Preparation method of nano particle layered composite material and preparation method of structural color material
By curing the nanoparticle dispersion on a low-surface energy substrate and controlling the exposure power with a 3D printer, the problem of cumbersome patterning of structural color materials in the prior art is solved, and the controllability and pattern fineness of nanoparticle layering are achieved, which improves its application potential in optical anti-counterfeiting materials.
Patent Information
- Application Number
- CN202510664587.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-22
- Publication Date
- 2025-07-25
AI Technical Summary
When preparing structural colored materials, the patterning process is complicated and the fineness is insufficient, which hinders its application in the fields of anti-counterfeiting and pattern printing.
By dispersing nanoparticles, initiators and light absorbers in acrylates, curing on a low-surface energy substrate using entropy effect, spontaneous migration and layering of nanoparticles are achieved, and structural color materials are prepared by controlling exposure power with a 3D printer.
The preparation process is simplified, the controllability of the nanoparticle layered structure is realized, and the pattern fineness and application potential of structural color materials are improved, especially in the field of optical anti-counterfeiting materials.
Smart Images
Figure CN120365501A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the technical field of structural color materials, and specifically relates to a preparation method of a composite material with layered nanoparticles and a preparation method of a structural color material. Background Art
[0002] The numerous colors in nature usually come from chemical colors (also known as pigment colors) brought by light absorption determined by molecular structures and / or physical colors (also known as structural colors) generated by the interaction between micro / nano structures of substances and light. Different from traditional pigments or dyes based on chemical colors, structural colors are physical colors generated by diffraction, interference, or scattering phenomena of light brought by micro / nano structures. Therefore, they are more resistant to chemical washing and light bleaching, and can also greatly reduce toxicity hazards. Structural color materials have gradually been applied in the fields of decoration, anti-counterfeiting, optics, display, sensing, photocatalysis, and biomedicine.
[0003] Artificial structural color materials with various properties can be prepared by arranging particles with a size of several hundred nanometers in a medium with a certain refractive index difference in a periodic manner. Currently, common preparation methods for artificial structural color materials include evaporation-induced self-assembly method, vertical deposition method, spin coating method, spraying method, electrophoretic deposition method, microfluidic method, etc. However, when using the above preparation methods to pattern structural color materials, multiple masking or cutting or splicing processes are required, and the process is cumbersome; at the same time, the fineness of the pattern is also greatly reduced, which hinders the application of structural color materials in the fields of anti-counterfeiting, pattern printing, etc.
[0004] Application Content
[0005] The purpose of this application is to provide a preparation method of a composite material with layered nanoparticles and a preparation method of a structural color material. The preparation method of this application is simple and easy to control, and can be used to prepare structural color materials.
[0006] This application provides a preparation method of a composite material with layered nanoparticles, including the steps of:
[0007] a) Dispersing nanoparticles, an initiator, and a light absorber in acrylate to obtain a dispersion;
[0008] b) Placing the dispersion on a low surface energy substrate for curing of acrylate, where the surface energy of the low surface energy substrate should be lower than the surface energy of the composite material matrix, and the composite material matrix refers to the resin matrix obtained by polymerization of the above acrylate.
[0009] It should be noted that in order to obtain the above dispersion, acrylate should be selected as acrylate that is liquid at room temperature.
[0010] During the curing process of the acrylate, based on the entropy effect, the nanoparticles spontaneously migrate towards the low surface energy substrate, resulting in a high degree of aggregation of the nanoparticles near the composite-substrate interface in the composite material, thereby obtaining a structure with layered nanoparticles, as shown in Figure 1 Shown.
[0011] Step a) is specifically as follows: First, the nanoparticles, initiator, light absorber, and acrylate are mixed and dispersed in an organic solvent by the solvent dispersion method, and then the organic solvent is removed by the evaporation method or volatilization method to obtain a dispersion.
[0012] The above organic solvent is selected to be an organic solvent that is miscible with the acrylate and in which the nanoparticles can be dispersed, such as methanol, ethanol, isopropanol, etc.
[0013] A more specific implementation manner of step a) is: First, the nanoparticles and the light absorber are dispersed in an organic solvent, then the initiator and the acrylate are added and dispersed continuously, and finally the mixed solution is heated to remove the organic solvent to obtain a dispersion. Among them, the mass of the organic solvent is 1.5 to 15 times that of the nanoparticles.
[0014] In step b), the curing can be thermal curing or photo-curing; when it is thermal curing, a thermal initiator is selected; when it is photo-curing, a photo-initiator is selected.
[0015] Optionally, step a) is carried out in the dark, for example, in a dark environment, to avoid sunlight and / or high-power light source irradiation.
[0016] Optionally, the average particle size of the nanoparticles is 20 nm to 500 nm. Further, the average particle size of the nanoparticles is 100 nm to 300 nm.
[0017] Optionally, the surface energy of the low surface energy substrate is not greater than 40 mN / m. Further, the surface energy of the low surface energy substrate is not greater than 30 mN / m.
[0018] Optionally, the mass percentage of the nanoparticles in the dispersion is 5% to 40%. Further, the mass percentage of the nanoparticles is 8% to 40%.
[0019] Optionally, the dosage of the initiator is 0.1% to 10% of the mass of the acrylate. Further, the dosage of the initiator is 0.5% to 5% of the mass of the acrylate.
[0020] Optionally, the dosage of the light absorber is 0 to 1% of the mass of the acrylate.
[0021] Optionally, the nanoparticles are one or more of silica, zinc sulfide, titanium dioxide, polystyrene, and zinc sulfide coated with silica.
[0022] Optionally, the initiator is one or more of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (819), and azobisisobutyronitrile (AIBN). Among them, TPO and 819 are photoinitiators, and AIBN is a thermal initiator.
[0023] Optionally, the light absorber is one or more of carbon black, carbon nanotubes, graphene, and polydopamine.
[0024] Optionally, the acrylate is one or more of ethylene glycol phenyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, hexanediol diacrylate, dipropylene glycol diacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, and bis-trimethylolpropane tetraacrylate.
[0025] Optionally, the low surface energy substrate is a copolymer of perfluoroethylene propylene, Teflon, polydimethylsiloxane, polyethylene terephthalate, or polymethyl methacrylate substrate, or a substrate surface-modified with an oligomer of a copolymer of perfluoroethylene propylene, Teflon, polydimethylsiloxane, polyethylene terephthalate, or polymethyl methacrylate.
[0026] On the other hand, the present application provides a method for preparing a structural color material, including:
[0027] Placing the dispersion on a low surface energy substrate, and performing single-layer photocuring or layer-by-layer photocuring on the dispersion; the exposure power of each layer is the same or different, and the exposure power of different regions in each layer is the same or different.
[0028] Specifically, a 3D printer can be used to prepare the above structural color material: a low surface energy substrate is arranged at the bottom of the material tank of the 3D printer, and the surface energy of the low surface energy substrate should be lower than the surface energy of the composite material matrix; the above dispersion is added to the material tank; the photocuring of the acrylate is carried out by controlling the exposure power of different regions through the 3D printer to obtain a material with a structural color pattern.
[0029] Optionally, the photocuring of the acrylate is layer-by-layer photocuring carried out according to a preset printing layer thickness. The printing layer thickness is generally set to 10 μm to 200 μm, and further set to 50 μm to 100 μm.
[0030] During the photocuring process of the acrylate, by controlling the exposure power of different regions, the layered thickness of nanoparticles in different regions is controlled, and the difference in the layered thickness brings about the difference in structural color, and finally a structural color pattern is presented.
[0031] Compared with the prior art, the present application has the following advantages and beneficial effects:
[0032] The preparation method of the composite material with nano-particle stratification in the present application is simple and controllable. By utilizing the entropy effect, during the curing process of acrylate, the nano-particles can spontaneously migrate towards the low-surface-energy substrate, obtaining a nano-particle stratified structure. By regulating the polymerization rate of acrylate, the control of the nano-particle stratification thickness can be achieved, and the difference in stratification thickness brings about the difference in structural color. The prepared composite material with nano-particle stratification can be applied to structural color materials and has great application prospects in the field of optical anti-counterfeiting materials. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0034] Figure 1 It is a schematic diagram of the stratification structure of nano-particles in the composite material of the present application;
[0035] Figure 2 It is a scanning electron micrograph of the cross-section of the composite materials prepared in Examples 1 to 25;
[0036] Figure 3 It is a scanning electron micrograph of the cross-section of the composite materials prepared in Examples 26 to 31, where (a) to (f) in the figure correspond to Examples 26 to 31 respectively;
[0037] Figure 4 It is a scanning electron micrograph of the cross-section of the composite material prepared in Example 32;
[0038] Figure 5 It is a scanning electron micrograph of the cross-section of the composite materials prepared in Examples 33 to 40, where (a) to (h) in the figure correspond to Examples 33 to 40 respectively;
[0039] Figure 6 It is a scanning electron micrograph of the cross-section of the composite materials prepared in Examples 41 to 52, where (a) to (l) in the figure correspond to Examples 41 to 52 respectively;
[0040] Figure 7 It is a scanning electron micrograph of the cross-section of the composite materials prepared in Examples 53 to 56, where (a) to (d) in the figure correspond to Examples 53 to 56 respectively;
[0041] Figure 8 It is a scanning electron micrograph of the cross-section of the composite materials prepared in Examples 57 to 60, where (a) to (d) in the figure correspond to Examples 57 to 60 respectively;
[0042] Figure 9 It is a schematic diagram of the light reflection mechanism of the composite material prepared in this application;
[0043] Figure 10 It is the reflection spectrum of the exposed surface of the composite materials prepared in Examples 37 - 40;
[0044] Figure 11 It is the reflection spectrum of the backlit surface of the composite materials prepared in Examples 28 - 31;
[0045] Figure 12 It is the infrared reflection spectrum of the exposed surface of the composite materials prepared in Examples 61 - 65;
[0046] Figure 13 It is the structural color pattern printed in Example 66 and the photos of the pattern at different incident light angles;
[0047] Figure 14 It is the structural color pattern printed in Example 67. Detailed implementation manners
[0048] To enable those skilled in the art to better understand the solution of this application, the following further detailed description of this application is provided in conjunction with the accompanying drawings and specific implementation manners. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the scope of protection of this application.
[0049] To further illustrate this application, the following detailed description is provided through the following examples. The experimental raw materials used in the following examples of this application are all general commercially available products. In the following examples, all 3D printers are digital light processing 3D printers, that is, DLP printers.
[0050] Examples 1 - 5
[0051] First, 2 g of nano - silica, 7 g of ethanol, and 0.001 g of carbon black are mixed and ultrasonically treated for 1 hour; then, 0.031 g of diphenyl(2,4,6 - trimethylbenzoyl)phosphine oxide (TPO), 5.01 g of ethylene glycol phenyl acrylate, 0.59 g of hydroxybutyl acrylate, and 0.63 g of polyethylene glycol dimethacrylate are added and ultrasonically treated for another half hour; finally, the mixed solution is placed in an oven at 70 °C for 8 hours to remove ethanol, obtaining an acrylate dispersion of silica. Among them, the particle size of the nano - silica is 128 ± 6 nm.
[0052] A transparent perfluoroethylene propylene copolymer film is set at the bottom of the material tank of a 3D printer. The dispersion liquid is placed in the material tank of the 3D printer, and the 3D printer is used to perform layer-by-layer photocuring on the dispersion liquid to obtain a square thin sheet with a side length of 1 cm and a thickness of 1 mm. When performing photocuring, the printing layer thickness is set to 50 μm, and the exposure powers for photocuring in Examples 1-5 are 2.0 mW / cm 2 、4.0 mW / cm 2 、11.6 mW / cm 2 、18.6 mW / cm 2 and 28.0 mW / cm 2 . The scanning electron microscope images of the cross-sections of the composite materials prepared in Examples 1-5 are shown in Figures (a-1)-(a-5) in Figure 2 respectively.
[0053] Examples 6-10
[0054] First, 2 g of nano-silica, 7 g of ethanol, and 0.001 g of carbon black are mixed and ultrasonically treated for 1 hour; then, 0.062 g of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), 5.01 g of ethylene glycol phenyl acrylate, 0.59 g of hydroxybutyl acrylate, and 0.63 g of polyethylene glycol dimethacrylate are added and ultrasonically treated for another half hour; finally, the mixed solution is placed in an oven at 70 °C for 8 hours to remove ethanol, and an acrylate dispersion liquid of silica is prepared. Among them, the particle size of the nano-silica is 128 ± 6 nm.
[0055] A transparent perfluoroethylene propylene copolymer film is set at the bottom of the material tank of a 3D printer. The dispersion liquid is placed in the material tank of the 3D printer, and the 3D printer is used to perform layer-by-layer photocuring on the dispersion liquid to obtain a square thin sheet with a side length of 1 cm and a thickness of 1 mm. When performing photocuring, the printing layer thickness is set to 50 μm, and the exposure powers for photocuring in Examples 6-10 are 2.0 mW / cm 2 、4.0 mW / cm 2 、11.6 mW / cm 2 、18.6 mW / cm 2 and 28.0 mW / cm 2 . The scanning electron microscope images of the cross-sections of the composite materials prepared in Examples 6-10 are shown in Figures (b-1)-(b-5) in Figure 2 respectively.
[0056] Examples 11-15
[0057] First, 2 g of nano-silica, 7 g of ethanol, and 0.001 g of carbon black were mixed and ultrasonically treated for 1 hour; then, 0.124 g of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), 5.01 g of ethylene glycol phenyl acrylate, 0.59 g of hydroxybutyl acrylate, and 0.63 g of polyethylene glycol dimethacrylate were added and ultrasonication was continued for half an hour; finally, the mixture was placed in an oven at 70 °C for 8 hours to remove ethanol, obtaining an acrylate dispersion of silica. Among them, the particle size of the nano-silica was 128 ± 6 nm.
[0058] A transparent perfluoroethylene propylene copolymer film was set at the bottom of the material tank of the 3D printer. The dispersion was placed in the material tank of the 3D printer, and the dispersion was subjected to layer-by-layer photocuring using the 3D printer to obtain a square thin sheet with a side length of 1 cm and a thickness of 1 mm; during photocuring, the printing layer thickness was set to 50 μm, and the exposure powers for photocuring in Examples 11 to 15 were 2.0 mW / cm 2 、4.0 mW / cm 2 、11.6 mW / cm 2 、18.6 mW / cm 2 and 28.0 mW / cm 2 . The scanning electron microscope images of the cross-sections of the composites prepared in Examples 11 to 15 are shown in Figures (c-1) to (c-5) in Figure 2 .
[0059] Examples 16 - 20
[0060] First, 2 g of nano-silica, 7 g of ethanol, and 0.001 g of carbon black were mixed and ultrasonically treated for 1 hour; then, 0.186 g of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), 5.01 g of ethylene glycol phenyl acrylate, 0.59 g of hydroxybutyl acrylate, and 0.63 g of polyethylene glycol dimethacrylate were added and ultrasonication was continued for half an hour; finally, the mixture was placed in an oven at 70 °C for 8 hours to remove ethanol, obtaining an acrylate dispersion of silica. Among them, the particle size of the nano-silica was 128 ± 6 nm.
[0061] A transparent perfluoroethylene propylene copolymer film was set at the bottom of the material tank of the 3D printer. The dispersion was placed in the material tank of the 3D printer, and the dispersion was subjected to layer-by-layer photocuring using the 3D printer to obtain a square thin sheet with a side length of 1 cm and a thickness of 1 mm; during photocuring, the printing layer thickness was set to 50 μm, and the exposure powers for photocuring in Examples 16 to 20 were 2.0 mW / cm 2 、4.0 mW / cm 2 、11.6 mW / cm 2 、18.6 mW / cm 2and 28.0 mW / cm 2 The scanning electron micrographs of the cross-sections of the composite materials prepared in Examples 16 to 20 are shown respectively in Figure 2 Figures (d-1) to (d-5) in
[0062] Examples 21 to 25
[0063] First, 2 g of nano-silica, 7 g of ethanol and 0.001 g of carbon black were mixed and ultrasonically treated for 1 hour; then, 0.31 g of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), 5.01 g of ethylene glycol phenyl acrylate, 0.59 g of hydroxybutyl acrylate and 0.63 g of polyethylene glycol dimethacrylate were added and ultrasonic treatment was continued for half an hour; finally, the mixture was placed in an oven at 70 °C for 8 hours to remove ethanol, and an acrylate dispersion of silica was prepared. Among them, the particle size of the nano-silica was 128 ± 6 nm.
[0064] A transparent perfluoroethylene propylene copolymer film was set at the bottom of the material tank of the 3D printer, the dispersion was placed in the material tank of the 3D printer, and the dispersion was subjected to layer-by-layer photocuring by the 3D printer to obtain a square thin sheet with a side length of 1 cm and a thickness of 1 mm; when photocuring was carried out, the printing layer thickness was set to 50 μm, and the exposure powers for photocuring in Examples 21 to 25 were 2.0 mW / cm 2 、4.0 mW / cm 2 、11.6 mW / cm 2 、18.6 mW / cm 2 and 28.0 mW / cm 2 The scanning electron micrographs of the cross-sections of the composite materials prepared in Examples 21 to 25 are shown respectively in Figure 2 Figures (e-1) to (e-5) in
[0065] Examples 26 to 31
[0066] First, nano-silica, 7 g of ethanol and 0.001 g of carbon black were mixed and ultrasonically treated for 1 hour; then, 0.031 g of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), 5.01 g of ethylene glycol phenyl acrylate, 0.59 g of hydroxybutyl acrylate and 0.63 g of polyethylene glycol dimethacrylate were added and ultrasonic treatment was continued for half an hour; finally, the mixture was placed in an oven at 70 °C for 8 hours to remove ethanol, and an acrylate dispersion of silica was prepared. Among them, the particle size of the nano-silica was 128 ± 6 nm.
[0067] A transparent perfluoroethylene propylene copolymer film is set at the bottom of the material tank of the 3D printer. The dispersion liquid is placed in the material tank of the 3D printer, and the 3D printer is used to perform layer-by-layer photocuring on the dispersion liquid to obtain a square thin sheet with a side length of 1 cm and a thickness of 1 mm. When performing photocuring, the printing layer thickness is set to 50 μm, and the exposure power for photocuring is 2.0 mW / cm 2 In Examples 26 - 31, the dosages of nano-silica are 0.67 g, 1.33 g, 2.0 g, 2.67 g, 3.33 g, and 4 g respectively. The scanning electron microscope images of the cross-sections of the composite materials prepared in Examples 26 - 31 are respectively shown in Figure 3 Figures (a) - (f) in
[0068] Example 32
[0069] First, 2 g of nano-silica, 7 g of ethanol, and 0.001 g of carbon black are mixed and ultrasonically treated for 1 hour; then, 5.01 g of ethylene glycol phenyl acrylate, 0.59 g of hydroxybutyl acrylate, and 0.63 g of polyethylene glycol dimethacrylate are added and ultrasonically treated for another half hour; then, the mixed solution is placed in an oven at 70 °C for 8 hours to remove ethanol; finally, 0.062 g of azobisisobutyronitrile (AIBN) is added and ultrasonically treated for 1 minute to prepare an acrylate dispersion liquid of silica. Among them, the particle size of the nano-silica is 128 ± 6 nm.
[0070] The dispersion liquid is dropped onto a glass slide and covered with a perfluoroethylene propylene copolymer film, and then placed in an oven to be cured at 80 °C for 5 hours to obtain a film with a thickness of about 150 μm. The scanning electron microscope image of the cross-section of the composite material prepared in this example is shown in Figure 4 。
[0071] Examples 33 - 40
[0072] First, 2 g of nano-silica, 7 g of ethanol, and 0.001 g of carbon black are mixed and ultrasonically treated for 1 hour; then, 0.031 g of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), 5.01 g of ethylene glycol phenyl acrylate, 0.59 g of hydroxybutyl acrylate, and 0.63 g of polyethylene glycol dimethacrylate are added and ultrasonically treated for another half hour; finally, the mixed solution is placed in an oven at 70 °C for 8 hours to remove ethanol to prepare an acrylate dispersion liquid of silica.
[0073] A transparent perfluoroethylene propylene copolymer film is set at the bottom of the material tank of the 3D printer. The dispersion liquid is placed in the material tank of the 3D printer, and the 3D printer is used to perform layer-by-layer photocuring on the dispersion liquid to obtain a square thin sheet with a side length of 1 cm and a thickness of 1 mm. When performing photocuring, the printing layer thickness is set to 50 μm, and the exposure power for photocuring is 2.0 mW / cm 2 。
[0074] In Examples 33 to 40, the particle sizes of the nano-silica used were 104±5 nm, 128±6 nm, 154±7 nm, 174±6 nm, 194±7 nm, 223±8 nm, 247±7 nm, and 286±6 nm, respectively. The scanning electron microscope images of the cross-sections of the composite materials prepared in Examples 33 to 40 are shown in Figure 5 Figures (a) to (h) in
[0075] Examples 41 to 52
[0076] First, 2 g of nano-silica, 7 g of ethanol, and 0.001 g of carbon black were mixed and ultrasonically treated for 1 hour; then, 0.031 g of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) and 6.23 g of acrylate were added and ultrasonically treated for another half hour; finally, the mixture was placed in an oven at 70 °C for 8 hours to remove ethanol, obtaining an acrylate dispersion of silica. Among them, the particle size of the nano-silica was 128±6 nm.
[0077] A transparent perfluoroethylene propylene copolymer film was set at the bottom of the material tank of the 3D printer. The dispersion was placed in the material tank of the 3D printer, and the dispersion was subjected to layer-by-layer photocuring using the 3D printer to obtain a square thin sheet with a side length of 1 cm and a thickness of 1 mm; during photocuring, the printing layer thickness was set to 50 μm, and the exposure power for photocuring was 2.0 mW / cm 2 .
[0078] The acrylate resins used in Examples 41 to 52 were ethylene glycol phenyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, hexanediol diacrylate, dipropylene glycol diacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, and bis-trimethylolpropane tetraacrylate, respectively.
[0079] The scanning electron microscope images of the cross-sections of the composite materials prepared in Examples 41 to 52 are shown in Figure 6 Figures (a) to (l) in
[0080] Examples 53 to 56
[0081] First, 2 g of nanoparticles, 7 g of ethanol, and 0.001 g of carbon black were mixed and ultrasonically treated for 1 hour; then, 0.031 g of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), 5.01 g of ethylene glycol phenyl acrylate, 0.59 g of hydroxybutyl acrylate, and 0.63 g of polyethylene glycol dimethacrylate were added and ultrasonication continued for half an hour; finally, the mixture was placed in an oven at 70 °C for 8 hours to remove ethanol, obtaining an acrylate dispersion of silica.
[0082] A transparent perfluoroethylene propylene copolymer film was set at the bottom of the trough of the 3D printer. The dispersion was placed in the trough of the 3D printer, and the dispersion was subjected to layer-by-layer photocuring using the 3D printer to obtain a square thin sheet with a side length of 1 cm and a thickness of 1 mm; during photocuring, the printing layer thickness was set to 50 μm, and the exposure power for photocuring was 2.0 mW / cm 2 .
[0083] The nanoparticles used in Examples 53 to 56 were zinc sulfide with a particle size of 112 ± 5 nm, titanium dioxide with a particle size of 300 ± 115 nm, polystyrene with a particle size of 156 ± 12 nm, and zinc sulfide coated with silica with a particle size of 165 ± 6 nm. Among them, the silica shell layer of the zinc sulfide coated with silica was 17 nm thick.
[0084] Examples 57 to 60
[0085] First, 2 g of nano-silica, 7 g of ethanol, and 0.001 g of carbon black were mixed and ultrasonically treated for 1 hour; then, 0.062 g of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), 5.01 g of ethylene glycol phenyl acrylate, 0.59 g of hydroxybutyl acrylate, and 0.63 g of polyethylene glycol dimethacrylate were added and ultrasonication continued for half an hour; finally, the mixture was placed in an oven at 70 °C for 8 hours to remove ethanol, obtaining an acrylate dispersion of silica. Among them, the particle size of the nano-silica was 128 ± 6 nm.
[0086] A transparent perfluoroethylene propylene copolymer film was set at the bottom of the trough of the 3D printer. The dispersion was placed in the trough of the 3D printer to obtain a square thin sheet with a side length of 1 cm and a thickness of 1 mm; during photocuring, the printing layer thickness was set to 0.1 mm, and the exposure power was 2.0 mW / cm 2 .
[0087] The materials of the films set on the bottom surface of the trough in Examples 57 to 60 were: polydimethylsiloxane, polyethylene terephthalate, polymethyl methacrylate, and polymethyl methacrylate coated with silicone oil.
[0088] Examples 61 to 65
[0089] First, 4 g of nano-silica, 7 g of ethanol, and 0.001 g of carbon black were mixed and ultrasonically treated for 1 hour; then, 0.062 g of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), 5.01 g of ethylene glycol phenyl acrylate, 0.59 g of hydroxybutyl acrylate, and 0.63 g of polyethylene glycol dimethacrylate were added and ultrasonication continued for half an hour; finally, the mixture was placed in an oven at 70 °C for 8 hours to remove ethanol, obtaining an acrylate dispersion of silica. Among them, the particle size of the nano-silica was 194 ± 7 nm.
[0090] A transparent perfluoroethylene propylene copolymer film was set at the bottom of the trough of the 3D printer, the dispersion was placed in the trough of the 3D printer, and the dispersion was subjected to layer-by-layer photocuring using the 3D printer to obtain a square thin sheet with a side length of 1 cm and a thickness of 1 mm; when performing photocuring, the printing layer thickness was set to 50 μm. The exposure powers for photocuring in Examples 61 - 65 were 2.0 mW / cm 2 、4.0 mW / cm 2 、11.6 mW / cm 2 、18.6 mW / cm 2 and 28.0 mW / cm 2 .
[0091] Examples 66 - 67
[0092] First, 4 g of nano-silica, 7 g of ethanol, and 0.001 g of carbon black were mixed and ultrasonically treated for 1 hour; then, 0.062 g of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), 5.01 g of ethylene glycol phenyl acrylate, 0.59 g of hydroxybutyl acrylate, and 0.63 g of polyethylene glycol dimethacrylate were added and ultrasonication continued for half an hour; finally, the mixture was placed in an oven at 70 °C for 8 hours to remove ethanol, obtaining an acrylate dispersion of silica. Among them, the particle size of the nano-silica was 194 ± 7 nm.
[0093] A transparent perfluoroethylene propylene copolymer film was set at the bottom of the trough of the 3D printer, and the dispersion was placed in the trough of the 3D printer. The 3D printer can separately set the exposure power for different exposure areas, thereby regulating the layer thickness of the nanoparticles, and the layer thickness affects the color display characteristics. Therefore, in this example, a 3D printer was used for structural color pattern printing. The slicing software of the 3D printer was used to convert the grayscale pattern into a slice file, and the exposure power of different exposure areas was controlled according to the slice file. The maximum exposure power was 32 mW / cm 2 , thereby obtaining a structural color pattern, as shown in Figures 13 - 14 . The structural color patterns printed in Examples 66 - 67 were a panda and a landscape painting, respectively, Figures 13 - 14The optical characteristics of the structural color patterns shown indicate the application prospects of this application in the field of optical anti-counterfeiting materials.
[0094] For the scanning electron microscope images of the cross-sections of the composite materials prepared in Examples 1 to 25 of this application, see Figure 2 , Figure 2 in which the abscissa represents the exposure power and the ordinate represents the TPO content, that is, the percentage of the mass of TPO in the mass of acrylate. Figure 2 It shows the variation trend of the hierarchical thickness of the nanoparticles with the amount of photoinitiator and the exposure power. By controlling the amount of photoinitiator or the exposure power, the polymerization reaction kinetics can be controlled, so as to obtain composite materials with different hierarchical thicknesses.
[0095] For the scanning electron microscope images of the cross-sections of the composite materials prepared in Examples 26 to 31 of this application, see Figure 3 , Figures (a) to (f) correspond to Examples 26 to 31 respectively, and the amount of nano-silica gradually increases, from Figure 3 It can be seen that composite materials with different hierarchical thicknesses can also be obtained by controlling the amount of nanoparticles.
[0096] For the scanning electron microscope image of the cross-section of the composite material prepared in Example 32 of this application, see Figure 4 , in Example 32, the thermal curing method is adopted. Due to the slowdown of the polymerization rate of the resin monomer under thermal curing, the layering of the nanoparticles in the composite material is obvious and the enrichment degree of the nanoparticles is large.
[0097] For the scanning electron microscope images of the cross-sections of the composite materials prepared in Examples 33 to 40 of this application, see Figure 5 , Figures (a) to (h) correspond to Examples 33 to 40 respectively. As the figures go from left to right, the corresponding particle sizes of the nano-silica gradually increase, from Figure 5 It can be seen that the influence of the particle size of the nanoparticles in the range of hundreds of nanometers on the layering degree can be ignored.
[0098] For the scanning electron microscope images of the cross-sections of the composite materials prepared in Examples 41 to 52 of this application, see Figure 6 , which shows the layering of nano-silica particles in different types of acrylates. From Figure 6 it can be seen that the nanoparticles can achieve layering in a variety of acrylates.
[0099] For the scanning electron microscope images of the cross-sections of the composite materials prepared in Examples 53 to 56 of this application, see Figure 7 , Figure 7 (a) to 7(d) correspond to zinc sulfide, titanium dioxide, polystyrene, and zinc sulfide coated with silica respectively. From Figure 7 it can be seen that different types of nanoparticles can achieve layering in the composite material.
[0100] SEM images of the cross-sections of the composite materials prepared in Examples 57 to 60 are shown in Figure 8 , Figure 8 (a) - 8(d) correspond to substrates of polydimethylsiloxane, polyethylene terephthalate, polymethyl methacrylate, and polymethyl methacrylate coated with silicone oil respectively. It can be seen that Figure 8 layered structures can be achieved using different types of low surface energy substrate nanoparticles.
[0101] Please refer to Figure 9 , which shows a schematic diagram of the light reflection mechanism of the composite material prepared in this application. Among them, Figure 9 (a) and Figure 9 (b) are two chromaticity modes of different types of structural colors of the composite material, Figure 9 (c) is a schematic diagram of the infrared reflection mechanism of the composite material.
[0102] For the composite material with layered nanoparticles in this application, the exposed surface refers to the surface where nanoparticles are enriched. On the enriched surface, nanoparticles are closely and disorderly packed, and the short-range correlation makes the exposed surface have the color of a photonic glass. The backlight surface is the opposite surface of the exposed surface, which maintains the original ordered structure and shows the color of a photonic crystal. Figures 10 - 11 Shown are the visible light reflection spectra of the exposed surface and the backlight surface of the composite material prepared in the examples. The visible light reflection spectra were recorded using a microscopic spectrometer CRAIC 20 / 30PV Pro, with a 100W halogen lamp as the light source and white Teflon tape as the white standard. It can be seen that Figures 10 - 11 by changing the dosage and particle size of nano-silica, the colors of the exposed surface and the backlight surface of the composite material can be adjusted.
[0103] Using a KBr beam splitter and an MCT detector, with a gold mirror as the total reflection standard, the infrared reflection spectra of the exposed surfaces of the composite materials prepared in Examples 61 to 65 were measured using an infrared microscopic spectroscopy system (Hyperion 1000, Bruker), as shown in Figure 12 . It can be seen that Figure 12 by controlling the exposure power, the degree of nanoparticle layering in the composite material can be controlled, thereby affecting the infrared light reflection ability of the exposed surface of the composite material.
[0104] The DLP printer can set the exposure power of different exposure areas as needed to regulate the degree of nanoparticle layering in different areas. Since the composite material prepared in this application has a certain transparency, when the degree of nanoparticle layering is small, the exposed surface can also show the structural color of the backlight surface photonic crystal. Based on the above principle, grayscale printing can be used to obtain structural color patterns with different chromaticity characteristics. Please refer to Figures 13 - 14 .
[0105] This structural color pattern is produced by different structural color development mechanisms, so it has differentiated angle dependence and can show different angle dependence under the naked eye. The exposure power of the panda pattern is low when printing, mainly showing the color of the photonic glass, and its color changes very little when the illumination angle changes; but the background exposure power is high, mainly showing the color of the photonic crystal, and its color changes greatly when the illumination angle changes. This structural color pattern has application value in fields such as optical anti-counterfeiting.
[0106] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present application.
Claims
1. A method for preparing a composite material with a nanoparticle layer structure, characterized in that, Comprising: a) Dispersing nanoparticles, an initiator, and a light absorber in acrylate to obtain a dispersion; b) Placing the dispersion on a low surface energy substrate for curing of the acrylate, wherein the surface energy of the low surface energy substrate should be lower than the surface energy of the composite matrix, and the composite matrix refers to the resin matrix obtained by polymerization of the acrylate.
2. The preparation method according to claim 1, characterized in that: The average particle size of the nanoparticles is 20 nm to 500 nm.
3. The preparation method according to claim 1, characterized in that: The surface energy of the low surface energy substrate is not greater than 40 mN / m.
4. The preparation method according to claim 1, characterized in that: The mass percentage of the nanoparticles in the dispersion is 5% to 40%; and the dosage of the initiator is 0.1% to 10% of the mass of the acrylate; and the dosage of the light absorber is 0 to 1% of the mass of the acrylate.
5. The preparation method according to claim 1, characterized in that: The nanoparticles are one or more of silica, zinc sulfide, titanium dioxide, polystyrene, and zinc sulfide coated with silica.
6. The preparation method according to claim 1, characterized in that: The initiator is diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, or azobisisobutyronitrile.
7. The preparation method according to claim 1, characterized in that: The light absorber is one or more of carbon black, carbon nanotubes, graphene, and polydopamine.
8. The preparation method according to claim 1, characterized in that: The acrylate is one or more of ethylene glycol phenyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, hexanediol diacrylate, dipropylene glycol diacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, and bis-trimethylolpropane tetraacrylate.
9. The preparation method according to claim 1, characterized in that: The low surface energy substrate is a copolymer of perfluoroethylene propylene, Teflon, polydimethylsiloxane, polyethylene terephthalate, or polymethyl methacrylate substrate, or a substrate surface-modified with an oligomer of a copolymer of perfluoroethylene propylene, Teflon, polydimethylsiloxane, polyethylene terephthalate, or polymethyl methacrylate.
10. A method for preparing a structural color material, characterized in that, Comprising: Placing the dispersion described in claim 1 on a low surface energy substrate, and performing single-layer photocuring or layer-by-layer photocuring on the dispersion; The exposure power of each layer is the same or different, and the exposure power of different regions in each layer is the same or different.