Anti-ultraviolet cellulose material, antibacterial anti-ultraviolet cellulose material, and preparation method and application thereof

Abstract

The invention discloses an anti-ultraviolet cellulose material, an antibacterial anti-ultraviolet cellulose material, and a preparation method and application thereof; the invention obtains a mixed solution by mixing curcumin, lysine, a formaldehyde solution and a solvent, and then puts a cellulose product into the mixed solution, and places it at 20-60°C for reaction for 1-16 hours; the obtained product is washed and / or dialyzed to obtain the anti-ultraviolet cellulose material. A silver nitrate solution with a mass concentration of 0.1%-3.0% is prepared, mixed evenly with the anti-ultraviolet cellulose material, and reacted at room temperature for 2-16 hours; the product is washed or dialyzed to obtain the antibacterial anti-ultraviolet cellulose material. The invention connects curcumin to the surface of the cellulose material by means of a covalent bond, and further reacts and loads nanosilver particles to give the cellulose antibacterial and anti-ultraviolet functions. The method is simple to operate and suitable for large-scale production. It provides new ideas and methods for the high-value utilization of cellulose and provides a new method for obtaining modified cellulose products.

Description

Technical Field

[0001] The invention belongs to the technical field of cellulose modification and organic-inorganic composite materials, and specifically relates to an anti-ultraviolet cellulose material, an antibacterial and anti-ultraviolet cellulose material, and a preparation method and application thereof. Background Art

[0002] Cellulose is a natural high molecular polymer formed by D-pyranose units connected by β (1→4) glycosidic bonds. Nanocellulose can be obtained by nano-crystallizing cellulose, and commonly used methods include sulfuric acid hydrolysis or TEMPO oxidation. There are hydrogen bonds between and within cellulose molecules and it has a high degree of crystallinity. This makes cellulose generally insoluble in organic solvents and water.

[0003] The surface of cellulose and nanocellulose contains abundant hydroxyl groups, which can be used to carry out oxidation, esterification and etherification of cellulose under certain conditions, and introduce many other structural groups on the glucose ring to give cellulose different functions. The modification of natural cellulose can make functional use of cellulose, which is of great significance to the sustainable development of the country.

[0004] A large number of researchers have tried various methods to prepare modified cellulose and modified nanocellulose. However, the inventors have found that these modification methods are cumbersome and may cause waste liquid treatment problems (Subbotina, E., Ram, F., Dvinskikh, SV, Berglund, LA & Olsén, P. Aqueous synthesis of highly functional, hydrophobic, and chemically recyclable cellulose nanomaterials through oximeligation. Nat. Commun. 13, 6924 (2022).). Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide an anti-ultraviolet cellulose material, an antibacterial and anti-ultraviolet cellulose material, and a preparation method and application thereof. The present invention performs cellulose modification based on a multi-component reaction. A multi-component reaction refers to a type of reaction in which three or more reactants are added to a reactor at the same time to react and generate a single product. Compared with conventional synthesis methods, the products of this type of reaction have many advantages, such as simple synthesis and purification steps, high atom economy, and product diversity. The present invention utilizes the high reactivity and reaction economy of multi-component reactions to impart antibacterial and anti-ultraviolet functions to cellulose-based materials.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] A method for preparing an ultraviolet resistant cellulose material comprises the following steps:

[0008] Curcumin, lysine, formaldehyde solution and solvent are mixed to obtain a mixed solution, and then the cellulose product is placed in the mixed solution and placed at 20-60° C. for reaction for 1-16 hours; the obtained product is washed and / or dialyzed to obtain an anti-ultraviolet cellulose material.

[0009] Preferably, the solvent is an ethanol / water mixed solution, the volume concentration of ethanol is 20%-80%; the concentration of curcumin in the mixed solution is 4.6-18.4 g / L, the concentration of lysine is 0.9-3.6 g / L, and the concentration of formaldehyde is 2.2-8.8 g / L.

[0010] Preferably, the cellulose product is nanocellulose or cotton fabric; the nanocellulose is cellulose nanocrystals or cellulose nanofibrils; and the cotton fabric is woven fabric or non-woven fabric.

[0011] Preferably, when the cellulose product is nanocellulose, the solid content of nanocellulose in the mixed solution is 0.5-3%, and the reaction is carried out under stirring at a speed of 100-500rpm; when the cellulose product is cotton fabric, the mass ratio of cotton fabric in the mixed solution is 1:10-1:50.

[0012] Preferably, when the cellulose product is nanocellulose, the obtained product is rinsed at least twice with 30%-100% ethanol and then dialyzed with deionized water;

[0013] Preferably, when the cellulose product is cotton fabric, the obtained product is rinsed with 30%-100% ethanol at least twice, and then rinsed with water at least three times.

[0014] An anti-ultraviolet cellulose material is prepared by the above preparation method.

[0015] A method for preparing an antibacterial and anti-ultraviolet cellulose material comprises the following steps:

[0016] A silver nitrate solution with a mass concentration of 0.1%-3.0% is prepared, mixed evenly with the above-mentioned anti-ultraviolet cellulose material, and reacted at room temperature for 2-16 hours; the product is washed or dialyzed to obtain the antibacterial and anti-ultraviolet cellulose material.

[0017] Preferably, when the anti-ultraviolet cellulose material is nanocellulose, the solid content of the nanocellulose in the mixed solution is 0.01-5%. When the anti-ultraviolet cellulose material is cotton fabric, the mass ratio of the cotton fabric in the mixed solution is 1:10-1:50.

[0018] An antibacterial and anti-ultraviolet cellulose material is prepared by the above preparation method.

[0019] Application of the above-mentioned anti-ultraviolet cellulose material and the above-mentioned antibacterial anti-ultraviolet cellulose material in papermaking, preparation of packaging materials, preparation of personal protection materials and preparation of air filtration materials

[0020] The mechanism of the present invention is as follows:

[0021] The present invention utilizes a multi-component reaction of curcumin, lysine, formaldehyde and cellulose (the reaction path is as follows) to connect curcumin to the surface of cellulose in the form of a covalent bond, thereby improving the anti-ultraviolet performance of cellulose and providing convenience for the loading of nano-silver.

[0022]

[0023] The Mannich reaction of the present invention is a three-component condensation reaction of a compound containing at least one active hydrogen with an amine and an aldehyde. In the Mannich reaction, carboxylic acids, ketones, phenols, hydroxyl groups, etc. can be used as acid components; amines, amino acids, etc. can be used as amine components; various monoaldehydes or dialdehydes can be used as aldehyde components.

[0024] The Mannich reaction of the present invention adopts a one-time feeding method, and there is no need to add reactants or perform operations such as separation of intermediates during the reaction process, which greatly reduces the chance of contact between operators and chemicals and avoids physical harm to operators. At the same time, the Mannich reaction has a high raw material utilization rate, which meets the requirements of green chemistry for atomic economy. The present invention adopts multiple multi-component Mannich reactions to connect curcumin to cellulose in the form of covalent bonds, and the anti-ultraviolet performance of the modified cellulose obtained is significantly improved. At the same time, nano-silver particles can be further loaded at a lower temperature to make it have antibacterial function.

[0025] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0026] (1) The present invention uses multi-component reaction surface modification to bind curcumin to cellulose molecules by covalent bonds, which, on the one hand, gives cellulose an anti-ultraviolet function, and on the other hand, is beneficial to the adsorption and reduction of silver ions.

[0027] (2) The multi-component reaction used in the present invention can directly modify cellulose or nanocellulose at room temperature, and then silver nanoparticles can also be generated by reaction at room temperature.

[0028] (3) The method of the present invention has mild reaction conditions, is easy to achieve mass production, and the preparation method is universal for a variety of fabrics. The modified cellulose obtained by the method of the present invention is suitable for application in the fields of papermaking, packaging, personal protection or air filtration.

[0029] (4) The anti-ultraviolet nanocellulose obtained by multi-component reaction surface modification in the present invention has both high anti-ultraviolet performance and visible light transmittance; and has antibacterial properties after silver ion deposition.

[0030] (5) The UV-resistant cellulose cotton fabric obtained by multi-component reaction surface modification in the present invention has significantly improved UV resistance; the UV resistance is further improved after silver ion deposition. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 These are ultraviolet transmission images of the multi-component reaction-modified nanocellulose membrane (CL-SCNF) of Example 1, the nanocellulose membrane (SCNF) without multi-component reaction modification, and the nanocellulose membrane directly doped with curcumin (Cur / SCNF).

[0032] Figure 2 This is the antibacterial effect diagram of the antibacterial and anti-ultraviolet nanocellulose film of Example 2 (a Escherichia coli, b Staphylococcus aureus, c Candida albicans).

[0033] Figure 3 This is a scanning electron microscope image of the antibacterial and anti-ultraviolet nanocellulose of Example 3 after being sprayed on a medical mask.

[0034] Figure 4 The antibacterial effect diagram of the antibacterial and anti-ultraviolet mask of Example 3 (a Escherichia coli, b Staphylococcus aureus, c Candida albicans).

[0035] Figure 5 This is a scanning electron microscope image of the antibacterial cotton fabric of Example 4.

[0036] Figure 6 This is the antibacterial effect diagram of the antibacterial cotton fabric of Example 4 (a Escherichia coli, b Staphylococcus aureus, c Candida albicans). DETAILED DESCRIPTION

[0037] The specific implementation of the present invention is further described below in conjunction with the examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that if there are processes that are not particularly described in detail below, they can be implemented or understood by those skilled in the art with reference to the prior art. If the manufacturer of the reagents or instruments used is not indicated, they are deemed to be conventional products that can be purchased commercially.

[0038] A modification method for an antibacterial and anti-ultraviolet cellulose product loaded with nano-silver particles, the preparation method comprising the following steps:

[0039] 1.1 Multi-component reaction surface modification: Curcumin, lysine and formaldehyde solution are mixed evenly, and then the cellulose product is placed in the solution and reacted at 20-60°C for 1-12 hours. The obtained product is rinsed or dialyzed to obtain a modified cellulose product.

[0040] 1.2 In-situ deposition of antibacterial silver particles: Prepare a 0.1%-3.0% silver nitrate solution, mix it evenly with the modified nanocellulose, and react it at room temperature for 2-12 hours. The product is washed or dialyzed to obtain an antibacterial nanocellulose product loaded with nano-metal particles.

[0041] Specifically, in step 1.1, the reaction solvent is ethanol aqueous solution with a concentration of 20%-80%, the concentration of curcumin is 4.6-18.4 g / L, the concentration of lysine is 0.9-1.8-3.6 g / L, the concentration of formaldehyde is 2.2-8.8 g / L, and the molar ratio of curcumin: lysine: formaldehyde is 1:1:0.5-1:1:4.

[0042] Specifically, the cellulose product described in the method can be either nanocellulose or cotton product. The nanocellulose can be cellulose nanocrystal or cellulose nanofiber. The cotton product can be a manufactured cloth or non-woven fabric, or a cloth product containing cotton components can be used.

[0043] Specifically, in step 1.1, the solid content of the nanocellulose during the reaction is 0.5-3%, the stirring speed is 100-500 rpm, and the ratio of cotton fabric in the reaction solution is 1:10-1:50.

[0044] Specifically, in step 1.1, the rinsing method is: rinsing twice with 50%-100% ethanol, and then rinsing three times with water.

[0045] Example 1

[0046] Preparation of UV-resistant nanocellulose

[0047] 1.1 Prepare 100 mL of 50% (volume ratio) ethanol solution, add 0.92 g of curcumin, 0.18 g of lysine, 1 ml of 37 wt% formaldehyde solution and 10 g of 5 wt% nanocellulose (SCNFs) solution, mix well, place on a magnetic stirrer at 300 rpm and react at room temperature for 12 hours. The resulting product was rinsed twice with 70% ethanol aqueous solution and dialyzed with deionized water to obtain modified nanocellulose CL-SCNFs.

[0048] 1.2 The modified nanocellulose is filtered to form a membrane to obtain a multi-component reaction-modified nanocellulose membrane (CL-SCNF);

[0049] The negative control was that curcumin was directly added (without lysine and formaldehyde), and the nanocellulose membrane (SCNFs) without multi-component reaction was obtained by the above steps. The nanocellulose solution directly doped with curcumin was evaporated to form a membrane as a positive control (Cur / SCNFs).

[0050] The UV transmission images of multi-component reaction-modified nanocellulose membrane (CL-SCNF), nanocellulose membrane without multi-component reaction modification (SCNF) and nanocellulose membrane directly doped with curcumin (Cur / SCNF) are shown in Figure 2. Figure 1 It can be seen that the multi-component reaction-modified membrane has excellent anti-ultraviolet performance. At the same time, compared with the positive control, the transmittance of CL-SCNF in the visible light range of 500nm-800nm ​​can reach 80%, which is significantly higher than the positive control product. The multi-component reaction-modified nanocellulose membrane prepared by the present invention has both high anti-ultraviolet performance and visible light transmittance.

[0051] Example 2

[0052] Preparation of antibacterial and anti-ultraviolet nanocellulose

[0053] 1.1 Multi-component reaction surface modification: Prepare 100 mL of 50% (volume ratio) ethanol solution, add 0.92 g of curcumin, 0.18 g of lysine, 1 ml of 37 wt% formaldehyde solution and 10 g of 5 wt% nanocellulose solution, mix well, place on a magnetic stirrer at 300 rpm and react at room temperature for 12 hours. The obtained product was rinsed twice with 70% ethanol aqueous solution and dialyzed with deionized water to obtain modified nanocellulose.

[0054] 1.2 In-situ deposition of antibacterial silver particles: Prepare a 0.1wt% silver nitrate solution and mix it evenly with the modified nanocellulose. The mass ratio of the modified nanocellulose in the reaction solution is 1:30. Place it on a magnetic stirrer and react at 300rpm at room temperature for 12 hours. The product is dialyzed with deionized water to obtain antibacterial and anti-ultraviolet nanocellulose loaded with nanosilver.

[0055] 1.3 Filter the antibacterial and anti-ultraviolet nanocellulose into a membrane;

[0056] The antibacterial effect of the antibacterial and anti-ultraviolet nanocellulose membrane is shown in the figure Figure 2 , it can be seen that the antibacterial and anti-UV nanocellulose film has excellent antibacterial properties.

[0057] Example 3

[0058] Preparation of antibacterial and anti-ultraviolet nanocellulose and its application in masks

[0059] 1.1 Multi-component reaction surface modification: Prepare 100 mL of 50% (volume ratio) ethanol solution, add 0.92 g of curcumin, 0.18 g of lysine, 1 ml of 37 wt% formaldehyde solution and 10 g of 5 wt% nanocellulose solution, mix well, place on a magnetic stirrer at 300 rpm and react at room temperature for 12 hours. The obtained product was rinsed twice with 70% ethanol aqueous solution and dialyzed with deionized water to obtain modified nanocellulose.

[0060] 1.2 In-situ deposition of antibacterial silver particles: Prepare a 0.1wt% silver nitrate solution and mix it evenly with the modified nanocellulose. The mass ratio of the modified nanocellulose in the reaction solution is 1:30. Place it on a magnetic stirrer at 300rpm and react at room temperature for 12 hours. The product is dialyzed against deionized water to obtain nanosilver-loaded antibacterial and anti-ultraviolet nanocellulose.

[0061] 1.3 The antibacterial and anti-ultraviolet nanocellulose is prepared into a 0.1wt% dispersion and sprayed on the outside of a medical mask to obtain an antibacterial and anti-ultraviolet mask;

[0062] Scanning electron microscope image of antibacterial and anti-ultraviolet mask Figure 3 ; The antibacterial effect of antibacterial masks is shown in the figure Figure 4 , it can be seen that the antibacterial mask has antibacterial function.

[0063] Example 4

[0064] Preparation of UV-resistant cellulose textiles and antibacterial UV-resistant cellulose textiles

[0065] 1.1 Multi-component reaction surface modification: Prepare 2L of 50% ethanol (volume ratio) solution, add 18.4g of curcumin, 3.6g of lysine and 20ml of 37wt% formaldehyde solution, mix well, and immediately immerse 200g of textile (woven fabric) in the reaction solution, react at room temperature for 12 hours. The obtained product is rinsed twice with 70% ethanol aqueous solution and washed with water 3 times to obtain the modified textile.

[0066] The textiles were immersed in curcumin solution and the solvent was evaporated to obtain unmodified textiles (direct doping) as a positive control.

[0067] The anti-ultraviolet effects of multi-component reaction modified textiles (CL textiles) and unmodified (directly doped with curcumin) textiles are shown in Table 1. The results show that the anti-ultraviolet performance of modified cellulose textiles is significantly improved compared with that of the control group.

[0068] 1.2 In-situ deposition of antibacterial silver particles: Prepare 2L of 0.1wt% silver nitrate solution, immerse the modified textile in the silver nitrate solution, adjust the mass ratio of the modified textile in the reaction solution to 1:30, and react at room temperature for 12 hours. The product is washed with water to obtain an antibacterial and anti-ultraviolet textile (AgCL textile).

[0069] Scanning electron microscopy images of antibacterial and UV-resistant textiles Figure 5 ; The antibacterial effect of antibacterial and anti-ultraviolet textiles is shown in the figure Figure 6It can be seen that the antibacterial and anti-ultraviolet textiles have antibacterial functions. The anti-ultraviolet properties of the modified fabric antibacterial and anti-ultraviolet textiles after in-situ deposition of antibacterial silver particles are shown in Table 1. It can be seen that the anti-ultraviolet properties of the antibacterial and anti-ultraviolet textiles (AgCL fabrics) after in-situ deposition of antibacterial silver particles are greatly improved.

[0070] Table 1 UPF values ​​of different fabrics

[0071] sample UPF Unmodified textiles (direct adulteration) 5.9±0.1 CL Textiles 465.9±21.9 AgCL Textiles >1000

[0072] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Changes, substitutions, modifications, etc. made by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope of the present invention.

Claims

1. A method for preparing an ultraviolet-resistant cellulose material, characterized in that: The steps include: Curcumin, lysine, formaldehyde solution and solvent are mixed to obtain a mixed solution, and then the cellulose product is placed in the mixed solution and placed at 20-60° C. for reaction for 1-16 hours; the obtained product is washed and / or dialyzed to obtain an anti-ultraviolet cellulose material.

2. The preparation method according to claim 1, characterized in that: The solvent is an ethanol / water mixed solution, the volume concentration of ethanol is 20%-80%; the concentration of curcumin in the mixed solution is 4.6-18.4 g / L, the concentration of lysine is 0.9-3.6 g / L, and the concentration of formaldehyde is 2.2-8.8 g / L.

3. The preparation method according to claim 1, characterized in that: The cellulose product is nanocellulose or cotton fabric; the nanocellulose is cellulose nanocrystal or cellulose nanofibril; and the cotton fabric is woven fabric or non-woven fabric.

4. The preparation method according to claim 1, characterized in that: When the cellulose product is nanocellulose, the solid content of nanocellulose in the mixed solution is 0.5-3%, and the reaction is carried out under stirring at a speed of 100-500rpm; when the cellulose product is cotton fabric, the mass ratio of cotton fabric in the mixed solution is 1:10-1:

50.

5. The preparation method according to claim 1, characterized in that: When the cellulose product is nanocellulose, the obtained product is rinsed at least twice with 30%-100% ethanol and then dialyzed with deionized water; When the cellulose product is cotton fabric, the obtained product is rinsed with 30%-100% ethanol at least twice, and then rinsed with water at least three times.

6. An anti-ultraviolet cellulose material, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 5.

7. A method for preparing an antibacterial and anti-ultraviolet cellulose material, characterized in that: The following steps are involved: A silver nitrate solution with a mass concentration of 0.1%-3.0% is prepared, mixed evenly with the anti-ultraviolet cellulose material according to claim 6, and reacted at room temperature for 2-16 hours; the product is washed or dialyzed to obtain the antibacterial and anti-ultraviolet cellulose material.

8. The preparation method according to claim 7, characterized in that: When the anti-ultraviolet cellulose material is nanocellulose, the solid content of the nanocellulose in the mixed solution is 0.01-5%; when the anti-ultraviolet cellulose material is cotton fabric, the mass ratio of the cotton fabric in the mixed solution is 1:10-1:

50.

9. An antibacterial and anti-ultraviolet cellulose material, characterized in that: The method is prepared according to claim 7 or 8.

10. Use of the anti-ultraviolet cellulose material of claim 6 and the antibacterial anti-ultraviolet cellulose material of claim 9 in papermaking, packaging material preparation, personal protection material preparation and air filtration material preparation.

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