A rare earth modified melamine polymer film, and a preparation method and application thereof
By utilizing the rare earth-modified melamine film preparation method, the dynamic coordination bonds formed between rare earth ions and melamine are utilized to catalyze self-assembly and cross-linking, generating films with excellent gas isolation, mechanical and fluorescent properties. This solves the problems of low self-assembly efficiency and single function, and achieves a multifunctional improvement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING XUANWUYUAN TECHNOLOGY DEVELOPMENT CO LTD
- Filing Date
- 2026-05-09
- Publication Date
- 2026-06-30
AI Technical Summary
Existing melamine films have low self-assembly efficiency and limited functionality. Introducing metal ions can interfere with the hydrogen bond network, leading to self-assembly failure or structural disorder.
By introducing rare earth elements, the rare earth ions form dynamic coordination bonds with the triazine ring nitrogen atoms in the melamine molecule, catalyzing self-assembly to form a highly ordered two-dimensional layered structure. Cross-linking is achieved through ultraviolet light curing, which enhances the mechanical strength and thermal stability of the film and endows it with specific functions such as photocatalytic activity and near-infrared luminescence properties.
The efficient self-assembly of melamine films was achieved, generating polymer films with excellent gas isolation, mechanical properties, and fluorescence properties, while also possessing the ability to photocatalytically degrade organic matter.
Smart Images
Figure CN122302202A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer materials technology, specifically to a rare earth modified melamine polymer film, its preparation method, and its application. Background Technology
[0002] Melamine, commonly known as melamine, is a triazine-based nitrogen-containing heterocyclic organic compound with the chemical formula C3H6N6 and a molecular weight of 126.12. It appears as white monoclinic crystals with a melting point of approximately 354°C (sublimation) and a density of 1.57 g / cm³. It is sparingly soluble in water, ethylene glycol, glycerol, and pyridine, and slightly soluble in ethanol. Melamine forms salts with acids (such as hydrochloric acid, sulfuric acid, formic acid, and oxalic acid), condenses with formaldehyde to form various hydroxymethyl melamines, and can polycondense with hydroxymethyl derivatives under slightly acidic conditions to form resins.
[0003] In recent years, with the rapid development of electronic products and new energy batteries, more stringent requirements have been placed on the flame retardant properties of polymer film materials. Melamine film, as a halogen-free bulk flame retardant material, has the advantages of high flame retardant performance, no release of toxic gases during combustion, and no dripping.
[0004] Currently, melamine films suffer from low self-assembly efficiency, limited functionality, and certain performance limitations. To address these issues, researchers have attempted to introduce catalysts or additives to improve the preparation process. However, existing technologies generally suggest that introducing metal ions interferes with the hydrogen bond network between melamine molecules, leading to self-assembly failure or structural disorder.
[0005] Rare earth elements possess strong coordination capabilities and electronic regulation properties due to their unique 4f electron shell structure. Rare earth ions can interact with nitrogen-containing heterocyclic compounds through coordination bonds, theoretically potentially regulating the assembly process. However, given the aforementioned technological biases, whether introducing rare earth ions into the melamine film preparation system can overcome hydrogen bonding interference, achieve catalytic self-assembly, and simultaneously improve material properties and endow new functions are all unpredictable technical issues. Summary of the Invention
[0006] The purpose of this invention is to provide a rare earth-modified melamine polymer film, its preparation method, and its application. By introducing rare earth elements, this invention enables the self-assembly polymerization reaction of melamine under ultraviolet light to generate a polymer film. This polymer film has excellent gas isolation performance, mechanical properties, high thermal decomposition performance, and fluorescence performance. Furthermore, by selecting rare earth elements, it can also be made to have the performance of photocatalytic degradation of organic matter.
[0007] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:
[0008] The first aspect of this invention provides a method for preparing a rare-earth modified melamine polymer film, the method comprising the following steps:
[0009] (a) Melamine monomer and rare earth salt are dissolved in water and the pH is adjusted to 7-9 to obtain a mixed solution;
[0010] (b) Under constant temperature conditions, spin-coat the mixture onto the substrate surface and keep it at that temperature for a period of time;
[0011] (c) After the heat preservation is completed, UV curing is performed, followed by washing and vacuum drying to obtain the rare earth modified melamine polymer film.
[0012] Preferably, in step (a), the concentration of melamine monomer in the mixture is 80~120g / L; the molar ratio of rare earth salt to melamine monomer is (0.1~3):100.
[0013] Preferably, in step (a), the rare earth salt is a nitrate or hydrochloride, and the rare earth element is La, Ce, or Er.
[0014] Preferably, in step (b), the temperature of the constant temperature condition is 50~70℃; the heat preservation time is 1.5~2.5h; and the substrate is selected from silicon wafers, glass, polyimide film or metal foil.
[0015] Preferably, in step (c), the ultraviolet light used for ultraviolet curing has a wavelength of 240~260nm, an irradiation distance of 5~10cm, and a time of 10~20min.
[0016] Preferably, in step (c), the washing includes ultrasonic washing with deionized water and anhydrous ethanol for 5-10 minutes in sequence; the vacuum drying temperature is 65-75°C.
[0017] A second aspect of the present invention provides a rare earth modified melamine polymer film prepared by the above preparation method, wherein the rare earth modified melamine polymer film has a two-dimensional layered structure.
[0018] The third aspect of this invention provides an application of the rare earth modified melamine polymer film prepared by the above-mentioned method in the preparation of food packaging materials, electronic device packaging materials, explosion-proof and stress-resistant structural materials, or gas separation membranes.
[0019] The fourth aspect of this invention provides an application of the rare earth modified melamine polymer film prepared by the above-described method in the preparation of optical devices.
[0020] The fifth aspect of this invention provides an application of the rare earth modified melamine polymer film prepared by the above-described method in the photocatalytic degradation of organic matter.
[0021] Compared with the prior art, the beneficial effects of the present invention include at least the following:
[0022] This invention breaks through the bias of existing technology and discovers that under specific concentration and pH conditions, rare earth ions (La3+, Ce3+, Er3+) can form dynamic coordination bonds with the triazine ring nitrogen atoms in melamine molecules, rather than stable complexes. This dynamic coordination produces the following synergistic effects: (1) Catalytic self-assembly: Rare earth ions act as "molecular anchors" to pre-organize melamine monomers through coordination, reducing the energy barrier of ordered arrangement, enabling melamine monomers to self-assemble and shortening the reaction time, thus improving efficiency. (2) Structural regulation: The steric hindrance effect of rare earth ions inhibits disordered aggregation and promotes the formation of a highly ordered two-dimensional layered structure, reducing the surface roughness of the film to Ra≤0.5μm. (3) Enhanced crosslinking: Rare earth ions form coordination bridges between layers, which, in synergy with UV-induced covalent crosslinking, significantly improve the mechanical strength and thermal stability of the film. (4) Functional endowment: Different rare earth ions endow the film with specific functions—La3+ enhances thermal stability, Ce3+ endows photocatalytic activity, and Er3+ endows near-infrared luminescence properties; In summary, by introducing rare earth elements, this invention can realize the self-assembly polymerization reaction of melamine under ultraviolet light to generate a polymer film. This polymer film has excellent gas isolation performance, mechanical properties, high thermal decomposition performance and fluorescence performance. At the same time, by selecting rare earth elements, it can also have the performance of photocatalytic degradation of organic matter. Attached Figure Description
[0023] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0024] Figure 1 The image shows the surface morphology of the Er3+ doped polymer film prepared in Example 1 of this invention using a scanning electron microscope (SEM).
[0025] Figure 2 The rare earth element analysis diagram of the Er3+ doped polymer film prepared in Example 1 of this invention is shown in the X-ray photoelectron spectroscopy (XPS).
[0026] Figure 3 The near-infrared fluorescence spectrum of the Er3+-doped polymer film prepared in Example 1 of this invention;
[0027] Figure 4 This is a schematic diagram of the coordination catalytic mechanism between rare earth ions and melamine monomers in Example 1 and Comparative Example 1 of the present invention.
[0028] Figure 5 This is a thermogravimetric analysis comparison diagram of the La3+ doped polymer film prepared in Example 2 of the present invention and the undoped film in Comparative Example 1;
[0029] Figure 6 This is a diagram illustrating the rare earth coordination catalysis mechanism of the rare earth modified melamine polymer film of the present invention. Detailed Implementation
[0030] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.
[0031] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.
[0032] This invention provides a method for preparing a rare-earth modified melamine polymer film, the method comprising the following steps:
[0033] (a) Melamine monomer and rare earth salt are dissolved in water and the pH is adjusted to 7-9 to obtain a mixed solution;
[0034] (b) Under constant temperature conditions, spin-coat the mixture onto the substrate surface and keep it at that temperature for a period of time;
[0035] (c) After the heat preservation is completed, UV curing is performed, followed by washing and vacuum drying to obtain the rare earth modified melamine polymer film.
[0036] In one embodiment, in step (a), the concentration of melamine monomer in the mixture is 80~120 g / L; the molar ratio of rare earth salt to melamine monomer is (0.1~3):100.
[0037] In one embodiment, in step (a), the rare earth salt is a nitrate or hydrochloride, and the rare earth element is La, Ce, or Er.
[0038] In one embodiment, in step (b), the temperature of the constant temperature condition is 50~70°C; the heat preservation time is 1.5~2.5h; and the substrate is selected from silicon wafers, glass, polyimide film or metal foil.
[0039] In one embodiment, in step (c), the ultraviolet light used for curing has a wavelength of 240~260nm, an irradiation distance of 5~10cm, and a time of 10~20min.
[0040] In one embodiment, step (c) includes ultrasonic washing with deionized water and anhydrous ethanol for 5-10 minutes in sequence; vacuum drying temperature is 65-75°C and drying time is 2.5-3.5 hours.
[0041] Another embodiment of the present invention provides a rare earth modified melamine polymer film prepared by the above preparation method.
[0042] Another embodiment of the present invention provides the application of the rare earth modified melamine polymer film prepared by the above preparation method in the preparation of food packaging materials, electronic device encapsulation materials or gas separation membranes.
[0043] Another embodiment of the present invention provides an application of the rare earth modified melamine polymer film prepared by the above preparation method in the preparation of optical devices.
[0044] Another embodiment of the present invention provides the application of the rare earth modified melamine polymer film prepared by the above preparation method in the photocatalytic degradation of organic matter.
[0045] The technical solution of the present invention will be further described in detail below through specific embodiments.
[0046] Example 1
[0047] This embodiment describes a method for preparing Er3+ modified melamine polymer films, with the rare earth coordination catalysis mechanism as follows: Figure 6 As shown; the preparation method includes the following steps:
[0048] (a) Melamine monomer (purity 99.8%, 10g) was dissolved in 100ml of deionized water and magnetically stirred for 30min. Then, 0.1g Er(NO3)3·6H2O was added to the solution (the molar ratio of rare earth salt to melamine was 0.3%, which was calculated to be 0.26mmolEr3+ corresponding to 87mmolmelamine). After stirring for 20min, the pH was adjusted to 8.0 with 0.5mol / L sodium hydroxide solution and stirred for another 20min to obtain a mixed solution.
[0049] (b) Under constant temperature of 60°C, the mixture was spin-coated onto the silicon wafer surface using a spin coater (spin coating speed 3000 rpm, spin coating time 30 seconds) and kept at the temperature for 2 hours.
[0050] (c) After the heat preservation is completed, UV curing is performed (under a 254nm UV lamp, irradiation distance of 8cm, treatment for 15min), followed by ultrasonic washing with deionized water and anhydrous ethanol for 8min in sequence to remove unreacted raw materials, and vacuum drying at 70℃ for 3h to obtain the Er3+ modified melamine polymer film.
[0051] The properties of the rare earth-modified melamine polymer film prepared above were tested:
[0052] Thin film thickness: 200 nm, measured using a profilometer;
[0053] Surface morphology: SEM observation showed that the surface was smooth, without obvious cracks or agglomerations, and the roughness Ra=0.4μm (e.g., Figure 1 (as shown)
[0054] Structural characterization: XPS analysis showed an Er 3d5 / 2 binding energy of 168.5 eV, confirming the presence of Er3+ (e.g., ...). Figure 2 (as shown)
[0055] TEM cross-sectional observation revealed a clear layered structure with an interlayer spacing of 0.33 nm;
[0056] Mechanical properties: Nanoindentation test hardness 4.2 GPa, elastic modulus 28 GPa; tensile test tensile strength 950 MPa, elongation at break 2.5%;
[0057] The near-infrared fluorescence spectra of the polymer films prepared in Example 1 and Comparative Example 1 of this invention are as follows: Figure 3 As shown; by Figure 3 The fluorescence performance is as follows: under 980nm excitation, Er3+ characteristic near-infrared emission was detected at 1530nm, with a fluorescence quantum yield of 8.5% and a fluorescence lifetime of 3.2ms.
[0058] Thermal stability: The thermal decomposition temperature (5% weight loss temperature) tested by TGA was 465℃, which is 22% higher than that of the undoped material.
[0059] The schematic diagrams of the coordination catalytic mechanism between rare earth ions and melamine monomers in the polymer films prepared in Example 1 and Comparative Example 1 of this invention are shown below. Figure 4 As shown in the figure, (a) is a schematic diagram of the preparation of polymer film in Comparative Example 1, and (b) is a schematic diagram of the preparation of polymer film in Example 1.
[0060] Example 2
[0061] This embodiment describes a method for preparing a La3+ modified melamine polymer film, the method comprising the following steps:
[0062] (a) Dissolve 10 g of melamine monomer (purity 99.8%) in 100 ml of deionized water and stir magnetically for 25 min. Then add 0.2 g of LaCl3·7H2O (rare earth salt to melamine molar ratio 0.8%) to the solution and stir for 20 min. Adjust the pH to 7.5 with 0.5 mol / L hydrochloric acid solution and continue stirring for 20 min to obtain a mixed solution.
[0063] (b) Under constant temperature of 60°C, the mixture was spin-coated (spin coating speed 2500 rpm, spin coating time 35 seconds) onto the surface of the ultrasonically cleaned glass substrate and kept at the temperature for 2 hours.
[0064] (c) After the heat preservation is completed, UV curing is performed (under a 254nm UV lamp, irradiation distance 7cm, treatment for 18min), followed by ultrasonic washing with deionized water and anhydrous ethanol for 8min to remove unreacted raw materials, and vacuum drying at 70℃ for 3h to obtain the La3+ modified melamine polymer film.
[0065] The properties of the rare earth-modified melamine polymer film prepared above were tested:
[0066] Thin film thickness: 250 nm, measured using a profilometer;
[0067] Mechanical properties: tensile strength 980 MPa (1.47 times that of undoped material), elastic modulus 32 GPa;
[0068] Thermogravimetric analysis comparison of polymer films prepared in Example 2 and Comparative Example 1 is shown in the figure below. Figure 5 As shown, by Figure 5 It can be seen that the thermal stability is as follows: the thermal decomposition temperature is 475℃, and the TGA curve shows that the main weight loss stage is delayed by 40℃.
[0069] Gas barrier properties: Tested using a differential pressure gas permeation apparatus (ASTM D1434), CO2 permeability was 0.7 × 10⁻¹⁴ cm³·cm / (cm²·s·Pa), and O₂ permeability was 3.8 × 10⁻¹⁵ cm³·cm / (cm²·s·Pa), representing reductions of 65% and 58% respectively compared to undoped materials.
[0070] Surface smoothness: Atomic force microscopy (AFM) test showed Ra=0.35nm, suitable as an electronic device packaging layer.
[0071] Example 3
[0072] This embodiment describes a method for preparing a Ce3+ modified melamine polymer film, the method comprising the following steps:
[0073] (a) Dissolve 10 g of melamine monomer (purity 99.8%) in 100 ml of deionized water and stir magnetically for 25 min. Then add 0.08 g of Ce(NO3)3·6H2O (rare earth salt to melamine molar ratio 0.02%) to the solution and stir for 20 min. Adjust the pH to 7.8 and continue stirring for 20 min to obtain a mixed solution.
[0074] (b) Under constant temperature of 55°C, the mixture was spin-coated (spin coating speed 3500 rpm, spin coating time 25 seconds) onto the surface of the ultrasonically cleaned glass substrate and kept at the temperature for 2.5 h.
[0075] (c) After the heat preservation is completed, UV curing is performed (under a 254nm UV lamp, irradiation distance of 6cm, treatment for 12min), followed by ultrasonic washing with deionized water and anhydrous ethanol for 8min to remove unreacted raw materials, and vacuum drying at 70℃ for 3h to obtain the Ce3+ modified melamine polymer film.
[0076] The properties of the rare earth-modified melamine polymer film prepared above were tested:
[0077] Thin film thickness: 150 nm, measured using a profilometer;
[0078] Cyclic stability: The degradation rate remains at 88% after 5 consecutive uses;
[0079] Mechanical properties: tensile strength 820MPa, thermal decomposition temperature 445℃.
[0080] Example 4
[0081] This embodiment is a method for preparing Er3+ modified melamine polymer film. The preparation method is basically the same as that in Example 1, except that in step (a), the pH value is adjusted to 7.0.
[0082] Results: Film formation was successful, with a tensile strength of 920 MPa and good surface smoothness, proving that pH 7.0 is a feasible endpoint.
[0083] Example 5
[0084] This embodiment is a method for preparing Er3+ modified melamine polymer film. The preparation method is basically the same as that in Example 1, except that in step (b), the constant temperature is 50°C and the holding time is 2.5h.
[0085] Results: The self-assembly time was extended to 2.5 hours (2 hours at 60℃), the tensile strength of the film was 880 MPa, and the surface quality was good, proving that 50℃ is feasible but the efficiency is lower than that at 60℃.
[0086] Example 6
[0087] This embodiment is a method for preparing Er3+ modified melamine polymer film. The preparation method is basically the same as that in Example 1, except that in step (b), the constant temperature is 70°C and the holding time is 1.5h.
[0088] Results: The self-assembly time was reduced to 1.5 hours, and the tensile strength of the film was 960 MPa, but the surface roughness increased slightly (Ra=0.6 μm), proving that 70℃ is the feasible upper limit.
[0089] Comparative Example 1
[0090] This comparative example illustrates a method for preparing a melamine polymer film (conventional method), which includes the following steps:
[0091] (a) Dissolve melamine monomer (purity 99.8%, 10g) in 100ml of deionized water, stir magnetically for 30min, adjust the pH to 7.5 with 0.5mol / L sodium hydroxide solution, and continue stirring for 20min to obtain a mixture;
[0092] (b) Under constant temperature of 60°C, the mixture was spin-coated onto the silicon wafer surface using a spin coater (spin coating speed 3000 rpm, spin coating time 30 seconds) and kept at the temperature for 24 hours.
[0093] (c) After the heat preservation is completed, UV curing is performed (under a 254nm UV lamp, irradiation distance of 8cm, treatment for 15min), followed by ultrasonic washing with deionized water and anhydrous ethanol for 8min to remove unreacted raw materials, and vacuum drying at 70℃ for 3h to obtain the melamine polymer film.
[0094] Results: The film had a tensile strength of 680 MPa, a surface roughness of Ra = 2.2 μm, and exhibited obvious cracks and pinholes. Its gas barrier properties were poor (CO2 permeability 2.1 × 10⁻¹⁴ cm³·cm / (cm²·s·Pa)). Strict humidity control is required during the self-assembly process; otherwise, white precipitates may easily form.
[0095] Comparative Example 2
[0096] This comparative example is a method for preparing a La3+ modified melamine polymer film. The preparation method is basically the same as that in Example 2, except that in step (b), LaCl3·7H2O is replaced with an equimolar amount of FeCl3·6H2O.
[0097] Results: The mixed solution immediately turned dark brown and failed to form a continuous film after spin coating, instead flaking off in powder form. Fe3+ formed an overly stable Fe-melamine complex (stability constant logK > 15) with melamine, preventing the hydrogen bond-driven self-assembly process. This demonstrates that transition metal ions cannot achieve the catalytic effect of rare earth ions.
[0098] Comparative Example 3
[0099] This comparative example is a method for preparing Er3+ modified melamine polymer film, which is basically the same as the preparation method in Example 1, except that in step (a), the pH value is adjusted to 6.0.
[0100] Results: The solubility of melamine was significantly reduced, the solution became turbid, the film formed after spin coating was uneven, with a large number of undissolved particles, the tensile strength of the film was only 450 MPa, and the surface roughness Ra > 3 μm. This proves that pH 6.0 is outside the suitable range.
[0101] Comparative Example 4
[0102] This comparative example is a method for preparing Er3+ modified melamine polymer film, which is basically the same as the preparation method in Example 1, except that in step (a), the pH value is adjusted to 10.0.
[0103] Results: Rare earth ions hydrolyzed to form hydroxide precipitates, making the solution turbid and unable to form a film; this proves that pH 10.0 is outside the suitable range.
[0104] Comparative Example 5
[0105] This comparative example is a method for preparing Er3+ modified melamine polymer film. The preparation method is basically the same as that in Example 1, except that in step (a), the amount of Er(NO3)3·6H2O is increased to 1.7g (molar ratio of rare earth salt to melamine is 5%).
[0106] Results: Significant rare earth ion aggregation was observed, resulting in white spots on the film, a decrease in tensile strength to 620 MPa, and a reduction in fluorescence quantum yield to 3.2%. This demonstrates that high concentrations of rare earth elements actually impair performance.
[0107] In this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0108] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0109] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which 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, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0110] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing a rare-earth modified melamine polymer film, characterized in that, The preparation method includes the following steps: (a) Melamine monomer and rare earth salt are dissolved in water and the pH is adjusted to 7-9 to obtain a mixed solution; (b) Under constant temperature conditions, spin-coat the mixture onto the substrate surface and keep it at that temperature for a period of time; (c) After the heat preservation is completed, UV curing is performed, followed by washing and vacuum drying to obtain the rare earth modified melamine polymer film.
2. The preparation method according to claim 1, characterized in that, In step (a), the concentration of melamine monomer in the mixture is 80~120g / L; the molar ratio of rare earth salt to melamine monomer is (0.1~3):
100.
3. The preparation method according to claim 1, characterized in that, In step (a), the rare earth salt is a nitrate or hydrochloride, and the rare earth element is La, Ce, or Er.
4. The preparation method according to claim 1, characterized in that, In step (b), the temperature of the constant temperature condition is 50~70℃; the heat preservation time is 1.5~2.5h; and the substrate is selected from silicon wafers, glass, polyimide film or metal foil.
5. The preparation method according to claim 1, characterized in that, In step (c), the ultraviolet light used for curing has a wavelength of 240~260nm, an irradiation distance of 5~10cm, and a time of 10~20min.
6. The preparation method according to claim 1, characterized in that, In step (c), the washing process includes ultrasonic washing with deionized water and anhydrous ethanol for 5-10 minutes in sequence; the vacuum drying temperature is 65-75℃.
7. The rare-earth modified melamine polymer film prepared by the method according to any one of claims 1 to 6, characterized in that, The rare earth modified melamine polymer film has a two-dimensional layered structure.
8. The application of the rare earth modified melamine polymer film prepared by any one of claims 1 to 6 in the preparation of food packaging materials, electronic device packaging materials, explosion-proof and stress-resistant structural materials or gas separation membranes.
9. The application of the rare earth modified melamine polymer film prepared by any one of claims 1 to 6 in the preparation of optical devices.
10. The application of the rare earth modified melamine polymer film prepared by any one of claims 1 to 6 in the photocatalytic degradation of organic matter.