Preparation method of preservative film containing rosemary essential oil

Abstract

The invention discloses a preparation method of a preservative film containing rosemary essential oil, which comprises the following steps: step 1, extraction and purification of rosemary essential oil, step 2, microencapsulation of rosemary essential oil, step 3, preparation and optimization of a spinning solution, step 4, preparation of a nanofiber preservative film by electrostatic spinning, and step 5, performance detection and application evaluation. According to the preparation method, through extraction and purification of rosemary essential oil and microencapsulation, ethylene removal, antibiosis and antioxidation are achieved, the shelf life of food is effectively prolonged, freshness and nutritional value are kept, low-cost and high-environmental-protection materials are adopted, the production cost is reduced, environmental pollution is reduced, the preparation process is simple and efficient, the production efficiency is improved, and the method is suitable for industrial production. And meanwhile, through strict detection, it is ensured that the product is safe and reliable.

Description

Technical Field

[0001] The invention relates to the technical field of fresh-keeping film preparation, in particular to a method for preparing fresh-keeping film containing rosemary essential oil. Background Art

[0002] Plastic wrap is a common food packaging material. It is made of polyethylene, polyvinyl chloride and other resins as the main raw materials. It has multiple functions such as preservation and cleaning. The main function of plastic wrap is to regulate the oxygen and moisture content around the preserved food, while blocking dust and bacteria in the air, thereby extending the shelf life of the food and avoiding food contamination and waste. From the material point of view, PE plastic wrap is a more common one on the market. It uses polyethylene resin as raw material, has good waterproof permeability and self-adhesion, and is suitable for packaging various meats, fresh fruits and vegetables, snacks and fried foods. PE plastic wrap is considered to be a safe packaging material that can directly contact food and is harmless to the human body. However, due to its good air permeability, PE plastic wrap is not suitable for packaging foods with high fat content and whose flavor is easily destroyed by oxygen. Another common plastic wrap material is PVC, PVC cling film has the characteristics of good transparency, high viscosity, good elasticity and not easy to break. However, plasticizers and other chemicals may be added to PVC cling film during the production process. These substances may be harmful to human health, especially when PVC cling film is heated or microwaved, it may crack and produce toxic vinyl chloride. Therefore, it is not recommended to use PVC cling film to package meat, cooked food and oily food. In addition to PE and PVC, there is also a cling film material called PVDC. PVDC cling film is composed of polyvinylidene chloride and a small amount of plasticizers, stabilizers and other additives. It has the characteristics of good freshness, strong and easy to adhere, and can prevent moisture evaporation. In terms of heat resistance and safety, PVDC cling film is superior to PVC cling film. It can be used for the packaging of cooked food, ham and other products, and can also be used for refrigerator preservation and microwave heating.

[0003] For example, the Chinese authorized patent "A cling film and its preparation method" with announcement number CN107804049B, the cling film includes a resin base film, an ethylene adsorption layer and a waterproof breathable layer which are stacked in sequence, the ethylene adsorption layer is composed of hollow porous polymer microspheres loaded with an adsorbent, the adsorbent includes potassium permanganate, and the adsorbent is at least partially loaded inside the hollow porous polymer microspheres. When the cling film is used to wrap fruits and vegetables, the waterproof breathable layer is in contact with the fruits and vegetables, and the ethylene produced by the respiration of the fruits and vegetables can pass through the waterproof breathable layer into the ethylene adsorption layer, and the potassium permanganate in the ethylene adsorption layer can remove the ethylene. Since the potassium permanganate is contained in the hollow porous polymer microspheres, it has a high specific surface area. At the same time, when ethylene enters the ethylene adsorption layer, it passes through a large number of microspheres to fully react with the potassium permanganate, thereby improving the reaction efficiency and raw material utilization rate, and can more efficiently remove ethylene, thereby improving the preservation effect and extending the preservation time.

[0004] Although the above-mentioned prior art focuses on the removal of ethylene and shows a certain degree of specificity, the functional design of this patent is relatively simple, mainly focusing on the single factor of ethylene, while other key factors that also affect the freshness of food, such as microbial growth and oxidation, are not sufficiently considered. This one-sidedness in function may lead to the fact that in actual applications, although ethylene is effectively removed, food may still deteriorate due to other factors, thereby limiting the applicability of this patent in a wider range of food preservation scenarios. Secondly, although the materials such as potassium permanganate-loaded hollow porous polymer microspheres used in this patent have a certain ethylene adsorption capacity, the cost is relatively high, and the biodegradability needs to be further verified, which not only increases the production cost, but also may cause environmental problems and pose a challenge to sustainable development. Although the multi-layer film stacking setting used in this patent may improve the ethylene removal efficiency, it also significantly increases the complexity and time cost of preparation, posing a potential threat to production efficiency and product quality stability, and therefore does not meet existing needs. In this regard, we propose a preparation method for a plastic wrap containing rosemary essential oil. Summary of the invention

[0005] The object of the present invention is to provide a method for preparing a cling film containing rosemary essential oil, so as to solve the problem that the preparation method of the cling film proposed in the above background technology leads to a single function, only targets ethylene treatment and has high cost and unknown degradability, and the multi-layer structure also increases the complexity and cost of preparation.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for preparing a fresh-keeping film containing rosemary essential oil, comprising the following steps:

[0007] Step 1: Extraction and purification of rosemary essential oil: 600 grams of fresh rosemary leaves were selected to ensure that the leaves were intact and undamaged, washed and naturally air-dried until no water remained, and the rosemary leaves were placed in a sealed distillation chamber for distillation using a modified steam distillation method. After the distillation was completed, 15 grams of essential oil was collected through a condensation device, dried with anhydrous sodium sulfate to remove moisture, and then further purified using a rotary evaporator at 40° C. to completely remove residual solvents and impurities;

[0008] Step 2: Microencapsulation of rosemary essential oil: gelatin and sodium alginate are mixed in a ratio of 1.5:1, rosemary essential oil is mixed with wall materials, 0.15g-0.75g of emulsifier Tween 80 is added, and emulsification is performed using a high-speed shear emulsifier to ensure uniform dispersion, and then slowly dripped into a cross-linking liquid containing 3% calcium chloride, and cross-linking and curing are promoted by gentle stirring to form microcapsules, and the obtained microcapsules are dried by a spray dryer to quickly remove moisture, and finely screened using a vibrating screen to ensure that the microcapsule particle size is evenly distributed in the range of 5-10 microns, so that the encapsulation rate reaches more than 90%;

[0009] Step 3: Preparation and optimization of spinning solution: 12 g of polylactic acid was dissolved in a mixed solvent consisting of dichloromethane and dimethylformamide, with a total amount of 120 ml, heated to 60°C and stirred continuously until the polymer was completely dissolved, and the rosemary essential oil microcapsules obtained in step 2 were added to the spinning solution, and glycerol was added as a plasticizer to improve the flexibility and processability of the film, and the spinning solution was fully stirred using a high-speed disperser to ensure that the microcapsules were evenly dispersed, and then allowed to stand for 4 hours to fully eliminate bubbles and ensure the stability of the spinning process;

[0010] Step 4: Preparation of nanofiber cling film by electrospinning: Inject the spinning solution into the electrospinning device, start the electrospinning device, and the spinning solution forms a jet flow under the action of the high voltage electric field, which is refined into nanofibers and deposited on the receiving plate. The receiving plate is made of aluminum foil material with good conductivity to collect more nanofibers. After the spinning is completed, carefully remove the nanofiber cling film on the receiving plate, place it in a fume hood to dry naturally for 48 hours to remove most of the solvent, and then place it in a vacuum drying oven and dry it at 50°C for 6 hours to completely remove the residual solvent;

[0011] Step 5: Performance testing and application evaluation: The prepared cling film is subjected to antibacterial performance testing, preservation effect evaluation and biocompatibility evaluation.

[0012] Preferably, in step 1, the sealed distillation chamber is set at a temperature of 110° C. and the distillation time is extended to 5 hours to improve the essential oil extraction efficiency.

[0013] Preferably, in step 1, the extraction rate of the essential oil is 2.5%, that is, 15 grams of essential oil are extracted from 600 grams of rosemary leaves.

[0014] Preferably, in step 2, the total mass of the mixture of gelatin and sodium alginate is 2.5 times the mass of rosemary essential oil, i.e. 75 grams, to enhance the stability and encapsulation efficiency of the microcapsules.

[0015] Preferably, in step three, the ratio of the polylactic acid to the mixed solvent consisting of dichloromethane and dimethylformamide is 6:4.

[0016] Preferably, in step three, the addition ratio of the rosemary essential oil microcapsules is 6% (w / w), and the addition ratio of the glycerol is 3% (w / w).

[0017] Preferably, in step 4, the voltage of the electrospinning device is adjusted to 20 kV, the receiving distance is set to 20 cm, and the spinning speed is set to 0.4 ml / hour to optimize the diameter and distribution of the nanofibers.

[0018] Preferably, in step five, the antibacterial property detection is to evaluate the antibacterial property of the nanofiber cling film by using an inhibition zone test, and Escherichia coli and Staphylococcus aureus are respectively inoculated on an agar plate containing the nanofiber cling film, and the diameter of the inhibition zone is measured after 48 hours of culture, wherein the diameter of the inhibition zone of Escherichia coli reaches 15 mm, and the diameter of the inhibition zone of Staphylococcus aureus reaches 12 mm.

[0019] Preferably, in step five, the fresh-keeping effect evaluation is to select fresh strawberries, apples and broccoli as test objects, divide each food into two groups, one group is packaged with nanofiber plastic wrap, and the other group is packaged with ordinary plastic wrap, store the two groups of food at room temperature, observe and record the sensory quality of the food, i.e., color, hardness and flavor changes, every day, after 7 days of storage, the food packaged with nanofiber plastic wrap still maintains good sensory quality.

[0020] Preferably, in step five, the biocompatibility assessment is a cytotoxicity test using mouse skin fibroblasts, the nanofiber cling film is placed in a cell culture medium, the cell growth is observed after 96 hours of culture, and the biocompatibility of the nanofiber cling film is assessed by measuring the cell survival rate. The test results show that the cell survival rate is above 95%, indicating that the nanofiber cling film has good biocompatibility.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present application extracts and purifies rosemary essential oil, and then microencapsulates it and integrates it into the spinning solution. The final plastic wrap prepared in the present application not only has the ability to remove ethylene, but also completely inhibits the growth of microorganisms and the oxidation process of food due to the antibacterial and antioxidant properties of rosemary essential oil itself. The stable embedding of rosemary essential oil is achieved by using microencapsulation technology, and the loss of essential oil in the spinning process is avoided, thereby ensuring the maximum function of the plastic wrap. This makes the plastic wrap perform well in a wider range of food preservation scenarios, effectively extending the shelf life of food while maintaining the freshness and nutritional value of food.

[0023] 2. The present application adopts relatively cheap and biodegradable materials. Rosemary is a natural plant resource, and its essential oil extraction cost is relatively low and environmentally friendly. At the same time, the use of bio-based polymers such as polylactic acid further improves the biodegradability of the material, reduces production costs, and reduces the risk of environmental pollution. This low-cost, highly environmentally friendly material selection not only makes the plastic wrap more competitive in the market, but also more in line with the concept of sustainable development. At the same time, the selection of this material reduces the production cost of the plastic wrap and improves its biodegradability, contributing to environmental protection and sustainable development.

[0024] 3. This application extracts rosemary essential oil by improved steam distillation method, and prepares microcapsules by efficient emulsification, cross-linking and spray drying technology, making the whole preparation process more concise and efficient. At the same time, the application of electrospinning technology makes the preparation of nanofiber cling film more precise and controllable, ensuring the stability and consistency of product quality. The optimization of this preparation process not only improves production efficiency and reduces energy consumption, but also ensures the stability and consistency of product quality, providing a strong guarantee for large-scale production.

[0025] 4. This application has fully verified the reliability and safety of the cling film in practical applications through strict antibacterial performance testing, preservation effect evaluation and biocompatibility evaluation. This comprehensive and detailed performance testing not only provides consumers with a safer and more reliable food preservation solution, but also lays a solid foundation for the widespread application of the cling film in the field of food preservation. At the same time, this testing process ensures the reliability and safety of the cling film in practical applications, and provides a scientific basis for the continuous improvement and optimization of product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a flow chart of a method for preparing a fresh-keeping film containing rosemary essential oil. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0028] See also Figure 1 The present invention provides an embodiment: a method for preparing a fresh-keeping film containing rosemary essential oil, comprising the following steps:

[0029] Step 1: Extraction and purification of rosemary essential oil: 600 grams of fresh rosemary leaves were selected to ensure that the leaves were intact and undamaged, washed and naturally air-dried until no water remained, and the rosemary leaves were placed in a sealed distillation chamber for distillation using a modified steam distillation method. After the distillation was completed, 15 grams of essential oil was collected through a condensation device, dried with anhydrous sodium sulfate to remove moisture, and then further purified using a rotary evaporator at 40° C. to completely remove residual solvents and impurities;

[0030] Step 2: Microencapsulation of rosemary essential oil: gelatin and sodium alginate are mixed in a ratio of 1.5:1, rosemary essential oil is mixed with wall materials, 0.15g-0.75g of emulsifier Tween 80 is added, and emulsification is performed using a high-speed shear emulsifier to ensure uniform dispersion, and then slowly dripped into a cross-linking liquid containing 3% calcium chloride, and cross-linking and curing are promoted by gentle stirring to form microcapsules, and the obtained microcapsules are dried by a spray dryer to quickly remove moisture, and finely screened using a vibrating screen to ensure that the microcapsule particle size is evenly distributed in the range of 5-10 microns, so that the encapsulation rate reaches more than 90%;

[0031] Step 3: Preparation and optimization of spinning solution: 12 g of polylactic acid was dissolved in a mixed solvent consisting of dichloromethane and dimethylformamide, with a total amount of 120 ml, heated to 60°C and stirred continuously until the polymer was completely dissolved, and the rosemary essential oil microcapsules obtained in step 2 were added to the spinning solution, and glycerol was added as a plasticizer to improve the flexibility and processability of the film, and the spinning solution was fully stirred using a high-speed disperser to ensure that the microcapsules were evenly dispersed, and then allowed to stand for 4 hours to fully eliminate bubbles and ensure the stability of the spinning process;

[0032] Step 4: Preparation of nanofiber cling film by electrospinning: Inject the spinning solution into the electrospinning device, start the electrospinning device, and the spinning solution forms a jet flow under the action of the high voltage electric field, which is refined into nanofibers and deposited on the receiving plate. The receiving plate is made of aluminum foil material with good conductivity to collect more nanofibers. After the spinning is completed, carefully remove the nanofiber cling film on the receiving plate, place it in a fume hood to dry naturally for 48 hours to remove most of the solvent, and then place it in a vacuum drying oven and dry it at 50°C for 6 hours to completely remove the residual solvent;

[0033] Step 5: Performance testing and application evaluation: The prepared cling film is subjected to antibacterial performance testing, preservation effect evaluation and biocompatibility evaluation.

[0034] Furthermore, in step 1, the temperature of the sealed distillation chamber is set at 110° C., and the distillation time is extended to 5 hours to improve the extraction efficiency of the essential oil, thereby ensuring that the effective ingredients in the rosemary essential oil are more fully extracted, providing a higher quality raw material basis for subsequent microencapsulation and plastic wrap preparation.

[0035] Furthermore, in step 1, the extraction rate of the essential oil is 2.5%, that is, 15 grams of essential oil are extracted from 600 grams of rosemary leaves. This high extraction rate not only improves the utilization rate of raw materials, but also reduces production costs, making the production of plastic wrap more economical and efficient.

[0036] Furthermore, in step 2, the total mixed mass of the gelatin and sodium alginate is 2.5 times the mass of the rosemary essential oil, i.e., 75 grams, so as to enhance the stability and encapsulation efficiency of the microcapsules, effectively prevent the leakage of the essential oil in the subsequent processing, and ensure the effective release and lasting effect of the essential oil in the plastic wrap.

[0037] Furthermore, in step three, the ratio of the polylactic acid to the mixed solvent consisting of dichloromethane and dimethylformamide is 6:4. The optimization of this ratio makes the spinning solution have better fluidity and fiber-forming properties, which is conducive to the preparation of nanofibers with uniform diameter and good distribution, thereby improving the mechanical properties and barrier properties of the cling film.

[0038] Furthermore, in step three, the addition ratio of the rosemary essential oil microcapsules is 6% (w / w), and the addition ratio of the glycerol is 3% (w / w). Such a ratio enables the cling film to effectively release the rosemary essential oil while maintaining good flexibility, exerting antibacterial and antioxidant effects, and improving the preservation effect.

[0039] Furthermore, in step four, the electrospinning device adjusts the voltage to 20 kV, sets the receiving distance to 20 cm, and sets the spinning speed to 0.4 ml / hour to optimize the diameter and distribution of the nanofibers. The optimization of these parameters enables the prepared nanofiber cling film to have a finer fiber diameter and a more uniform fiber distribution, thereby improving the air permeability and barrier properties of the cling film, which is beneficial to the preservation of food and extending the shelf life.

[0040] Furthermore, in step five, the antibacterial performance test is to evaluate the antibacterial performance of the nanofiber cling film by using an inhibition zone test, and Escherichia coli and Staphylococcus aureus are respectively inoculated on an agar plate containing the nanofiber cling film, and the inhibition zone diameters are measured after 48 hours of culture. The inhibition zone diameters of Escherichia coli and Staphylococcus aureus reach 15 mm and 12 mm, respectively. This result shows that the nanofiber cling film has a significant antibacterial effect, can effectively inhibit the growth of common pathogens in food, and ensure food safety.

[0041] Furthermore, in step five, the fresh-keeping effect evaluation is to select fresh strawberries, apples and broccoli as test objects, divide each food ingredient into two groups, one group is packaged with nanofiber plastic wrap, and the other group is packaged with ordinary plastic wrap, store the two groups of food ingredients at room temperature, observe and record the sensory quality of the food ingredients, i.e., color, hardness and flavor changes, every day, after 7 days of storage, the food ingredients packaged with nanofiber plastic wrap still maintain good sensory quality, this result proves the significant advantages of nanofiber plastic wrap in extending the shelf life of food and maintaining the freshness of food.

[0042] Furthermore, in step five, the biocompatibility assessment is a cytotoxicity test using mouse skin fibroblasts, the nanofiber cling film is placed in a cell culture medium, the cell growth is observed after 96 hours of culture, and the biocompatibility of the nanofiber cling film is assessed by measuring the cell survival rate. The test results show that the cell survival rate is over 95%, indicating that the nanofiber cling film has good biocompatibility, which is of great significance for ensuring the safety of food packaging materials.

[0043] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A method for preparing a fresh-keeping film containing rosemary essential oil, characterized in that: The steps include: Step 1: Extraction and purification of rosemary essential oil: 600 grams of fresh rosemary leaves were selected to ensure that the leaves were intact and undamaged, washed and naturally air-dried until no water remained, and the rosemary leaves were placed in a sealed distillation chamber for distillation using a modified steam distillation method. After the distillation was completed, 15 grams of essential oil was collected through a condensation device, dried with anhydrous sodium sulfate to remove moisture, and then further purified using a rotary evaporator at 40° C. to completely remove residual solvents and impurities; Step 2: Microencapsulation of rosemary essential oil: gelatin and sodium alginate are mixed in a ratio of 1.5:1, rosemary essential oil is mixed with wall materials, 0.15g-0.75g of emulsifier Tween 80 is added, and emulsification is performed using a high-speed shear emulsifier to ensure uniform dispersion, and then slowly dripped into a cross-linking liquid containing 3% calcium chloride, and cross-linking and curing are promoted by gentle stirring to form microcapsules, and the obtained microcapsules are dried by a spray dryer to quickly remove moisture, and finely screened using a vibrating screen to ensure that the microcapsule particle size is evenly distributed in the range of 5-10 microns, so that the encapsulation rate reaches more than 90%; Step 3: Preparation and optimization of spinning solution: 12 g of polylactic acid was dissolved in a mixed solvent consisting of dichloromethane and dimethylformamide, with a total amount of 120 ml, heated to 60°C and stirred continuously until the polymer was completely dissolved, and the rosemary essential oil microcapsules obtained in step 2 were added to the spinning solution, and glycerol was added as a plasticizer to improve the flexibility and processability of the film, and the spinning solution was fully stirred using a high-speed disperser to ensure that the microcapsules were evenly dispersed, and then allowed to stand for 4 hours to fully eliminate bubbles and ensure the stability of the spinning process; Step 4: Preparation of nanofiber cling film by electrospinning: Inject the spinning solution into the electrospinning device, start the electrospinning device, and the spinning solution forms a jet flow under the action of the high voltage electric field, which is refined into nanofibers and deposited on the receiving plate. The receiving plate is made of aluminum foil material with good conductivity to collect more nanofibers. After the spinning is completed, carefully remove the nanofiber cling film on the receiving plate, place it in a fume hood to dry naturally for 48 hours to remove most of the solvent, and then place it in a vacuum drying oven and dry it at 50°C for 6 hours to completely remove the residual solvent; Step 5: Performance testing and application evaluation: The prepared cling film is subjected to antibacterial performance testing, preservation effect evaluation and biocompatibility evaluation.

2. The method for preparing a preservative film containing rosemary essential oil according to claim 1, wherein: In step 1, the temperature of the sealed distillation chamber is set at 110° C. and the distillation time is extended to 5 hours to improve the essential oil extraction efficiency.

3. The preparation method of a fresh-keeping film containing rosemary essential oil according to claim 1, wherein: In step 1, the extraction rate of the essential oil is 2.5%, that is, 15 grams of essential oil are extracted from 600 grams of rosemary leaves.

4. The method for preparing a preservative film containing rosemary essential oil according to claim 1, wherein: In step 2, the total mass of the mixture of gelatin and sodium alginate is 2.5 times the mass of rosemary essential oil, i.e. 75 grams, to enhance the stability and encapsulation efficiency of the microcapsules.

5. The method for preparing a preservative film containing rosemary essential oil according to claim 1, wherein: In step three, the ratio of the polylactic acid to the mixed solvent consisting of dichloromethane and dimethylformamide is 6:

4.

6. The method for preparing a preservative film containing rosemary essential oil according to claim 1, wherein: In step 3, the addition ratio of the rosemary essential oil microcapsules is 6% (w / w), and the addition ratio of the glycerol is 3% (w / w).

7. The method for preparing a fresh-keeping film containing rosemary essential oil according to claim 1, wherein: In step 4, the voltage of the electrospinning device was adjusted to 20 kV, the receiving distance was set to 20 cm, and the spinning speed was set to 0.4 ml / h to optimize the diameter and distribution of the nanofibers.

8. The method for preparing a fresh-keeping film containing rosemary essential oil according to claim 1, wherein: In step five, the antibacterial performance test is to evaluate the antibacterial performance of the nanofiber cling film by using an inhibition zone test. Escherichia coli and Staphylococcus aureus are respectively inoculated on an agar plate containing the nanofiber cling film. After 48 hours of cultivation, the diameter of the inhibition zone is measured. The diameter of the inhibition zone of Escherichia coli reaches 15 mm, and the diameter of the inhibition zone of Staphylococcus aureus reaches 12 mm.

9. The method for preparing a fresh-keeping film containing rosemary essential oil according to claim 1, wherein: In step five, the fresh-keeping effect evaluation is to select fresh strawberries, apples and broccoli as test objects, divide each food into two groups, one group is packaged with nanofiber plastic wrap, and the other group is packaged with ordinary plastic wrap, store the two groups of food at room temperature, observe and record the sensory quality of the food every day, that is, the color, hardness and flavor changes, after 7 days of storage, the food packaged with nanofiber plastic wrap still maintains good sensory quality.

10. The method for preparing a fresh-keeping film containing rosemary essential oil according to claim 1, wherein: In step five, the biocompatibility assessment is to conduct a cytotoxicity test using mouse skin fibroblasts, the nanofiber cling film is placed in a cell culture medium, the cell growth is observed after 96 hours of culture, and the biocompatibility of the nanofiber cling film is assessed by measuring the cell survival rate. The test results show that the cell survival rate is above 95%, indicating that the nanofiber cling film has good biocompatibility.

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