Preparation method of leather cultural relic protection material based on hydrophobic antibacterial type eutectic solvent

Abstract

The application discloses a preparation method of a leather cultural relic protection material based on a hydrophobic antibacterial eutectic solvent, and specifically comprises the following steps: preparing a hydrophobic antibacterial eutectic solvent DES; mixing the hydrophobic antibacterial eutectic solvent DES and water, emulsifying, dissolving gelatin in the above solution, hydrating, and stirring and reacting under temperature rise to obtain a gelatin solution; dispersing tannic acid in the hydrophobic antibacterial eutectic solvent DES, adding the tannic acid dropwise into the gelatin solution, adjusting the pH of the system, and stirring and reacting to obtain the leather cultural relic protection material. The phenolic alcohol groups on the hydrogen bond acceptor in the eutectic solvent can react with the cell membrane or cell wall of bacteria and molds, so that the antibacterial and moldproof effects are achieved; the hydrophobic chain segments on the hydrogen bond donor can improve the hydrophobicity of the leather cultural relics, and fundamentally prevent the breeding of bacteria and molds. The material prepared by the application can be applied to the protection of leather cultural relics, and can effectively improve the mechanical properties and antibacterial and moldproof properties of the leather cultural relics.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cultural relic protection material preparation, and particularly relates to a preparation method of a leather cultural relic protection material based on a hydrophobic antibacterial eutectic solvent. BACKGROUND

[0002] Leather cultural relics are a kind of natural polymer materials, which are easily affected by humidity, temperature, bacteria and mold in the environment, and the main components such as collagen and tanning agent are degraded or lost, thereby problems such as decay and mold occur. Therefore, a functional reinforcing protection material needs to be developed for leather cultural relic protection. Gelatin is a partial hydrolysis product of animal collagen, which has good biodegradability and biocompatibility, and is homologous to leather, so it is expected to be applied to leather cultural relic protection to supplement the lost collagen component of leather cultural relics. However, the gelatin alone is prone to problems such as brittleness, strong hydrophilicity and easy bacterial erosion, so it needs to be modified. Tannin is a plant polyphenol with good antioxidant properties, which can be used as a crosslinking agent and tanning agent to improve the physical and mechanical properties of gelatin and leather.

[0003] A deep eutectic solvent (DES) is a two-component or three-component low eutectic mixture composed of a certain stoichiometric ratio of a hydrogen bond acceptor (quaternary ammonium salt, etc.) and a hydrogen bond donor (such as amide, carboxylic acid, polyol), which has the characteristics of low toxicity and easy availability, and is widely used in the preparation of functional materials. The composition can be designed, and if a natural antibacterial agent is used as a hydrogen bond donor and a hydrophobic material is used as a hydrogen bond acceptor, a hydrophobic antibacterial deep eutectic solvent can be obtained. The use of a hydrophobic antibacterial deep eutectic solvent for the modification of gelatin can endow the gelatin with good hydrophobicity and antibacterial properties, which is more conducive to the application of gelatin-based composite materials in leather cultural relic protection. SUMMARY

[0004] The purpose of the present application is to provide a preparation method of a leather cultural relic protection material based on a hydrophobic antibacterial deep eutectic solvent, which solves the problem of poor antibacterial performance of existing leather cultural relic protection materials.

[0005] The technical solution adopted by the present application is a preparation method of a leather cultural relic protection material based on a hydrophobic antibacterial deep eutectic solvent, which is implemented according to the following steps:

[0006] Step 1: preparing a hydrophobic antibacterial deep eutectic solvent DES;

[0007] Step 2: mixing 2-10 parts of the hydrophobic antibacterial deep eutectic solvent DES and 0.5-1.5 parts of water, emulsifying under room temperature conditions, and then dissolving 0.5-1.5 parts of gelatin in the above solution, hydrating at room temperature first, and then stirring and reacting at a temperature of 30-50 DEG C to obtain a gelatin solution;

[0008] Step 3: 0.02-0.1 parts of tannic acid is dispersed in 0.5-1.5 parts of hydrophobic antibacterial DES, then added dropwise into the gelatin solution, and then the pH of the system is adjusted to 7.0±0.2 by using sodium bicarbonate solution, and the reaction is stirred to obtain the Gel / TA-DES composite material, which is the leather cultural relic protection material.

[0009] The application also has the characteristics that,

[0010] In step 1, specifically, 1-4 parts of antibacterial agent is mixed with 1-4 parts of dodecanoic acid, and the mixture is subjected to magnetic stirring reaction at 50-80 DEG C for 20-40 min, and then cooled to room temperature to obtain a transparent liquid, which is the hydrophobic antibacterial DES.

[0011] The antibacterial agent is any one of thymol, menthol, gallic acid and tannic acid.

[0012] In step 2, the emulsification time is 10-30 min, the hydration time is 5-15 min, and the stirring reaction time is 0.5-1.0 h.

[0013] In step 3, the dropping speed is 30-40 drops / min, the stirring reaction temperature is 30-50 DEG C, and the stirring reaction time is 3-6 h.

[0014] The application has the beneficial effects that the natural antibacterial agent and the long-chain carboxylic acid are used to construct the hydrophobic antibacterial DES, and the tannic acid with tanning effect is used to modify the gelatin, so that the physical mechanical properties and the antibacterial and mildew-proof properties of the gelatin can be improved. The prepared composite material is applied to the leather cultural relic protection, and the mechanical properties and the antibacterial and mildew-proof properties of the leather cultural relic can be effectively improved. The phenolic alcohol groups on the hydrogen bond acceptor in the DES can react with the cell membrane or the cell wall of bacteria and fungi, so that the antibacterial and mildew-proof effects can be achieved; the hydrophobic segments on the hydrogen bond donor can improve the hydrophobicity of the leather cultural relic, so that the breeding of bacteria and fungi can be fundamentally prevented, and the efficient antibacterial and mildew-proof of the leather cultural relic can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is the water contact angle diagram of the leather before and after being protected by the gelatin / tannic acid, DES-gelatin / tannic acid material;

[0016] Figure 2 is the antibacterial performance photo diagram of the leather cultural relic simulation sample before and after being protected by the material of the application. DETAILED DESCRIPTION

[0017] The application will be described in detail below in combination with the specific embodiments and the drawings.

[0018] The application is based on a preparation method of a leather cultural relic protection material of a hydrophobic antibacterial type deep eutectic solvent, and is specifically implemented according to the following steps:

[0019] Step 1: preparing a hydrophobic antibacterial type deep eutectic solvent (DES);

[0020] Specifically, 1-4 parts of an antibacterial agent is mixed with 1-4 parts of dodecanoic acid, and magnetic stirring is performed at 50-80 DEG C for 20-40 min, and then the mixture is slowly cooled to room temperature to obtain a transparent liquid, which is the hydrophobic antibacterial type deep eutectic solvent DES.

[0021] The antibacterial agent is any one of thymol, menthol, gallic acid and tannic acid;

[0022] The antibacterial agent acts as a hydrogen bond donor, and the dodecanoic acid acts as a hydrogen bond acceptor;

[0023] Step 2: 2-10 parts of the hydrophobic antibacterial deep eutectic solvent and 0.5-1.5 parts of water are mixed, and emulsification is performed at room temperature for 10-30 min; then 0.5-1.5 parts of gelatin is dissolved in the above solution, and hydration is performed at room temperature for 5-15 min; then the temperature is increased to 30-50 DEG C, and stirring is performed for 0.5-1.0 h to obtain a gelatin solution;

[0024] Step 3: 0.02-0.1 parts of tannic acid is dispersed in 0.5-1.5 parts of the hydrophobic antibacterial type deep eutectic solvent, and is slowly added to the gelatin solution at a speed of 30-40 drops / min; then a sodium bicarbonate solution is used to adjust the pH of the system to 7.0±0.2; and then stirring is continuously performed at 30-50 DEG C for 3-6 h to obtain a Gel / TA-DES composite material, which is the leather cultural relic protection material.

[0025] The above prepared Gel / TA-DES composite material is applied to a leather cultural relic simulation sample by using a circulating brush coating method. The Gel / TA-DES composite material is brushed on the surface of the leather cultural relic simulation sample, and after natural drying at room temperature (25±0.5 DEG C), the above operation is repeated for 10-30 times, so that the composite material is uniformly formed on the surface of the leather cultural relic simulation sample to achieve a protection effect.

[0026] Example 1

[0027] The application is based on a preparation method of a leather cultural relic protection material of a hydrophobic antibacterial type deep eutectic solvent, and is specifically implemented according to the following steps:

[0028] Step 1: 3.0 parts of thymol is taken as a hydrogen bond donor, and 2.0 parts of dodecanoic acid is taken as a hydrogen bond acceptor; magnetic stirring is performed in a flask at 60 DEG C for 20 min; and then the mixture is slowly cooled to room temperature to obtain a transparent liquid, which is the DES.

[0029] Step 2: Take 8 parts of hydrophobic antibacterial eutectic solvent and 1.2 parts of water, emulsify at room temperature for 20 min, then dissolve 1.2 parts of gelatin in the above solution, hydrate at room temperature for 5 min, then gradually heat to 30 DEG C, and stir at 400 r / min for 0.5 h until the gelatin is completely dissolved, to prepare a gelatin solution.

[0030] Step 3: Take 0.08 parts of tannic acid and disperse in 1.0 parts of eutectic solvent, and slowly add to the gelatin solution at a speed of 30 drops / min, then adjust the pH of the system to 7.0 with sodium bicarbonate solution, and continue to stir at 30 DEG C for 3 h to prepare a Gel / TA-DES composite material.

[0031] Example 2

[0032] The application is based on the preparation method of the hydrophobic antibacterial eutectic solvent leather cultural relic protection material, which is specifically implemented according to the following steps:

[0033] Step 1: Take 3.0 parts of menthol as a hydrogen bond donor, 1.0 parts of dodecanoic acid as a hydrogen bond acceptor, and stir at 50 DEG C in a silk mouth bottle for 30 min, and then slowly cool to room temperature to obtain a transparent liquid, which is a DES.

[0034] Step 2: Take 4.0 parts of hydrophobic antibacterial eutectic solvent and 0.6 parts of water, emulsify at room temperature for 20 min, then dissolve 0.5 parts of gelatin in the above solution, hydrate at room temperature for 10 min, then gradually heat to 40 DEG C, and stir at 400 r / min for 1.0 h until the gelatin is completely dissolved, to prepare a gelatin solution.

[0035] Step 3: Take 0.04 parts of tannic acid and disperse in 1.0 parts of eutectic solvent, and slowly add to the gelatin solution at a speed of 35 drops / min, then adjust the pH of the system to 7.1 with sodium bicarbonate solution, and continue to stir at 45 DEG C for 4 h to prepare a Gel / TA-DES composite material.

[0036] Example 3

[0037] The application is based on the preparation method of the hydrophobic antibacterial eutectic solvent leather cultural relic protection material, which is specifically implemented according to the following steps:

[0038] Step 1: Take 4.0 parts of gallic acid as a hydrogen bond donor, 1.0 parts of dodecanoic acid as a hydrogen bond acceptor, and stir at 70 DEG C in a silk mouth bottle for 40 min, and then slowly cool to room temperature to obtain a transparent liquid, which is a DES.

[0039] Step 2: Take 4 parts of hydrophobic antibacterial eutectic solvent and 1.0 parts of water, emulsify at room temperature for 20 min, then dissolve 1.0 parts of gelatin in the above solution, hydrate at room temperature for 5 min, then gradually heat to 30 DEG C, and stir at 400 r / min for 1.0 h until the gelatin is completely dissolved, to prepare a gelatin solution.

[0040] Step 3: Take 0.08 parts of tannic acid and disperse in 1.0 parts of eutectic solvent, and slowly drop into the gelatin solution at a speed of 40 drops / min, then adjust the pH of the system to 7.0 with sodium bicarbonate solution, and continue to stir at 30 DEG C for 6 h to prepare a Gel / TA-DES composite material.

[0041] Example 4

[0042] The application is based on the preparation method of the leather cultural relic protection material of the hydrophobic antibacterial eutectic solvent, and is specifically implemented according to the following steps:

[0043] Step 1: Take 1.0 parts of tannic acid as a hydrogen bond donor, and 4.0 parts of dodecanoic acid as a hydrogen bond acceptor, and stir at 80 DEG C in a magnetic stirrer for 40 min, and then slowly cool to room temperature to obtain a transparent liquid, which is a DES.

[0044] Step 2: Take 2.0 parts of hydrophobic antibacterial eutectic solvent and 1.5 parts of water, emulsify at room temperature for 20 min, then dissolve 1.0 parts of gelatin in the above solution, hydrate at room temperature for 5 min, then gradually heat to 50 DEG C, and stir at 400 r / min for 0.8 h until the gelatin is completely dissolved, to prepare a gelatin solution.

[0045] Step 3: Take 0.06 parts of tannic acid and disperse in 1.5 parts of eutectic solvent, and slowly drop into the gelatin solution at a speed of 40 drops / min, then adjust the pH of the system to 7.0 with sodium bicarbonate solution, and continue to stir at 50 DEG C for 5 h to prepare a Gel / TA-DES composite material.

[0046] Figure 1 The water contact angles of the gelatin / tannic acid (Gel / TA) and the Gel / TA-DES of Example 1 and the leather cultural relic simulation samples before and after protection by the Gel / TA-DES are shown in the figure, and it can be seen that the water contact angle of the Gel / TA is 51.2 DEG, the water contact angle of the Gel / TA-DES is 102.0 DEG, and the water contact angle of the leather cultural relic simulation sample after protection by the Gel / TA-DES is increased from 85.5 DEG to 108.5 DEG. The results show that the DES can effectively improve the hydrophobicity of the gelatin and the leather.

[0047] Figure 2The table is the antibacterial performance characterization results of the leather cultural relic simulation samples before and after the protection without material protection and with the Gel / TA-DES protection of Embodiment 1. As shown in the table, the growth inhibition of the leather cultural relic simulation sample after the Gel / TA-DES protection on the Escherichia coli and Staphylococcus aureus is obviously enhanced. The results show that the Gel / TA-DES composite material has high efficient antibacterial performance, and can significantly improve the antibacterial performance of the leather cultural relic.

Claims

1. A method for preparing leather artifact preservation materials based on hydrophobic, antibacterial, eutectic solvents, characterized in that, The specific steps are as follows: Step 1: Preparation of hydrophobic antibacterial eutectic solvent DES; Specifically: Mix 1-4 parts of antibacterial agent with 1-4 parts of dodecanoic acid, stir magnetically at 50-80℃ for 20-40 min, cool to room temperature to obtain a transparent liquid, which is the hydrophobic antibacterial eutectic solvent DES. The antibacterial agent is any one of thymol, menthol, gallic acid, and tannic acid; Step 2: Mix 2-10 parts of hydrophobic antibacterial eutectic solvent DES and 0.5-1.5 parts of water, emulsify at room temperature, then dissolve 0.5-1.5 parts of gelatin in the above solution, hydrate at room temperature first, then heat to 30-50℃ and stir to react, to obtain a gelatin solution. Step 3: Disperse 0.02-0.1 parts of tannic acid in 0.5-1.5 parts of hydrophobic antibacterial eutectic solvent DES, then add it dropwise to gelatin solution, and adjust the pH of the system to 7.0±0.2 with sodium bicarbonate solution. Stir the reaction to obtain Gel / TA-DES composite material, which is the material for the preservation of leather cultural relics.

2. The preparation method of leather cultural relic preservation material based on hydrophobic antibacterial eutectic solvent as described in claim 1, characterized in that, In step 2, the emulsification time is 10-30 min; the hydration time is 5-15 min; and the stirring reaction time is 0.5-1.0 h.

3. The preparation method of leather cultural relic preservation material based on hydrophobic antibacterial eutectic solvent as described in claim 1, characterized in that, In step 3, the dropping rate is 30-40 drops / min; the stirring reaction temperature is 30-50℃; and the stirring reaction time is 3-6h.

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