050] (3) Preparation of 240 nm PS microspheres (used to prepare a red photonic crystal coating):

[0051] 20 mL of styrene and 1.0 mL of acrylic acid were placed in a three-necked flask, and 100 mL of pure water was added. The oil bath temperature was controlled at 100 ℃, and the mixture was mechanically stirred at 280 r / min for 10 min. Then, 0.09 g of potassium persulfate and 0.02 g of sodium dodecyl sulfate were added, and the mixture was stirred continuously for two hours to obtain the product. The product was washed four times by centrifugation with alcohol and pure water. Finally, the product was dried to obtain PS microspheres with a particle size of 240 nm (PDI < 0.05) powder for later use.

[0052] (4) Disperse the PS microspheres obtained in steps (1)-(3) in water and add 0.25wt% carbon black to obtain three 8wt% nano-microsphere dispersions.

[0053] (5) A photomask with a partitioned, hollowed-out structure is attached to the substrate surface. According to the preset pattern and partition design, a nanosphere dispersion is sprayed onto the corresponding hollowed-out areas of the photomask. After drying, the nanospheres in each partition on the substrate surface spontaneously and orderly assemble to form a photonic crystal coating, resulting in a structural color pattern with a visually three-dimensional effect. The results are shown in [Figure number missing]. Figure 1-4 .in, Figure 1 The substrate is a black, densely woven twill fabric, coated with 180nm and 240nm PS microsphere dispersions by partitioning. Figure 2The substrate is black needle-punched nonwoven fabric, and 180nm PS microsphere dispersion is sprayed in sections. Figure 3-4 The substrate is white meltblown nonwoven fabric, and it is coated with 200nm and 240nm PS microsphere dispersions in separate sections.

[0054] Example 2

[0055] This embodiment relates to a method for preparing a structural color pattern with a visual three-dimensional effect, comprising the following steps:

[0056] 200nm and 240nm PS microsphere dispersions were prepared according to Example 1, and structural color patterns with a visual three-dimensional effect were obtained by partial spraying using a mask. Figure 5 The constructed color partitions incorporate the principles of multi-point perspective and color difference creation from art theory, for reference. Figure 6 .

[0057] Comparative Example 1

[0058] Referring to Example 1, by adjusting the amount of St used during the sphere assembly, the particle size of PS nanospheres can be controllably adjusted to obtain PS nanospheres of 180, 190, and 200 nm (blue, yellow-green, and green), thereby achieving color control of the PS spheres. The prepared solution was sprayed onto the fabric through a template using a spraying device. After completing one layer of patterning, it was dried in a 60 °C oven for 5 minutes, and then the spraying and drying process was repeated three times. The results are as follows... Figure 7 As shown, the entire spraying process is simple, but the color rendering effect is average, with uneven and unclear colors.

[0059] In summary, this invention utilizes the cutouts in a mask to achieve partitioning, and uses these partitions to achieve the deposition of different structural colors in different areas. The structural color partitioning allows for artistic perspective effects, light and shadow effects, and masking effects in different areas, resulting in a more vivid and realistic three-dimensional visual effect for the structural color pattern. Furthermore, it distinguishes structural colors from chemical dyes. The invention employs a simple spraying technique, making operation convenient and safe. The cutout partitions in the mask avoid the need for multiple printheads in inkjet printing, reducing reliance on equipment and lowering costs.

[0060] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A method for preparing a structural color pattern with a visual three-dimensional effect, characterized in that, Includes the following steps: S1. Disperse two or more monodisperse PS nanospheres with different particle sizes in water to obtain two or more nanosphere dispersions. S2. A mask with a partitioned hollow structure is attached to the substrate surface. According to the preset pattern and partition design, the two or more nanosphere dispersions are sprayed onto the corresponding hollow areas of the mask. After drying, the nanospheres in each partition on the substrate surface spontaneously and orderly assemble to form a photonic crystal coating, resulting in a structural color pattern with a visual three-dimensional effect.

2. The method for preparing a structural color pattern with a visual three-dimensional effect as described in claim 1, characterized in that, The PS nanospheres have a particle size of 180-260 nm and a PDI < 0.

05.

3. The method for preparing a structural color pattern with a visual three-dimensional effect as described in claim 1, characterized in that, The concentration of the nanosphere dispersion is 6-10 wt%.

4. The method for preparing a structural color pattern with a visual three-dimensional effect as described in claim 1, characterized in that, The preparation method of the PS nanospheres is as follows: Styrene, acrylic acid, and water were mixed, heated, and then potassium persulfate and sodium dodecyl sulfate were added to react and obtain the PS microspheres.

5. The method for preparing a structural color pattern with a visual three-dimensional effect as described in claim 4, characterized in that, The volume ratio of styrene to acrylic acid is (15-25):1; the mass ratio of potassium persulfate to sodium dodecyl sulfate is (6-8):

1.

6. The method for preparing a structural color pattern with a visual three-dimensional effect as described in claim 4, characterized in that, The volume-to-mass ratio of styrene to potassium persulfate is 20 mL: (0.1-0.2) g.

7. The method of producing a structural color pattern with a visual stereoscopic effect according to claim 4, wherein The heat treatment involves heating to 90-110℃.

8. The method of producing a structural color pattern with a visual stereoscopic effect according to claim 1, wherein The spraying conditions are: spray gun pressure 0.15-0.3MPa.

9. The method of producing a structural color pattern with a visual stereoscopic effect according to claim 1, wherein The drying condition is room temperature.

10. The method of producing a structural color pattern with a visual stereoscopic effect according to claim 1, wherein The substrate is one of paper, fabric, plastic, metal, ceramic, or wood.

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