阅读说明：本技术 一种自修复、耐酸碱、抗菌多层膜涂层的制备方法 (Preparation method of self-repairing, acid-base-resistant and antibacterial multilayer film coating ) 是由 李辉 史宏博 巫林浣仪 余富友 于 2021-09-01 设计创作，主要内容包括：本发明公开一种自修复、耐酸碱、抗菌多层膜涂层的制备方法,属于高分子薄膜制备领域；该方法首先将预处理过的基底置于壳聚糖溶液中浸泡,取出后用去离子水漂洗,然后置于多巴胺接枝改性的羧甲基纤维素溶液中浸泡,取出后用去离子水漂洗,重复上述过程,得到CS/DA-g-CMC多层膜改性的基底,最后采用高碘酸钠对多层膜改性的基底进行氧化交联,制得自修复、耐酸碱、抗菌的多层膜；本发明制备成本低廉、操作简便、设备简单、条件温和,多层膜结构和性能可控,并兼具自修复、耐酸碱和抗菌三种功能,在生物医用材料、食品包装材料等领域具有广泛的应用前景。(The invention discloses a preparation method of a self-repairing, acid-base-resistant and antibacterial multilayer film coating, belonging to the field of preparation of high polymer films; the method comprises the steps of firstly soaking a pretreated substrate in a chitosan solution, taking out the substrate, rinsing the substrate with deionized water, soaking the substrate in a dopamine graft modified carboxymethyl cellulose solution, taking out the substrate, rinsing the substrate with deionized water, and repeating the above steps to obtain CS/DA- g The substrate modified by the CMC multilayer film is subjected to oxidative crosslinking by sodium periodate to prepare a self-repairing, acid-alkali-resistant and antibacterial multilayer film; the invention has the advantages of low preparation cost, simple and convenient operation, simple equipment, mild conditions, controllable structure and performance of the multilayer film, three functions of self-repairing, acid and alkali resistance and antibiosis, and wide application prospect in the fields of biomedical materials, food packaging materials and the like.)

1. A preparation method of a self-repairing, acid-base-resistant and antibacterial multilayer film coating is characterized by comprising the following steps:

(1) putting the substrate into a sodium periodate solution, and carrying out light-shielding treatment at the temperature of 30-50 ℃ to obtain a pretreated substrate;

(2) soaking the pretreated substrate in a chitosan solution for 10-30 min, rinsing with deionized water for 3-5 times to obtain a chitosan layer modified substrate, soaking the chitosan layer modified substrate in a dopamine-grafted carboxymethyl cellulose solution for 10-30 min, rinsing with deionized water for 3-5 times to obtain a double-layer film modified substrate, repeating the modification process for 5-15 times to obtain a multi-layer film modified substrate, and drying at 40-60 ℃;

(3) and (3) placing the dried multilayer film modified substrate in a sodium periodate solution for normal-temperature light-shielding treatment, and drying to finish the preparation of the multilayer film coating.

2. The preparation method of the self-repairing, acid and alkali resistant and antibacterial multilayer film coating of claim 1, characterized in that: the concentration of the sodium periodate in the step (1) is 1-3 g/L, and the light-shielding treatment time is 1-3 h.

3. The preparation method of the self-repairing, acid and alkali resistant and antibacterial multilayer film coating of claim 1, characterized in that: the carboxymethyl cellulose grafted with dopamine in the step (2) is prepared by adding 1-2 g of carboxymethyl cellulose into 100mL of disodium hydrogen phosphate-citric acid buffer solution with the pH value of 3-5, stirring at 37 ℃ for 4-6 h, then adding 0.4-0.6 g of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and 0.2-0.4 g N-hydroxysuccinimide, continuously stirring for 20-40min, then adding 2-4 mL of dopamine hydrochloride solution with the pH value of 2-4 and 170-230 mg/mL, placing the mixture into a shaking table, reacting in a dark place at 37 ℃ and 100-180 r/min under the condition of nitrogen for 24-36 h, dialyzing the solution obtained by reaction in distilled water by using a dialysis bag for 1-2 days, and freeze-drying the dialyzed solution.

4. The preparation method of the self-repairing, acid and alkali resistant and antibacterial multilayer film coating of claim 1, characterized in that: in the step (2), the concentration of the chitosan solution is 1-3 g/L, and the pH value is 5-5.6; the concentration of the dopamine-grafted carboxymethyl cellulose solution is 1-3 g/L, and the pH value is 6.5-7.5.

5. The preparation method of the self-repairing, acid and alkali resistant and antibacterial multilayer film coating of claim 1, characterized in that: in the step (3), the concentration of the sodium periodate solution is 0.1-0.3g/L, the treatment time is 2-6 h, and the drying temperature is 35-45 ℃.

6. The preparation method of the self-repairing, acid and alkali resistant and antibacterial multilayer film coating of claim 1, characterized in that: the substrate is paper or cotton fabric.

Technical Field

The invention relates to a preparation method of a multilayer film coating capable of self-repairing, acid and alkali resistance and antibiosis, belonging to the field of preparation of polymer films.

Background

The material is influenced by external mechanical, chemical and other acting forces in the using process, local damage and fine cracks are inevitably generated, if the damaged parts cannot be repaired in time, the normal use performance of the material is influenced, the service life of the material is shortened, and macroscopic cracks and even breakage are caused, so that greater potential safety hazards are caused. The self-repairing material can perform self-repairing when the material is damaged, and has the effects of prolonging the service life, reducing the replacement cost and increasing the safety. In addition, the pollution of surface microorganisms and the subsequent biofilm pollution of the material in the using process can generate great threats to the service life and even the use safety of the material, for example, biomedical materials and food packaging materials have high requirements on the antibacterial performance of the material. Therefore, the coating with self-repairing and antibacterial functions has potential application value in the fields of biomedicine and food packaging materials.

Chinese patent CN20210132441.8 discloses a preparation method of a self-repairing transparent antibacterial coating, namely, firstly, a layer-by-layer self-assembly technology is adopted to alternately deposit anion and cation polyelectrolytes on the surface of a substrate to prepare the substrate with the self-repairing multilayer film coating, and then the substrate is soaked in an antibacterial agent solution for a period of time to obtain the self-repairing transparent antibacterial coating. However, the driving force of the layer-by-layer self-assembly technology adopted in the patent is weak electrostatic interaction force, so that the prepared self-repairing multilayer film coating has insufficient stability and cannot resist the damage caused by harsh external environment (such as acid-base corrosion). So far, no research and development work report about a layer-by-layer self-assembled multilayer film coating with self-repairing, acid-base-resistant and antibacterial functions is reported.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a preparation method of a multilayer film coating capable of self-repairing, acid and alkali resistance and antibiosis, which specifically comprises the following steps:

(1) putting a substrate (paper and cotton fabric) into a sodium periodate solution, and carrying out light-proof treatment under a certain temperature condition to obtain a pretreated substrate;

the concentration of the sodium periodate is 1-3 g/L, and the photophobic treatment time is 1-3 h at 30-50 ℃;

(2) soaking the pretreated substrate in a Chitosan (CS) solution for 10-30 min, rinsing with deionized water for 3-5 times to obtain a CS layer modified substrate, and soaking the CS layer modified substrate in dopamine-grafted carboxymethyl cellulose (DA-gCMC) solution for 10-30 min, and then rinsing with deionized water for 3-5 times to obtain CS/DA-g-CMC double-layer film modified substrate, repeating the above modification process 5-15 times to obtain (CS/DA-g-CMC)_nDrying the substrate modified by the multilayer film at 40-60 ℃;

said DA-g-the preparation of CMC is as follows: adding 1-2 g of CMC (carboxyl methyl cellulose) into 100mL of disodium hydrogen phosphate-citric acid buffer solution with the pH value of 3-5, stirring for 4-6 h at 37 ℃, then respectively adding 0.4-0.6 g of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and 0.2-0.4 g N-hydroxysuccinimide, continuing stirring for 20-40min, and then adding pH is 2-4, and 170-230 mg/mL dopamine hydrochloride (DA) solution is 2-4 mL, the mixture is placed in a shaking table to react for 24-36 hours at 37 ℃ under the condition of keeping out of the sun and under the condition of nitrogen, the solution obtained after the reaction is dialyzed in distilled water for 1-2 days by a dialysis bag, and the solution after the dialysis is freeze-dried to obtain DA plus materialsg-CMC；

The concentration of the CS solution is 1-3 g/L, and the pH value is 5-5.6; DA-gThe concentration of the CMC solution is 1-3 g/L, and the pH value is 6.5-7.5;

(3) placing the dried multilayer film modified substrate in a sodium periodate solution for normal-temperature light-shielding treatment, and then drying at a certain temperature to complete the preparation of the multilayer film coating;

in the step (3), the concentration of the sodium periodate solution is 0.1-0.3g/L, the treatment time is 2-6 h, and the drying temperature is 35-45 ℃.

The invention has the beneficial effects that:

(1) the chitosan and the carboxymethyl cellulose used in the invention belong to natural polysaccharide and derivatives, are nontoxic and renewable;

(2) the method is simple to operate, mild in process conditions and suitable for industrial production;

(3) the multilayer film coating prepared by the invention has three functions of self-repairing, acid and alkali resistance and antibiosis, and has good application prospect in the fields of biomedical materials and food packaging materials.

Drawings

FIG. 1 shows (CS/DA-g-CMC)₅A microscope photo of the multilayer film coating in the self-repairing process under the action of deionized water, wherein the left image is before repairing, and the right image is after repairing;

FIG. 2 is DA-gFTIR (A) and HNMR (B) spectra of CMC.

Detailed Description

The invention is described in more detail below with reference to the figures and examples, but the scope of the invention is not limited to the description.

Example 1

(1) The dopamine grafted carboxymethyl cellulose is prepared by adding 1g of carboxymethyl cellulose into 100mL of disodium hydrogen phosphate-citric acid buffer solution with pH of 3, stirring at 37 deg.C for 4 hr, and addingAdding 0.6g 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and 0.2g N-hydroxysuccinimide, stirring for 20min, adding 4mL dopamine hydrochloride solution with pH of 2 and concentration of 175mg/mL, placing in a shaking table, reacting at 37 deg.C and 150r/min under nitrogen and keeping out of the light for 24h, dialyzing the solution obtained by the reaction in distilled water for 1 day by using a dialysis bag, freeze-drying the dialyzed solution to obtain the final product, wherein the carboxymethyl cellulose grafted with dopamine and HNMR spectrogram are shown in figure 2, and FTIR spectrogram in figure 2 (A) is compared with original carboxymethyl cellulose, and dopamine modified at 1735 and 1080 cm^-1Two new characteristic absorption peaks appear, which are caused by tensile vibration of-COOH groups and C-N, and indicate that dopamine is successfully grafted on the carboxymethyl cellulose; from the HNMR spectrum in the graph (B) in FIG. 2, it can be observed that the original carboxymethyl cellulose has no characteristic absorption peak at about 7.0ppm, while the carboxymethyl cellulose reacted with dopamine has a characteristic absorption peak at about 7.0ppm, which further indicates that dopamine is successfully grafted to the carboxymethyl cellulose;

(2) putting the common paper into 1g/L sodium periodate solution, and carrying out light-shielding treatment for 3h at 35 ℃ to obtain a pretreated substrate; soaking the pretreated substrate in Chitosan (CS) solution with pH =5 and 1g/L for 10min, then rinsing with deionized water for 3 times to obtain a CS layer modified substrate, soaking the CS layer modified substrate in carboxymethyl cellulose (DA-g-CMC) solution with pH =6.5 and 1g/L grafted with dopamine for 10min, then rinsing with deionized water for 3 times to obtain a CS/DA-g-CMC bilayer membrane modified substrate, and repeating the above modification process for 5 times to obtain (CS/DA-g-CMC)₅A multilayer film modified substrate is dried at 40 ℃; placing the dried multilayer film modified substrate in 0.1g/L sodium periodate solution for normal-temperature light-shielding treatment for 2h, and then drying at 35 ℃ to complete the preparation of the self-repairing, acid-base-resistant and antibacterial multilayer film coating;

placing the paper with the multilayer film coating prepared in the embodiment on a glass slide, then manufacturing a scratch on the surface of the paper by using a sharp blade, dripping deionized water on the scratch at room temperature, and observing the healing condition of the scratched part of the paper by a microscope; the multilayer film coating has certain swelling property, the multilayer film coatings on two sides of the scratch are swelled and contacted with each other by adding water, the process is accompanied by covalent and non-covalent interaction, after 5min, the flatness of the surface of the multilayer film coating is basically recovered to the original state along with evaporation and drying of water, and the result is shown in figure 1, and the result shows that the multilayer film coating has good self-repairing performance.

The paper bacteriostasis is detected by adopting a shake flask method, a paper sample with the size of 1 multiplied by 1.5cm is immersed into 5mL of paper sample with the concentration of 10⁶ Shaking CFU/mL bacterial suspension at 37 deg.C at 180r/min for 4 h; then 10 times of gradient dilution is carried out, and 10 times of dilution is taken^-3Coating 0.1mL of diluted bacterial suspension on a sterile agar culture dish, inverting the coated culture dish, culturing at 37 ℃ for 24h, and recording the number of colonies; the bacteriostasis rate of the paper sample is calculated by comparing with a blank group, and the bacteriostasis rate of the paper with the multilayer film coating on staphylococcus aureus is 93.2 percent and the bacteriostasis rate on escherichia coli is 91.3 percent;

the paper with the multilayer film coating prepared in the embodiment is respectively placed in an HCl solution with pH =3 and a NaOH solution with pH =12 for etching treatment for 9h, and then the bacteriostatic activity of the paper is detected by a shaking bottle method, so that the bacteriostatic rate of the paper with the multilayer film coating on staphylococcus aureus and escherichia coli can still reach more than 90.6%.

Example 2

(1) The carboxymethyl cellulose grafted with dopamine is prepared by adding 2g of carboxymethyl cellulose into 100mL of disodium hydrogen phosphate-citric acid buffer solution with the pH value of 4, stirring for 6 hours at 37 ℃, then adding 0.5g of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and 0.3g N-hydroxysuccinimide, continuously stirring for 30 minutes, adding 3mL of dopamine hydrochloride solution with the pH value of 3 and the concentration of 200mg/mL, placing the dopamine solution into a shaking table, reacting for 30 hours in a dark place at 37 ℃ and 120r/min under the nitrogen condition, dialyzing the solution obtained by the reaction in distilled water for 2 days by using a dialysis bag, and freeze-drying the dialyzed solution;

(2) putting the paper into a sodium periodate solution of 2g/L, and carrying out light-shielding treatment for 2 hours at 45 ℃ to obtain a pretreated substrate; soaking the pretreated substrate in 2g/L Chitosan (CS) solution at pH =5.3 for 20min, and then rinsing with deionized waterWashing for 4 times to obtain a CS layer modified substrate, and soaking the CS layer modified substrate in 2g/L of carboxymethyl cellulose (DA-g-CMC) solution for 20min, and then rinsing with deionized water for 4 times to obtain CS/DA-g-CMC bilayer film modified substrate, repeating the above modification process 10 times to obtain (CS/DA-g-CMC)₁₀Multilayer film modified substrates, then dried at 50 ℃; placing the substrate modified by the dried multilayer film in 0.2g/L sodium periodate solution for normal-temperature dark treatment for 4h, and then drying at 40 ℃ to complete the preparation of the self-repairing, acid-base-resistant and antibacterial multilayer film coating;

the self-repairing performance of the paper with the multilayer film coating in the embodiment is detected, the method is the same as that in embodiment 1, the paper with the multilayer film coating prepared in the embodiment can be self-repaired and scratched after 7.5min, and the flatness of the surface of the multilayer film coating is basically recovered to the original state;

the bacteriostasis rate detection method is the same as that of the embodiment 1, the bacteriostasis rate to staphylococcus aureus is 95.7%, and the bacteriostasis rate to escherichia coli is 93.6%. Meanwhile, after 9 hours of etching treatment by acidic and alkaline solutions with pH =3 and pH =12, the bacteriostatic rate of the multilayer film coating on staphylococcus aureus and escherichia coli can still reach more than 92.5%.

Example 3

(1) The carboxymethyl cellulose grafted with dopamine is prepared by adding 1.5g of carboxymethyl cellulose into 100mL of disodium hydrogen phosphate-citric acid buffer solution with the pH value of 5, stirring for 5h at 37 ℃, then adding 0.4g of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and 0.3g N-hydroxysuccinimide, continuously stirring for 40min, adding 2mL of dopamine hydrochloride solution with the pH value of 4 and the concentration of 225mg/mL, placing the dopamine hydrochloride solution into a shaking table, reacting for 35h in a dark place at 37 ℃ and under the nitrogen condition at 150r/min, dialyzing the solution obtained by the reaction in distilled water for 2 days by using a dialysis bag, and freeze-drying the dialyzed solution;

(2) placing the cotton fabric into a periodic acid solution of 3g/L, and carrying out light-proof treatment for 1h at 50 ℃ to obtain a pretreated substrate; soaking the pretreated substrate in a (CS) solution of chitosan pH =5.6, 3g/L for 30min, then rinsing 5 times with deionized water to obtain a CS layer modified substrate, soaking the CS layer modified substrate at pH =7.5, 3gDopamine grafted carboxymethyl cellulose (DA-g-CMC) solution for 20min, and then rinsing with deionized water for 5 times to obtain CS/DA-g-CMC bilayer film modified substrate, repeating the above modification process 15 times to obtain (CS/DA-g-CMC)₁₅Drying the multilayer film modified substrate at 60 ℃; placing the dried multilayer film modified substrate in 0.3g/L sodium periodate solution for normal-temperature light-shielding treatment for 6h, and then drying at 45 ℃ to complete the preparation of the self-repairing, acid-base-resistant and antibacterial multilayer film coating;

the self-repairing performance of the cotton fabric with the multilayer film coating is detected, the method is the same as that in the embodiment 1, the cotton fabric with the multilayer film coating prepared in the embodiment can self-repair scratches after 9min, and the flatness of the surface of the multilayer film coating is basically recovered to the original state;

the bacteriostasis rate detection method is the same as the example 1, the bacteriostasis rate to staphylococcus aureus is 100 percent, and the bacteriostasis rate to escherichia coli is 100 percent; meanwhile, after 9 hours of etching treatment by acidic and alkaline solutions with pH =3 and pH =12, the bacteriostatic rate of the multilayer film coating on staphylococcus aureus and escherichia coli can still reach over 95.1%.