A method for achieving structural color patterning by controlling the wrinkles of a double-layer system based on inorganic salt inkjet

Abstract

This application discloses a method for achieving structural color patterning of a double-layer system by regulating the wrinkles of a double-layer system through inorganic salt inkjet printing, which relates to the field of optical information patterning technology. The method comprises: stirring and mixing polydimethylsiloxane and a curing agent in a mass ratio of 10:1, centrifuging, and curing at 60°C for 8 hours to obtain a cured polydimethylsiloxane; spin-coating a PVA solution on a substrate at a rotation speed of 500-9500 rpm to obtain a double-layer system; inkjet printing an inorganic salt solution on the double-layer system to obtain a double-layer system printed with an inkjet pattern; and sequentially stretching and releasing the double-layer system printed with the inkjet pattern to form a structural color pattern. In this way, the technology for achieving structural color patterning does not require the substrate itself, but only requires spin coating and inkjet printing on the substrate. The structural color patterning method is simple to operate, practical, low-cost, and also convenient for large-scale production. The pattern acquisition conditions are simple, requiring only stretching and release.

Description

Technical Field

[0001] The present application relates to the technical field of optical information patterning, and in particular to a method for achieving structural color patterning by regulating the wrinkles of a double-layer system based on inorganic salt inkjet. Background Art

[0002] With the advancement of science and technology, surface science is playing an increasingly important role in fields such as materials science, optics, and biology. Structural color, a non-pigmented color produced by microscopic structures, has garnered widespread attention due to its unique optical properties and environmental friendliness. Structural color is widely found in nature, such as butterfly wings and bird feathers, and its generation is primarily based on physical processes such as interference, diffraction, and scattering of light. In recent years, researchers have been dedicated to developing various artificial structural color materials to mimic these natural phenomena.

[0003] Among the numerous methods for creating structural color materials, methods based on wrinkling a polymer bilayer system have attracted considerable attention due to their simplicity and efficiency. This method typically involves coating a hard polymer film on a pre-stretched elastic substrate. The pre-stress is then released, causing the hard polymer layer to develop a periodic wrinkled structure. These wrinkled structures can produce specific structural color effects by altering the propagation path of light. However, traditional wrinkling methods often require complex physical or chemical processing steps and struggle to achieve fine patterning control.

[0004] Compared with the preparation of a gradient double-layer system material and its application in anti-counterfeiting labels in patent CN103578353A, the pattern achieved by this patent requires ultraviolet exposure, the preparation process is complex, the cost is high, and fine pattern control cannot be achieved.

[0005] In order to solve these problems, a method of regulating the wrinkles of a double-layer system based on inorganic salt inkjet printing technology came into being. Summary of the Invention

[0006] In order to solve the above-mentioned technical problems existing in the prior art, the present application provides a method for achieving structural color patterning by regulating the wrinkles of a double-layer system based on inorganic salt inkjet, so as to solve the technical problems in the prior art of high preparation process, high cost and inability to achieve fine patterning control.

[0007] In order to achieve the above objectives, the technical solutions of the embodiments of the present application are:

[0008] The first aspect of the present application provides a method for achieving structural color patterning by regulating the wrinkles of a double-layer system based on inorganic salt inkjet, comprising:

[0009] The polydimethylsiloxane and the curing agent were stirred and mixed in a mass ratio of 10:1, centrifuged, and then cured at 60° C. for 8 h to obtain cured polydimethylsiloxane;

[0010] The cured polydimethylsiloxane is used as a base material, and the PVA solution is spin-coated on the base material at a rotation speed of 500 to 9500 rpm to obtain a double-layer system;

[0011] inkjet printing an inorganic salt solution on the double-layer system to obtain a double-layer system printed with an inkjet pattern;

[0012] The double-layer system printed with the inkjet pattern is stretched and released in sequence to form a structural color pattern; there is a difference between the inkjet area with the structural color pattern and the non-inkjet area, and the structural color pattern disappears under humidity response and reappears under mechanical response.

[0013] In combination with the first aspect, preferably, the centrifugal speed is 5000-8000 rpm, and the centrifugal time is 8-15 min.

[0014] In combination with the first aspect, preferably, the base material has a thickness of 1 to 2 mm.

[0015] In combination with the first aspect, preferably, the amount of the PVA solution added is 50 to 500 μL.

[0016] In combination with the first aspect, preferably, the inorganic salt solution is one or more of LiCl solution and NaCl solution.

[0017] In combination with the first aspect, preferably, the distance between two inkjet points in the inkjet pattern is 10-100 μm.

[0018] In combination with the first aspect, preferably, when performing inkjet printing, the inkjet pressure is 0-50 bar, the nozzle temperature is 0-50° C., the printing frequency is 0-5000 Hz, the voltage waveform is the preset waveform of the microelectronic printer, and the inkjet voltage is 0-35V.

[0019] In combination with the first aspect, preferably, during the stretching, the stretching pre-strain is 10 to 100%.

[0020] In combination with the first aspect, preferably, there is a difference between the inkjet area and the non-inkjet area having the structural color pattern, including: the inkjet area has no wrinkles, and the non-inkjet area has wrinkles.

[0021] Compared with the prior art, the advantages or beneficial effects of the embodiments of the present application include at least:

[0022] The embodiment of the present application provides a method for achieving structural color patterning by regulating the wrinkles of a double-layer system based on inorganic salt inkjet. On the one hand, under a certain ratio, a rigid material is spin-coated on a soft base material to form a double-layer system. Due to the mismatch of the elastic modulus of the double-layer system, the wrinkles on the surface of the double-layer system are generated by releasing the double-layer film after uniaxial stretching; on the other hand, the ions in the inorganic salt solution can destroy the hydrogen bonds between the PVA chains to achieve the regulation of the wrinkles, and the wrinkles will affect the formation of its structural color, resulting in no structural color in the inkjet area and structural color in the non-inkjet area; thirdly, The technology for achieving structural color patterning does not need to focus on the base material itself, but only requires spin coating and inkjet printing on the base material. The structural color patterning method is simple to operate, practical, low-cost, and easy to mass produce; fourthly, the structural color patterning method can achieve patterning simply and quickly, and the conditions for obtaining the pattern are simple, only requiring stretching and then releasing; the structural color patterning method is of a higher level, and patterning can only be achieved when a certain amount of stretching is reached, and the inkjet printing technology can accurately control the printing position of the ink; fifthly, the method has a high degree of precision and is easy to achieve the disappearance and appearance of the pattern.

[0023] The method provided in this application can be applied to various fields, such as patterning on device packaging and patterning on labels. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a sample diagram of the double-layer system material in Example 1;

[0025] Figure 2 A sample image of a double-layer system printed with an inkjet pattern provided in Example 1;

[0026] Figure 3 The patterned sample image with a structural color pattern provided in Example 1;

[0027] Figure 4 This is a sample image of patterned elimination of a structural color pattern in response to humidity in Example 1;

[0028] Figure 5 This is a sample image of patterned reproduction of a structural color pattern under mechanical response in Example 1;

[0029] Figure 6 This is a structural diagram of the inkjet area and the non-inkjet area of ​​Example 1 under a micro microscope. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limiting this application. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0031] In the following description, reference is made to "some embodiments," which describe a subset of all possible embodiments. However, it will be understood that "some embodiments" may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict. Unless otherwise defined, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by those skilled in the art to which the embodiments of this application pertain. The terms used in the embodiments of this application are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0032] In the following description of this embodiment, the terms "include", "comprising", "having" and "containing" are open-ended terms, meaning including but not limited to.

[0033] It should be noted that all raw materials / reagents in the examples of the present application can be purchased on the market or prepared according to conventional methods familiar to those skilled in the art; the term "and / or" in the examples of the present application is only used to describe the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B represents three situations: A exists alone, B exists alone, and A and B exist at the same time, wherein A and B can be singular or plural, and the character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship.

[0034] In the following description of this embodiment, the term "at least one" refers to one or more, and "plurality" refers to two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0035] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0036] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0037] It will be understood by those skilled in the art that the numerical ranges in the examples of this application are to be understood as also specifically disclosing each intermediate value between the upper and lower limits of the ranges. Each smaller range between any stated value and the intermediate value in the stated range, as well as any other stated value or intermediate value in the stated range, is also encompassed by this application. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

[0038] Unless otherwise indicated, the technical / scientific terms used herein have the same meanings as those generally understood by those skilled in the art described in this application. Although this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the embodiments or test examples of this application. All documents mentioned in this specification are generally incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of any conflict with any incorporated document, the content of this application shall prevail.

[0039] It should be noted that all raw materials and / or reagents in the examples of the present application were purchased on the market or prepared according to conventional methods well known to those skilled in the art.

[0040] In a first aspect, the present invention provides a method for achieving structural color patterning by controlling the wrinkles of a double-layer system by inkjet printing with inorganic salts, comprising:

[0041] The polydimethylsiloxane and the curing agent were stirred and mixed in a mass ratio of 10:1, centrifuged, and then cured at 60° C. for 8 h to obtain cured polydimethylsiloxane;

[0042] The cured polydimethylsiloxane is used as a base material, and the PVA solution is spin-coated on the base material at a rotation speed of 500 to 9500 rpm to obtain a double-layer system;

[0043] inkjet printing an inorganic salt solution on the double-layer system to obtain a double-layer system printed with an inkjet pattern;

[0044] The double-layer system printed with the inkjet pattern is stretched and released in sequence to form a structural color pattern; there is a difference between the inkjet area with the structural color pattern and the non-inkjet area, and the structural color pattern disappears under humidity response and reappears under mechanical response.

[0045] The embodiment of the present application provides a method for achieving structural color patterning by regulating the wrinkles of a double-layer system based on inorganic salt inkjet. On the one hand, under a certain ratio, a rigid material is spin-coated on a soft base material to form a double-layer system. Due to the mismatch of the elastic modulus of the double-layer system, the wrinkles on the surface of the double-layer system are generated by releasing the double-layer film after uniaxial stretching; on the other hand, the ions in the inorganic salt solution can destroy the hydrogen bonds between the PVA chains to achieve the regulation of the wrinkles, and the wrinkles will affect the formation of its structural color, resulting in no structural color in the inkjet area and structural color in the non-inkjet area; thirdly, The technology for achieving structural color patterning does not need to focus on the base material itself, but only requires spin coating and inkjet printing on the base material. The structural color patterning method is simple to operate, practical, low-cost, and easy to mass produce; fourthly, the structural color patterning method can achieve patterning simply and quickly, and the conditions for obtaining the pattern are simple, only requiring stretching and then releasing; the structural color patterning method is of a higher level, and patterning can only be achieved when a certain amount of stretching is reached, and the inkjet printing technology can accurately control the printing position of the ink; fifthly, the method has a high degree of precision and is easy to achieve the disappearance and appearance of the pattern.

[0046] The present application provides a method for achieving structural color patterning by regulating the wrinkles of a double-layer system based on inorganic salt inkjet. First, a soft base material is synthesized and a layer of rigid material is spin-coated on the base. Due to the different properties of the double-layer materials, the elastic modulus of the double-layer system does not match, and the surface wrinkles are generated by uniaxial stretching and then releasing the double-layer film. It is worth noting that in the double-layer system, the wrinkles are regulated by an inorganic salt solution. The pattern used for inkjet is formed by the ions in the inorganic salt solution destroying the hydrogen bonds between the PVA chains, thereby affecting the formation of its wrinkles. Because the wrinkles affect its structural color, no structural color is generated in the inkjet area, while there is structural color in the non-inkjet area. This is the main reason why patterning can be achieved by forming a pattern with structural color.

[0047] It should be noted that the purpose of the centrifugal treatment is to remove bubbles generated when polydimethylsiloxane reacts with the curing agent.

[0048] It should be noted that the cured polydimethylsiloxane sample needs to be cut into samples with a size of 2.5 cm×2.5 cm.

[0049] It should be noted that the concentration of the PVA solution is 6-10 wt %, and the PVA model is 1788.

[0050] It should be noted that the device used for inkjet printing is a microelectronic printer.

[0051] In a specific embodiment, the centrifugal speed of the embodiment of the present application is preferably 5000-8000 rpm, and the centrifugal time is preferably 8-15 min.

[0052] Excessively high centrifugal speeds can cause excessive agitation of the mixture, leading to heating or unnecessary stress, which can affect material properties. Excessively low centrifugal speeds can prevent complete bubble removal, potentially leading to defects within the cured material. Furthermore, sufficient centrifugation time ensures thorough mixing of the PDMS base and curing agent, preventing inconsistent material properties caused by uneven mixing.

[0053] In a specific embodiment, the thickness of the base material of the embodiment of the present application is preferably 1 to 2 mm.

[0054] When the substrate is relatively thick, its bending stiffness is high and deformation is not easy to occur. The stress transfer efficiency at the film-substrate interface will be reduced, resulting in the need for greater external force to wrinkle the film. Wrinkle formation may be inhibited, so that wrinkling can only be observed under greater tensile strain. When the substrate is thin, due to its easy deformation, the shape and position of the wrinkles may change dynamically with changes in external force, increasing the instability and variability of the wrinkles.

[0055] In a specific embodiment, the amount of the PVA solution added in the embodiment of the present application is preferably 50 to 500 μL.

[0056] If the amount of PVA added is too much, the top film will be too thick, thus affecting the formation of structural color. If the amount of PVA added is too little, the edge of the top film cannot be spin-coated.

[0057] In a specific embodiment, the inorganic salt solution of the embodiment of the present application is preferably one of LiCl solution and NaCl solution.

[0058] In a specific embodiment, the distance between two inkjet points in the inkjet pattern of the embodiment of the present application is preferably 10-100 μm.

[0059] In a specific embodiment, when performing inkjet printing in the embodiment of the present application, the inkjet pressure is preferably 0-50 bar, the nozzle temperature is preferably 0-50°C, the printing frequency is preferably 0-5000Hz, the voltage waveform is preferably the preset waveform of the microelectronic printer, and the inkjet voltage is 0-35V.

[0060] Among them, a frequency that is too high will cause the ink to be discharged too quickly, and a frequency that is too low will cause the ink to be discharged too slowly. Both too high and too low frequencies will affect the patterning effect printed on the double-layer system.

[0061] In a specific embodiment, when stretching is performed in the embodiment of the present application, the stretching pre-strain is preferably 10 to 100%.

[0062] In a specific embodiment, there is a difference between the inkjet area and the non-inkjet area with the structural color pattern in the embodiment of the present application. Preferably, the inkjet area does not form wrinkles, while the non-inkjet area does form wrinkles.

[0063] The advantage of the method provided in this application lies in its non-contact operation, which allows for the rapid and accurate generation of complex structural color patterns on substrates. Furthermore, by adjusting the type and concentration of inorganic salts, the period and depth of wrinkles can be controlled, thereby adjusting the hue, brightness, and other optical properties of the structural color. Therefore, the method of controlling the wrinkles of a double-layer system using inorganic salt inkjet printing provides new ideas and technical support for the preparation and application of structural color materials.

[0064] The technical method of the present application will be further described below with reference to specific embodiments.

[0065] Example 1

[0066] This embodiment 1 provides a method for achieving structural color patterning by regulating the wrinkles of a double-layer system based on inorganic salt inkjet, and the specific steps are as follows:

[0067] (1) 18.3 g of the main agent polydimethylsiloxane and 1.83 g of the curing agent were mixed in a centrifuge tube and stirred for 10 min. The mixture was centrifuged at a speed of 5000 rpm for 10 min to remove the bubbles generated during stirring. After centrifugation, the mixture was poured into a 13 cm × 13 cm culture dish and cured at 60 ° C for 8 h. The sample was cut into 2.5 cm × 2.5 cm samples to obtain the polydimethylsiloxane substrate.

[0068] (2) 1.6 g of PVA was dissolved in 18.4 mL of pure water. 130 μL of the prepared PVA solution was spin-coated on a polydimethylsiloxane substrate at a speed of 7500 rpm for 60 s to obtain a double-layer system.

[0069] (3) 2 mL of 40 wt% inorganic salt solution was loaded into the inkjet ink bag. The inkjet pressure was 0, the nozzle temperature was 25°C, the printing frequency was 4000 Hz, the voltage waveform was the preset waveform of the microelectronic printer, and the inkjet voltage was 0-35 V.

[0070] (4) The sample is clamped in a uniaxially stretchable fixture and then stretched with a pre-strain of 10 to 100% for 0 to 30 minutes. The sample is then restored to its original shape, thereby forming a pattern with structural color.

[0071] In order to verify the patterning performance of the structural color pattern, the structural color pattern was characterized. The characterization results are as follows: Figures 1 to 6 shown. Figure 1 This is a sample picture of the double-layer system material in Example 1. Figure 2 A sample image of a two-layer system printed with an inkjet pattern provided in Example 1. Figure 3 This is a patterned sample image with a structural color pattern provided in Example 1. Figure 4 This is a sample image of Example 1 with patterned elimination of the structural color pattern in response to humidity. Figure 5 This is a sample image of Example 1 showing patterned reproduction of a structural color pattern under mechanical response. Figure 6 This is a structural diagram of the inkjet area and the non-inkjet area of ​​Example 1 under a micro microscope.

[0072] according to Figure 1 It can be seen that the double-layer system material obtained in Example 1 is in a transparent state without any mechanical response and does not produce any structural color.

[0073] according to Figure 2 It can be seen that in the two-layer system sample printed with the inkjet pattern obtained in Example 1, the pattern is difficult to observe when no structural color is formed.

[0074] according to Figure 3 It can be seen that in the sample with structural color patterning obtained in Implementation Case 1, its response mode is relatively simple, and only mechanical response is required to obtain its result image.

[0075] according to Figure 4 It can be seen that the pattern with structural color obtained in Example 1 is exhaled to increase the effect of humidity on the wrinkles of the sample, so that the pattern with structural color of the sample disappears, and then stretched with a pre-strain of 10 to 100%, and then the sample is restored to its original shape, thereby realizing the pattern with structural color.

[0076] The results refer to Figure 5 , Example 5 was repeated five times, achieving both patterning with a structural color pattern and erasing the structural color pattern. This demonstrates that the structural color patterning produced by the double-layer film in this application can be repeatedly patterned. That is, after the structural color patterning is eliminated by high humidity, the structural color patterning can be re-created, thus achieving the reuse of pattern labeling.

[0077] according to Figure 6 It can be seen that no wrinkles are formed in the inkjet area, while wrinkles are formed in the non-inkjet area, thereby forming a structural color pattern.

[0078] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for achieving structural color patterning based on inorganic salt inkjet control of double-layer system wrinkles, characterized in that: include: The polydimethylsiloxane and the curing agent were stirred and mixed in a mass ratio of 10:1, centrifuged, and then cured at 60°C for 8 hours to obtain cured polydimethylsiloxane; The cured polydimethylsiloxane is used as a base material, and the PVA solution is spin-coated on the base material at a rotation speed of 500-9500 rpm to obtain a double-layer system; inkjet printing an inorganic salt solution on the double-layer system to obtain a double-layer system printed with an inkjet pattern; The double-layer system printed with the inkjet pattern is sequentially stretched and released to form a structural color pattern; the inkjet area with the structural color pattern is different from the non-inkjet area, and the structural color pattern disappears in response to humidity and reappears in response to mechanical force; The centrifugal speed is 5000-8000 rpm, and the centrifugation time is 8-15 min; the thickness of the substrate material is 1-2 mm; the amount of the PVA solution added is 50-500 μL; the inorganic salt solution is one or more of a LiCl solution and a NaCl solution; the distance between two inkjet points in the inkjet pattern is 10-100 μm; when performing inkjet printing, the inkjet pressure is 0-50 bar, the nozzle temperature is 0-50°C, the printing frequency is 0-5000 Hz, the voltage waveform is the preset waveform of the microelectronic printer, and the inkjet voltage is 0-35 V.

2. The method for achieving structural color patterning based on inorganic salt inkjet control of double-layer system wrinkles according to claim 1, characterized in that: During the stretching, the stretching prestrain is 10-100%.

3. The method for achieving structural color patterning based on inorganic salt inkjet-controlled double-layer system wrinkles according to claim 1, characterized in that: There is a difference between the inkjet area and the non-inkjet area having the structural color pattern, including: the inkjet area has no wrinkles, and the non-inkjet area has wrinkles.

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