A method for manufacturing a hydrophobic, color-changing, transparent substrate based on soft lithography

Abstract

The application discloses a kind of based on soft photoetching's hydrophobic color-changing transparent substrate manufacturing method, and the application belongs to the field of micro-nano manufacturing.The application is characterized in that semiconductor photoelectric characteristic metal oxide nano material is selected, and the large specific surface area, light transmission and photoelectric characteristic of such nano material are used to carry out large-area multi-scale patterning manufacturing by PDMS soft photoetching technology, to realize simultaneously good light transmission, hydrophobicity and color-changing transparent substrate.The method not only has the characteristics of imprinting technology, such as large area, high efficiency, low cost, simple and reliable, etc., but also can use the large specific surface area of nanoparticle material to adsorb different dyes and its photoelectric characteristics to realize the antifouling, self-cleaning and photochromic properties of transparent substrate, which can be widely used in building glass, automotive glass, optical lenses, optoelectronic device panels and other fields.

Description

Technical Field

[0001] This invention belongs to the field of micro-nano manufacturing technology, specifically relating to a soft imprint lithography method for metal oxide nanoparticle materials. Background Technology

[0002] Superhydrophobic surfaces with high light transmittance have enormous potential applications, including architectural and automotive glass, cultural relic preservation, optical lenses, and photovoltaic devices, showing great promise. While superhydrophobic surfaces possess excellent properties such as self-cleaning, anti-fouling, and anti-fogging, a single superhydrophobic surface is no longer sufficient for daily production and life needs. Hydrophobic surfaces that possess both superhydrophobic properties and maintain their light transmittance without being compromised by a hydrophobic coating structure have become a focus of attention. The wetting behavior of a hydrophobic surface is determined by its surface free energy (chemical composition) and surface roughness (micro / nanostructure morphology). The micro / nanostructure morphology of the surface is a necessary condition for achieving superhydrophobic properties, but it inevitably affects the surface's light transmittance. In particular, the scattering characteristics of visible light by micron-sized structures are particularly pronounced, leading to a significant reduction in light transmittance. However, surface micron-sized structures composed of nanoparticles much smaller than the wavelength of visible light exhibit high light transmittance, such as metal oxide nanomaterials with semiconductor properties like ZnO and TiO2. Furthermore, these nanomaterials possess a large specific surface area and certain photoelectric properties, enabling them to significantly degrade organic pollutants on the coating surface, thus maintaining long-term superhydrophobic properties outdoors and achieving self-cleaning. Therefore, assembling these nanoparticles using micro-nano manufacturing technology to create superhydrophobic surfaces with micro-nano structural morphologies will result in excellent light transmittance.

[0003] Soft lithography is a recently developed method for manufacturing micro- and nanostructures. This method utilizes flexible polymer materials (such as PDMS) to replicate a master mold, creating a soft template for imprinting various micro- and nanostructures. Traditional soft lithography requires combination with UV curing technology, using UV-polymerizable polymers to cure and mold under soft template imprinting conditions to prepare superhydrophobic surface micro- and nanostructures. Therefore, improving traditional manufacturing processes to achieve the direct construction and control of surface material micro- and nanostructures, thereby obtaining superhydrophobic surfaces with high light transmittance and photochromic properties as needed, is a problem that needs to be solved. Summary of the Invention

[0004] This invention provides a method for manufacturing a hydrophobic color-changing transparent substrate based on soft lithography. By utilizing the advantages of nanomaterials, a transparent surface with good light transmittance, hydrophobicity, and the ability to change color as needed is obtained through soft lithography.

[0005] To achieve the above objectives, the present invention provides a method for manufacturing a hydrophobic color-changing transparent substrate based on soft lithography, comprising the following steps:

[0006] S1. Prepare a soft photolithography template with a multi-level structure, wherein the multi-level structure includes a periodic microstructure array and the surface of the periodic microstructure has a submicron-level structure;

[0007] S2. Prepare metal oxide nanoparticle thin films with semiconductor properties on a substrate;

[0008] S3. Soft photolithography is used to form a metal oxide nanoparticle film with semiconductor properties to obtain a nanoparticle film with a metal oxide micro-nano multi-level composite structure.

[0009] S4. The nanoparticle film is cured and demolded to obtain a substrate with a micro-nano composite structure surface;

[0010] S5. Color and photochromic properties are applied to the nanoparticle film on the substrate to obtain a colored transparent substrate. The colored transparent substrate is then subjected to fluorination superhydrophobic treatment to obtain a hydrophobic color-changing transparent substrate.

[0011] Furthermore, the S1 process is as follows: a periodic patterned structure master is prepared on the substrate surface, a flexible polymer material stamp mold is obtained through a flexible polymer material replication process, and then the surface of the flexible polymer material stamp mold is bombarded with plasma to perform submicron-level roughening treatment to obtain a soft photolithography template with micro-nano multi-level structure.

[0012] Furthermore, the flexible polymer material stamp mold has a periodic microstructure array, the spacing of which is denoted as S, the hole diameter as D, and the D / S ratio is 1:16 to 1:5.

[0013] Furthermore, the S2 process involves preparing a nanoparticle slurry by combining nanoparticles, ethanol, and a low-temperature binder, and depositing the nanoparticle slurry onto a substrate to obtain a nanoparticle film of uniform thickness.

[0014] Furthermore, the mass ratio of metal oxide nanoparticles, ethanol, and low-temperature binder is (1-10):(80-100):1.

[0015] Furthermore, the S3 process involves adsorbing a soft photolithography template onto a substrate on which a nanoparticle film has been deposited, allowing the nanoparticle film to fill the cavity of the soft photolithography template, thereby obtaining a nanoparticle film with a metal oxide micro-nano hierarchical composite structure.

[0016] Furthermore, the S4 process involves placing a substrate with a nanoparticle film containing a metal oxide micro-nano multi-level composite structure on a heated surface until the solvent is fully evaporated, thereby solidifying and shaping the substrate. The soft photolithography template is then removed to obtain a substrate with a micro-nano composite structure surface.

[0017] Furthermore, in S5, the process of color and photochromic properties processing is as follows: the transparent substrate with micro-nano composite structure is immersed in a dye solution of the desired color to obtain a colored transparent substrate. The large specific surface area and photoelectric properties of nanoparticle materials are used to adsorb dye molecules to realize the photochromic properties of the transparent substrate.

[0018] Furthermore, in S5, the transparent substrate with the micro-nano composite structure is immersed in a dye solution for more than 3 hours.

[0019] Furthermore, in S5, the fluorination superhydrophobic treatment process is as follows: the colored transparent substrate is immersed in a fluorosilane solution for more than half an hour to allow fluorine molecules to be adsorbed onto the nanoparticles. The colored transparent substrate is then removed and baked to obtain a hydrophobic color-changing transparent substrate.

[0020] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0021] This invention utilizes soft lithography to fabricate metal oxide nanoparticles with semiconductor material properties into thin films with micro-nano hierarchical structures. This ensures both good light transmittance of the transparent substrate and achieves superhydrophobic properties. The superhydrophobic properties of the film are mainly determined by its unique micro-nano hierarchical composite structure. The nanoparticles ensure nanoscale roughness across the entire surface, while plasma etching of the PDMS stamp replicates its submicron-level structure, guaranteeing submicron-level roughness. The periodic micron-level array structure ensures micron-level roughness, reducing the adverse effects of increased gap size on the superhydrophobic properties. The combination of these features... This ensures the superhydrophobic properties of the surface. The micro-nano multi-level composite structure consists of an array of nanoparticles. The diameter of the nanoparticles is much smaller than the wavelength of visible light, resulting in weak light scattering. The micropillar array structure formed by these nanoparticles has large gaps, thus ensuring good light transmittance of the film. As for its color-changing properties, due to the large specific surface area and photoelectric properties of the nanoparticles, different colors and functions of dyes can be adsorbed on the surface of the nanoparticles, achieving a transparent hydrophobic surface with different colors and light response characteristics. At the same time, it can effectively degrade organic pollutants under light, thus maintaining long-term superhydrophobic properties outdoors and achieving self-cleaning.

[0022] This invention overcomes the limitation of low light transmittance in traditional superhydrophobic surfaces by employing metal oxide nanomaterials with semiconductor optoelectronic properties. Leveraging the large specific surface area, light transmittance, and optoelectronic properties inherent in these nanomaterials, large-area, multi-scale patterning is achieved using PDMS soft lithography. This allows for the one-time molding of micro-nano multi-level composite structures of semiconductor metal oxide nanomaterials. This method not only possesses the advantages of imprinting technology, such as large area, high efficiency, low manufacturing cost, and simple and reliable process route, but also utilizes the large specific surface area of ​​the nanoparticles to adsorb different dyes and their optoelectronic properties to achieve anti-fouling, self-cleaning, and photochromic properties of transparent substrates. The resulting micro-nano composite structure surface with transparent, superhydrophobic, and photochromic properties can be widely used in architectural and automotive glass, optical instruments and eyeglass lenses, and optoelectronic devices. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the flexible stamp structure obtained by PDMS replication according to the present invention;

[0024] Figure 2 This is a schematic diagram of a soft photolithography template obtained after plasma surface roughening treatment of the PDMS stamp in this invention.

[0025] Figure 3 This is a schematic diagram illustrating the deposition of nano-slurry onto a transparent substrate using spin coating or screen printing, as described in this invention.

[0026] Figure 4 This is a schematic diagram of the metal oxide nanoparticle micro-nano composite structure fabricated using soft photolithography in this invention;

[0027] Figure 5a This is a schematic diagram of the metal oxide nanoparticle micro-nano composite film after demolding and curing according to the present invention;

[0028] Figure 5b This is a schematic diagram of a metal oxide nanoparticle micro-nano composite structure.

[0029] Figure 6a This is a schematic diagram illustrating the adsorption of different colored dyes on the micro-nano composite structure of metal oxide nanoparticles according to the present invention.

[0030] Figure 6b A schematic diagram of nanoparticles with surface adsorbed dye molecules;

[0031] Figure 7a This is a schematic diagram of the metal oxide nanoparticle micro-nano composite structure after fluorination treatment according to the present invention.

[0032] Figure 7b A schematic diagram showing the re-adsorption of fluorine-containing molecular layers by nanoparticles that adsorb dye molecules.

[0033] In the attached figures: 1. Replicated flexible transparent PDMS stamp; 2. Soft photolithography template; 3. Substrate; 4. Nanoparticle film; 5. Surface of micro-nano composite structure; 6. Submicron-scale structure composed of nanoparticles; 7. Micron-scale array structure; 8. Nanoparticles; 9. Dye molecules; 10. Fluorosilane; R, Submicron-scale surface structure. Detailed Implementation

[0034] To make the objectives and technical solutions of this invention clearer and easier to understand, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0035] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] This invention utilizes soft lithography to fabricate micro / nano structures based on metal oxide nanoparticles. It leverages the mature and widely applied advantages of soft lithography, while also offering convenience and high efficiency, enabling the replication of high-quality micro / nano composite structures. This method is easy to operate, highly reproducible, and a simple and effective way to prepare surfaces that simultaneously possess light transmittance, hydrophobicity, and color-changing properties.

[0037] A process for fabricating a hydrophobic, color-changing transparent substrate based on soft lithography includes the following steps:

[0038] Step 1: Replicating the Flexible PDMS Stamp: A periodic microstructure array master is prepared on the silicon wafer surface using photolithography. A PDMS replication process is then employed to obtain a replica flexible transparent PDMS stamp 1 with a periodic microstructure array. This replica flexible transparent PDMS stamp 1 has a periodic microstructure array with a periodic microstructure array. The period P of the periodic microstructure array is 6μm-1000μm, the spacing S is 5μm-1000μm, the aspect ratio H / D is 1:1 to 8:1, and the aperture diameter D is 1μm-200μm. Preferably, the duty cycle D / P is 1:16-1:5. (Refer to...) Figure 1 As shown;

[0039] The second step involves nano-roughening the replica flexible transparent PDMS stamp 1, referring to... Figure 2 The surface of the flexible transparent PDMS stamp 1, which is replicated by plasma bombardment, has a periodic microstructure array. Submicron-level roughening treatment is performed to improve the roughness of the micron structure on the mold surface, so as to obtain a surface submicron-level structure [R], and obtain a soft photolithography template 2 with a micro-nano composite structure array; the surface submicron-level structure includes various columnar and porous structures smaller than 1μm.

[0040] The third step involves the thin film deposition of a metal oxide nanoparticle slurry with semiconductor optoelectronic properties, as described above. Figure 3 Using a transparent material as a substrate, metal oxide nanoparticles 8, ethanol, and a low-temperature binder are mixed at a mass ratio of (1-10):(80-100):1 to prepare a nanoparticle slurry. The nanoparticle slurry is deposited on a substrate 3 using screen printing, blade coating, or spin coating, forming a uniformly thick nanoparticle film 4 on the substrate 3, resulting in a substrate with deposited nanoparticle film 4. The metal oxide nanoparticles 8 can be any of TiO2 or ZnO, etc. Metal oxide nanoparticles with semiconductor photoelectric properties possess both light transmittance and photoelectric properties. The transparent material can be optical glass, transparent plastic, etc.

[0041] The fourth step is the soft photolithography formation of metal oxide micro-nano composite thin films, referring to... Figure 4 The soft lithography template 2 is placed on a substrate on which the nanoparticle film 4 is deposited. A certain pressure F (1-1000 mN / mm) is applied to the soft lithography template 2. 2 This allows it to adhere to the substrate on which the nanoparticle film 4 is deposited, and the nanoparticle paste of the nanoparticle film 4 fills the cavity of the soft photolithography template 2, such as... Figure 4 As shown; due to the large spacing of the periodic array cavities in the soft lithography template 2, the nanoparticle paste can quickly fill the cavities of the soft lithography template 2. After the nanoparticle paste has filled the cavities, the pressure F is removed, as shown. Figure 4 As shown;

[0042] Step 5, curing and demolding of the metal oxide micro-nano composite thin film, refer to... Figure 5a and Figure 5b After the soft lithography template 2 cavity is filled with nanoparticle slurry, it is placed on a hot plate at 100℃-150℃ and heated for 10-20 minutes. Due to the good permeability of the PDMS soft lithography template 2, the solvent in the nanoparticle film 4 can be fully evaporated, thus solidifying and forming the film. The soft lithography template 2 is then removed to obtain a transparent substrate with a micro-nano composite structure surface 5. (Refer to...) Figure 5b The surface 5 of the micro-nano composite structure includes a bottom surface, on which a micron-level array structure 7 composed of nanoparticles 8 is provided. The micron-level array structure 7 includes several spaced columnar micron-level structures. The bottom surface and the upper end of the micron-level array structure 7 are provided with a submicron-level structure 6 composed of several nanoparticles 8.

[0043] Step 6: Sensitization of the metal oxide micro-nano composite thin film with colored dyes, referring to... Figure 6a and Figure 6b The dried transparent substrate with micro-nano composite structure is immersed in a solution of dye 9 of the desired color for more than 3 hours. Due to the large specific surface area of ​​nanoparticles 8, they can adsorb most of the dye molecules 9, thereby obtaining a colored transparent substrate. For dyes with photochromic properties, the photochromic properties of the transparent substrate can be realized.

[0044] Step 7: Fluorination superhydrophobic treatment of metal oxide micro-nano composite thin films, refer to... Figure 7a and Figure 7b A colored transparent substrate with a micro-nano composite structure for adsorbing dyes is immersed in a low-concentration solution of 0.1wt%-1wt% fluorosilane 10 for more than half an hour, so that most of the fluorine molecules 10 can be adsorbed on the nanoparticles 8. The colored transparent substrate is then removed and baked at a low temperature of 80℃-160℃ for more than 1 hour to obtain a surface with superhydrophobic properties, thus obtaining a hydrophobic color-changing transparent substrate.

[0045] The transparent substrate prepared by the above method has good light transmittance, superhydrophobic properties and photochromic properties.

[0046] Example 1

[0047] S1. PDMS replication process: Using a master template, a replica flexible transparent PDMS stamp 1 with a periodic microstructure array is obtained. This replica flexible transparent PDMS stamp 1 has a periodic microstructure array with a period P of 1000 μm, a duty cycle D / P of 1:5, a hole diameter D of 200 μm, a spacing S of 800 μm, and an aspect ratio H / D of 1:1. (Refer to...) Figure 1 As shown;

[0048] S2, Reference Figure 2 The surface of the flexible transparent PDMS stamp 1, which is replicated by plasma bombardment, has a periodic microstructure array. Submicron-level roughening treatment is performed to improve the roughness of the micron structure on the mold surface, so as to obtain the surface submicron-level structure [R], and obtain a soft photolithography template 2 with a micro-nano composite structure array; the surface submicron-level structure includes various columnar and porous structures smaller than 1μm;

[0049] S3. Reference Figure 3 Using optical glass as a substrate, metal oxide nanoparticles 8, ethanol, and low-temperature binder are mixed in a mass ratio of 1:80:1 to prepare a nanoparticle slurry. The nanoparticle slurry is deposited on the substrate 3 by screen printing, blade coating, or spin coating, and a uniform nanoparticle film 4 is formed on the substrate 3 to obtain a substrate with deposited nanoparticle film 4. The metal oxide nanoparticles 8 can be any one of TiO2 or ZnO, etc. Metal oxide nanoparticles with semiconductor photoelectric properties have light transmittance and photoelectric properties.

[0050] S4, Reference Figure 4 The soft lithography template 2 is placed on a substrate on which the nanoparticle film 4 is deposited, and a pressure of 1 mN / mm is applied to the soft lithography template 2. 2 The pressure F causes it to adhere to the substrate on which the nanoparticle film 4 is deposited, and the nanoparticle paste of the nanoparticle film 4 fills the cavity of the soft photolithography template 2, such as... Figure 4 As shown; due to the large spacing of the periodic array cavities in the soft lithography template 2, the nanoparticle paste can quickly fill the cavities of the soft lithography template 2. After the nanoparticle paste has filled the cavities, the pressure F is removed, as shown. Figure 4 As shown;

[0051] S5. Reference Figure 5a and Figure 5b After the soft lithography template 2 cavity is filled with nanoparticle slurry, it is placed on a hot plate at 100°C and heated for 20 minutes. Due to the good permeability of the PDMS soft lithography template 2, the solvent in the nanoparticle film 4 can be fully evaporated, thus solidifying and forming the film. Then, the soft lithography template 2 is removed, yielding a transparent substrate with a micro-nano composite structure surface 5. (Refer to...) Figure 5b The surface 5 of the micro-nano composite structure includes a bottom surface, on which a micron-level array structure 7 composed of nanoparticles 8 is provided. The micron-level array structure 7 includes several spaced columnar micron-level structures. The bottom surface and the upper end of the micron-level array structure 7 are provided with a submicron-level structure 6 composed of several nanoparticles 8.

[0052] S6, Reference Figure 6a and Figure 5bThe dried transparent substrate with micro-nano composite structure is immersed in a solution of dye 9 of the desired color for more than 3 hours. Due to the large specific surface area of ​​nanoparticles 8, they can adsorb most of the dye molecules 9, thereby obtaining a colored transparent substrate. For dyes with photochromic properties, the photochromic properties of the transparent substrate can be realized.

[0053] S7, Reference Figure 7a and Figure 7b A colored transparent substrate with a micro-nano composite structure for adsorbing dyes is immersed in a low-concentration solution of 0.1 wt% fluorosilane 10 for more than half an hour, so that most of the fluorine molecules 10 can be adsorbed on the nanoparticles 8. The colored transparent substrate is then removed and baked at 80°C for more than 2 hours to obtain a surface with superhydrophobic properties, thus obtaining a hydrophobic color-changing transparent substrate.

[0054] Example 2

[0055] S1. PDMS replication process: Using a master template, a replica flexible transparent PDMS stamp 1 with a periodic microstructure array is obtained. This replica flexible transparent PDMS stamp 1 has a periodic microstructure array with a period P of 800 μm, a duty cycle D / P of 1:10, a hole diameter D of 80 μm, a spacing S of 720 μm, and a depth-to-width ratio H / D of 2:1. (Refer to...) Figure 1 As shown;

[0056] S2, Reference Figure 2 The surface of the flexible transparent PDMS stamp 1, which is replicated by plasma bombardment, has a periodic microstructure array. Submicron-level roughening treatment is performed to improve the roughness of the micron structure on the mold surface, so as to obtain the surface submicron-level structure [R], and obtain a soft photolithography template 2 with a micro-nano composite structure array; the surface submicron-level structure includes various columnar and porous structures smaller than 1μm;

[0057] S3. Reference Figure 3 Using optical glass as a substrate, metal oxide nanoparticles 8, ethanol, and low-temperature binder are mixed in a mass ratio of 5:100:1 to prepare a nanoparticle slurry. The nanoparticle slurry is deposited on the substrate 3 by screen printing, blade coating, or spin coating, and a uniform nanoparticle film 4 is formed on the substrate 3, resulting in a substrate with deposited nanoparticle film 4. The metal oxide nanoparticles 8 can be any one of TiO2 or ZnO, etc. Metal oxide nanoparticles with semiconductor photoelectric properties have both light transmittance and photoelectric properties.

[0058] S4, Reference Figure 4 The soft lithography template 2 is placed on a substrate on which the nanoparticle film 4 is deposited, and a pressure of 10 mN / mm is applied to the soft lithography template 2. 2The pressure F causes it to adhere to the substrate on which the nanoparticle film 4 is deposited, and the nanoparticle paste of the nanoparticle film 4 fills the cavity of the soft photolithography template 2, such as... Figure 4 As shown; due to the large spacing of the periodic array cavities in the soft lithography template 2, the nanoparticle paste can quickly fill the cavities of the soft lithography template 2. After the nanoparticle paste has filled the cavities, the pressure F is removed, as shown. Figure 4 As shown;

[0059] S5. Reference Figure 5a and Figure 5b After the soft lithography template 2 cavity is filled with nanoparticle slurry, it is placed on a hot plate at 110°C and heated for 18 minutes. Due to the good permeability of the PDMS soft lithography template 2, the solvent in the nanoparticle film 4 can be fully evaporated, thus solidifying and forming the film. Then, the soft lithography template 2 is removed, yielding a transparent substrate with a micro-nano composite structure surface 5. (Refer to...) Figure 5b The surface 5 of the micro-nano composite structure includes a bottom surface, on which a micron-level array structure 7 composed of nanoparticles 8 is provided. The micron-level array structure 7 includes several spaced columnar micron-level structures. The bottom surface and the upper end of the micron-level array structure 7 are provided with a submicron-level structure 6 composed of several nanoparticles 8.

[0060] S6, Reference Figure 6a and Figure 5b The dried transparent substrate with micro-nano composite structure is immersed in a solution of dye 9 of the desired color for more than 3 hours. Due to the large specific surface area of ​​nanoparticles 8, they can adsorb most of the dye molecules 9, thereby obtaining a colored transparent substrate. For dyes with photochromic properties, the photochromic properties of the transparent substrate can be realized.

[0061] S7, Reference Figure 7a and Figure 7b A colored transparent substrate with a micro-nano composite structure for adsorbing dyes is immersed in a low-concentration solution of 0.3wt% fluorosilane 10 for more than half an hour, so that most of the fluorine molecules 10 can be adsorbed on the nanoparticles 8. The colored transparent substrate is then removed and baked at 120°C for more than 3 hours to obtain a surface with superhydrophobic properties, thus obtaining a hydrophobic color-changing transparent substrate.

[0062] Example 3

[0063] S1. PDMS replication process: Using a master template, a replica flexible transparent PDMS stamp 1 with a periodic microstructure array is obtained. This replica flexible transparent PDMS stamp 1 has a periodic microstructure array with a period P of 500 μm, a duty cycle D / P of 1:5, a hole diameter D of 100 μm, a spacing S of 400 μm, and a depth-to-width ratio H / D of 4:1. (Refer to...) Figure 1 As shown;

[0064] S2, Reference Figure 2 The surface of the flexible transparent PDMS stamp 1, which is replicated by plasma bombardment, has a periodic microstructure array. Submicron-level roughening treatment is performed to improve the roughness of the micron structure on the mold surface, so as to obtain the surface submicron-level structure [R], and obtain a soft photolithography template 2 with a micro-nano composite structure array; the surface submicron-level structure includes various columnar and porous structures smaller than 1μm;

[0065] S3. Reference Figure 3 Using transparent plastic as a substrate, metal oxide nanoparticles 8, ethanol, and low-temperature binder are mixed in a mass ratio of 10:80:1 to prepare a nanoparticle slurry. The nanoparticle slurry is deposited on the substrate 3 by screen printing, blade coating, or spin coating, and a uniform nanoparticle film 4 is formed on the substrate 3, resulting in a substrate with deposited nanoparticle film 4. The metal oxide nanoparticles 8 can be any one of TiO2 or ZnO, etc. Metal oxide nanoparticles with semiconductor photoelectric properties have both light transmittance and photoelectric properties.

[0066] S4, Reference Figure 4 The soft lithography template 2 is placed on a substrate on which the nanoparticle film 4 is deposited, and an application of 100 mN / mm² is applied to the soft lithography template 2. 2 The pressure F causes it to adhere to the substrate on which the nanoparticle film 4 is deposited, and the nanoparticle paste of the nanoparticle film 4 fills the cavity of the soft photolithography template 2, such as... Figure 4 As shown; due to the large spacing of the periodic array cavities in the soft lithography template 2, the nanoparticle paste can quickly fill the cavities of the soft lithography template 2. After the nanoparticle paste has filled the cavities, the pressure F is removed, as shown. Figure 4 As shown;

[0067] S5. Reference Figure 5a and Figure 5b After the soft lithography template 2 cavity is filled with nanoparticle slurry, it is placed on a hot plate at 120°C and heated for 15 minutes. Due to the good permeability of the PDMS soft lithography template 2, the solvent in the nanoparticle film 4 can be fully evaporated, thus solidifying and forming the film. Then, the soft lithography template 2 is removed, yielding a transparent substrate with a micro-nano composite structure surface 5. (Refer to...) Figure 5b The surface 5 of the micro-nano composite structure includes a bottom surface, on which a micron-level array structure 7 composed of nanoparticles 8 is provided. The micron-level array structure 7 includes several spaced columnar micron-level structures. The bottom surface and the upper end of the micron-level array structure 7 are provided with a submicron-level structure 6 composed of several nanoparticles 8.

[0068] S6, Reference Figure 6a and Figure 5bThe dried transparent substrate with micro-nano composite structure is immersed in a solution of dye 9 of the desired color for more than 3 hours. Due to the large specific surface area of ​​nanoparticles 8, they can adsorb most of the dye molecules 9, thereby obtaining a colored transparent substrate. For dyes with photochromic properties, the photochromic properties of the transparent substrate can be realized.

[0069] S7, Reference Figure 7a and Figure 7b A colored transparent substrate with a micro-nano composite structure for adsorbing dyes is immersed in a low-concentration solution of 0.5wt% fluorosilane 10 for more than half an hour, so that most of the fluorine molecules 10 can be adsorbed on the nanoparticles 8. The colored transparent substrate is then removed and baked at 160℃ for more than 2 hours to obtain a surface with superhydrophobic properties, thus obtaining a hydrophobic color-changing transparent substrate.

[0070] Example 4

[0071] S1. PDMS replication process: Using a master template, a replica flexible transparent PDMS stamp 1 with a periodic microstructure array is obtained. This replica flexible transparent PDMS stamp 1 has a periodic microstructure array with a period P of 160 μm, a duty cycle D / P of 1:16, a hole diameter D of 10 μm, a spacing S of 150 μm, and a depth-to-width ratio H / D of 5:1. (Refer to...) Figure 1 As shown;

[0072] S2, Reference Figure 2 The surface of the flexible transparent PDMS stamp 1, which is replicated by plasma bombardment, has a periodic microstructure array. Submicron-level roughening treatment is performed to improve the roughness of the micron structure on the mold surface, so as to obtain the surface submicron-level structure [R], and obtain a soft photolithography template 2 with a micro-nano composite structure array; the surface submicron-level structure includes various columnar and porous structures smaller than 1μm;

[0073] S3. Reference Figure 3 Using transparent plastic as a substrate, metal oxide nanoparticles 8, ethanol, and low-temperature binder are mixed in a mass ratio of 5:80:1 to prepare a nanoparticle slurry. The nanoparticle slurry is deposited on the substrate 3 by screen printing, blade coating, or spin coating, and a uniform nanoparticle film 4 is formed on the substrate 3, resulting in a substrate with deposited nanoparticle film 4. The metal oxide nanoparticles 8 can be any one of TiO2 or ZnO, etc. Metal oxide nanoparticles with semiconductor photoelectric properties have both light transmittance and photoelectric properties.

[0074] S4, Reference Figure 4 The soft lithography template 2 is placed on a substrate on which the nanoparticle film 4 is deposited, and a pressure of 500 mN / mm is applied to the soft lithography template 2. 2The pressure F causes it to adhere to the substrate on which the nanoparticle film 4 is deposited, and the nanoparticle paste of the nanoparticle film 4 fills the cavity of the soft photolithography template 2, such as... Figure 4 As shown; due to the large spacing of the periodic array cavities in the soft lithography template 2, the nanoparticle paste can quickly fill the cavities of the soft lithography template 2. After the nanoparticle paste has filled the cavities, the pressure F is removed, as shown. Figure 4 As shown;

[0075] S5. Reference Figure 5a and Figure 5b After the soft lithography template 2 cavity is filled with nanoparticle slurry, it is placed on a hot plate at 130°C and heated for 13 minutes. Due to the good permeability of the PDMS soft lithography template 2, the solvent in the nanoparticle film 4 can be fully evaporated, thus solidifying and forming the film. Then, the soft lithography template 2 is removed, yielding a transparent substrate with a micro-nano composite structure surface 5. (Refer to...) Figure 5b The surface 5 of the micro-nano composite structure includes a bottom surface, on which a micron-level array structure 7 composed of nanoparticles 8 is provided. The micron-level array structure 7 includes several spaced columnar micron-level structures. The bottom surface and the upper end of the micron-level array structure 7 are provided with a submicron-level structure 6 composed of several nanoparticles 8.

[0076] S6, Reference Figure 6a and Figure 5b The dried transparent substrate with micro-nano composite structure is immersed in a solution of dye 9 of the desired color for more than 3 hours. Due to the large specific surface area of ​​nanoparticles 8, they can adsorb most of the dye molecules 9, thereby obtaining a colored transparent substrate. For dyes with photochromic properties, the photochromic properties of the transparent substrate can be realized.

[0077] S7, Reference Figure 7a and Figure 7b A colored transparent substrate with a micro-nano composite structure for adsorbing dyes is immersed in a low-concentration solution of 0.8wt% fluorosilane 10 for more than half an hour, so that most of the fluorine molecules 10 can be adsorbed on the nanoparticles 8. The colored transparent substrate is then removed and baked at 90°C for more than 2 hours to obtain a surface with superhydrophobic properties, thus obtaining a hydrophobic color-changing transparent substrate.

[0078] Example 5

[0079] S1. PDMS replication process: Using a master template, a replica flexible transparent PDMS stamp 1 with a periodic microstructure array is obtained. This replica flexible transparent PDMS stamp 1 has a periodic microstructure array with a period P of 6 μm, a duty cycle D / P of 1:6, a hole diameter D of 1 μm, a spacing S of 5 μm, and a depth-to-width ratio H / D of 8:1. (Refer to...) Figure 1 As shown;

[0080] S2, Reference Figure 2 The surface of the flexible transparent PDMS stamp 1, which is replicated by plasma bombardment, has a periodic microstructure array. Submicron-level roughening treatment is performed to improve the roughness of the micron structure on the mold surface, so as to obtain the surface submicron-level structure [R], and obtain a soft photolithography template 2 with a micro-nano composite structure array; the surface submicron-level structure includes various columnar and porous structures smaller than 1μm;

[0081] S3. Reference Figure 3 Using transparent plastic as a substrate, metal oxide nanoparticles 8, ethanol, and low-temperature binder are mixed in a mass ratio of 6:90:1 to prepare a nanoparticle slurry. The nanoparticle slurry is deposited on the substrate 3 by screen printing, blade coating, or spin coating, and a uniform nanoparticle film 4 is formed on the substrate 3, resulting in a substrate with deposited nanoparticle film 4. The metal oxide nanoparticles 8 can be any one of TiO2 or ZnO, etc. Metal oxide nanoparticles with semiconductor photoelectric properties have both light transmittance and photoelectric properties.

[0082] S4, Reference Figure 4 The soft lithography template 2 is placed on a substrate on which the nanoparticle film 4 is deposited, and 1000 mN / mm is applied to the soft lithography template 2. 2 The pressure F causes it to adhere to the substrate on which the nanoparticle film 4 is deposited, and the nanoparticle paste of the nanoparticle film 4 fills the cavity of the soft photolithography template 2, such as... Figure 4 As shown; due to the large spacing of the periodic array cavities in the soft lithography template 2, the nanoparticle paste can quickly fill the cavities of the soft lithography template 2. After the nanoparticle paste has filled the cavities, the pressure F is removed, as shown. Figure 4 As shown;

[0083] S5. Reference Figure 5a and Figure 5b After the soft lithography template 2 cavity is filled with nanoparticle slurry, it is placed on a hot plate at 150°C and heated for 10 minutes. Due to the good permeability of the PDMS soft lithography template 2, the solvent in the nanoparticle film 4 can be fully evaporated, thus solidifying and forming the film. Then, the soft lithography template 2 is removed, yielding a transparent substrate with a micro-nano composite structure surface 5. (Refer to...) Figure 5b The surface 5 of the micro-nano composite structure includes a bottom surface, on which a micron-level array structure 7 composed of nanoparticles 8 is provided. The micron-level array structure 7 includes several spaced columnar micron-level structures. The bottom surface and the upper end of the micron-level array structure 7 are provided with a submicron-level structure 6 composed of several nanoparticles 8.

[0084] S6, Reference Figure 6a and Figure 5bThe dried transparent substrate with micro-nano composite structure is immersed in a solution of dye 9 of the desired color for more than 3 hours. Due to the large specific surface area of ​​nanoparticles 8, they can adsorb most of the dye molecules 9, thereby obtaining a colored transparent substrate. For dyes with photochromic properties, the photochromic properties of the transparent substrate can be realized.

[0085] S7, Reference Figure 7a and Figure 7b A colored transparent substrate with a micro-nano composite structure for adsorbing dyes is immersed in a 1 wt% low-concentration solution of fluorosilane 10 for more than half an hour, so that most of the fluorine molecules 10 can be adsorbed on the nanoparticles 8. The colored transparent substrate is then removed and baked at 155°C for more than 2 hours to obtain a surface with superhydrophobic properties, thus obtaining a hydrophobic color-changing transparent substrate.

[0086] The superhydrophobic properties of this invention are mainly determined by its unique micro-nano multi-level composite structure. Nanoparticles 8 ensure nanoscale roughness across the entire surface. Plasma etching of the PDMS stamp replicates its submicron-level structure R, guaranteeing submicron-level roughness, while the periodic micron-level array structure 7 ensures micron-level roughness. Together, these elements ensure the surface's superhydrophobic properties. The micro-nano multi-level composite structure consists of an array of nanoparticles 8. The diameter of the nanoparticles 8 is much smaller than the wavelength of visible light, resulting in weak light scattering. The micropillar array structure they form has large gaps between the arrays (D / P ratio between 1:16 and 1:5), thus ensuring good light transmittance of the film. Regarding its color-changing properties, due to the large specific surface area and photoelectric properties of the nanoparticles 8, dyes with different colors and functions can be selected to achieve transparent hydrophobic surfaces with different colors and photoresponse characteristics. Simultaneously, the photoelectric properties of the nanoparticles enable effective degradation of organic pollutants, thus maintaining long-term functional properties outdoors.

[0087] This invention overcomes the limitation of low light transmittance in traditional superhydrophobic surfaces by employing metal oxide nanomaterials with semiconductor optoelectronic properties. Leveraging the large specific surface area, light transmittance, and optoelectronic properties of these nanomaterials, large-area, multi-scale patterning is achieved using PDMS soft lithography. This allows for the one-time molding of micro-nano multi-level composite structures of semiconductor metal oxide nanomaterials. This method not only possesses the advantages of imprinting technology, such as large area, high efficiency, low manufacturing cost, and simple and reliable process route, but also utilizes the large specific surface area of ​​the nanoparticles to adsorb different dyes and their optoelectronic properties to achieve anti-fouling, self-cleaning, and photochromic properties of transparent substrates. The resulting micro-nano composite structure surface with transparent, superhydrophobic, and photochromic properties can be widely used in architectural and automotive glass, optical instruments and eyeglass lenses, and optoelectronic devices.

[0088] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for manufacturing a hydrophobic color-changing transparent substrate based on soft photolithography, characterized in that, Includes the following steps: S1. Prepare a soft photolithography template with a multi-level structure (2), wherein the multi-level structure includes a periodic microstructure array and the surface of the periodic microstructure has a submicron level structure; S2. Prepare a metal oxide nanoparticle thin film with semiconductor properties on the substrate (3); S3. Using a soft photolithography template (2), a metal oxide nanoparticle film with semiconductor properties is formed by soft photolithography to obtain a nanoparticle film with a metal oxide micro-nano multi-level composite structure. S4. The nanoparticle film is cured and demolded to obtain a substrate with a micro-nano composite structure surface; S5. Color and photochromic properties are applied to the nanoparticle film on the substrate to obtain a colored transparent substrate. The colored transparent substrate is then subjected to fluorination superhydrophobic treatment to obtain a hydrophobic color-changing transparent substrate. The process of S1 is as follows: a periodic patterned structure master is prepared on the substrate surface, a flexible polymer material stamp mold is obtained through a flexible polymer material replication process, and then the surface of the flexible polymer material stamp mold is bombarded with plasma to perform submicron-level roughening treatment to obtain a soft photolithography template with micro-nano multi-level structure (2). The flexible polymer material stamp mold has a periodic microstructure array, the spacing of the periodic microstructure array is denoted as S, the hole diameter is denoted as D, and the D / S ratio is 1:16 to 1:

5. The process of S4 is as follows: the substrate (3) with a nanoparticle film of metal oxide micro-nano multi-level composite structure is placed and heated until the solvent is fully evaporated, thereby solidifying and shaping, and the soft photolithography template (2) is removed to obtain a substrate with a micro-nano composite structure surface. In S5, the process of color and photochromic properties processing is as follows: a transparent substrate with a micro-nano composite structure is immersed in a dye solution of the desired color to obtain a colored transparent substrate. The large specific surface area and photoelectric properties of nanoparticle materials are used to adsorb dye molecules to achieve the photochromic properties of the transparent substrate. In S5, the fluorination superhydrophobic treatment process is as follows: the colored transparent substrate is immersed in a fluorosilane solution for more than half an hour to allow fluorine molecules to be adsorbed onto the nanoparticles, and the colored transparent substrate is then removed and baked to obtain a hydrophobic color-changing transparent substrate.

2. The method for manufacturing a hydrophobic color-changing transparent substrate based on soft lithography according to claim 1, characterized in that, The process of S2 is as follows: nanoparticles, ethanol and low temperature binder are prepared into nanoparticle slurry, and the nanoparticle slurry is deposited on substrate (3) to obtain a nanoparticle film with uniform thickness.

3. The method for manufacturing a hydrophobic color-changing transparent substrate based on soft lithography according to claim 2, characterized in that, The mass ratio of metal oxide nanoparticles, ethanol and low-temperature binder is (1-10):(80-100):

1.

4. The method for manufacturing a hydrophobic color-changing transparent substrate based on soft lithography according to claim 1, characterized in that, The process of S3 is as follows: the soft photolithography template (2) is adsorbed onto the substrate on which the nanoparticle film is deposited, so that the nanoparticle film fills the cavity of the soft photolithography template (2) to obtain a nanoparticle film with a metal oxide micro-nano multi-level composite structure.

5. The method for manufacturing a hydrophobic color-changing transparent substrate based on soft lithography according to claim 1, characterized in that, In step S5, the transparent substrate with the micro-nano composite structure is immersed in the dye solution for more than 3 hours.

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