Photocatalytic antibacterial composite plastic preservative film
By setting a photocatalytic heterojunction antibacterial functional layer on the surface of plastic cling film, and utilizing the generation of electrons and holes by the TiO2/ZnO heterojunction, the problem of insufficient antibacterial performance in the existing technology is solved, achieving efficient sterilization and improved mechanical strength, extending the shelf life of food, and improving food safety.
Patent Information
- Application Number
- CN202520278981.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-20
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2035-02-20
AI Technical Summary
Existing photocatalytic antibacterial plastic film has shortcomings in antibacterial performance, making food susceptible to microbial contamination during storage, shortening shelf life and affecting food safety.
The antibacterial functional layer of the photocatalytic heterojunction is adopted. The TiO2/ZnO heterojunction generates electrons and holes under light, which prolongs the carrier lifetime, enhances the antibacterial effect, and achieves efficient sterilization.
It improves the antibacterial properties of plastic cling film, extends the shelf life of food, enhances food safety, and improves the mechanical strength and functional versatility of cling film.
Smart Images
Figure CN223658837U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of antibacterial plastic preservation film technology, specifically, to a photocatalytic antibacterial composite plastic preservation film. Background Technology
[0002] With increasing demands for food safety and preservation, traditional food preservation films, relying solely on their physical barrier function, are no longer sufficient to meet the requirements of modern food packaging. Food spoilage during storage has long been a global concern. The primary cause of food spoilage is the growth and reproduction of microorganisms that contaminate food, and foodborne illnesses caused by these microorganisms have become a serious public health problem worldwide. Controlling the growth and spread of foodborne microorganisms and ensuring the stability of food during storage is crucial. This is not only vital for human health and safety but also essential for reducing food loss and waste. Existing food preservation films have significant shortcomings in antibacterial properties, making food susceptible to microbial contamination during storage, thereby shortening shelf life and affecting food safety.
[0003] In recent years, photocatalytic antibacterial technology has received widespread attention. Semiconductors, as a common photocatalytic material, can generate active groups under light irradiation, effectively killing bacteria and decomposing organic matter. Semiconductors are excited with light of a specific wavelength, and the electrons and holes generated participate in redox reactions. When the energy is greater than or equal to the semiconductor's band gap, the semiconductor electrons transition from the valence band (VB) to the conduction band (CB), generating electrons and holes, forming electron / hole pairs (electrons, holes, and electrons). - / h + Titanium dioxide (TiO2), reacting with oxygen and water, produces reactive groups. The reaction of the bacterial cell membrane with these reactive groups induces leakage of internal substances, further inactivating bacterial DNA and proteins, thus killing the bacteria. As one of the most promising and well-known semiconductors, titanium dioxide has attracted widespread interest in fields such as solar energy conversion, hydrogen production, photocatalysis, and gas sensors. Titanium dioxide possesses advantages such as high cost-effectiveness, no secondary pollutants, non-toxicity, and good photochemical stability, making it a promising photocatalyst. However, using titanium dioxide nanoparticles alone presents problems such as poor dispersibility and low photocatalytic efficiency. The low charge mobility of electron / hole pairs leads to a rapid recombination rate, and the wide bandgap and narrow absorption range limit the high performance of titanium dioxide (TiO2).
[0004] Currently, the antibacterial properties of existing photocatalytic antibacterial plastic food preservation films still need to be improved. Utility Model Content
[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one objective of the first aspect of the present invention is to provide a photocatalytic antibacterial composite plastic food preservation film that not only has barrier properties but also enhances the antibacterial performance of the plastic food preservation film, achieving highly efficient sterilization.
[0006] The photocatalytic antibacterial composite plastic food preservation film according to an embodiment of the present invention includes:
[0007] The composite plastic food preservation film body includes a substrate layer and a photocatalytic heterojunction antibacterial functional layer, wherein the photocatalytic heterojunction antibacterial functional layer is disposed on the surface of the substrate layer.
[0008] The sterilization principle of the photocatalytic antibacterial composite plastic food preservation film of this utility model embodiment is as follows: Due to the presence of a photocatalytic heterojunction in the photocatalytic heterojunction antibacterial functional layer, for example, a TiO2 / ZnO heterojunction, under the action of light, electrons in the two materials (such as TiO2 and ZnO) of the photocatalytic heterojunction undergo electron transitions and generate holes respectively. Because the heterojunction formed by the two materials (such as TiO2 and ZnO) narrows the band gap, it hinders the recombination of electron / hole (e- / h+) pairs, prolongs the carrier lifetime, and allows electrons to move more freely in the heterojunction. At the interface, free movement generates an additional electric field, making it easier for photo-excited electrons and holes to migrate at the heterojunction. Electrons from one material (e.g., TiO2) transfer to another material (e.g., ZnO), while holes from the other material (e.g., ZnO) transfer to one material (e.g., TiO2). This increases the number of holes in one material (e.g., TiO2) and the number of electrons in the other material (e.g., ZnO). These electrons and holes can then react with substances such as water and oxygen to generate reactive groups. The reaction between the bacterial cell membrane and these reactive groups induces leakage of internal substances, further inactivating bacterial DNA and proteins, thus achieving highly efficient sterilization. This prevents food from being contaminated by microorganisms during storage, extends shelf life, and improves food safety.
[0009] The photocatalytic antibacterial composite plastic food preservation film of this utility model embodiment has the following advantages: On the one hand, by setting a photocatalytic heterojunction antibacterial functional layer on the surface of the substrate layer, the presence of a photocatalytic heterojunction in the photocatalytic heterojunction antibacterial functional layer reduces the band gap, making it easier for photo-excited electrons and holes to migrate at the heterojunction, thus avoiding electron / hole (e) - / h +The recombination of electrons and holes significantly increases the number of cells, allowing them to react with water, oxygen, and other substances to generate active groups. The reaction between the bacterial cell membrane and these active groups induces leakage of internal substances, further inactivating bacterial DNA and proteins, thus achieving highly efficient bacterial killing. This enhances the antibacterial effect of the photocatalytic heterojunction antibacterial functional layer itself, preventing microbial contamination of food during storage, extending shelf life, and improving food safety. Furthermore, the photocatalytic heterojunction antibacterial functional layer, located on the surface of the substrate layer, not only enhances the antibacterial properties of the plastic film surface but also improves the mechanical strength and functional versatility of the film. The photocatalytic antibacterial composite plastic film of this invention has significant application value and market prospects.
[0010] In some embodiments, the photocatalytic heterojunction antibacterial functional layer includes a photocatalytic heterojunction antibacterial microbead structure dispersed and embedded on the surface of the substrate layer.
[0011] In some embodiments, the photocatalytic heterojunction antibacterial microbead structure includes a microbead carrier and photocatalytic heterojunction antibacterial nanoparticles dispersed and fixed on the surface of the microbead carrier.
[0012] In some embodiments, the microbead carrier is a hollow microbead carrier.
[0013] In some embodiments, the microbead carrier is a hollow glass microbead carrier.
[0014] In some embodiments, the photocatalytic heterojunction antibacterial nanoparticles are TiO2 / ZnO heterojunction nanoparticles.
[0015] In some embodiments, the photocatalytic heterojunction antibacterial nanoparticles include a TiO2 shell and a ZnO core located within the TiO2 shell, wherein the TiO2 shell and the ZnO core form TiO2 / ZnO heterojunction nanoparticles.
[0016] In some embodiments, the substrate layer is a plastic film layer.
[0017] In some embodiments, the substrate layer is a polyethylene film layer.
[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0019] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0020] Figure 1This is a schematic diagram of the photocatalytic antibacterial composite plastic food preservation film of this utility model;
[0021] Figure 2 for Figure 1 Schematic diagram of the structure at point A;
[0022] Figure 3 for Figure 2 A schematic diagram of the photocatalytic heterojunction antibacterial microbead structure.
[0023] Figure label:
[0024] Photocatalytic antibacterial composite plastic food preservation film 1000; composite plastic food preservation film body 1; substrate layer 101; photocatalytic heterojunction antibacterial functional layer 102; photocatalytic heterojunction antibacterial microbead structure 1021; microbead carrier 10211; photocatalytic heterojunction antibacterial nanoparticles 10212. Detailed Implementation
[0025] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.
[0026] The following is combined Figures 1 to 3 This invention describes a photocatalytic antibacterial composite plastic food preservation film 1000 according to an embodiment of the present invention.
[0027] like Figures 1 to 2 As shown, the photocatalytic antibacterial composite plastic food preservation film 1000 according to an embodiment of the present invention includes a composite plastic food preservation film body 1. The composite plastic food preservation film body 1 includes a substrate layer 101 and a photocatalytic heterojunction antibacterial functional layer 102. The substrate layer 101 has barrier properties, and the photocatalytic heterojunction antibacterial functional layer 102 is disposed on the surface of the substrate layer 101.
[0028] The sterilization principle of the photocatalytic antibacterial composite plastic food preservation film 1000 in this embodiment of the invention is as follows: Because the photocatalytic heterojunction antibacterial functional layer 102 contains a photocatalytic heterojunction, for example, a TiO2 / ZnO heterojunction, under light irradiation, electrons in the two materials (such as TiO2 and ZnO) of the photocatalytic heterojunction undergo electron transitions and generate holes respectively. Since the heterojunction formed by the two materials (such as TiO2 and ZnO) narrows the band gap, it hinders the electron / hole transition (e... - / h +The recombination of electrons and holes in a heterojunction extends the lifetime of charge carriers, allowing electrons to move freely at the interface and generating an additional electric field. This makes it easier for photo-excited electrons and holes to migrate at the heterojunction. Electrons from transitions in one material (such as TiO2) transfer to another material (such as ZnO), while holes from the other material (such as ZnO) transfer to one material (such as TiO2). This increases the number of holes in one material (such as TiO2) and the number of electrons in the other material (such as ZnO). These electrons and holes can then react with substances such as water and oxygen to generate active groups. The reaction between the bacterial cell membrane and these active groups induces leakage of internal substances, further inactivating bacterial DNA and proteins, thus achieving highly efficient sterilization. This prevents food from being contaminated by microorganisms during storage, extends shelf life, and improves food safety.
[0029] The photocatalytic antibacterial composite plastic food preservation film 1000 of this utility model embodiment has the following advantages: On the one hand, by providing a photocatalytic heterojunction antibacterial functional layer 102 on the surface of the substrate layer 101, the presence of a photocatalytic heterojunction in the photocatalytic heterojunction antibacterial functional layer 102 reduces the band gap, making it easier for photo-excited electrons and holes to migrate at the heterojunction, thus avoiding electron / hole (e) - / h + The recombination of electrons and holes significantly increases the number of cells, allowing them to react with substances such as water and oxygen to generate active groups. The reaction between the bacterial cell membrane and these active groups induces leakage of internal substances, further inactivating bacterial DNA and proteins, thus achieving efficient bacterial killing. This enhances the antibacterial effect of the photocatalytic heterojunction antibacterial functional layer 102, preventing microbial contamination of food during storage, extending shelf life, and improving food safety. Furthermore, the photocatalytic heterojunction antibacterial functional layer 102, disposed on the surface of the substrate layer 101, not only enhances the antibacterial properties of the plastic preservation film surface but also improves its mechanical strength and functional versatility. The photocatalytic antibacterial composite plastic preservation film 1000 of this embodiment has significant application value and market prospects.
[0030] In some embodiments, such as Figure 2 and Figure 3 As shown, the photocatalytic heterojunction antibacterial functional layer 102 includes a photocatalytic heterojunction antibacterial microbead structure 1021 dispersed and embedded on the surface of the substrate layer 101. The photocatalytic heterojunction antibacterial microbead structure 1021 dispersed and embedded on the surface of the substrate layer 101 enables the immobilization of antibacterial active ingredients on the surface of the substrate layer 101, which not only enhances the antibacterial properties of the food preservation film surface but also improves the mechanical strength and functional versatility of the food preservation film.
[0031] In some embodiments, the photocatalytic heterojunction antibacterial microbead structure 1021 includes a microbead carrier 10211 and photocatalytic heterojunction antibacterial nanoparticles 10212 dispersed and fixed on the surface of the microbead carrier 10211. The microbead carrier 10211 has low density, high specific surface area, and good chemical stability. The surface of the microbead carrier 10211 is uniformly loaded with photocatalytic heterojunction antibacterial nanoparticles 10212 by a sol-gel method. Therefore, after being mixed with plastic, the photocatalytic heterojunction antibacterial microbead structure 1021 can accumulate on the surface of the substrate layer 101, realizing the uniform dispersion and loading of the antibacterial active ingredient, namely the photocatalytic heterojunction antibacterial nanoparticles 10212, on the surface of the substrate layer 101. This not only enhances the antibacterial properties of the food preservation film surface but also improves the mechanical strength and functional versatility of the food preservation film.
[0032] In some embodiments, the microbead carrier 10211 is a hollow microbead carrier. The hollow microbead carrier has low density, high specific surface area, and good chemical stability. The surface of the hollow microbead carrier is uniformly loaded with photocatalytic heterojunction antibacterial nanoparticles 10212 via a sol-gel method. Therefore, the photocatalytic heterojunction antibacterial microbead structure 1021 can accumulate on the surface of the substrate layer 101 after being mixed with plastic, achieving uniform dispersion and loading of the antibacterial active ingredient, namely the photocatalytic heterojunction antibacterial nanoparticles 10212, on the surface of the substrate layer 101. This not only enhances the antibacterial properties of the food preservation film surface but also improves the mechanical strength and functional versatility of the food preservation film.
[0033] In some embodiments, the microbead carrier 10211 is a hollow glass microbead carrier. The hollow microbead carrier has low density, high specific surface area and good chemical stability. The surface of the hollow microbead carrier is uniformly loaded with photocatalytic heterojunction antibacterial nanoparticles 10212 by the sol-gel method. Therefore, the photocatalytic heterojunction antibacterial microbead structure 1021 can accumulate on the surface of the substrate layer 101 after being mixed with plastic and a specific surface modifier is added. This achieves uniform dispersion and loading of the antibacterial active ingredient, namely the photocatalytic heterojunction antibacterial nanoparticles 10212, on the surface of the substrate layer 101. This not only enhances the antibacterial properties of the food preservation film surface, but also achieves good transparency, flexibility and barrier properties. Most importantly, it has excellent antibacterial and food preservation functions.
[0034] In some embodiments, the photocatalytic heterojunction antibacterial nanoparticles 10212 are TiO2 / ZnO heterojunction nanoparticles. Under illumination, electrons in the TiO2 and ZnO materials undergo transitions and generate holes, respectively. Because the heterojunction formed by the TiO2 and ZnO materials narrows the band gap, it hinders the electron / hole transition. - / h +The recombination of electrons and charges prolongs the lifetime of charge carriers, allowing electrons to move freely at the heterojunction interface and generating an additional electric field. This makes it easier for photo-excited electrons and holes to migrate at the heterojunction. Electrons from TiO2 material transfer to ZnO material, while holes from ZnO material transfer to TiO2 material. This increases the number of holes in TiO2 and the number of electrons in ZnO. These electrons and holes can then react with water, oxygen, and other substances to generate reactive groups. The reaction between the bacterial cell membrane and these reactive groups induces leakage of internal substances, further inactivating bacterial DNA and proteins, thus killing the bacteria. Reactive groups can also cause oxidative stress within bacteria. Extracellular reactive groups can enter the bacteria, causing a sharp increase in intracellular reactive group levels, which then react with antioxidant enzymes, disrupting the intracellular oxidative and antioxidant balance, thereby achieving highly efficient sterilization. This prevents food from being contaminated by microorganisms during storage, extends shelf life, and improves food safety.
[0035] In some embodiments, the photocatalytic heterojunction antibacterial nanoparticles 10212 include a TiO2 shell and a ZnO core located within the TiO2 shell, forming a TiO2 / ZnO heterojunction nanoparticle. Under illumination, electron transitions in the TiO2 shell generate holes, and electron transitions in the ZnO core also generate holes. Electrons from the TiO2 shell transfer to the ZnO core, and holes from the ZnO core transfer to the TiO2 shell, thus avoiding electron / hole (electron / hole) transitions. - / h + The recombination of electrons and holes significantly increases the number of electrons and holes. These electrons and holes can react with substances such as water and oxygen to produce active groups, thereby achieving a significant and efficient sterilization effect.
[0036] In some embodiments, the substrate layer 101 is a plastic film layer with good transparency, flexibility and barrier properties.
[0037] In some embodiments, the substrate layer 101 is a polyethylene film layer with good transparency, flexibility and barrier properties.
[0038] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0039] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.
Claims
1. A photocatalytic antibacterial composite plastic food preservation film, characterized in that, include: A composite plastic food preservation film body, the composite plastic food preservation film body comprising a substrate layer and a photocatalytic heterojunction antibacterial functional layer, the photocatalytic heterojunction antibacterial functional layer being disposed on the surface of the substrate layer; The photocatalytic heterojunction antibacterial functional layer includes a photocatalytic heterojunction antibacterial microbead structure dispersed and embedded on the surface of the substrate layer; The photocatalytic heterojunction antibacterial microbead structure includes a microbead carrier and photocatalytic heterojunction antibacterial nanoparticles dispersed and fixed on the surface of the microbead carrier.
2. The photocatalytic antibacterial composite plastic food preservation film according to claim 1, characterized in that, The microbead carrier is a hollow microbead carrier.
3. The photocatalytic antibacterial composite plastic food preservation film according to claim 2, characterized in that, The microsphere carrier is a hollow glass microsphere carrier.
4. The photocatalytic antibacterial composite plastic food preservation film according to claim 1, characterized in that, The photocatalytic heterojunction antibacterial nanoparticles are TiO2 / ZnO heterojunction nanoparticles.
5. The photocatalytic antibacterial composite plastic food preservation film according to claim 4, characterized in that, The photocatalytic heterojunction antibacterial nanoparticles include a TiO2 shell and a ZnO core located within the TiO2 shell, wherein the TiO2 shell and the ZnO core form TiO2 / ZnO heterojunction nanoparticles.
6. The photocatalytic antibacterial composite plastic food preservation film according to any one of claims 1-5, characterized in that, The substrate layer is a plastic film layer.
7. The photocatalytic antibacterial composite plastic food preservation film according to claim 6, characterized in that, The substrate layer is a polyethylene film layer.