A transparent super-hydrophobic cultural relics protection material and preparation method thereof

Abstract

The present invention discloses a transparent super-hydrophobic cultural relic protection material and a preparation method thereof. The method first grafts a hydrolyzed silane coupling agent onto the surface of silica, and then utilizes the amino group of the hydrolyzed silane coupling agent to react with the carboxyl group of a chain fatty acid to graft a chain alkyl group onto the surface of silica particles. The prepared material has excellent super-hydrophobicity, a large contact angle of water droplets on the coating surface, and a small rolling angle, making it difficult for water droplets to stay on the coating surface, thereby effectively preventing moisture penetration. At the same time, due to the transparency of the silica particles and the chain fatty acid, the coating can maintain a high transparency and will not block or change the original color and pattern of the cultural relic. The silane coupling agent acts as a bridge connecting the silica particles and the chain fatty acid, which can enhance the chemical bonding inside the coating, making the coating less prone to aging and cracking, and giving the material good high-temperature resistance and the advantage of resisting ultraviolet light, thereby extending the preservation life of the cultural relic.

Description

Technical Field

[0001] The invention belongs to the technical field of functional coating development and relates to a transparent super-hydrophobic cultural relic protection material and a preparation method thereof. Background Art

[0002] Paper artifacts, as carriers of history and culture, are an important part of cultural heritage. They contain a large number of precious cultural historical materials and records, and are also one of the most difficult types of artifacts to preserve for a long time. Since the main components of paper artifacts are plant fibers such as cellulose, and the oxygen bridges in cellulose have the ability to attract H + The characteristics of cellulose, combined with the presence of easily oxidized groups in its structure (such as CH2OH and -OH), make cellulose susceptible to a series of chemical reactions, ultimately leading to cellulose chain breakage. Consequently, during the preservation process, paper artifacts are easily affected by environmental factors such as humidity and ultraviolet light, causing chain breakage. This reduces mechanical strength, breeds bacteria and pests, and leads to damage such as yellowing, brittleness, and fragmentation, significantly reducing their storage lifespan and their value for viewing and research.

[0003] Inspired by the super-hydrophobic properties of organisms such as lotus leaves and butterfly wings in nature, researchers have explored the possibility of implementing hydrophobic modification on the surface of paper documents, aiming to give these documents the function of self-cleaning. Low surface energy and unique surface roughness structure are the two key elements to achieve this performance. At present, a number of technologies have been applied to the preparation of super-hydrophobic coatings, including but not limited to layer-by-layer self-assembly technology, electrospinning technology, chemical vapor deposition, plasma treatment, sol-gel method, impregnation method, chemical etching and spraying methods. Among the many methods, spraying is a simple and practical method that can prepare super-hydrophobic materials on a large scale. However, most of the existing super-hydrophobic coatings are added with nanoparticles. After spraying, they will affect the handwriting on the surface of paper documents, seriously affecting the visual experience when reading. Excessive spraying may even cause the loss of important information recorded on the paper. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention provides a transparent super-hydrophobic cultural relics protection material and a preparation method thereof, thereby solving the technical problem of poor transparency of the super-hydrophobic coating in the prior art.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for preparing a transparent super-hydrophobic cultural relic protection material comprises the following steps:

[0007] S1: adding a silane coupling agent to a mixture of an organic solvent and water, stirring and reacting to obtain a hydrolyzed silane coupling agent;

[0008] S2: adding the hydrolyzed silane coupling agent to the organic dispersion of silica particles, stirring and reacting to obtain silica@silane coupling agent particles;

[0009] S3: adding the silica@silane coupling agent particles to an organic solution of a chain fatty acid, wherein the carbon chain length of the chain fatty acid is 14 to 20, and stirring the solution to react, thereby obtaining the transparent and removable superhydrophobic material.

[0010] Preferably, the silane coupling agent is added to a mixture of an organic solvent and water, and the volume ratio of the organic solvent to water and the silane coupling agent is (20-16):(4-1):(2-0.5).

[0011] Preferably, the ratio of the silane coupling agent to the silica particles is (2-0.5) mL: (1-3) g.

[0012] Preferably, in step S2, the reaction temperature of the hydrolyzed silane coupling agent and the silica particles is 25-65° C., and the reaction time is 4-8 h.

[0013] Preferably, the chain fatty acid is one of stearic acid, myristic acid, palmitic acid, pearly acid, and arachidic acid.

[0014] Preferably, the ratio of the silicon dioxide@silane coupling agent particles to the chain fatty acid is (1~2):1.

[0015] Preferably, the reaction temperature for adding the silicon dioxide@silane coupling agent particles to the chain fatty acid is 30-60° C., and the reaction time is 2-3 h.

[0016] A transparent super-hydrophobic cultural relic protection material is prepared by the above method.

[0017] A transparent and removable super-hydrophobic coating is prepared by coating the above-mentioned transparent super-hydrophobic cultural relics protection material on the surface of a substrate.

[0018] The transparent and removable super-hydrophobic coating has a water contact angle of 153° to 160°. Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] The present invention discloses a method for preparing a super-hydrophobic and transparent super-hydrophobic material. The method comprises the following steps: hydrolyzing a silane coupling agent and grafting it onto the surface of silica particles. Then, the amino groups on the hydrolyzed silane coupling agent react with the carboxyl groups on a chain fatty acid to graft a chain alkyl group onto the surface of the silica particles. The material prepared by grafting the chain alkyl group onto the surface of the silica particles has excellent super-hydrophobicity. The contact angle of water droplets on the coating surface is large and the rolling angle is small, making it difficult for water droplets to stay on the coating surface, thereby effectively preventing water penetration. At the same time, due to the transparency of the silica particles and the chain fatty acid, the coating can maintain a high transparency and will not obstruct or change the original color and pattern of the cultural relic. The silane coupling agent acts as a bridge connecting the silica particles and the chain fatty acid, which can enhance the chemical bonding inside the coating, making the coating less prone to aging and cracking, and giving the material good high-temperature resistance and the advantage of resisting ultraviolet light, thereby extending the preservation life of the cultural relic.

[0020] Furthermore, a silane coupling agent is added to a mixture of an organic solvent and water, wherein the volume ratio of the organic solvent to water and the silane coupling agent is (20-16):(4-1):(2-0.5), so that the silane coupling agent can be fully hydrolyzed.

[0021] Furthermore, the ratio of the silane coupling agent to the silica particles is (2-0.5) mL: (1-3) g, which can graft -NH2 groups onto the silica surface.

[0022] Furthermore, in step S2, the reaction temperature of the hydrolyzed silane coupling agent and the silica particles is 25-65° C., and the reaction time is 4-8 h, so that the silane coupling agent and silica can fully react.

[0023] Furthermore, the chain fatty acid is one of stearic acid, myristic acid, palmitic acid, pearl fatty acid, and arachidic acid, which can graft long-chain fatty acids onto the surface of the silica@silane coupling agent particles to reduce surface activation energy.

[0024] Furthermore, the ratio of the silica@silane coupling agent particles to the chain fatty acid is (1-2):1, which allows the silica@silane coupling agent particles to fully react with the chain fatty acid.

[0025] Furthermore, the reaction temperature for adding the silica@silane coupling agent particles to the chain fatty acid is 30-60° C. and the reaction time is 2-3 h, so that the silica@silane coupling agent particles and the chain fatty acid can fully react. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 Schematic diagram of a process for preparing a transparent super-hydrophobic cultural relics protection material in the present invention;

[0028] Figure 2 These are super depth images of the coatings obtained by spraying the materials prepared in Examples 1 to 3 of the present invention on paper documents; wherein, Figures (a1) and (a2) are super depth images of the original paper documents, Figures (b1) and (b2) are super depth images of SA:SiO2@KH550=1:1, Figures (c1) and (c2) are super depth images of SA:SiO2@KH550=1:2, and Figures (d1) and (d2) are super depth images of SA:SiO2@KH550=1:4;

[0029] Figure 3 These are SEM images of the coatings obtained by spraying the materials prepared in Examples 1 to 3 of the present invention on paper documents; wherein, Figures (a1) and (a2) are SEM images of the original paper documents, Figures (b1) and (b2) are SEM images of SA:SiO2@KH550=1:1, Figures (c1) and (c2) are SEM images of SA:SiO2@KH550=1:2, and Figures (d1) and (d2) are SEM images of SA:SiO2@KH550=1:4;

[0030] Figure 4 The effect of the superhydrophobic coating on the surface of paper documents and its contact angle before and after removal. (a1), (b1), and (c1) show the SEM images at different magnifications before coating removal, while (a2), (b2), and (c2) correspond to the SEM images after coating removal.

[0031] Figure 5 The contact angles of paper documents under different aging treatment conditions are shown;

[0032] Figure 6 Scans of paper documents before and after spraying. DETAILED DESCRIPTION

[0033] To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used in the specification and claims. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art regarding the present invention. In the event of conflict, the definitions in this specification shall prevail.

[0034] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0035] All features, such as values, amounts, contents, and concentrations, described herein as numerical ranges or percentage ranges are provided for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to include and specifically disclose all possible subranges and individual values ​​within the range (including integers and fractions).

[0036] In this document, unless otherwise specified, “include,” “including,” “contains,” “has” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0037] In this document, for the sake of brevity, not all possible combinations of the various technical features in each embodiment or example are described. Therefore, as long as there are no contradictions in the combination of these technical features, the various technical features in each embodiment or example can be combined in any way, and all possible combinations should be considered to be within the scope of this specification.

[0038] like Figure 1 As shown, the present invention provides a method for preparing a transparent super-hydrophobic cultural relics protection material, comprising the following steps:

[0039] (1) Drying the silica particles in an oven to pre-treat them to effectively remove adsorbed moisture;

[0040] The silicon dioxide is one of quartz, cristobalite, tridymite, and amorphous silicon dioxide. The mass of silicon dioxide is 1-3 g. During the drying pretreatment, the temperature is 100-150 ° C and the time is 10-20 h.

[0041] (2) In organic solvent A, the pretreated silica is magnetically stirred at room temperature to fully disperse the silica;

[0042] The ratio of silica to organic solvent A is (1-3) g: (60-120) mL, and the rotation speed is 300-500 r / min;

[0043] (3) Adding a silane coupling agent to a mixture of organic solvent A and water to perform hydrolysis at room temperature;

[0044] The silane coupling agent is one of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane; the volume ratio of the organic solvent to water and the silane coupling agent is (20-16):(4-1):(2-0.5);

[0045] (4) In an organic solvent A, the silane coupling agent hydrolyzed in step (3) and the silicon dioxide dispersion in step (2) are uniformly mixed and subjected to magnetic stirring reaction and then dried to prepare silicon dioxide@silane coupling agent particles;

[0046] The reaction temperature is 25-65°C, the reaction time is 4-8 hours, and the rotation speed is 300-500 r / min. Finally, the product is placed in an oven at 100-150°C and dried for 10-12 hours. The solidified sample is taken out and ground into powder to obtain silica@silane coupling agent particles.

[0047] (5) In organic solvent A, C 14 -C 20 The long-chain fatty acid is used as a modifier, which is uniformly mixed with the silica@silane coupling agent particles in step (3) and subjected to magnetic stirring. After the reaction is complete, it is sprayed on the surface of the paper document using a spray gun to construct a superhydrophobic coating.

[0048] C 14 -C 20 The long-chain fatty acid is one of stearic acid, myristic acid, palmitic acid, pearly fatty acid, and arachidic acid; the mass ratio of the long-chain fatty acid to the silica@silane coupling agent particles is preferably 1:(1-2), the reaction temperature is 30-60°C, the reaction time is 2-3 h, and the rotation speed is 300-500 r / min.

[0049] When preparing the coating, a spraying method can be used. Specifically, the prepared transparent and removable super-hydrophobic material is poured into a spray gun and evenly sprayed on the surface of the paper document. The spraying times are 2 to 3 times. The sprayed paper document is placed in an oven at 30 to 50°C for drying. The distance between the spray gun and the paper is controlled at about 8 to 12 cm.

[0050] The raw materials of the present invention are safe, non-toxic, easy to obtain, widely available, and low in cost; the preparation process of the present invention is simple and can be mass-produced; the super-hydrophobic coating prepared by the present invention has excellent super-hydrophobicity, thermal stability, and UV resistance, and has a certain degree of removability, which complies with the principle of "restoring cultural relics to their original state."

[0051] The present invention proposes a highly transparent, removable super-hydrophobic coating for preventive protection of paper cultural relics and a preparation method thereof, the specific steps of which are as follows:

[0052] First, SiO2 particles are pretreated in an oven to remove moisture. Next, the pretreated SiO2 particles are dispersed in anhydrous ethanol and magnetically stirred at room temperature to ensure uniform distribution. A silane coupling agent is then added to the mixture of anhydrous ethanol and deionized water, and the mixture is allowed to stand for a period of time to complete the hydrolysis process. Subsequently, the hydrolyzed silane coupling agent solution is slowly dripped into the ethanol solution containing the SiO2 particles and thoroughly stirred again using a magnetic stirrer to ensure effective bonding. After stirring, the mixture is dried to obtain SiO2@silane coupling agent composite particles.

[0053] Next, the composite particles and long-chain fatty acids are added to anhydrous ethanol and further treated with magnetic stirring to ensure thorough mixing. This mixed solution is then transferred to a spray gun, held approximately 10 cm from the surface of the paper artifact being treated, and evenly sprayed onto the document. After spraying, the paper is dried in a 50°C oven to solidify the coating, ultimately forming a modified superhydrophobic paper document. Removal of this coating requires only spraying with an organic solvent, such as ethanol.

[0054] The super-hydrophobic coating developed by this invention not only exhibits excellent super-hydrophobicity, thermal stability, and UV resistance, but also exhibits good removability, strictly adhering to the fundamental principle of "repairing the old as it was" in the field of cultural relic restoration. Furthermore, this coating technology is not limited to the protection of paper-based cultural relics but also has the potential to be expanded to a wider range of cultural heritage protection fields.

[0055] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0056] The following examples were prepared using conventional instruments and equipment in the art. Experimental methods in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or according to the conditions recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, were conventional commercially available products, with specifications conventional in the art. In the present specification and the following examples, unless otherwise specified, "%" indicates percentage by weight, "part" indicates parts by weight, and "ratio" indicates weight ratio.

[0057] Example 1

[0058] A method for preparing a transparent super-hydrophobic cultural relic protection material comprises the following steps:

[0059] (1) Dry 1.0 g of 30 nm amorphous silica in an oven at 120 °C for 12 h.

[0060] (2) Add the dried amorphous silica to 60 mL of anhydrous ethanol solution and magnetically

[0061] Stir vigorously for 1 h;

[0062] (3) Add 1 mL of 3-aminopropyltriethoxysilane to a mixed solution of 18 mL of anhydrous ethanol and 2 mL of deionized water and allow to hydrolyze for 1 h.

[0063] (4) The hydrolyzed 3-aminopropyltriethoxysilane solution was added dropwise to the silica solution in step (1), stirred at 65 °C and 500 r / min for 4 h, and then dried in a blast drying oven at 120 °C for 12 h. The obtained powder was ground and recorded as silica@3-aminopropyltriethoxysilane;

[0064] (5) 0.1 g of stearic acid and 0.1 g of silica@3-aminopropyltriethoxysilane in step (4) were added to 30 mL of anhydrous ethanol solution and stirred at 50 °C for 2 h to obtain a transparent and removable superhydrophobic material.

[0065] The super-hydrophobic material was poured into a spray gun and sprayed on the paper document three times from left to right. The distance between the spray gun and the paper was controlled at about 10 cm. The sprayed paper was placed in a 50°C oven to dry, thereby forming a super-hydrophobic coating on the surface of the paper document.

[0066] Example 2

[0067] The difference from Example 1 is that the mass of silicon dioxide@3-aminopropyltriethoxysilane added in step (5) is 0.2 g.

[0068] Example 3

[0069] The difference from Example 1 is that the mass of silicon dioxide@3-aminopropyltriethoxysilane added in step (5) is 0.4 g.

[0070] Example 4

[0071] A method for preparing a transparent super-hydrophobic cultural relic protection material comprises the following steps:

[0072] (1) Dry 1.5 g of 30 nm amorphous silicon dioxide in an oven at 120 °C for 12 h.

[0073] (2) Add the dried amorphous silica to 80 mL of water-ethanol solution and magnetically

[0074] Stir vigorously for 1 h.

[0075] (3) Add 1 mL of 3-aminopropyltriethoxysilane to a mixed solution of 18 mL of anhydrous ethanol and 2 mL of deionized water and allow to hydrolyze for 1 h.

[0076] (4) The hydrolyzed 3-aminopropyltriethoxysilane solution was added dropwise to the silica solution in step (1), stirred at 65 and 500 r / min for 4 h, and then dried in a blast drying oven at 120 °C for 12 h. The obtained powder was ground and recorded as silica@3-aminopropyltriethoxysilane;

[0077] (5) 0.1 g of myristic acid and 0.1 g of silica@3-aminopropyltriethoxysilane in step (4) were added to 30 mL of anhydrous ethanol solution and stirred at 50 °C for 2 h to obtain a transparent and removable superhydrophobic material.

[0078] The super-hydrophobic material was poured into a spray gun and sprayed on the paper document three times from left to right. The distance between the spray gun and the paper was controlled at about 10 cm. The sprayed paper was placed in a 50°C oven to dry, thereby forming a super-hydrophobic coating on the surface of the paper document.

[0079] Example 5

[0080] The difference from Example 4 is that the mass of silicon dioxide@3-aminopropyltriethoxysilane added in step (5) is 0.2 g.

[0081] Example 6

[0082] The difference from Example 4 is that the mass of silicon dioxide@3-aminopropyltriethoxysilane added in step (5) is 0.4 g.

[0083] Example 7

[0084] A method for preparing a transparent super-hydrophobic cultural relic protection material comprises the following steps:

[0085] (1) Dry 2 g of 30 nm amorphous silicon dioxide in an oven at 120 °C for 12 h;

[0086] (2) Add the dried amorphous silica to 100 mL of water-ethanol solution and magnetically

[0087] Stir vigorously for 1 h.

[0088] (3) Add 1 mL of 3-aminopropyltriethoxysilane to a mixed solution of 18 mL of anhydrous ethanol and 2 mL of deionized water and allow to hydrolyze for 1 h.

[0089] (4) The hydrolyzed 3-aminopropyltriethoxysilane solution was added dropwise to the silica solution in step (1), stirred at 65 °C and 500 r / min for 4 h, and then dried in a blast drying oven at 120 °C for 12 h. The obtained powder was ground and recorded as silica@3-aminopropyltriethoxysilane;

[0090] (5) 0.1 g of palmitic acid and 0.1 g of silica@3-aminopropyltriethoxysilane in step (4) were added to 30 mL of anhydrous ethanol solution and stirred at 50 °C for 2 h to obtain a transparent and removable superhydrophobic material.

[0091] The super-hydrophobic material was poured into a spray gun and sprayed on the paper document three times from left to right. The distance between the spray gun and the paper was controlled at about 10 cm. The sprayed paper was placed in a 50°C oven to dry, thereby forming a super-hydrophobic coating on the surface of the paper document.

[0092] Example 8

[0093] The difference from Example 7 is that the mass of silicon dioxide@3-aminopropyltriethoxysilane added in step (5) is 0.2 g.

[0094] Example 9

[0095] The difference from Example 7 is that the mass of silicon dioxide@3-aminopropyltriethoxysilane added in step (5) is 0.4 g.

[0096] Example 10

[0097] A method for preparing a transparent super-hydrophobic cultural relic protection material comprises the following steps:

[0098] (1) Dry 2.5 g of 30 nm amorphous silicon dioxide in an oven at 120 °C for 12 h.

[0099] (2) Add the dried amorphous silica to 100 mL of water-ethanol solution and stir magnetically at room temperature for 1 h.

[0100] (3) Add 1 mL of 3-aminopropyltriethoxysilane to a mixed solution of 18 mL of anhydrous ethanol and 2 mL of deionized water and allow to hydrolyze for 1 h.

[0101] (4) The hydrolyzed 3-aminopropyltriethoxysilane solution was added dropwise to the silica solution in step (1), stirred at 65 °C and 500 r / min for 4 h, and then dried in a blast drying oven at 120 °C for 12 h. The obtained powder was ground and recorded as silica@3-aminopropyltriethoxysilane;

[0102] (5) 0.1 g of pearlescent fatty acid and 0.1, 0.2, and 0.4 g of silica@3-aminopropyltriethoxysilane in step (4) were added to 30 mL of anhydrous ethanol solution and stirred at 50 °C for 2 h to obtain a transparent and removable superhydrophobic material.

[0103] The super-hydrophobic material was poured into a spray gun and sprayed on the paper document three times from left to right. The distance between the spray gun and the paper was controlled at about 10 cm. The sprayed paper was placed in a 50°C oven to dry, thereby forming a super-hydrophobic coating on the surface of the paper document.

[0104] Example 11

[0105] The difference from Example 10 is that the mass of silicon dioxide@3-aminopropyltriethoxysilane added in step (5) is 0.2 g.

[0106] Example 12

[0107] The difference from Example 10 is that the mass of silica@3-aminopropyltriethoxysilane added in step (5) is 0.4 g.

[0108] Example 13

[0109] A method for preparing a transparent super-hydrophobic cultural relic protection material comprises the following steps:

[0110] (1) Dry 3 g of 30 nm amorphous silicon dioxide in an oven at 120 °C for 12 h;

[0111] (2) Add the dried amorphous silica to 120 mL of anhydrous ethanol solution and stir magnetically at room temperature for 1 hour.

[0112] (3) Add 1 mL of 3-aminopropyltriethoxysilane to a mixed solution of 18 mL of anhydrous ethanol and 2 mL of deionized water and allow to hydrolyze for 1 h.

[0113] (4) The hydrolyzed 3-aminopropyltriethoxysilane solution was added dropwise to the silica solution in step (1), stirred at 65 °C and 500 r / min for 4 h, and then dried in a blast drying oven at 120 °C for 12 h. The obtained powder was ground and recorded as silica@3-aminopropyltriethoxysilane;

[0114] (5) 0.1 g of arachidic acid and 0.1 g of silica@3-aminopropyltriethoxysilane in step (4) were added to 30 mL of anhydrous ethanol solution and stirred at 50 °C for 2 h to obtain a transparent and removable superhydrophobic material.

[0115] The super-hydrophobic material was poured into a spray gun and sprayed on the paper document three times from left to right. The distance between the spray gun and the paper was controlled at about 10 cm. The sprayed paper was placed in a 50°C oven to dry, thereby forming a super-hydrophobic coating on the surface of the paper document.

[0116] Example 14

[0117] The difference from Example 13 is that the mass of silica@3-aminopropyltriethoxysilane added in step (5) is 0.2 g.

[0118] Example 15

[0119] The difference from Example 13 is that the mass of silica@3-aminopropyltriethoxysilane added in step (5) is 0.4 g.

[0120] The super-hydrophobic coatings prepared in Examples 1 to 5 all have good super-hydrophobicity, thermal stability and UV resistance. The super-hydrophobic coatings prepared in Examples 1 to 3 are used as examples for illustration.

[0121] Figure 2 These are super-depth images of the coatings obtained by spraying the materials prepared in Examples 1-3 of the present invention onto paper documents. Figures (a1) and (a2) are super-depth images of the original paper document, Figures (b1) and (b2) are super-depth images of a 1:1 ratio of stearic acid:SiO2@KH550 (SA:SiO2@KH550=1:1), Figures (c1) and (c2) are super-depth images of a 1:2 ratio of SA:SiO2@KH550, and Figures (d1) and (d2) are super-depth images of a 1:4 ratio of SA:SiO2@KH550. Figures (a1) and (a2) show that the surface of the original paper document is smooth and flat, with clearly visible fibers and no particles. Figures (b1) and (b2) show that a small amount of particles are deposited on the fiber surface of the modified paper document. Figures (c1) and (c2) show that a large number of particles are deposited on the fiber surface after modification, and the distribution is relatively uniform. Figures (d1) and (d2) show that a large number of particles are deposited on the fiber surface after modification, and the distribution is uneven, with obvious agglomeration.

[0122] Figure 3The following are SEM images of the coatings obtained by spraying the materials prepared in Examples 1-3 of the present invention onto paper documents. Figures (a1) and (a2) are SEM images of the original paper document, Figures (b1) and (b2) are SEM images of the SA:SiO2@KH550 ratio of 1:1, Figures (c1) and (c2) are SEM images of the SA:SiO2@KH550 ratio of 1:2, and Figures (d1) and (d2) are SEM images of the SA:SiO2@KH550 ratio of 1:4. Figures (a1) and (a2) show that the surface of the original paper document is smooth and flat, with clearly visible fibers and no particles. As the SiO2@KH550 particle content increases, the number of particles deposited on the fiber surface gradually increases. When the SA:SiO2@KH550 ratio is 1:4, the nanoparticles show obvious agglomeration on the fiber surface, which is consistent with the conclusions drawn from the ultra-depth-of-field microscope.

[0123] Figure 4 The effect of the superhydrophobic coating on the surface of paper documents and their contact angles before and after removal is shown. Among them, (a1), (b1), and (c1) respectively show SEM images at different magnifications before the coating is removed. It can be seen that the nanoparticles are evenly covered on the surface of the paper fibers, making the original fiber structure difficult to identify. (a2), (b2), and (c2) correspond to SEM images after the coating is removed. At this time, the fiber structure of the paper is clearly visible, although there are still a small amount of nanoparticles remaining on the fiber surface. It is particularly noteworthy that Figure (c1) contains a contact angle illustration, which shows that in the presence of the superhydrophobic coating, the contact angle of the paper document can reach 157.1°, showing excellent superhydrophobic properties. In contrast, the contact angle illustration in Figure (c2) shows that after the coating is removed, the contact angle of the paper document drops to 67.5°, indicating that its superhydrophobic properties have dropped significantly.

[0124] Figure 5 The contact angles of paper documents under different aging conditions are shown. After three days of dry heat aging (105°C), wet heat aging (105°C, 65% relative humidity), and UV aging, the spray-treated paper maintained high contact angles, indicating no significant difference in surface properties compared to before aging. This demonstrates that the applied superhydrophobic coating not only exhibits excellent superhydrophobic properties but also exhibits good thermal stability and UV resistance.

[0125] Table 1 shows the color difference and visual perception of paper documents before and after modification. As can be seen from Table 1, the color difference between paper documents before and after modification gradually increases with increasing SiO2 content, reaching a maximum ΔE of 2.12. When the SA:SiO2 ratio is 1:2, ΔE = 1.41, which is less than 1.5 and difficult to distinguish with the naked eye. In line with the principle of "restoring cultural relics to their original state," the SA:SiO2 mass ratio should be kept between 1:2.

[0126] Table 1 Color difference and visual perception of paper documents before and after modification

[0127]

[0128] Figure 6 Scans of a paper document before and after treatment at a ratio of SA:SiO2 = 1:2. The images show little change in the document's appearance before and after treatment, with the superhydrophobic coating not blurring or obscuring the writing, aligning with the principle of "restoring the original" for cultural relics.

[0129] Table 1 Color difference and visual perception of paper documents before and after modification

[0130]

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A transparent super-hydrophobic paper cultural relic protective coating, characterized in that: The transparent super-hydrophobic cultural relics protection material is coated on the surface of the substrate; The method for preparing the transparent super-hydrophobic cultural relics protection material comprises the following steps: S1: adding a silane coupling agent to a mixture of an organic solvent and water, stirring and reacting to obtain a hydrolyzed silane coupling agent; S2: adding the hydrolyzed silane coupling agent to the organic dispersion of silica particles, stirring and reacting to obtain silica@silane coupling agent particles; S3: adding the silica@silane coupling agent particles to an organic solution of a chain fatty acid, wherein the carbon chain length of the chain fatty acid is 14 to 20, and stirring the mixture to react to obtain a transparent super-hydrophobic cultural relic protection material; The silane coupling agent is added to a mixture of an organic solvent and water, wherein the volume ratio of the organic solvent to the water and the silane coupling agent is (20-16):(4-1):(2-0.5); The ratio of the silane coupling agent to the silica particles is (2-0.5) mL: (1-3) g; The chain fatty acid is one of stearic acid, myristic acid, palmitic acid, pearly fatty acid, and arachidic acid; The ratio of the silicon dioxide@silane coupling agent particles to the chain fatty acid is (1~2):

1.

2. A transparent super-hydrophobic paper cultural relics protective coating according to claim 1, characterized in that, In step S2, the reaction temperature of the hydrolyzed silane coupling agent and the silica particles is 25-65° C., and the reaction time is 4-8 h.

3. A transparent super-hydrophobic paper cultural relics protective coating according to claim 1, characterized in that, The reaction temperature of adding the silicon dioxide@silane coupling agent particles to the chain fatty acid is 30-60° C., and the reaction time is 2-3 h.

4. A transparent super-hydrophobic paper cultural relics protective coating according to claim 1, characterized in that, The water contact angle of the coating is 153° to 160°.

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