Dyeing microsphere emulsion for structural color layer, microspheres and constructed structural color layer

Abstract

The invention relates to the technical field of structural color decoration, and particularly discloses a dyeing microsphere emulsion for a structural color layer, microspheres and a constructed structural color layer. The preparation method of the dyeing microsphere emulsion comprises the following steps: mixing ammonium persulfate, sodium dodecyl benzene sulfonate, water and ethanol, adding a styrene monomer under stirring and oil bath heating, and obtaining a PSt microsphere emulsion after the reaction is finished; mixing the PSt microsphere emulsion with the disperse dye liquor, and reacting in a boiling state to obtain a dyed PSt microsphere emulsion; and performing centrifugal cleaning on the dyed PSt microsphere emulsion for multiple times to obtain the dyed microsphere emulsion for the structural color layer. And coating and spreading the structural color layer on the surface of the base material by using the dyeing microsphere emulsion, and drying to obtain the structural color layer. According to the invention, the color decoration of a structural color layer constructed by white microspheres such as PSt microspheres during diffuse reflection can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of structural color decoration, and in particular to a dyeing microsphere emulsion for a structural color layer, a microsphere and a constructed structural color layer. BACKGROUND

[0002] In nature, there are two ways of coloring, pigment color and structural color. Structural color is the color produced by the periodic arrangement of the surface structure of a substance. Compared with pigment color, structural color is more brilliant, has high color saturation, and will not fade as long as the periodic ordered structure does not change, showing good durability. In recent years, artificial structural coloring technology has been widely studied and used in decoration, display, anti-counterfeiting, sensing, textiles and other fields.

[0003] In related technologies, three-dimensional photonic crystals are a kind of microstructure that can produce structural color and are widely studied. Using colloidal microspheres as raw materials, three-dimensional photonic crystal structures can be quickly constructed by a "bottom-up" self-assembly method. When the forbidden band characteristic region of the photonic crystal is within the visible light wavelength range, the reflected visible light color can be observed. The coloring effect of the photonic crystal is usually bright and brilliant, with high color saturation. The forbidden band characteristics of amorphous photonic crystals are greatly weakened, and it is often necessary to add black substances or directly synthesize microspheres with black substances to improve the light absorption capacity of amorphous photonic crystals, so as to show a dull color. According to the Bragg diffraction equation, when the angle between the incident light and the reflected light changes, the wavelength responded by the photonic crystal will also change. This coloring with angle dependence is called iridescence effect.

[0004] Although the photonic crystal with iridescence effect exhibits beautiful and varied colors, such coloring is usually under the condition that the angle of the incident light and the angle of observation (the angle of the reflected light) are not much different, i.e. under the condition of normal reflection. When the angle of observation is greatly different from the angle of the incident light, the color observed is the diffuse reflection color of the structural color layer, i.e. the color of the building block. In the diffuse reflection state, the structural color layer constructed by white microspheres such as PSt or SiO2 exhibits a grayish white color. That is, the color decoration of the structural color layer constructed by white microspheres is poor in the diffuse reflection state. SUMMARY

[0005] In order to improve the color decoration of the structural color layer constructed by white microspheres in the diffuse reflection state, the present application provides a dyeing microsphere emulsion for a structural color layer, a microsphere and a constructed structural color layer.

[0006] In a first aspect, the present application provides a preparation method of a dyeing microsphere emulsion for a structural color layer, which adopts the following technical scheme:

[0007] The preparation method of the dyeing microsphere emulsion for a structural color layer comprises the following steps:

[0008] S1, ammonium persulfate, sodium dodecyl benzene sulfonate, water and ethanol are mixed, under stirring and oil bath heating, styrene monomer is added, the reaction is kept under stirring and oil bath heating, after the reaction is completed, a PSt microsphere emulsion is obtained;

[0009] S2, the PSt microsphere emulsion is mixed with a disperse dye dyeing solution, under stirring, the oil bath is heated to boiling state, the reaction is kept under boiling state, after the reaction is completed, the temperature is lowered to room temperature, a dyed PSt microsphere emulsion is obtained;

[0010] S3, the dyed PSt microsphere emulsion is centrifuged, solid-liquid separation is carried out, the upper liquid and microsphere solids are obtained, water is added to the microsphere solids, after ultrasonic oscillation, emulsion-1 is obtained;

[0011] S4, the upper liquid is formed into emulsion-2 according to the above S3 step, emulsion-1 and emulsion-2 are combined, a mixed emulsion is obtained, the mixed emulsion is obtained according to the above S3 step, and a structural color layer dyed microsphere emulsion is obtained.

[0012] In one specific implementation, the average particle size of the PSt microspheres in the PSt microsphere emulsion is 180-280 nm.

[0013] In a second aspect, the application provides a structural color layer dyed microsphere, which adopts the following technical solution:

[0014] A structural color layer dyed microsphere, the above structural color layer dyed microsphere emulsion is dried to obtain a structural color layer dyed microsphere.

[0015] In a third aspect, the application provides a preparation method of a structural color layer, which adopts the following technical solution:

[0016] A preparation method of a structural color layer, comprising the following steps:

[0017] The structural color layer dyed microsphere emulsion is coated and spread on the surface of the substrate, and dried to obtain a structural color layer.

[0018] In one specific implementation, the surface of the substrate is ground and purged in advance, and then the dyed microsphere emulsion is coated and spread on the surface of the substrate.

[0019] In summary, the application has the following beneficial effects:

[0020] 1, the method of the application can prepare PSt microspheres dyed with color dyes, PSt microsphere emulsions and structural color layers constructed by dyed PSt microspheres.

[0021] 2, The maximum color proportion of the structural color layer constructed by the dyed PSt microspheres of the application is significantly improved, the coloration is more uniform, and the color is more bright. However, under the conditions of regular reflection, the color of the dye itself does not appear in the coloration of the structural color layer. The coloration effect of the structural color layer constructed by the dyed PSt microspheres is more abundant under the conditions of regular reflection and diffuse reflection than that of the white PSt microspheres without dyeing. It is helpful to improve the color decoration of the structural color layer constructed by white microspheres such as PSt microspheres under diffuse reflection. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The schematic diagram of the method for taking the regular reflection and diffuse reflection appearance for the characterization of the iridescence coloration performance in the performance test of the application is shown in the figure.

[0023] Figure 2 The working schematic diagram of the fiber optic spectrometer with self-made variable angle test sample table for the characterization of the iridescence coloration performance in the performance test of the application is shown in the figure.

[0024] Figure 3 The characterization result figure for the characterization of the microsphere appearance, particle size and coefficient of variation in the performance test of the application is shown in the figure.

[0025] Figure 4 The reflection spectrum figure for the characterization of the regular reflection coloration performance under the vertical light source in the performance test of the application is shown in the figure.

[0026] Figure 5 The macroscopic appearance figure for the characterization of the regular reflection coloration performance under the vertical light source in the performance test of the application is shown in the figure.

[0027] Figure 6 The regular reflection iridescence effect figure for the characterization of the iridescence coloration performance in the performance test of the application is shown in the figure.

[0028] Figure 7 The iridescence effect reflection spectrum figure for the characterization of the iridescence coloration performance in the performance test of the application is shown in the figure.

[0029] Figure 8 The diffuse reflection iridescence effect figure for the characterization of the iridescence coloration performance in the performance test of the application is shown in the figure.

[0030] Figure 9 The iridescence effect scattering spectrum figure for the characterization of the iridescence coloration performance in the performance test of the application is shown in the figure. DETAILED DESCRIPTION

[0031] The raw materials used in the application are commercially available, except for special instructions.

[0032] The styrene monomer was purchased from Shanghai Macklin. The ammonium persulfate and sodium dodecyl benzene sulfonate were purchased from Shanghai Lingfeng Chemical. The anhydrous ethanol was purchased from Nanjing Chemical Reagent Co., Ltd. The experimental water was ultrapure water, which was prepared in the laboratory by using a Plus-E3 ultrapure water machine (18.2 MΩ·cm, Nanjing EPED Co., Ltd.). The trembling poplar wood was provided by Alberta, Canada, and was placed in the atmospheric environment to maintain the air-dry moisture content of about 6%. Disperse Red 3B, Disperse Yellow Brown H2RL and Disperse Blue 2BLN dyes were purchased from the Taobao store "AICOLOR dyeing store".

[0033] The application will be further described in detail in combination with the examples and comparative examples.

[0034] Example

[0035] Example 1

[0036] The present example provides a preparation method of a dyeing microsphere emulsion for a structural color layer, comprising the following steps:

[0037] S1, 0.15 g of ammonium persulfate, 130 mg of sodium dodecyl benzene sulfonate, 100 mL of water and 40 mL of ethanol were added into a three-necked flask. The three necks of the flask were respectively equipped with a thermometer and a spherical condenser at the left and right necks, and a top-mounted stirrer was installed at the top neck and the rotation speed was set to 400 rpm. The three-necked flask was heated in the form of an oil bath until the temperature was in the range of 75-80℃, 18 g of styrene monomer was added, and the reaction was kept at a temperature in the range of 75-80℃ for 10 h under stirring to obtain a PSt microsphere emulsion with an average particle size of 256.8 nm.

[0038] S2, the PSt microsphere emulsion and the disperse dye dyeing solution were placed in a three-necked flask, the rotation speed of the top-mounted stirrer was set to 50 rpm, the condenser reflux device was set, the temperature was raised to 130℃ in the form of an oil bath, and the boiling state was kept for 2 h, then the temperature was lowered to room temperature, and a dyeing PSt microsphere emulsion was obtained. The volume ratio of the PSt microsphere emulsion to the disperse dye dyeing solution was 1:10. The disperse dye dyeing solution was a 1% (owf) aqueous solution of disperse red 3B.

[0039] S3, the dyeing PSt microsphere emulsion was placed in a table type high-speed centrifuge and centrifuged at 11000 r / min for 10 min, the solid-liquid was separated, the water was added to the microsphere solid, and the ultrasonic cleaning machine was placed in the ultrasonic cleaning machine, and the ultrasonic vibration was kept for 20 min to obtain emulsion-1.

[0040] S4, centrifuging, solid-liquid separation, adding water, and ultrasonic oscillation were performed on the upper layer liquid according to the step S3 to form an emulsion-2, the emulsion-1 and the emulsion-2 were combined to obtain a mixed emulsion, and centrifugation, solid-liquid separation, adding water, and ultrasonic oscillation were performed on the mixed emulsion according to the step S3 to obtain the dyeing microspheres for structural color layer.

[0041] The dyeing microspheres for structural color layer were prepared according to the following steps: drying the dyeing microspheres for structural color layer emulsion to obtain the dyeing microspheres for structural color layer.

[0042] The embodiment also provides a preparation method of the structural color layer, including the following steps:

[0043] The dyeing microspheres for structural color layer emulsion was coated and spread in a glass culture dish, and dried in a 50℃ air drying oven to obtain the structural color layer.

[0044] Example 2

[0045] The difference between the embodiment and the example 1 is that the step S1 is as follows: 0.15 g of ammonium persulfate, 140 mg of sodium dodecyl benzene sulfonate, 100 mL of water and 40 mL of ethanol were added into a three-necked flask. The three necks of the flask were respectively equipped with a thermometer and a spherical condenser at the left and right necks, and a top-mounted stirrer was arranged at the top neck and set at a speed of 400 rpm. The three-necked flask was heated in the form of an oil bath until the temperature was in the range of 70-75℃, 18 g of styrene monomer was added, and the reaction was maintained at a temperature in the range of 70-75℃ for 10 h under stirring to obtain a PSt microsphere emulsion with an average particle size of 221.7 nm of PSt microspheres.

[0046] Example 3

[0047] The difference between the embodiment and the example 1 is that the preparation method of the structural color layer in the embodiment is as follows:

[0048] The surface of the tremble poplar wood was treated by using a 400-mesh sand belt grinding, and the surface of the tremble poplar wood was blown by using compressed air to remove the attached wood powder. A line frame with a size of 3.5 cm×3.5 cm was drawn on the surface of the tremble poplar wood by using a pencil.

[0049] The dyeing microspheres for structural color layer emulsion was taken by using a pipette, and the emulsion was coated and spread in the line frame, and then the sample was smoothly moved into an air drying oven, and dried at 50℃ to obtain the structural color layer.

[0050] Example 4

[0051] The difference between the embodiment and the example 2 is that the preparation method of the structural color layer in the embodiment is as follows:

[0052] The surface of the poplar wood was treated by 400 mesh sand belt grinding, and the surface of the poplar wood was blown by compressed air to remove the attached wood powder. A 3.5 cm x 3.5 cm line frame was drawn on the surface of the poplar wood by a pencil.

[0053] The structural color layer was prepared by using a pipette to suck the structural color layer dyeing microsphere emulsion, spreading the emulsion in the line frame, and then smoothly moving the sample into a blow drying oven for drying at 50°C.

[0054] Example 5

[0055] The difference between this example and Example 1 is only that the S1 step is as follows: 0.15 g of ammonium persulfate, 135 mg of sodium dodecyl benzene sulfonate, 100 mL of water and 40 mL of ethanol were added into a three-necked flask. Thermometers and spherical condensers were arranged at the left and right openings of the three-necked flask, and an overhead stirrer was arranged at the top opening of the three-necked flask and set at a speed of 400 rpm. The three-necked flask was heated in the form of an oil bath until the temperature was in the range of 80-85°C, 18 g of styrene monomer was added, and the reaction was maintained at a temperature in the range of 80-85°C for 10 h under stirring to obtain a PSt microsphere emulsion with an average particle size of 230.0 nm of PSt microspheres.

[0056] In the S2 step, the dispersion dyeing solution was a water solution of Disperse Yellow Brown H2RL with a concentration of 1% (owf).

[0057] Example 6

[0058] The difference between this example and Example 1 is only that the S1 step is as follows: 0.15 g of ammonium persulfate, 175 mg of sodium dodecyl benzene sulfonate, 100 mL of water and 40 mL of ethanol were added into a three-necked flask. Thermometers and spherical condensers were arranged at the left and right openings of the three-necked flask, and an overhead stirrer was arranged at the top opening of the three-necked flask and set at a speed of 400 rpm. The three-necked flask was heated in the form of an oil bath until the temperature was in the range of 70-75°C, 18 g of styrene monomer was added, and the reaction was maintained at a temperature in the range of 70-75°C for 10 h under stirring to obtain a PSt microsphere emulsion with an average particle size of 183.1 nm of PSt microspheres.

[0059] In the S2 step, the dispersion dyeing solution was a water solution of Disperse Yellow Brown H2RL with a concentration of 1% (owf).

[0060] Example 7

[0061] The difference between this example and Example 5 is only that the preparation method of the structural color layer of this example is as follows:

[0062] The surface of the poplar wood was treated by 400-mesh abrasive belt grinding, and the wood powder adhered to the surface of the poplar wood was removed by compressed air blowing. A 3.5 cm x 3.5 cm line frame was drawn on the surface of the poplar wood by a pencil.

[0063] The structural color layer was obtained by using a pipette to suck the structural color layer dyeing microsphere emulsion, spreading the emulsion in the line frame, and then smoothly moving the sample into a blast drying oven for drying at 50°C.

[0064] Example 8

[0065] The difference between this example and Example 6 is only that the preparation method of the structural color layer of this example is as follows:

[0066] The surface of the poplar wood was treated by 400-mesh abrasive belt grinding, and the wood powder adhered to the surface of the poplar wood was removed by compressed air blowing. A 3.5 cm x 3.5 cm line frame was drawn on the surface of the poplar wood by a pencil.

[0067] The structural color layer was obtained by using a pipette to suck the structural color layer dyeing microsphere emulsion, spreading the emulsion in the line frame, and then smoothly moving the sample into a blast drying oven for drying at 50°C.

[0068] Example 9

[0069] The difference between this example and Example 1 is only that the S1 step is as follows: 0.15 g of ammonium persulfate, 165 mg of sodium dodecyl benzene sulfonate, 100 mL of water and 40 mL of ethanol were added into a three-necked flask. The left and right openings of the flask were respectively equipped with a thermometer and a spherical condenser, the top opening was equipped with an overhead stirrer and was set at a speed of 400 rpm. The three-necked flask was heated in the form of an oil bath until the temperature was in the range of 70-75°C, 18 g of styrene monomer was added, and the reaction was kept at a temperature in the range of 70-75°C for 10 h under stirring to obtain a PSt microsphere emulsion with an average particle size of 193.7 nm of PSt microspheres.

[0070] In the S2 step, the dispersion dyeing solution was a 1% (owf) aqueous solution of disperse blue 2BLN.

[0071] Example 10

[0072] The difference between this example and Example 1 is only that the S1 step is as follows: 0.15 g of ammonium persulfate, 140 mg of sodium dodecyl benzene sulfonate, 100 mL of water and 40 mL of ethanol are added together into a three-necked flask. The three necks of the flask are respectively provided with a thermometer and a spherical condenser at the left and right necks, and a top-mounted stirrer is provided at the top neck and set at a rotation speed of 400 rpm. The three-necked flask is heated in the form of an oil bath until the temperature is in the range of 75-80°C, 18 g of styrene monomer is added, and the reaction is kept at a temperature in the range of 75-80°C for 10 h under stirring to obtain a PSt microsphere emulsion with an average particle size of 235.3 nm of PSt microspheres.

[0073] In the S2 step, the dispersion dyeing solution is a water solution of dispersion blue 2BLN with a concentration of 1% (owf).

[0074] Example 11

[0075] The difference between this example and Example 9 is only that the preparation method of the structural color layer of this example is as follows:

[0076] The surface of the trembling poplar wood is treated by 400-mesh sand belt grinding, the surface of the trembling poplar wood is blown by compressed air to remove the attached wood powder. A 3.5 cm x 3.5 cm line frame is drawn on the surface of the trembling poplar wood by a pencil.

[0077] The structural color layer is obtained by using a pipette to suck the dyeing microsphere emulsion for the structural color layer, carrying out emulsion coating and spreading in the line frame, and then smoothly moving the sample into a blast drying oven for drying at 50°C.

[0078] Example 12

[0079] The difference between this example and Example 10 is only that the preparation method of the structural color layer of this example is as follows:

[0080] The surface of the trembling poplar wood is treated by 400-mesh sand belt grinding, the surface of the trembling poplar wood is blown by compressed air to remove the attached wood powder. A 3.5 cm x 3.5 cm line frame is drawn on the surface of the trembling poplar wood by a pencil.

[0081] The structural color layer is obtained by using a pipette to suck the dyeing microsphere emulsion for the structural color layer, carrying out emulsion coating and spreading in the line frame, and then smoothly moving the sample into a blast drying oven for drying at 50°C.

[0082] Performance detection test

[0083] For Examples 1-12, the following performance detection is carried out:

[0084] (1) Microsphere morphology, particle size and coefficient of variation characterization

[0085] The PSt microspheres obtained by drying the emulsion of PSt microspheres obtained in Step S1 of Example 1 and the dyed microspheres obtained by drying the emulsion of dyed microspheres obtained in Step S4 were observed as observation samples for FE-SEM (Regulus 8100, Hitachi, Ltd.). The electron micrograph of the PSt microspheres obtained by drying the emulsion of PSt microspheres obtained in Step S1 is shown in Figure 3 a. The dyed microspheres obtained by drying the emulsion of dyed microspheres obtained in Step S4 of the structural color layer are shown in Figure 3 b.

[0086] The PSt microspheres obtained by drying the emulsion of PSt microspheres obtained in Step S1 of Examples 1-2, 5-6, 9-10 and the dyed microspheres obtained by drying the emulsion of dyed microspheres obtained in Step S4 of the structural color layer were observed as observation samples for FE-SEM (Regulus 8100, Hitachi, Ltd.). The average particle diameter and the coefficient of variation were characterized based on the method of particle measurement in the electron micrograph. The monodispersity of the microspheres was evaluated in this way. The particle diameter variation obtained from the numerical analysis of the electron micrograph is shown in Figure 3 c. The correspondence between the abscissa of each microsphere and Figure 3 c is shown in Table 1.

[0087] (2) Characterization of the color-producing properties of the structural color layer

[0088] The emulsion of PSt microspheres obtained in Step S1 of Examples 3-4, 7-8, 11-12 was used to produce the structural color layer according to the method described in the examples for the production of the structural color layer.

[0089] 1) Characterization of the color-producing properties of the structural color layer under a vertical light source

[0090] The structural color layer produced from the emulsion of PSt microspheres obtained in Step S1 of Examples 3-4, 7-8, 11-12 and the structural color layer on the surface of the trembling aspen wood obtained in Examples 3-4, 7-8, 11-12 were characterized for the reflectance spectra of the structural color layer, Disperse Red 3B dye, Disperse Yellow Brown H2RL dye, and Disperse Blue 2BLN dye using a UV-Vis spectrophotometer with an integrating sphere assembly (U3900, Hitachi, Ltd.).

[0091] The reflectance spectra of each structural color layer and dye are shown in Figure 4 . The correspondence between the reflectance curve of each structural color layer and dye and the reflectance spectrum in Figure 4 is shown in Table 2.

[0092] The dyed microspheres were obtained by centrifuging the emulsion of dyed microspheres obtained in Step S4 of Examples 1-12 at 11000 r / min for 10 min and then separating the solid and liquid.

[0093] The dyeing microspheres obtained by centrifugation of the dyeing microsphere emulsions above and the structural color layers obtained in Examples 1-12 were photographed to record the vertical reflection appearance of the structural color layers under the only white light source using a digital camera (Nikon D7000, Nikon Imaging Equipment Sales (China) Co., Ltd.). The light source was vertically irradiated to the sample, and the camera was vertically photographed to the sample. The macroscopic appearance photographs taken are shown in Figure 5 . The corresponding relationship between each dyeing microsphere and structural color layer and Figure 5 is shown in Table 5. Among them, Figure 5 the photograph of each dyeing microsphere obtained by centrifugation of the dyeing microsphere emulsion is the photograph of the dyeing microspheres in the centrifugation bottle with the arc bottom.

[0094] 2) Color performance characterization of iridescent effect

[0095] The structural color layers made of the PSt microsphere emulsion obtained in S1 of Examples 3-4, 7-8, 11-12, and the structural color layers made of the dyeing microsphere emulsion obtained in S4 of Examples 3-4, 7-8, 11-12 were characterized as follows:

[0096] The digital camera was used to photograph and record the front reflection appearance and the diffuse reflection appearance of the structural color layers under the only white light source. During the photographing process, the camera parameters were set to be the same. When taking the front reflection photograph, the structural color layer was placed on the platform, and the vertical line thereof was the normal line. The light source and the camera were rotated in the opposite direction around the normal line at the same angle, as shown in Figure 1 a, to record the front reflection appearance under the conditions of 15°, 30°, 45°, 60°, and 75°. When taking the diffuse reflection photograph, the vertical line of the structural color layer was also used as the normal line. The light source was kept vertically incident, i.e., the included angle between the light source and the normal line was 0°, and the camera formed an included angle with the normal line to capture the diffuse reflection appearance under the conditions of 30° and 60°, as shown in Figure 1 b. The hue numerical extraction of the iridescent effect photograph, the theoretical color simulation, and the vertical state were the same. The characterization results are shown in Figure 6 , Figure 8 and Figure 9 . The corresponding relationship between the structural color layer obtained in each example and Figure 6 , Figure 8 and Figure 9 is shown in Table 3.

[0097] The fiber spectrometer was used to characterize the multi-angle reflection spectrum and the diffuse reflection spectrum of the structural color layer and the dispersed red fuel by using the self-made variable-angle test sample table (USB2000+, Ocean Optics (Shanghai) Co., Ltd.), as shown in Figure 2The light source (10 W, Nanjing SuYu E-commerce Co., Ltd.) was a halogen lamp close to natural light, which was installed in a black box and transmitted to the structural color layer through optical fiber 1. The reflected light or diffuse reflected light from the structural color layer was accurately received by a self-made variable-angle test sample table and transmitted to the fiber spectrometer through optical fiber 2 to convert into an electrical signal. The OceanView software was used to complete the data processing of the electrical signal in the computer system.

[0098] The whole test was carried out in a dark environment to ensure that the light source transmitted by optical fiber 1 was the only light source. Since the stage carrying optical fiber 1 and optical fiber 2 had a certain width and could not be merged in parallel, when measuring the normal reflectance spectrum of the structural color layer, the angle between optical fiber 1 and optical fiber 2 and the normal line was 0°. At this time, a Y-shaped optical fiber was used to merge the two (Shenzhen Xinrui Photonics Technology Co., Ltd.), and the incident light and the captured reflected light were emitted through the same interface, as shown in Figure 2 a. When measuring the multi-angle reflectance spectrum of the structural color layer, the angle between the stage carrying optical fiber 1 and optical fiber 2 and the normal line was adjusted by sliding to keep consistent, and the reflectance spectrum of the incident light was obtained, as shown in Figure 2 b. When measuring the multi-angle diffuse reflectance spectrum of the structural color layer, the stage carrying optical fiber 1 was fixed at an angle of 0° with the normal line, and the stage carrying optical fiber 2 was adjusted, and the obtained was the diffuse reflectance spectrum of the incident light, as shown in Figure 2 c.

[0099] The characterization results are shown in Figure 7 The corresponding relationship between the structural color layer obtained in each example and the iridescent effect reflectance spectrum in Figure 7 is shown in Table 4.

[0100] Table 1

[0101]

[0102]

[0103] Table 2

[0104]

[0105]

[0106] Table 3

[0107]

[0108] Table 4

[0109]

[0110] Table 5

[0111]

[0112]

[0113] In conjunction with Examples 1-2, 5-6, and 9-10 and Table 1, Figure 3 It can be seen that, Figure 3 a and Figure 3 In b, both the microspheres before and after staining are regular spherical, and the assembled photonic crystal structure is arranged in an orderly manner. Figure 3 a and Figure 3 No impurities such as disperse dyes were observed in sample b, indicating that the residual dye molecules did not affect the self-assembly of the microspheres; they were either too small in size or too scarce to be observed. During the self-assembly of the microsphere emulsion on the wood surface, driven by emulsion evaporation, the microspheres converged towards the liquid surface and spontaneously assembled, initially forming small, plate-like photonic crystals that gradually thickened. As the emulsion volume continued to shrink, the small photonic crystals bonded together, inevitably generating significant grain boundary defects in the process. Figure 3 In the middle, stained microspheres ( Figure 3 b) has significantly fewer grain boundary defects than unstained microspheres ( Figure 3 a). This suggests that the introduction of dye alters the surface properties of the microspheres, thereby affecting their self-assembly behavior. This improvement in large-size grain boundary defects will significantly enhance the optical performance and overall quality of the color layer in the photonic crystal structure.

[0114] As shown in Table 1 and Figure 3 As shown in Figure c, compared to the PST microspheres obtained from the dried PST microsphere emulsion in step S1, the average particle size of the three types of dyed microspheres for structural color layers obtained in step S4 all showed varying degrees of increase, with an increase of approximately 6 nm. It can be inferred that under heating conditions, the small dye molecules, with increased inter-chain spacing between the polymer molecules in the microspheres, entered the interior of the microspheres or adsorbed onto the surface, increasing the microsphere particle size and thus dyeing the microspheres. Furthermore, the dyeing ability of various disperse dyes on microspheres of different particle sizes was comparable under the same dye concentration and process conditions, and the ability of PST microspheres to carry various dyes was also similar. Before and after dyeing, the coefficient of variation of the particle size of each microsphere was less than 0.08, indicating good monodispersity, making them suitable for the ordered self-assembly construction of structural color layers.

[0115] In conjunction with Examples 3-4, 7-8, and 11-12 and Table 2, Figure 4 It can be seen that, Figure 4 The red-red curve in a(1) and Figure 4 The disperse red curves of c are very similar, both showing a small peak at 541 nm, which is a characteristic peak of the disperse red 3B dye itself. The difference lies in the rising wavelength range of 550–620 nm. Figure 4The red-red curve in a(1) has a prominent peak of structural color at 599 nm. This indicates that this reflectance curve reflects the dual characteristics of structural color and pigment color. In addition, between 416-599 nm, Figure 4 The red curve in a(1) presents high reflectance, while Figure 4 The reflectance of the red-red curve in a(1) gradually forms a very low trough, indicating that the dyeing microspheres have good absorption of light waves in this band, which will further highlight the structural color effect. Compared with the structural color layer made of the PSt microsphere emulsion obtained in step S1, the structural color layer made of the dyeing microsphere emulsion obtained in step S4 should have a more vibrant color effect.

[0116] Similarly, Figure 4 The yellow-yellow curve in a(2) has a similar trend as Figure 4 The c-dispersed yellow-brown curve, in the rising band of 450-650 nm, Figure 4 The structural color characteristic peak of the yellow-yellow curve in a(2) is prominent, but small. The dye pigment color effect affects the relative intensity of the structural color reflection peak, and thus affects the color effect of the structural color layer. Unlike the curves of the structural color layers dyed with the above two kinds of same color system dyes, it is relatively special that Figure 4 The blue-blue curve in a(3) still has a similar trend as Figure 4 The c-dispersed blue curve, coincidentally, the structural color characteristic peak coincides with the pigment color peak, rather than the rising band, thereby forming the shape of the main peak plus the shoulder peak.

[0117] And Figure 4 The structural color characteristic peak of the red-green curve in b(1) is at 537.5 nm, which is located Figure 4 In the reflectance trough interval of the c-dispersed red curve. Similarly, Figure 4 The structural color characteristic peak of the yellow-violet curve in b(2) is 447 nm, which appears Figure 4 In the reflectance trough interval of the c-dispersed yellow-brown. Figure 4 The structural color characteristic peak of the blue-orange curve in b(3) is 563 nm, which appears Figure 4 In the reflectance trough interval of the c-dispersed blue.

[0118] Therefore, the main reflection peak positions of the structural color layers made of the PSt microsphere emulsion obtained in steps S1 of Examples 3-4, 7-8, and 11-12, and the structural color layers on the surfaces of the trembling aspen wood obtained in Examples 3-4, 7-8, and 11-12 all move to the long wave direction. The reflection peak movement degree of the structural color layer made of the dyeing microsphere emulsion obtained in step S4 of Examples 4, 8, and 12 is more obvious. Figure 4 The red-green curve in b(1), Figure 4 The yellow-violet curve in b(2), Figure 5b(3) blue-orange curve is moved by 15.5, 15.5, 10 nm respectively.

[0119] However, the structural color layer obtained by the S4 step of Examples 3, 7 and 11 has a smaller red shift degree of the reflection peak of the structural color layer made of the dyeing microsphere emulsion. Figure 5 a(1) red-red curve, Figure 5 a(2) yellow-yellow curve, Figure 5 a(3) blue-blue curve is moved by 1.5, 3.5, 6 nm respectively. According to the Bragg diffraction equation, the theoretical response wavelength increment caused by the increase of 6 nm in the particle size of the microspheres is about 14.1 nm. Obviously, the theoretical response wavelength increment caused by the increase of the particle size of the dyeing microspheres (about 5.3 nm, 7.1 nm and 5.8 nm respectively) in the structural color layer obtained by the S4 step of Examples 3, 7 and 11 does not match the actual red shift degree of the reflection peak of the structural color layer. The formation of this phenomenon should be that the reflection spectrum curve of the structural color layer is formed by fitting the two color characteristics of the structure and the pigment, thereby affecting the peak position of the photonic crystal band gap characteristic peak. When the characteristic peaks of the structural color and the pigment color overlap, that is, the microspheres are dyed by using the preparation method of Examples 3, 7 and 11, the steep reflectance curve of the pigment color affects the structural color characteristic peak, causing a shift. When the structural color characteristic peak appears in the wave trough of the pigment color, that is, the microspheres are dyed by using the preparation method of Examples 4, 8 and 12, the low and flat wave trough curve of the pigment color does not affect the peak position of the structural color characteristic peak.

[0120] In combination with Examples 1-12 and Table 5, Figure 6 It can be seen that the color effect of the structural color is different under different states. Figure 4 a(1), b(1), c(1), d(1), e(1) and f(1) are mainly in the dye color, but in the strong reflection area of light, they present a dazzling structural color luster. Figure 6 a(2), b(2), c(2), d(2), e(2) and f(2) are raised with drying stress, the flat area is illuminated vertically, the color is bright, and the structural color is mainly in the color. Figure 7 a(3), b(3), c(3), d(3), e(3) and f(3) have high vertical appearance flatness, reduced surface roughness and bright color, and the structural color is mainly in the color. According to the differences of the structural color layer under the three states, it can be speculated that no matter which dye is used, the color of the structural color layer is mainly in the structural color under the condition of normal reflection (that is, the incident angle is equal to the reflection angle), and the dye pigment color is not obvious, which should be due to the fact that the structural color is stronger than the pigment color. Under the condition of diffuse reflection (that is, the incident angle is not equal to the reflection angle), the color of the structural color layer gradually becomes mainly in the pigment color.

[0121] In combination with Examples 3-4, 7-8, 11-12 andFigure 7 As shown in Table 3, when the incident light changes at the same angle to the normal relative to the line of sight, the positive reflection iridescence effect of the structural color layer can be observed. The color of the structural color layer constructed by the dye-dyed microspheres continuously shifts to blue as the observation angle increases. This change process conforms to the Bragg diffraction equation.

[0122] As sinθ in the equation increases, the resulting λ value decreases, meaning the reflected light wave shifts towards shorter wavelengths. When the incident ray angle reaches 75°, the colors of all structural color layers lighten, appearing grayish-white, which is related to grazing reflection. The grazing angle is the angle between the incident ray and the surface normal. When the incident angle is less than the critical angle, some light rays are refracted, and some are reflected. When the incident ray angle is greater than the critical angle, all light rays are reflected, and no further refraction occurs. The specific value of the critical angle is determined by the refractive indices of both media and can be defined as the maximum grazing angle from one medium to another. That is, in this application, the maximum grazing angle of the structural color layer constructed from PSt microspheres is approximately 75°. At this point, the structural color layer reflects a large amount of light, appearing grayish-white in the photograph. Before staining, the PSt microspheres are white, and the main color of the structural color layer is relatively dark. After staining, the main color of the structural color layer becomes more vibrant. The above color adjustment results are different from traditional pigment colors. Adding colored substances will increase the hue of pigment colors, while in this application, colored dyes are added. In the positive reflection iridescence effect, the structural color layer is mainly characterized by structural color generation, and the dyes make the structural color more vivid.

[0123] Combining Examples 3-4, 7-8, 11-12 and Figure 4 , Figure 7 , Figure 7 Table 4 shows that this application uses fiber optic spectroscopy to characterize the reflectance spectrum of the iridescent effect of the structural color layer. To comprehensively represent the overall iridescent effect of the structural color layer, three different points were measured for each sample, and the data were averaged to plot the spectrum. Figure 6 As shown. Comparison Figure 6 and Figure 7 The reflectance curves generated under the two testing methods (when the incident light is 0° to the normal) show that the UV-Vis spectrophotometer reflects the reflectance characteristics of the structural color layer over a large area, with fluctuating curves that reflect the combined effects of factors such as wood surface roughness and dye pigments; while the fiber optic spectrometer shows the reflectance characteristics of the structural color layer over a small area, with small curve fluctuations that fully reflect the structural characteristics of the photonic crystal itself.

[0124] exist Figure 7 In the process, as the angle between incident and reflected light increases, the peak reflectance of each structural color layer gradually shifts towards shorter wavelengths, and... Figure 8The exhibited color blue shift phenomenon is consistent. Compared to the state where the incident light coincides with the normal, when the angle is 15°, the movement of the reflectance peak to the short wave direction is <10 nm; when the angle increases to 30°, 45° and 60°, the blue shift degree is obvious. Assuming that the crystal structure of the structural color layer is face-centered cubic, D represents the particle size of the microspheres, and combining the Bragg diffraction equation, when the angle increases from 0° to 15°, the corresponding change in the reflection peak position λ0-15 is as follows:

[0125]

[0126] When the incident and reflection angles increase from 15° to 30°, the change in the reflection peak position λ15-30 is as follows:

[0127]

[0128] By analogy, λ30-45 and λ45-60 are 0.1573D and 0.1703D, respectively, gradually increasing. This verifies the phenomenon that the corresponding reflection peak position changes increase as the incident light angle increases. When the angle is 75°, the reflectance curves of all structural color layers present a straight line without peaks, which is consistent with the gray-white photos presented in Figure 8 , and therefore is not reflected in Figure 8 .

[0129] The multi-angle peak shape of each structural color layer presents a trend of widening as the incident light angle increases. When the incident light coincides with the normal, the reflectance curve presents a main peak and a shoulder peak, indicating that even a small range of fiber light source irradiation will still be affected by the micro unevenness of the structural color layer, forming diffuse reflection. After the incident light forms an angle with the normal, the reflected light received by the optical fiber is mainly the reflection of the flat structural color layer, and the light intensity is more uniform. Figure 8 The reflection peak height of each structural color layer in increases first and then decreases, which represents the change in relative reflection intensity. The incident light angle at which the highest reflection peak appears for different structural color layers is not fixed, but the highest reflection peak always appears in the range of 450 nm to 500 nm, which may be related to factors such as halogen light source, standard white board, fiber spectrum equipment, etc.

[0130] Combining Examples 3-4, 7-8, 11-12 and Figure 8 , Table 3, it can be seen that when the structural color layer is applied to the surface decoration of an object, the structural color layer observed by the human eye will definitely have a reflection light angle that is not equal to the incident light angle, and at this time, what is seen is the diffuse reflection iridescence effect of the structural color layer. When taking macroscopic appearance and diffuse reflection spectrum, the incident light remains perpendicular to the direction of the structural color layer, and the light receiving direction of the camera and the fiber spectrum instrument is changed, so that the camera and the fiber can capture the diffuse reflection light of the structural color layer.

[0131] like Figure 8 As shown, after dyeing PSt microspheres with three disperse dyes—Disperse Red 3B, Disperse Yellow Brown H2RL, and Disperse Blue 2BLN—the constructed structural color layer exhibited a significant color change under scattering conditions. Unlike the positive reflection iridescence effect, in the diffuse reflection effect, pigment coloration is significantly more prominent than structural coloration. However, it can also be observed that the structural color layers obtained in step S4 of Examples 3-4, 7-8, and 11-12, when prepared using the dyed microsphere emulsion, are still affected by the color of the structural dye itself.

[0132] by Figure 8 Taking the red group, red-red group, green group, and red-green group as examples, Figure 8 The red group appears pale blue in the 30° scattering photo. This pale blue color is due to the fact that visible light is incident on the structure color layer along the normal direction. The red light is directionally reflected out of the structure color layer under the action of the photon bandgap, while the light of other colors is reflected and scattered by the white microspheres and then captured by the camera.

[0133] like Figure 8 As shown in the red group photos, the color of the dyed PSt microspheres themselves mixes with the color scattered by the structural color layer, resulting in the structural color layer constructed by the dyed PSt microspheres appearing purplish-red under the scattering state.

[0134] like Figure 4 As shown in the medium green group of images, the structural color layer constructed from unstained PSt microspheres appears pale purple in the 30° image. (See image for reference.) Figure 7 As shown in the red-green group photos, the color of the PSt microspheres themselves after staining and the color scattering from the structural color layer jointly produce color. The colors produced by the two color-producing mechanisms enhance each other, making the overall structural color layer bright red after staining.

[0135] contrast Figure 9 As can be seen from the mid-red and red-green group photos, for the structural chromatic layer constructed by stained PST microspheres, the color change of the structural chromatic layer is not significant when the difference between the incident and reflected light angles increases, i.e., from 30° to 60°. Similarly, in comparison... Figure 9 As can be seen from the yellow group, yellow-yellow group, blue group, blue-blue group, purple group, yellow-purple group, orange group, and blue-orange group, the other two dyes also exhibit the same synergistic color generation pattern in the structural color layer.

[0136] Combining Examples 3-4, 7-8, 11-12 and Figure 9 , Figure 4 , Figure 7 Table 2-4 shows that when the diffuse reflectance spectrum of the structural chromatic layer is measured using a fiber optic spectrometer, the incident light is always perpendicular to the plane of the structural chromatic layer during the test, while the angle of the fiber optic stage receiving the light can be varied to 30° and 60°. The resulting... Figure 9The reflectance curve shown.

[0137] Figure 7 The overall trend of the diffuse reflectance spectrum curve is the same as that of the c reflectance spectrum curve. This shows that, in the diffuse reflection state, the main color of the structural color layer comes from the pigment color of the dye, and the characteristic peak of the diffuse reflection comes from the photonic crystal, which belongs to the synergistic coloration of both, and together constitutes the diffuse reflection color of the structural color layer. Figure 7

[0138] Compared with the high reflectivity of the normal reflectance spectrum in the ​ , the diffuse reflectivity of the structural color layer constructed by the dyed PSt microspheres is not more than 80%, indicating that the light intensity of the diffuse reflection is weak. ​ , the peak positions of the reflection peaks in each diffuse reflectance spectrum at 30° are approximately the same as those at 15° in the ​ , and the peak positions of the reflection peaks at 60° are approximately the same as those at 30° in the ​ . It is shown that the 30° and 60° diffuse reflections under the vertical light source are equivalent to the normal reflection rainbow effect formed by rotating the normal by 15° and 30°, but the amount of reflected light is much smaller.

[0139] In summary, the present application uses color dispersion dyes to dye PSt microspheres, and constructs a structural color layer on the surface of wood using the dyed PSt microspheres. The analysis and research on the properties of the dyed microspheres, the reflection spectrum of the structural color layer, the macroscopic appearance and the rainbow effect can know that:

[0140] (1) The dyeing ability of various colored dyes on PSt microspheres of different particle sizes is equivalent. The average particle size of the dyed PSt microspheres increases by about 6 nm.

[0141] (2) The overall reflectivity curve of the structural color layer constructed by the dyed PSt microspheres fluctuates similarly to the reflectivity curve of the corresponding dye itself, and the bandgap characteristic peak of the photonic crystal appears on the dye reflectivity curve, showing a mixed coloration characteristic.

[0142] (3) The maximum color proportion of the structural color layer constructed by the dyed PSt microspheres is significantly improved, the coloration is more uniform, and the color is more vivid. However, under the condition of normal reflection, the color of the dye itself does not appear in the coloration of the structural color layer.

[0143] (4) The coloration effect of the structural color layer constructed by the dyed PSt microspheres is more abundant than that of the white PSt microspheres under the conditions of normal reflection and diffuse reflection.

[0144] Therefore, the dyed microspheres and the structural color layer constructed by the dyed microspheres prepared in the present application can help to improve the color decoration of the structural color layer constructed by white microspheres such as PSt microspheres in the diffuse reflection.

[0145] ​The embodiments are only illustrative of the present application, and are not intended to limit the present application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for producing a dyeing microsphere emulsion for a structural color layer, characterized by, The method comprises the following steps: S1, mixing ammonium persulfate, sodium dodecyl benzene sulfonate, water and ethanol, adding styrene monomer under stirring and oil bath heating, keeping stirring and oil bath heating, obtaining PSt microsphere emulsion after reaction; S2, mixing PSt microsphere emulsion and disperse dye solution, heating to boiling state under stirring and oil bath heating, keeping boiling state, cooling to room temperature after reaction, obtaining dyed PSt microsphere emulsion; S3, centrifuging dyed PSt microsphere emulsion, solid-liquid separation, obtaining upper liquid and microsphere solid, adding water to microsphere solid, obtaining emulsion-1 after ultrasonic oscillation; S4, forming emulsion-2 according to S3, combining emulsion-1 and emulsion-2, obtaining mixed emulsion, obtaining structural color layer dyed microsphere emulsion according to S3.

2. The method for producing a colored microsphere emulsion for a structural color layer according to claim 1, characterized by, The average particle size of PSt microspheres in the PSt microsphere emulsion is 180-280 nm.

3. A dyed microsphere for a structural color layer, characterized by The structural color layer dyed microsphere emulsion prepared by the preparation method of any one of claims 1-2 is dried to obtain structural color layer dyed microspheres.

4. A method for producing a structural color layer, characterized by, The structural color layer dyed microsphere emulsion prepared by the preparation method of any one of claims 1-2 is coated and spread on the surface of a substrate, and dried to obtain a structural color layer.

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