Preparation Method and Application of an Antibacterial and Freshness-Preserving Superhydrophobic Paper
Through the coordination effect of tea polyphenols with Fe3+ ion and the hydrophobic modification of silver ion reduction combined with palm wax, the problem of low sterilization efficiency of existing superhydrophobic materials was solved, and antibacterial fresh-preserved superhydrophobic paper with high efficiency sterilization for bacteria was prepared.
Patent Information
- Application Number
- CN202310716410.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-16
- Publication Date
- 2025-07-18
- Estimated Expiration
- 2043-06-16
AI Technical Summary
Existing superhydrophobic materials have problems such as low sterilization efficiency, slow speed and poor broad-spectrum sterilization in terms of antibacterial properties.
The coordination effect of tea polyphenols and Fe3+ ions is adopted to form a microstructure on the surface of the paper by self-assembly layer by layer, and silver ions are reduced in situ, so that the surface microstructure is firmly combined with the paper, and antibacterial fresh-preserved superhydrophobic paper is prepared with palm wax hydrophobic modification.
The prepared antibacterial fresh-preserved superhydrophobic paper has an antibacterial and bactericidal rate of Gram-necked E. coli and Gram-necked Staphylococcus aureus as high as 99.9%, showing excellent antibacterial and hydrophobic properties.
Smart Images
Figure CN116856202B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical fields of superhydrophobic functional paper and food packaging technology, and particularly relates to a preparation method and application of antibacterial and fresh-keeping superhydrophobic paper. Background Art
[0002] Problems of bacterial adhesion, transmission and infection generally exist in important fields such as food safety, medical and health care, biomedical equipment, marine ships, oil pipelines and the like. While causing major economic problems, it even threatens human health and leads to human death due to bacterial infection, and has become one of the major public health problems. Therefore, in the past few decades, people have been committed to developing antibacterial materials that can inhibit bacterial growth or even achieve effective sterilization.
[0003] Superhydrophobic surfaces inspired by the "lotus effect" are often used for antibacterial adhesion. On the one hand, the stagnant air layer between the micro-nano rough structure surfaces is utilized to reduce the contact area between bacteria and the substrate surface, thereby greatly reducing the adhesion force of bacteria on its surface; on the other hand, it is based on the bactericidal mechanism in terms of physical properties, that is, without adding chemical bactericides, when the bacterial cell wall is subjected to physical tearing force exceeding its bearing capacity, it will cause the rupture of the bacterial cell structure and death. However, a single superhydrophobic antibacterial strategy often fails to completely eliminate bacterial adhesion and bacterial infection phenomena. Here, the antibacterial effect of silver nanoparticles has to be mentioned. Silver nanoparticles have broad-spectrum antibacterial properties and can interfere with cell wall synthesis, damage cell membranes, inhibit protein synthesis and interfere with nucleic acid synthesis, and can effectively inhibit or even kill most bacteria, fungi, viruses, etc. Therefore, combining the passive bactericidal effect of superhydrophobic materials and the active bactericidal effect of silver ions can effectively improve the antibacterial performance of the material. Summary of the Invention
[0004] The present invention relates to a preparation method and application of antibacterial and fresh-keeping superhydrophobic paper, and solves the problems of low sterilization efficiency, slow speed and poor broad-spectrum bactericidal property of existing single-performance surfaces.
[0005] One of the technical solutions adopted by the present invention is:
[0006] A preparation method of antibacterial and fresh-keeping superhydrophobic paper is provided, including the following operation steps:
[0007] (1) Prepare a tea polyphenol solution with a certain concentration, immerse the paper base therein for a certain time, and then take it out and wash it;
[0008] (2) Prepare an FeCl3 solution with a certain concentration, mix it with the tea polyphenol solution in step (1) to obtain a mixed solution; continue to immerse the paper base washed in step (1) in the mixed solution for a certain time, and then take it out and wash it;
[0009] (3) Prepare a silver ammonia aqueous solution with a certain concentration; immerse the paper substrate cleaned in step (2) in the silver ammonia aqueous solution for a certain period of time again, take it out and wash it with water;
[0010] (4) After repeating steps (1), (2) and (3) 4 - 8 times, dry the paper substrate after repeated impregnation and washing;
[0011] (5) Dissolve palm wax in chloroform, immerse the paper substrate dried in step (4) in the palm wax solution for a certain period of time, take it out and dry it to obtain a superhydrophobic antibacterial paper.
[0012] Furthermore, the concentration of the tea polyphenol solution in step (1) is 0.1 mg / ml - 0.3 mg / ml; the impregnation time is 5 min.
[0013] Furthermore, the concentration of the FeCl3 solution in step (2) is 0.1 mg / ml - 1 mg / ml, and the mass ratio of the tea polyphenol solution to the FeCl3 solution in the mixed solution is 1:1 - 3:1; the impregnation time is 5 - 10 min.
[0014] Furthermore, the molar concentration of the silver ammonia aqueous solution in step (3) is 10 mM - 20 mM; the impregnation time is 10 - 20 min.
[0015] Furthermore, the drying temperature in step (4) is 100 °C.
[0016] Furthermore, the concentration of the palm wax solution in step (5) is 2.2 mg / ml - 2.6 mg / ml; the impregnation time is 5 - 10 min; the drying temperature is 105 °C.
[0017] Furthermore, the paper substrate is filter paper, cardboard, corrugated paper or paperboard.
[0018] The second technical solution adopted by the present invention is:
[0019] Provide the application of the antibacterial and fresh - keeping superhydrophobic paper prepared by the aforementioned preparation method in antibacterial and hydrophobic papers for food and medical use.
[0020] The beneficial effects of the present invention:
[0021] Through the coordination of tea polyphenols and Fe 3+ ions and the layer - by - layer self - assembly method, a micro - structure is constructed on the paper surface. At the same time, the in - situ reduced silver ions make the surface micro - structure firmly combined with the paper, showing good mechanical properties. Through the hydrophobic modification of surface palm wax, it shows good hydrophobic properties, and the water contact angle can reach 156°. Due to the uniform coverage of silver ions and combined with the hydrophobic properties, the paper prepared by the present invention has a bacteriostatic and bactericidal rate of up to 99.9% against Gram - negative Escherichia coli and Gram - positive Staphylococcus aureus, showing excellent antibacterial properties. Description of the Drawings
[0022] Figure 1 Contact angle of the superhydrophobic and antibacterial paper prepared in Example 1 of the present invention
[0023] Figure 2 Scanning electron micrographs of the superhydrophobic and antibacterial paper prepared in Example 1 at different magnifications
[0024] Figure 3 Colony number graph after diluting the Escherichia coli solution of the blank paper by 10 3 times
[0025] Figure 4 Colony number graph after diluting the Escherichia coli solution of the superhydrophobic and antibacterial paper in Example 1 by 10 3 times
[0026] Figure 5 Colony number graph after diluting the Staphylococcus aureus solution of the blank paper by 10 3 times
[0027] Figure 6 Colony number graph after diluting the Staphylococcus aureus solution of the superhydrophobic and antibacterial paper in Example 1 by 10 3 times
[0028] Figure 7 Effect of Fe 3+ concentration change on the wetting performance of the antibacterial paper of the present invention
[0029] Figure 8 Effect of the ratio change of tea polyphenol / Fe 3+ on the wetting performance of the antibacterial paper of the present invention
[0030] Figure 9 Effect of silver ammonia solution concentration change on the wetting performance of the antibacterial paper of the present invention
[0031] Figure 10 Effect of dipping times on the wetting performance of the antibacterial paper of the present invention
[0032] Figure 11 Effect of palm wax concentration on the wetting performance of the antibacterial paper of the present invention Detailed Description of the Invention
[0033] To clearly illustrate the technical features of the solution, the present invention will be described in detail below through specific embodiments in conjunction with the accompanying drawings.
[0034] Example 1
[0035] A preparation method of an antibacterial and fresh-keeping superhydrophobic paper, comprising the following steps:
[0036] Step 1: Weigh 100 mg of tea polyphenols and dissolve them in 500 ml of deionized water to obtain a 0.2 mg / ml tea polyphenol solution. Take 50 ml of the tea polyphenol solution, immerse the paper substrate in it for 5 minutes, then take it out and wash it;
[0037] Step 2: Weigh 50 mg of FeCl3 and dissolve it in 500 ml of deionized water to obtain a 0.1 mg / ml FeCl3 solution. Take 50 ml of the FeCl3 solution and mix it with 50 ml of the tea polyphenol solution. Immerse the paper substrate in the mixed solution for 10 minutes, then take it out and wash it;
[0038] Step 3: Prepare a 10 mM silver ammonia aqueous solution; Immerse the paper substrate obtained in Step 2 in 100 ml of the silver ammonia solution for 20 minutes, then take it out and wash it with water;
[0039] Step 4: Repeat Step 1, Step 2, and Step 3 four times, and dry it at 100 °C;
[0040] Step 5: Dissolve 120 mg of palm wax in 50 ml of chloroform. Immerse the paper substrate dried in Step 4 in the palm wax solution for 5 minutes, then take it out and dry it at 105 °C to obtain the superhydrophobic antibacterial paper.
[0041] Example 2
[0042] A preparation method of an antibacterial and fresh-keeping superhydrophobic paper, comprising the following steps:
[0043] Step 1: Weigh 50 mg of tea polyphenols and dissolve them in 500 ml of deionized water to obtain a 0.1 mg / ml tea polyphenol solution. Take 50 ml of the tea polyphenol solution, immerse the paper substrate in it for 5 minutes, then take it out and wash it;
[0044] Step 2: Weigh 50 mg of FeCl3 and dissolve it in 500 ml of deionized water to obtain a 0.1 mg / ml FeCl3 solution. Take 50 ml of the FeCl3 solution and mix it with 50 ml of the tea polyphenol solution. Immerse the paper substrate in the mixed solution for 10 minutes, then take it out and wash it;
[0045] Step 3: Prepare a 10 mM silver ammonia aqueous solution; Immerse the paper substrate obtained in Step 2 in 100 ml of the silver ammonia solution for 20 minutes, then take it out and wash it with water;
[0046] Step 4: Repeat Step 1, Step 2, and Step 3 five times, and dry it at 100 °C;
[0047] Step 5: Dissolve 120 mg of palm wax in 50 ml of chloroform. Immerse the paper substrate dried in Step 4 in the palm wax solution for 5 minutes, then take it out and dry it at 105 °C to obtain the superhydrophobic antibacterial paper.
[0048] Example 3
[0049] A preparation method of antibacterial and fresh-keeping superhydrophobic paper, comprising the following steps:
[0050] Step 1: Weigh 150 mg of tea polyphenols and dissolve them in 500 ml of deionized water to obtain a 0.3 mg / ml tea polyphenol solution. Take 50 ml of the tea polyphenol solution, immerse the paper substrate in it for 5 minutes, and then take it out and wash it;
[0051] Step 2: Weigh 50 mg of FeCl3 and dissolve it in 500 ml of deionized water to obtain a 0.1 mg / ml FeCl3 solution. Take 50 ml of the FeCl3 solution and mix it with 50 ml of the tea polyphenol solution. Immerse the paper substrate in the mixed solution for 10 minutes, and then take it out and wash it;
[0052] Step 3: Prepare a 10 mM silver ammonia aqueous solution; immerse the paper substrate obtained in Step 2 in 100 ml of the silver ammonia solution for 20 minutes, take it out and wash it with water;
[0053] Step 4: Repeat Step 1, Step 2, and Step 3 six times, and dry it at 100 °C;
[0054] Step 5: Dissolve 120 mg of palm wax in 50 ml of chloroform, immerse the paper substrate dried in Step 4 in the palm wax solution for 5 minutes, take it out and dry it at 105 °C to obtain superhydrophobic antibacterial paper.
[0055] As Figure 1 , it shows that the water contact angle of the superhydrophobic antibacterial paper prepared in the foregoing Example 1 can reach 156°, indicating its excellent hydrophobic ability.
[0056] As Figure 3 , Figure 4 , Figure 5 and Figure 6 , it shows that the antibacterial and bactericidal rates of the superhydrophobic antibacterial paper prepared by the steps of Example 1 against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus are as high as 99.9% compared with the blank kraft paper, and it has excellent antibacterial performance.
[0057] The influence of the key steps and condition parameters of the foregoing preparation method of the present invention on the quality of the prepared antibacterial and fresh-keeping superhydrophobic paper is as follows in the following preparation method test.
[0058] I. Influence of different concentrations of Fe 3+ on the wetting performance of antibacterial and fresh-keeping superhydrophobic paper
[0059] The preparation method of the antibacterial and fresh-keeping superhydrophobic paper comprises the following steps:
[0060] Step 1: Weigh 100 mg of tea polyphenols and dissolve them in 500 ml of deionized water to obtain a 0.2 mg / ml tea polyphenol solution. Take 50 ml of the tea polyphenol solution, immerse the paper substrate in it for 5 minutes, and then take it out and wash it;
[0061] Step 2: Weigh appropriate amounts of FeCl3 and dissolve them in deionized water to obtain FeCl3 solutions with concentrations of 0 mg / ml, 0.025 mg / ml, 0.05 mg / ml, 0.1 mg / ml, 0.2 mg / ml, 0.4 mg / ml, and 1 mg / ml. Take 50 ml of each FeCl3 solution and mix it with 50 ml of tea polyphenol solution. Immerse the paper substrate in the mixed solution for 10 minutes and then take it out for cleaning.
[0062] Step 3: Prepare a 10 mM silver ammonia aqueous solution. Immerse the paper substrates obtained in Step 2 in 100 ml of silver ammonia solution for 20 minutes respectively, and then take them out for cleaning with water.
[0063] Step 4: Repeat the impregnation steps in Step 1, Step 2, and Step 3 four times respectively, and dry them at 100 °C.
[0064] Step 5: Dissolve 120 mg of palm wax in 50 ml of chloroform. Immerse the paper substrates dried in Step 4 in the palm wax solution for 5 minutes respectively, and then take them out and dry at 105 °C to obtain superhydrophobic antibacterial paper.
[0065] As Figure 7 shown, when the concentration of Fe 3+ is 0, only physically adsorbed tea polyphenols exist on the surface of kraft paper, and the in-situ reduced silver nanoparticles are not enough to cover the cellulose nanofibers, so superhydrophobicity cannot be achieved. As the concentration of iron ions gradually increases, the static contact angle on the surface of the antibacterial paper also increases. Taking the dynamic rolling angle as the judgment standard, as the concentration of Fe 3+ increases, the rolling angle first decreases, then increases, and finally stabilizes. This law corresponds to the change of the static contact angle. The optimal concentration of iron ions is 0.1 mg / ml.
[0066] II. Influence of different mass ratios of tea polyphenol / Fe 3+ on the wetting performance of antibacterial and fresh-keeping superhydrophobic paper
[0067] The preparation method of the antibacterial and fresh-keeping superhydrophobic paper includes the following steps:
[0068] Step 1: Weigh appropriate amounts of tea polyphenols and dissolve them in deionized water to obtain tea polyphenol solutions with concentrations of 0.05 mg / ml, 0.1 mg / ml, 0.2 mg / ml, 0.3 mg / ml, 0.4 mg / ml, and 0.5 mg / ml. Take 50 ml of each tea polyphenol solution, and immerse the paper substrate in it for 5 minutes respectively and then take it out for cleaning.
[0069] Step 2: Weigh 50 mg of FeCl3 and dissolve it in 500 ml of deionized water to obtain a 0.1 mg / ml FeCl3 solution. Take 50 ml of the FeCl3 solution and mix it with 50 ml of the corresponding concentration of tea polyphenol solution in Step 1. Immerse the paper substrate in the mixed solution for 10 min and then take it out for cleaning.
[0070] Step 3: Prepare a 10 mM silver ammonia aqueous solution; Immerse the paper substrate obtained in Step 2 in 100 ml of the silver ammonia solution for 20 min, and then take it out for cleaning with water.
[0071] Step 4: Repeat the immersion steps in Step 1, Step 2, and Step 3 4 times respectively, and dry at 100 °C.
[0072] Step 5: Dissolve 120 mg of palm wax in 50 ml of chloroform. Immerse the dried paper substrate in Step 4 in the palm wax solution for 5 min, take it out and dry at 105 °C to obtain the superhydrophobic antibacterial paper.
[0073] As Figure 8 shown, with the increase of the tea polyphenol concentration, the static contact angle on the surface of the superhydrophobic antibacterial paper shows a trend of first increasing and then stabilizing, which is mainly related to the surface roughness. As the tea polyphenol concentration increases, the number of silver ions participating in reduction increases, constructing the roughness required for the superhydrophobic structure. The rolling angle first decreases because the roughness is increasing, and then decreases because the reduced silver nanoparticles increase, the surface is uneven, and too much palm wax is adsorbed on the surface, resulting in a decrease in surface roughness. Therefore, the optimal tea polyphenol concentration is 0.2 mg / ml.
[0074] III. Influence of silver ammonia solutions with different molar concentrations on the wetting performance of the antibacterial and fresh-keeping superhydrophobic paper
[0075] The preparation method of the antibacterial and fresh-keeping superhydrophobic paper includes the following steps:
[0076] Step 1: Weigh 100 mg of tea polyphenol and dissolve it in 500 ml of deionized water to obtain a 0.2 mg / ml tea polyphenol solution. Take 50 ml of the tea polyphenol solution, immerse the paper substrate in it for 5 min and then take it out for cleaning.
[0077] Step 2: Weigh 50 mg of FeCl3 and dissolve it in 500 ml of deionized water to obtain a 0.1 mg / ml FeCl3 solution. Take 50 ml of the FeCl3 solution and mix it with 50 ml of the tea polyphenol solution. Immerse the paper substrate in the mixed solution for 10 min and then take it out for cleaning.
[0078] Step 3: Prepare 1 mM, 5 mM, 10 mM, 15 mM, and 20 mM silver ammonia aqueous solutions respectively; Immerse the paper substrate obtained in Step 2 in 100 ml of each concentration of silver ammonia solution for 20 min, and then take it out for cleaning with water.
[0079] Step 4: Repeat the impregnation steps in Step 1, Step 2, and Step 3 four times respectively, and dry at 100 °C.
[0080] Step 5: Dissolve 120 mg of palm wax in 50 ml of chloroform. Immerse the paper substrates dried in Step 4 in the palm wax solution for 5 min respectively, take them out and dry at 105 °C to obtain superhydrophobic antibacterial paper.
[0081] As Figure 9 shown, with the change of silver ion concentration, the static contact angle first increases and then stabilizes, which is related to the coverage of silver nanoparticles on the surface of the antibacterial paper. When the concentration of silver ammonia solution is too low, it is not sufficient to construct the required roughness. Combining with the analysis of the dynamic rolling angle, when the concentration is 10 mmol / L, the static contact angle is the largest and the rolling angle meets the condition of being less than 10°. Therefore, the effect is the best when the concentration of silver ammonia solution is 10 mmol / L.
[0082] IV. Influence of impregnation operations with different repetition times on the wettability of antibacterial and fresh-keeping superhydrophobic paper
[0083] The preparation method of the antibacterial and fresh-keeping superhydrophobic paper includes the following steps:
[0084] Step 1: Weigh 100 mg of tea polyphenols and dissolve them in 500 ml of deionized water to obtain a 0.2 mg / ml tea polyphenol solution. Take 50 ml of the tea polyphenol solution, immerse the paper substrate in it for 5 min and then take it out and wash.
[0085] Step 2: Weigh 50 mg of FeCl3 and dissolve it in 500 ml of deionized water to obtain a 0.1 mg / ml FeCl3 solution. Take 50 ml of the FeCl3 solution and mix it with 50 ml of the tea polyphenol solution. Immerse the paper substrate in the mixed solution for 10 min and then take it out and wash.
[0086] Step 3: Prepare a 10 mM silver ammonia aqueous solution; immerse the paper substrate obtained in Step 2 in 100 ml of the silver ammonia solution for 20 min, take it out and wash with water.
[0087] Step 4: Repeat Step 1, Step 2, and Step 3 2, 4, 6, and 8 times respectively, and dry at 100 °C.
[0088] Step 5: Dissolve 120 mg of palm wax in 50 ml of chloroform. Immerse the paper substrates dried in Step 4 in the palm wax solution for 5 min respectively, take them out and dry at 105 °C to obtain superhydrophobic antibacterial paper.
[0089] As Figure 10 shown, when the reduction times is 2, due to insufficient silver nanoparticles, enough roughness cannot be constructed. When the times is 4 or more, the contact angle is greater than 150° and tends to be stable. The most suitable number of times is 4.
[0090] V. Influence of Palm Wax Solutions with Different Concentrations on the Wettability of Antibacterial and Freshness-Preserving Superhydrophobic Paper
[0091] The preparation method of the antibacterial and freshness-preserving superhydrophobic paper includes the following steps:
[0092] Step 1: Weigh 100 mg of tea polyphenols and dissolve them in 500 ml of deionized water to obtain a 0.2 mg / ml tea polyphenol solution. Take 50 ml of the tea polyphenol solution, immerse the paper substrate in it for 5 minutes, and then take it out and wash it.
[0093] Step 2: Weigh 50 mg of FeCl3 and dissolve it in 500 ml of deionized water to obtain a 0.1 mg / ml FeCl3 solution. Take 50 ml of the FeCl3 solution and mix it with 50 ml of the tea polyphenol solution. Immerse the paper substrate in the mixed solution for 10 minutes, and then take it out and wash it.
[0094] Step 3: Prepare a 10 mM silver ammonia aqueous solution; immerse the paper substrate obtained in Step 2 in 100 ml of the silver ammonia solution for 20 minutes, and then take it out and wash it with water.
[0095] Step 4: Repeat Step 1, Step 2, and Step 3 six times, and dry it at 100 °C.
[0096] Step 5: Dissolve the corresponding amount of palm wax in 50 ml of chloroform to obtain palm wax solutions with concentrations of 2 mg / ml, 2.2 mg / ml, 2.4 mg / ml, 2.6 mg / ml, 2.8 mg / ml, 3 mg / ml, and 4 mg / ml respectively. Immerse the paper substrate dried in Step 4 in the palm wax solution for 5 minutes, take it out, and dry it at 105 °C to obtain the superhydrophobic antibacterial paper.
[0097] As Figure 11 shown, the optimal palm wax concentration is 2.4 mg / ml. At this time, the rolling angle is the smallest and less than 10°, and the superhydrophobic performance is the best.
[0098] The above specific implementation manners cannot be used as a limitation on the protection scope of the present invention. For those skilled in the art of this technology, any alternative improvement or transformation made to the implementation manner of the present invention falls within the protection scope of the present invention.
[0099] Where the present invention is not described in detail, it is all well-known technology to those skilled in the art of this technology.
Claims
1. A preparation method of an antibacterial and fresh-keeping superhydrophobic paper, characterized in that, The operation steps are as follows: (1) Prepare a tea polyphenol solution with a concentration of 0.1 mg / ml - 0.3 mg / ml. Immerse the paper substrate in it for 5 minutes, then take it out and wash it; (2) Prepare an FeCl3 solution with a concentration of 0.1 mg / ml - 1 mg / ml, and mix it with the tea polyphenol solution in step (1) to obtain a mixed solution. The mass ratio of the tea polyphenol solution to the FeCl3 solution in the mixed solution is 1:1 - 3:1; Immerse the paper substrate washed in step (1) in the mixed solution for 5 - 10 minutes, then take it out and wash it; (3) Prepare a silver ammonia aqueous solution with a concentration of 10 mM - 20 mM; Immerse the paper substrate washed in step (2) in the silver ammonia aqueous solution again for 10 - 20 minutes, then take it out and wash it with water; (4) After repeating steps (1), (2), and (3) 4 - 8 times, dry the paper substrate after repeated immersion and washing at 100 °C; (5) Dissolve palm wax in chloroform to obtain a palm wax solution with a concentration of 2.2 mg / ml - 2.6 mg / ml. Immerse the paper substrate dried in step (4) in the palm wax solution for 5 - 10 minutes, then take it out and dry it at 105 °C to obtain a superhydrophobic antibacterial paper.
2. The preparation method of an antibacterial and fresh-keeping superhydrophobic paper according to claim 1, characterized in that The paper substrate is filter paper, cardboard, corrugated paper or paperboard.
3. Application of the antibacterial and fresh-keeping superhydrophobic paper prepared by the preparation method as described in claim 1 or 2 in food and medical antibacterial hydrophobic paper.