Leather cultural relic protection material with multiple synergistic protection effects as well as preparation method and application of leather cultural relic protection material

Abstract

The invention discloses a leather cultural relic protection material with multiple synergistic protection effects as well as a preparation method and application thereof, choline chloride is taken as a hydrogen bond receptor, tannic acid and ethylene glycol are taken as hydrogen bond donors, and a deep eutectic solvent with antibacterial property and oxidation resistance is constructed through hydrogen bond interaction. The preparation method comprises the following steps: adding a TiO2 nano fluid with an antibacterial property into a deep eutectic solvent to prepare a deep eutectic solvent / TiO2 nano fluid; and then, adding the deep eutectic solvent / TiO2 nano fluid into a carboxymethyl chitosan aqueous solution with antibacterial property and oxidation resistance, so as to prepare the carboxymethyl chitosan / deep eutectic solvent / TiO2 nano fluid. The carboxymethyl chitosan / deep eutectic solvent / TiO2 nano fluid prepared by the invention is used as a cultural relic protection material, and is expected to improve the antibacterial property, oxidation resistance and mechanical property of leather cultural relics and prolong the storage life of the leather cultural relics.

Description

Technical Field

[0001] The present invention belongs to the technical field of leather cultural relic protection materials, and in particular relates to a leather cultural relic protection material with multiple synergistic protection effects, and also relates to a preparation method and application of the leather cultural relic protection material with multiple synergistic protection effects. Background Art

[0002] Leather artifacts, as important carriers of tradition, civilization, art, and behavior, are the crystallization of ancient art and culture, and play a vital role in information transmission. However, leather is essentially a natural polymer composed of collagen fibers, which is susceptible to bacterial erosion and oxidation during long-term preservation, leading to degradation. This degradation manifests as the fracture of the collagen fiber network, the destruction of the cross-linked structure, and the decline of physical and mechanical properties, which can lead to the complete destruction of the artifact and the permanent loss of the information it carries. Therefore, the development of protective materials with antibacterial, antioxidant, and mechanical strengthening properties is of great significance for delaying the aging of leather artifacts and improving the quality of their preservation.

[0003] At present, the materials such as fatliquors and reinforcements commonly used in the protection of leather cultural relics mainly target a single aging factor, and it is difficult to comprehensively deal with the multiple problems faced by leather cultural relics, such as bacterial erosion, oxidative degradation and mechanical strength loss. TiO2 nanofluids have antibacterial properties, tannic acid-based deep eutectic solvents have antibacterial and antioxidant properties, and carboxymethyl chitosan has antibacterial, antioxidant and reinforcement properties. Applying the three together to leather cultural relics can achieve multiple protections for leather cultural relics. Nano-TiO2 in TiO2 nanofluids and phenolic hydroxyl groups in tannic acid-based deep eutectic solvents and -NH3 of carboxymethyl chitosan + It can provide synergistic antibacterial properties, blocking bacterial growth and reproduction. The phenolic hydroxyl groups in the tannic acid-based deep eutectic solvent and the hydroxyl groups on carboxymethyl chitosan both have free radical-scavenging properties, which can impart antioxidant properties to leather artifacts. The TiO2 nanofluid, tannic acid-based deep eutectic solvent, carboxymethyl chitosan, and leather collagen fibers form a multi-point cross-linked network, jointly enhancing the mechanical properties of leather artifacts. The preparation of this protective material is expected to overcome the limitations of traditional protective materials, which suffer from limited functionality and efficacy, and provide new insights into the long-term preservation of leather artifacts. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing a leather cultural relic protection material with multiple synergistic protection effects, so as to solve the problems of poor antioxidant performance and mechanical properties of the leather cultural relic protection material.

[0005] The present invention also aims to provide a leather cultural relic protection material having multiple synergistic protection effects.

[0006] The present invention also aims to provide an application of a leather cultural relic protection material having multiple synergistic protection effects.

[0007] The first technical solution adopted by the present invention is a method for preparing a leather cultural relic protection material with multiple synergistic protective effects. Choline chloride is used as a hydrogen bond acceptor, and tannic acid and ethylene glycol are used as hydrogen bond donors. A deep eutectic solvent with antibacterial and antioxidant properties is constructed through hydrogen bond interactions; a TiO2 nanofluid with antibacterial properties is added to the deep eutectic solvent to prepare a deep eutectic solvent / TiO2 nanofluid; then, the deep eutectic solvent / TiO2 nanofluid is added to a carboxymethyl chitosan aqueous solution to prepare a carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid. The specific operating steps are as follows: Step 1: Disperse nano-TiO2 in deionized water to obtain a nano-TiO2 dispersion; add dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride dropwise to the nano-TiO2 dispersion, and stir at 25°C for 12-24 hours to obtain solution A; centrifuge solution A, wash the precipitate with deionized water and methanol 2-3 times, and then vacuum dry to obtain quaternized modified nano-TiO2; Step 2: Disperse the quaternized modified nano-TiO2 in a sodium sulfate aqueous solution of nonylphenol ether, stir and react at 70°C for 24-48 hours, extract the mixed solution 2-3 times with 60°C hot toluene, and vacuum dry the extract to obtain a TiO2 nanofluid. Step 3: Weigh choline chloride, tannic acid, and ethylene glycol, and stir at 70-90°C until a uniform and stable liquid is formed to obtain a deep eutectic solvent; Step 4: Add the TiO2 nanofluid to the deep eutectic solvent, stir and react for 20-40 minutes to obtain the deep eutectic solvent / TiO2 nanofluid; weigh a 4% mass fraction of carboxymethyl chitosan aqueous solution, add the deep eutectic solvent / TiO2 nanofluid, stir and react for 20-40 minutes, add glycerol, continue to stir and react for 20-40 minutes, and cool to room temperature to obtain the carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid.

[0008] The present invention is also characterized in that: Furthermore, in step 1, the mass ratio of nano-TiO2 to deionized water is 1-2:50-80, and the mass ratio of nano-TiO2 to dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride is 1-2:5-10.

[0009] Furthermore, in step 2, the mass ratio of the quaternized modified nano-TiO2 to the aqueous solution of sodium sulfate of nonylphenol oxyethylene ether is 1:20-40.

[0010] Furthermore, in step 3, the molar ratio of choline chloride, tannic acid and ethylene glycol is 60-20:1:60-20.

[0011] Furthermore, in step 4, the mass ratio of the TiO2 nanofluid to the deep eutectic solvent is 1-4:10; the mass ratio of the deep eutectic solvent / TiO2 nanofluid to the carboxymethyl chitosan aqueous solution is 0.2-0.8:50.

[0012] Furthermore, the vacuum drying conditions in step 1 are: vacuum drying at 60°C for 12-24 h.

[0013] Furthermore, the vacuum drying conditions of the extract in step 2 are: vacuum drying at 60°C for 48 h.

[0014] The second technical solution adopted by the present invention is that the leather cultural relic protection material with multiple synergistic protection effects is prepared using the above-mentioned preparation method.

[0015] The third technical solution adopted by the present invention is: the application of leather cultural relic protection materials with multiple synergistic protection effects, using a brush dipped in carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid, brushing it to the surface of the leather cultural relic, leaving it at room temperature for no less than 20 minutes, rinsing with deionized water, and naturally drying to constant weight. Repeating the above brushing twice can effectively protect the leather cultural relic.

[0016] Preparation mechanism of the present invention: Since the flexible long chains of the TiO2 nanofluid shell have ether bonds, the deep eutectic solvent contains phenolic hydroxyl groups and hydroxyl groups, and carboxymethyl chitosan has hydroxyl groups, carboxyl groups and amino groups, the present invention mainly prepares composite materials through hydrogen bonding and electrostatic interactions among the three. The nano-TiO2 and quaternary ammonium salt structure in the TiO2 nanofluid, the phenolic hydroxyl groups in the deep eutectic solvent, and the protonated amino groups in the carboxymethyl chitosan jointly exert antibacterial effects; the phenolic hydroxyl groups in the deep eutectic solvent and the hydroxyl groups in the carboxymethyl chitosan jointly exert antioxidant effects; the TiO2 nanofluid, the deep eutectic solvent, and the carboxymethyl chitosan can all undergo multi-point hydrogen bond cross-linking with leather collagen to enhance the mechanical properties of the leather. Therefore, this material is expected to achieve a joint enhancement of the antibacterial, antioxidant and mechanical properties of leather artifacts; specifically: Protonated -NH3 in carboxymethyl chitosan +It can destroy the bacterial cell membrane through electrostatic action, thereby killing the bacteria; the nano-TiO2 in the core layer of the TiO2 nano-fluid has photocatalytic antibacterial properties; the phenolic hydroxyl group in the deep eutectic solvent can destroy the bacterial cell membrane and protein, thereby killing the bacteria. The three can play a synergistic role and jointly improve the antibacterial properties of leather; the rich phenolic hydroxyl group in the deep eutectic solvent and the -OH in carboxymethyl chitosan have antioxidant properties, which can slow down the aging of leather; the ether bond in the TiO2 nano-fluid, the phenolic hydroxyl group in the deep eutectic solvent and the -NH3 + Active groups such as -OH and -COOH can form a multi-point cross-linking network with groups such as -NH2 and -COOH in leather collagen fibers to enhance the mechanical properties of leather artifacts.

[0017] The beneficial effects of the present invention are: This invention combines a TiO2 nanofluid, a deep eutectic solvent, and carboxymethyl chitosan to create a leather cultural relic preservation material with antibacterial, antioxidant, and mechanically reinforcing properties. This material overcomes the limitations of traditional single-function protective materials by achieving a combined enhancement of these three properties, offering a new approach to leather cultural relic preservation. The material is expected to enhance the antibacterial, antioxidant, and mechanical properties of leather cultural relics, extending their shelf life. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is the inhibition rate of aged leather treated with carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid against Escherichia coli and Staphylococcus aureus; Figure 2 is the antioxidant properties of aged leather before and after treatment with carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid; Figure 3 The mechanical properties of aged leather before and after treatment with carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid. DETAILED DESCRIPTION

[0019] The present invention will be further described below with reference to the accompanying drawings and examples.

[0020] The method for preparing the leather cultural relic protection material with multiple synergistic protection effects of the present invention comprises the following specific steps: The quantities involved below are all in parts by mass: Example 1 Step 1: Weigh 1 part nano-TiO2 and disperse it in 50 parts deionized water to obtain a nano-TiO2 dispersion. Add 5 parts dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride dropwise to the nano-TiO2 dispersion and stir at 25°C for 24 hours to obtain a white solution. Centrifuge and wash the precipitate three times with deionized water and methanol. Dry under vacuum at 60°C for 24 hours to obtain quaternized nano-TiO2. The quaternized nano-TiO2 is then dispersed in 20 parts of an aqueous solution of sodium sulfate (nonylphenol para-oxyethylene ether). Stir at 70°C for 24-48 hours. Extract the mixture three times with 60°C hot toluene. Dry the extract at 60°C under vacuum for 48 hours to obtain a TiO2 nanofluid.

[0021] Step 2: Choline chloride, tannic acid, and ethylene glycol were weighed and blended in a molar ratio of 50:1:50, and stirred at 80° C. until a uniform and stable liquid was formed to obtain a deep eutectic solvent.

[0022] Step 3: Weigh 3 parts of TiO2 nanofluid and add them to 10 parts of deep eutectic solvent. Stir and react for 30 minutes to obtain a deep eutectic solvent / TiO2 nanofluid. Weigh 50 parts of a 4% carboxymethyl chitosan aqueous solution and add 0.2 parts of the deep eutectic solvent / TiO2 nanofluid. Stir and react for 30 minutes. Add 0.5 parts of glycerol and continue stirring for 20 minutes. Cool to room temperature to obtain a carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid.

[0023] Example 2 Step 1: Weigh 1 part nano-TiO2 and disperse it in 50 parts deionized water to obtain a nano-TiO2 dispersion. Add 5 parts dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride dropwise to the nano-TiO2 dispersion and stir at 25°C for 24 hours to obtain a white solution. Centrifuge and wash the precipitate three times with deionized water and methanol. Dry under vacuum at 60°C for 24 hours to obtain quaternized nano-TiO2. The quaternized nano-TiO2 is then dispersed in 20 parts of an aqueous solution of sodium sulfate (nonylphenol para-oxyethylene ether). Stir at 70°C for 24-48 hours. Extract the mixture three times with 60°C hot toluene. Dry the extract at 60°C under vacuum for 48 hours to obtain a TiO2 nanofluid.

[0024] Step 2: Choline chloride, tannic acid, and ethylene glycol were weighed and blended in a molar ratio of 40:1:40, and stirred at 80° C. until a uniform and stable liquid was formed to obtain a deep eutectic solvent.

[0025] Step 3: Weigh 3 parts of TiO2 nanofluid and add them to 10 parts of deep eutectic solvent. Stir and react for 30 minutes to obtain a deep eutectic solvent / TiO2 nanofluid. Weigh 50 parts of a 4% carboxymethyl chitosan aqueous solution and add 0.4 parts of the deep eutectic solvent / TiO2 nanofluid. Stir and react for 30 minutes. Add 0.5 parts of glycerol and continue stirring for 20 minutes. Cool to room temperature to obtain a carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid.

[0026] Example 3 Step 1: Weigh 1 part nano-TiO2 and disperse it in 50 parts deionized water to obtain a nano-TiO2 dispersion. Add 5 parts dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride dropwise to the nano-TiO2 dispersion and stir at 25°C for 24 hours to obtain a white solution. Centrifuge and wash the precipitate three times with deionized water and methanol. Dry under vacuum at 60°C for 24 hours to obtain quaternized nano-TiO2. The quaternized nano-TiO2 is then dispersed in 20 parts of an aqueous solution of sodium sulfate (nonylphenol para-oxyethylene ether). Stir at 70°C for 24-48 hours. Extract the mixture three times with 60°C hot toluene. Dry the extract at 60°C under vacuum for 48 hours to obtain a TiO2 nanofluid.

[0027] Step 2: Choline chloride, tannic acid, and ethylene glycol were weighed and blended in a molar ratio of 30:1:30, and stirred at 80° C. until a uniform and stable liquid was formed to obtain a deep eutectic solvent.

[0028] Step 3: Weigh 3 parts of TiO2 nanofluid and add them to 10 parts of deep eutectic solvent. Stir and react for 30 minutes to obtain a deep eutectic solvent / TiO2 nanofluid. Weigh 50 parts of a 4% carboxymethyl chitosan aqueous solution and add 0.6 parts of the deep eutectic solvent / TiO2 nanofluid. Stir and react for 30 minutes. Add 0.5 parts of glycerol and continue stirring for 20 minutes. Cool to room temperature to obtain a carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid.

[0029] Example 4 Step 1: Weigh 1 part nano-TiO2 and disperse it in 50 parts deionized water to obtain a nano-TiO2 dispersion. Add 5 parts dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride dropwise to the nano-TiO2 dispersion and stir at 25°C for 24 hours to obtain a white solution. Centrifuge and wash the precipitate three times with deionized water and methanol. Dry under vacuum at 60°C for 24 hours to obtain quaternized nano-TiO2. The quaternized nano-TiO2 is then dispersed in 20 parts of an aqueous solution of sodium sulfate (nonylphenol para-oxyethylene ether). Stir at 70°C for 24-48 hours. Extract the mixture three times with 60°C hot toluene. Dry the extract at 60°C under vacuum for 48 hours to obtain a TiO2 nanofluid.

[0030] Step 2: Choline chloride, tannic acid, and ethylene glycol were weighed and blended in a molar ratio of 20:1:20, and stirred at 80° C. until a uniform and stable liquid was formed to obtain a deep eutectic solvent.

[0031] Step 3: Weigh 3 parts of TiO2 nanofluid and add them to 10 parts of deep eutectic solvent. Stir and react for 30 minutes to obtain a deep eutectic solvent / TiO2 nanofluid. Weigh 50 parts of a 4% carboxymethyl chitosan aqueous solution and add 0.8 parts of the deep eutectic solvent / TiO2 nanofluid. Stir and react for 30 minutes. Add 0.5 parts of glycerol and continue stirring for 20 minutes. Cool to room temperature to obtain a carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid.

[0032] Example 5 Step 1: Weigh 2 parts of nano-TiO2 and disperse it in 50 parts of deionized water to obtain a nano-TiO2 dispersion. Add 5 parts of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride dropwise to the nano-TiO2 dispersion and stir at 25°C for 24 hours to obtain a white solution. Centrifuge and wash the precipitate three times with deionized water and methanol. Dry under vacuum at 60°C for 24 hours to obtain quaternized nano-TiO2. The quaternized nano-TiO2 is then dispersed in 20 parts of an aqueous solution of sodium sulfate (nonylphenol para-oxyethylene ether). Stir at 70°C for 24 hours. Extract the mixture three times with 60°C hot toluene. Dry the extract at 60°C for 48 hours to obtain a TiO2 nanofluid.

[0033] Step 2: Choline chloride, tannic acid, and ethylene glycol were weighed and blended in a molar ratio of 50:1:50, and stirred at 80° C. until a uniform and stable liquid was formed to obtain a deep eutectic solvent.

[0034] Step 3: Weigh 3 parts of TiO2 nanofluid and add them to 10 parts of deep eutectic solvent. Stir and react for 30 minutes to obtain a deep eutectic solvent / TiO2 nanofluid. Weigh 50 parts of a 4% carboxymethyl chitosan aqueous solution and add 0.8 parts of the deep eutectic solvent / TiO2 nanofluid. Stir and react for 30 minutes. Add 0.5 parts of glycerol and continue stirring for 20 minutes. Cool to room temperature to obtain a carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid.

[0035] Example 6 Step 1: Weigh 2 parts of nano-TiO2 and disperse it in 50 parts of deionized water to obtain a nano-TiO2 dispersion. Add 5 parts of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride dropwise to the nano-TiO2 dispersion and stir at 25°C for 24 hours to obtain a white solution. Centrifuge and wash the precipitate three times with deionized water and methanol. Dry under vacuum at 60°C for 24 hours to obtain quaternized nano-TiO2. The quaternized nano-TiO2 is then dispersed in 20 parts of an aqueous solution of sodium sulfate (nonylphenol para-oxyethylene ether), stirred at 70°C for 48 hours, and the mixture is extracted three times with 60°C hot toluene. The extract is dried under vacuum at 60°C for 48 hours to obtain a TiO2 nanofluid.

[0036] Step 2: Choline chloride, tannic acid, and ethylene glycol were weighed and blended in a molar ratio of 40:1:40, and stirred at 80° C. until a uniform and stable liquid was formed to obtain a deep eutectic solvent.

[0037] Step 3: Weigh 1 part of TiO2 nanofluid and add it to 10 parts of deep eutectic solvent. Stir and react for 30 minutes to obtain a deep eutectic solvent / TiO2 nanofluid. Weigh 50 parts of a 4% carboxymethyl chitosan aqueous solution and add 0.8 parts of the deep eutectic solvent / TiO2 nanofluid. Stir and react for 30 minutes. Add 0.5 parts of glycerol and continue stirring for 20 minutes. Cool to room temperature to obtain a carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid.

[0038] The method of applying the present invention to leather cultural relics is as follows: dip a brush into carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid, apply it to the surface of the leather cultural relics, place it at room temperature for 20 minutes, rinse it with deionized water, dry it naturally to constant weight, and repeat the above brushing twice.

[0039] Figure 1 The inhibition rate of the leather artifact simulant against Escherichia coli and Staphylococcus aureus after the treatment with carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid in Example 4. Figure 1It can be seen that the antibacterial rates of the treated aged leather against Escherichia coli and Staphylococcus aureus are 98.8% and 97.3%, respectively, indicating that the antibacterial property of the treated aged leather is significantly improved.

[0040] Figure 2 The antioxidant properties of the leather artifact simulant before and after treatment with carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid in Example 4. Figure 2 It can be seen that the scavenging rates of the aged leather for free radical indicators ABTS and DPPH increased from 40.5% and 38.0% to 75.7% and 75.4%, respectively, after treatment, indicating that the antioxidant activity of the aged leather was significantly improved after treatment.

[0041] Figure 3 The mechanical properties of the leather artifact simulant before and after treatment with carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid in Example 4. Figure 3 It can be seen that the tensile strength and elongation at break of the aged leather after treatment increased from 15.5 MPa and 79.9% to 18.3 MPa and 87.9% respectively, indicating that the mechanical properties of the aged leather after treatment were significantly improved.

[0042] The content of the present invention is not limited to the embodiments listed. Any equivalent transformation of the technical solution of the present invention made by ordinary technicians in this field after reading the description of the present invention is covered by the claims of the present invention.

Claims

1. A method for preparing a leather cultural relic protection material having multiple synergistic protection effects, characterized in that: A deep eutectic solvent with antibacterial and antioxidant properties was constructed through hydrogen bonding interactions using choline chloride as a hydrogen bond acceptor and tannic acid and ethylene glycol as hydrogen bond donors. A TiO2 nanofluid with antibacterial properties was added to the deep eutectic solvent to prepare a deep eutectic solvent / TiO2 nanofluid. Subsequently, the deep eutectic solvent / TiO2 nanofluid is added into the carboxymethyl chitosan aqueous solution to prepare the carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid.

2. The method for preparing the leather cultural relic protection material with multiple synergistic protection effects according to claim 1, characterized in that: The specific steps are as follows: Step 1: Disperse nano-TiO2 in deionized water to obtain a nano-TiO2 dispersion; add dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride dropwise to the nano-TiO2 dispersion, and stir at 25°C for 12-24 hours to obtain solution A; centrifuge solution A, wash the precipitate with deionized water and methanol 2-3 times, and then vacuum dry to obtain quaternized modified nano-TiO2; Step 2: Disperse the quaternized modified nano-TiO2 in a sodium sulfate aqueous solution of nonylphenol ether, stir and react at 70°C for 24-48 hours, extract the mixed solution 2-3 times with 60°C hot toluene, and vacuum dry the extract to obtain a TiO2 nanofluid. Step 3: Weigh choline chloride, tannic acid, and ethylene glycol, and stir at 70-90°C until a uniform and stable liquid is formed to obtain a deep eutectic solvent; Step 4: Add the TiO2 nanofluid to the deep eutectic solvent, stir and react for 20-40 minutes to obtain the deep eutectic solvent / TiO2 nanofluid; weigh a 4% mass fraction of carboxymethyl chitosan aqueous solution, add the deep eutectic solvent / TiO2 nanofluid, stir and react for 20-40 minutes, add glycerol, continue to stir and react for 20-40 minutes, and cool to room temperature to obtain the carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid.

3. The method for preparing the leather cultural relic protection material with multiple synergistic protection effects according to claim 2, characterized in that: In step 1, the mass ratio of the nano-TiO2 to deionized water is 1-2:50-80, and the mass ratio of the nano-TiO2 to dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride is 1-2:5-10.

4. The method for preparing the leather cultural relic protection material with multiple synergistic protection effects according to claim 2, characterized in that: The mass ratio of the quaternized modified nano-TiO2 in step 2 to the aqueous solution of sodium sulfate of nonylphenol oxyethylene ether is 1:20-40.

5. The method for preparing the leather cultural relic protection material with multiple synergistic protection effects according to claim 2, characterized in that: The molar ratio of choline chloride, tannic acid and ethylene glycol in step 3 is 60-20:1:60-20.

6. The method for preparing the leather cultural relic protection material with multiple synergistic protection effects according to claim 2, characterized in that: In step 4, the mass ratio of the TiO2 nanofluid to the deep eutectic solvent is 1-4:10; the mass ratio of the deep eutectic solvent / TiO2 nanofluid to the carboxymethyl chitosan aqueous solution is 0.2-0.8:

50.

7. The method for preparing the leather cultural relic protection material with multiple synergistic protection effects according to claim 2, characterized in that: The vacuum drying conditions in step 1 are: vacuum drying at 60°C for 12-24 hours.

8. The method for preparing the leather cultural relic protection material with multiple synergistic protection effects according to claim 2, characterized in that: The vacuum drying conditions of the extract in step 2 are: vacuum drying at 60°C for 48 h.

9. Leather cultural relic protection material with multiple synergistic protection effects, characterized in that: The leather cultural relic protection material is prepared by the preparation method of the leather cultural relic protection material with multiple synergistic protection effects as described in any one of claims 1 to 8.

10. Application of leather cultural relic protection material with multiple synergistic protection effects, characterized in that: Dip a brush in carboxymethyl chitosan / deep eutectic solvent / TiO2 nanofluid and apply it to the surface of the leather artifact. Leave it at room temperature for no less than 20 minutes, rinse with deionized water, and dry naturally to constant weight. Repeat the above brushing process twice.

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