Polyimide single rare earth ion coordination acid response data encryption material with phenanthroline benzimidazole structure and preparation method and application of polyimide single rare earth ion coordination acid response data encryption material

Abstract

The invention discloses a phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid response data encryption material and a preparation method and application thereof, and belongs to the technical field of polymer acid response data encryption material preparation. The phenanthroline and benzimidazole structure polyimide single rare earth ion coordination acid response data encryption material comprises phenanthroline and benzimidazole structure polyimide, rare earth ions and an organic small molecule ligand of a beta-diketone structure which are combined through coordination. The material shows rapid acid response under the condition that different proportions of organic acid / inorganic acid are added, and the function of data encryption can be achieved through the acid response effect.

Description

Technical Field

[0001] The present application relates to a phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid responsive data encryption material and a preparation method and application thereof, belonging to the technical field of polymer acid responsive data encryption material preparation. Background Art

[0002] Information security has received more and more attention in daily life, which has also promoted the development of new materials and technologies for encryption, anti-counterfeiting and information security storage. By combining multiple anti-counterfeiting technologies or using multiple external stimuli (such as light, temperature, pH and humidity) to decrypt information, the encrypted information becomes difficult to interpret and copy, thereby effectively improving the security of information storage. However, integrating different types of anti-counterfeiting technologies into a system often requires complex assembly methods and it is difficult to avoid mutual interference. At the same time, complex decryption operations usually require expensive and clumsy decryption equipment. Therefore, how to achieve secure storage of information through simple encryption / decryption methods is a challenging problem.

[0003] In addition, rewritable materials can reversibly write / erase information under the presence / removal of specific stimuli (such as light, solvents, ions, acids / bases or competing guest molecules), which has attracted great attention in the field of information storage. However, most of the rewritable materials reported so far are chemically reactive or based on gel systems. They are easily affected by chemical residues / accumulation or undergo volume changes with solvent evaporation, which limits rewritability and sensitivity. Therefore, it is necessary to develop a rewritable material with fast response speed, rewritability, simple preparation and mild conditions.

[0004] Fluorescent materials are materials that can absorb external energy (temperature, light, electricity, etc.) and release fluorescence. Because they can emit many bright colors visible to the naked eye, fluorescent materials play an indispensable role in the fields of coatings, lamps, fluorescent signs, etc. These fluorescent materials are combined with some acid-responsive molecules. Acid-stimulated response refers to an intelligent response material in which the fluorescence color and intensity of the material molecules change significantly under the influence of the environmental pH. Most acid-induced color-changing material molecules contain groups that can interact with acids / bases, such as amino, pyridine, carboxyl, phenolic hydroxyl or other nitrogen-containing heterocyclic groups that can react with acids / bases. Under the action of acid or base, the molecular structure receives protons under the stimulation of external acid and undergoes a protonation effect, thereby changing the electron cloud distribution or molecular stacking mode of the compound to induce a significant change in the fluorescence / absorption spectrum of the material molecule. Such acid-stimulated responsive materials have broad applications and prospects in the fields of pH sensors, acid-base switches, and optoelectronic devices.

[0005] At present, the introduction of lanthanide ions into HOFs framework materials not only improves the stability of HOFs, but also provides a unique luminescence center, promotes the fluorescence resonance energy transfer between the HOFs framework host and the guest molecule, provides efficient light response performance, and enriches the color change of color-changing materials. However, the stability of HOFs materials themselves limits their application scope.

[0006] Polyimide (PI) is widely recognized for its excellent thermal stability, chemical resistance, dimensional stability and mechanical strength. However, in the field of optoelectronics, rare earth metals can be introduced into PI through a post-polymerization coordination strategy, which can theoretically produce coordinated PI with superior performance. Introducing acid-responsive groups into the molecular structure of polyimide can achieve acid-induced color change, thereby achieving the purpose of data encryption.

[0007] With the advancement of science and technology and the development of information, material molecules with a single stimulus-responsive characteristic can no longer meet people's diverse needs. In order to achieve the diversity and diversification of materials that respond to multiple stimuli, we explore the integration of multiple stimulus-responsive principles and the construction of multi-stimulus-responsive materials. By modifying the materials to have multiple response characteristics, we can solve the single function of the material and obtain functional materials with multi-functional application potential, which is more conducive to further expanding the application scope of such materials. Summary of the invention

[0008] In order to solve the problems of relatively poor solubility, thermal performance, and luminescence in the prior art of materials with stimulus response characteristics, the present application provides a phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid responsive data encryption material and its preparation method and application, which introduces a phenanthroline benzimidazole structure to give it excellent rare earth metal ion coordination ability. On this basis, the β-diketone small molecule ligand with sensitization characteristics for rare earth ions reacts with the polyimide molecule phenanthroline benzimidazole ligand to generate PI-Ln 3+ Coordinated polyimide. The phenanthroline benzimidazole structure has a strong response to proton acid. When different amounts of proton acid are added, Ln 3+ Under the sensitization of organic ligands, the luminescence efficiency will change greatly. As a result, the wavelength and intensity of fluorescence emission will change, realizing acid-responsive data encryption. The rigid structure of phenanthroline benzimidazole gives the material good thermal stability and chemical stability. At the same time, the twisted structure increases the free volume of the polymer material, enhances the solubility of the polymer material, and improves the processability tolerance of the material. Compared with the organic light-emitting materials currently studied, the solubility, thermal properties, and luminescence properties of the polymer material have been greatly improved, with potential commercial value and low production cost, and can be mass-produced and applied.

[0009] This application adopts the following technical solutions:

[0010] According to one aspect of the present application, a phenanthroline benzimidazole structure polyimide single rare earth ion coordinated acid responsive data encryption material is provided, comprising a phenanthroline benzimidazole structure polyimide, a rare earth ion, and an organic small molecule ligand of a β-diketone structure combined by coordination;

[0011] The phenanthroline benzimidazole structure polyimide has a general structure shown in Formula I:

[0012]

[0013] wherein Ar is the residue of a dianhydride monomer;

[0014] M is selected from C6-C 40 At least one of the arylene groups;

[0015] 0.5<n≤1,n+m=1;

[0016] The organic small molecule ligand of the β-diketone structure has a structure of the general formula shown in Formula Ia:

[0017]

[0018] Optionally, the phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid responsive data encryption material has a structure of the general formula shown in Formula II:

[0019]

[0020] Among them, Ln represents rare earth ions, and Ligand represents organic small molecule ligands;

[0021] Ar is the residue of a dianhydride monomer;

[0022] M is selected from C6-C 40 At least one of the arylene groups;

[0023] 0.5<n≤1,n+m=1.

[0024] Optionally, the rare earth ion is selected from at least one element ion of Tb, Eu, Ce, Yb, Sm, and Gd;

[0025] Optionally, the molar ratio of the rare earth ions to the N atoms in the phenanthroline benzimidazole structure polyimide is 0.025 to 0.5:1;

[0026] Optionally, the organic small molecule ligand of the β-diketone structure is selected from at least one of α-thienyltrifluoroacetone (TTA), acetylacetone (acac), dibenzoylmethane (DBM), benzoylacetone (BA), benzoyltrifluoroacetone (BFA), and β-naphthoyltrifluoroacetone (β-NTA).

[0027] Optionally, the organic small molecule ligand of the β-diketone structure is selected from compounds of at least one of the following structural formulas:

[0028]

[0029] Optionally, Ar is selected from any one of the groups of the structure shown in formula III;

[0030]

[0031] Optionally, M is selected from any one of the groups of the structure shown in formula IV;

[0032]

[0033] Optionally, the glass transition temperature of the phenanthroline benzimidazole structure polyimide is greater than or equal to 290°C.

[0034] Optionally, the initial decomposition temperature (T d5％ ) is greater than or equal to 504℃.

[0035] Optionally, the residual carbon rate of the phenanthroline benzimidazole structure polyimide is greater than or equal to 50%.

[0036] Optionally, the molecular weight of the phenanthroline benzimidazole structure polyimide is greater than or equal to 20,000 g / mol.

[0037] Optionally, the glass transition temperature of the phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid responsive data encryption material is greater than or equal to 250°C.

[0038] Optionally, the initial decomposition temperature (T d5％ ) is greater than or equal to 350℃.

[0039] Optionally, the residual carbon rate of the phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid response data encryption material is greater than or equal to 55%.

[0040] Optionally, the phenanthroline benzimidazole structure polyimide single rare earth ion coordinated acid responsive data encryption material realizes acid responsive data encryption under the action of proton acid, and controls the interaction between the proton acid and the imidazole group and the small molecule ligand Ligand in the phenanthroline imidazole, thereby affecting the sensitization characteristics of the ligand to the rare earth ion Ln to realize the fluorescence intensity of the rare earth ion Ln, and then realizes the adjustment of its fluorescence emission spectrum.

[0041] According to another aspect of the present application, a method for preparing the above-mentioned phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid responsive data encryption material is provided, firstly, 1,10-phenanthroline-2,9-diacid and o-phenylenediamine are used as raw materials to prepare 2,9-bis(1 hydrogen-benzimidazole-2-yl)-1,10-phenanthroline, and then the 2,9-bis(1 hydrogen-benzimidazole-2-yl)-1,10-phenanthroline and 1-fluoro- The dinitro compound 2,9-bis(1-(4-nitro-2-trifluoromethyl)-phenyl)-1-hydrogen-benzimidazol-2-yl-1,10-phenanthroline is prepared by a nucleophilic substitution reaction using 4-nitro-2-trifluoromethylbenzene as a monomer in the presence of a catalyst, and then the dinitro compound 2,9-bis(1-(4-nitro-2-trifluoromethyl)-phenyl)-1-hydrogen-benzimidazol-2-yl-1,10-phenanthroline is reacted with a catalyst and a reducing agent. The invention relates to a method for preparing a diamine monomer 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1 hydrogen-benzimidazole-yl))bis(3-(trifluoromethyl)aniline by reduction reaction in the presence of 2-nitropropene; and then the 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1 hydrogen-benzimidazole-yl))bis(3-(trifluoromethyl)aniline is polymerized with aromatic diamine and aromatic dianhydride to prepare a phenanthroline benzimidazole structure polyimide; then, under an inactive atmosphere, a rare earth metal chloride salt and a small molecule ligand of a β-diketone structure are reacted in an alkaline mixed solution to prepare an organic small molecule rare earth complex; finally, under an inactive atmosphere, the small molecule rare earth metal complex and a polyimide polymer containing a phenanthroline benzimidazole structure are coordinated in an organic solvent to prepare a phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid response data encryption material.

[0042] The preparation method of the phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid responsive data encryption material of the present application comprises the following steps:

[0043] S1, adding a monomer mixture containing 1,10-phenanthroline-2,9-dicarboxylic acid and o-phenylenediamine to polyphosphorus, reacting I, to obtain 2,9-bis(1H-benzimidazol-2-yl)-1,10-phenanthroline;

[0044] S2, reacting a mixture containing 2,9-bis(1-hydrogen-benzimidazol-2-yl)-1,10-phenanthroline and 1-fluoro-4-nitro-2-trifluoromethylbenzene (1-fluoro-4-nitro-2-(trifluoromethyl)-benzene), catalyst I, and solvent I with II to obtain a dinitro compound 2,9-bis(1-(4-nitro-2-trifluoromethyl)-phenyl)-1H-benzo[d]imidazol-2-yl)-1,10-phenanthroline; in step S2, the monomer is subjected to a nucleophilic substitution reaction under the action of the catalyst to prepare a product;

[0045] S3, under an inert atmosphere, reacting a mixture containing a dinitro compound 2,9-bis(1-(4-nitro-2-trifluoromethyl)-phenyl)-1-hydrogen-benzimidazole-2-yl-1,10-phenanthroline, a catalyst II, a reducing agent, and a solvent II with III to obtain a diamine monomer 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1-hydrogen-benzimidazole-yl))bis(3-(trifluoromethyl)aniline (4,4'-((1,10-phenanthroline-2,9-diyl)-bis(1H-benzo[d]imidazole-2,1-diyl))-bis(3-(trifluoromethyl)-aniline)); step S3 is to carry out a reduction reaction in the presence of a catalyst and a reducing agent to prepare a product;

[0046] S4, under an inert atmosphere, reacting a mixture containing a diamine monomer 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1H-benzo[d]imidazole-2,1-diyl))bis(3-(trifluoromethyl)aniline (4,4'-((1,10-phenanthroline-2,9-diyl)-bis(1H-benzo[d]imidazole-2,1-diyl))-bis(3-(trifluoromethyl)-aniline)), a dianhydride monomer containing an Ar structure, a diamine monomer containing an M structure, and a solvent III, performing a reaction IV-a, then adding a catalyst III to the product, continuing the reaction IV-b, and then adding ethanol to the product to form a precipitate to obtain the phenanthroline benzimidazole structure polyimide;

[0047] S5, adding rare earth metal chloride and an organic small molecule ligand with a β-diketone structure to the alkaline mixed solution, reacting IV, and obtaining a small molecule rare earth complex;

[0048] S6, mixing the phenanthroline benzimidazole structure polyimide and the small molecule rare earth complex in solvent IV, and coordinating them to obtain the phenanthroline benzimidazole structure polyimide single rare earth ion coordinated acid responsive data encryption material.

[0049] Optionally, in step S1, the molar ratio of 1,10-phenanthroline-2,9-diacid to o-phenylenediamine is 1:2.0-2.2.

[0050] Optionally, in step S1, the conditions of reaction I include: reaction temperature of 200-240° C., and reaction time of 5-8 h.

[0051] Optionally, step S1 further includes pouring the reaction solution into an ice-water mixture after reaction I, adjusting the pH to 8.5-9.5 with aqueous ammonia to form a precipitate, and washing and drying the precipitate.

[0052] Optionally, in step S1, the process schematic diagram of reaction I is as follows:

[0053]

[0054] Optionally, in step S2, the molar ratio of 2,9-bis(1-hydrogen-benzimidazol-2-yl)-1,10-phenanthroline to 1-fluoro-4-nitro-2-trifluoromethylbenzene is 1:2.0-2.2.

[0055] Optionally, in step S2, the conditions of reaction II include: reaction temperature of 80 to 120° C., and reaction time of 12 to 24 h.

[0056] Optionally, step S2 further comprises, after reaction II, pouring the reaction solution into water to form a precipitate, and washing and drying the precipitate.

[0057] Optionally, in step S2, the process schematic diagram of reaction II is as follows:

[0058]

[0059] Optionally, in step S2, catalyst I is selected from at least one of potassium carbonate, cesium carbonate and calcium carbonate.

[0060] Optionally, in step S2, solvent I is selected from at least one of N-methylpyrrolidone, NN-dimethylformamide, and NN-dimethylacetamide.

[0061] Optionally, in step S3, catalyst II is a 5% dry palladium carbon catalyst (Pb / C catalyst, Pd loading is 5%).

[0062] Optionally, in step S3, the amount of catalyst II used is 8-12% by weight of the dinitro compound.

[0063] Optionally, in step S3, the reducing agent is 85% hydrazine hydrate (85% content of N2H4·H2O).

[0064] Optionally, in step S3, the amount of the reducing agent used is 5 to 10 times the weight of the dinitro compound.

[0065] Optionally, in step S3, the conditions of reaction III include: reaction temperature of 80 to 120° C., and reaction time of 12 to 24 h.

[0066] Optionally, in step S3, the mixture containing the dinitro compound 2,9-bis(1-(4-nitro-2-trifluoromethyl)-phenyl)-1 hydrogen-benzimidazol-2-yl-1,10-phenanthroline, catalyst II, reducing agent, and solvent II is obtained by adding the reducing agent dropwise to the mixture containing the dinitro compound 2,9-bis(1-(4-nitro-2-trifluoromethyl)-phenyl)-1 hydrogen-benzimidazol-2-yl-1,10-phenanthroline, catalyst II, and solvent II.

[0067] Optionally, step S3 further comprises filtering to remove catalyst II after reaction III, removing solvent I by rotary evaporation, and drying the obtained solid powder.

[0068] Optionally, in step S3, solvent II is selected from at least one of ethanol, NN-dimethylformamide, and NN-dimethylacetamide.

[0069] Optionally, in step S4, the ratio of the diamine monomer 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1-hydrogen-benzimidazole-yl))bis(3-(trifluoromethyl)aniline, the dianhydride monomer containing the Ar structure, and the diamine monomer containing the M structure is 1:1:1.

[0070] Optionally, in step S4, catalyst III is selected from isoquinoline.

[0071] Optionally, in step S4, the conditions of reaction IV-a include: reaction time at 80°C to 90°C for 1 to 2 hours.

[0072] Optionally, in step S4, a reaction material liquid containing a diamine monomer 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1H-benzo[d]imidazole-2,1-diyl))-bis(3-(trifluoromethyl)-aniline), a diamine monomer containing an M structure, and a solvent III is stirred and dissolved at 80 to 100° C. in an inert atmosphere for 0.5 to 2 h, and then a dianhydride monomer containing an Ar structure is added to obtain the mixture.

[0073] Optionally, in step S4, the conditions of reaction IV-b include: reaction time at 150°C to 160°C for 2 to 4 hours, then heating to 190°C to 200°C for 12 to 18 hours.

[0074] Optionally, step S4 further includes gradually adding ethanol to the reaction solution after reaction IV-b to form a Dalian fibrous precipitate, filtering, washing with water, washing with alcohol, and drying.

[0075] Optionally, in step S4, solvent III is selected from at least one of m-cresol, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0076] Optionally, in step S5, the molar ratio of the rare earth metal chloride salt to the organic small molecule ligand of the compound β-diketone structure is 1:3 to 3.1.

[0077] Optionally, in step S5, the conditions for reaction V include: heating to 60° C., reacting at this temperature for 0.5 to 4 hours, and naturally cooling under continuous stirring after the reaction until precipitation is complete.

[0078] Optionally, step S5 further comprises filtering the precipitate after reaction V, dissolving the precipitate with benzene, adding n-hexane to mix, standing for 8 to 16 hours, filtering, and drying the solid product.

[0079] Optionally, in step S5, the process schematic diagram of reaction V is as follows:

[0080]

[0081] Optionally, in step S5, the pH of the alkaline mixed solution is greater than or equal to 8, and the alkaline mixed solution includes a mixture of ethanol and water, and the volume ratio of ethanol to water is 1:8-20.

[0082] Optionally, in step S6, the molar ratio of the small molecule rare earth metal complex to the phenanthroline imidazole group in the phenanthroline benzimidazole structure polyimide is 0.1-0.3:1.

[0083] Optionally, in step S6, the conditions of reaction VI include: reaction temperature of 50 to 120° C., reaction time of 8 to 15 h, and continuous stirring during the reaction.

[0084] Optionally, step S6 further comprises concentrating the reaction solution by rotary evaporation after reaction VI, adding the solution dropwise into ethanol to induce formation of a precipitate, and washing the precipitate with water, alcohol, and drying.

[0085] Optionally, in step S6, the process schematic diagram of reaction VI is as follows:

[0086]

[0087] Optionally, solvent IV is selected from at least one of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0088] According to another aspect of the present application, there is also provided an application of at least one of the above-mentioned phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid responsive data encryption material or the phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid responsive data encryption material prepared by the above method in a polymer acid responsive data encryption material.

[0089] Optionally, the phenanthroline benzimidazole structure polyimide single rare earth ion coordinated acid response data encryption material realizes acid response data encryption under the action of protonic acid;

[0090] By adjusting the amount of proton acid added, the interaction between proton acid and the imidazole group and the β-diketone organic small molecule ligand in the phenanthroline benzimidazole structure polyimide is controlled to affect the sensitization characteristics of rare earth ions, and different fluorescence emission spectra of the data encryption material that responds to the single rare earth ion coordination acid of the phenanthroline benzimidazole structure polyimide are achieved;

[0091] Optionally, the acid response data encryption method is as shown in Formula V:

[0092]

[0093] Among them, H + It is a protonic acid, and the protonic acid is selected from organic acids and inorganic acids.

[0094] Optionally, the organic acid is selected from at least one of formic acid, acetic acid and propionic acid.

[0095] Optionally, the inorganic acid is selected from at least one of hydrochloric acid, sulfuric acid and phosphoric acid.

[0096] The beneficial effects of this application include:

[0097] The phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid response data encryption material provided in the present application realizes acid response data encryption under the action of proton acid, and controls the interaction between the proton acid and the imidazole group and the small molecule ligand Ligand in the phenanthroline imidazole, thereby affecting the sensitization characteristics of the ligand to the rare earth ion Ln to realize the fluorescence intensity of the rare earth ion Ln, and then realizes the adjustment of its fluorescence emission spectrum. The glass transition temperature of the phenanthroline benzimidazole structure polyimide in the encryption material of the present application is above 300°C, and the initial decomposition temperature (T d5％ ) is above 500°C, the residual carbon rate is above 50%, the glass transition temperature of the phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid responsive data encryption material is above 250°C, the initial decomposition temperature (T d5％ ) is above 350°C, the residual carbon rate is above 55%, and the molecular weight of the phenanthroline benzimidazole structure polyimide is above 25000g / mol. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] Figure 1 This is the NMR spectrum of 2,9-bis(1-hydrogen-benzimidazol-2-yl)-1,10-phenanthroline prepared in the examples of the present application.

[0099] Figure 2 This is the NMR spectrum of the dinitro compound 2,9-bis(1-(4-nitro-2-trifluoromethyl)-phenyl)-1 hydrogen-benzimidazol-2-yl-1,10-phenanthroline prepared in the examples of the present application.

[0100] Figure 3 This is the NMR spectrum of the diamine monomer 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1-hydrogen-benzimidazolyl))bis(3-(trifluoromethyl)aniline prepared in the examples of the present application.

[0101] Figure 4 This is the NMR spectrum of the phenanthroline benzimidazole structure polyimide polymer PI-1 prepared in the examples of the present application.

[0102] Figure 5 This is the GPC test result of the phenanthroline benzimidazole structure polyimide polymer PI-1 prepared in the examples of the present application.

[0103] Figure 6 This is a matrix color coding diagram of a phenanthroline benzimidazole structured polyimide single rare earth ion coordinated acid responsive data encryption material prepared in an embodiment of the present application. (a) is under sunlight, (b) is under ultraviolet light, and (c) is the decryption of the matrix color coding diagram after adding an equal amount of acetic acid.

[0104] Figure 7 For the different THF solutions in the test examples of this application CH3COOH Content of PI-Ligand-Eu 3+ -10% of the fluorescence emission spectrum.

[0105] Figure 8 PI-Ligand-Eu with different CH3COOH contents in THF solution in the test example of this application 3+ -10% color change diagram, where (a) is PI-Ligand-Eu 3+ -10%, (b) PI-Ligand-Eu 3+ -10% plus 5% acetic acid, (c) is PI-Ligand-Eu 3+ -10% plus 10% acetic acid. DETAILED DESCRIPTION

[0106] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0107] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0108] Unless otherwise specified, conventional methods were used for testing and instrument settings were those recommended by the manufacturer.

[0109] Data testing conditions and methods in the examples of this application:

[0110] Nuclear Magnetic Resonance Spectroscopy (NMR): 1 H NMR was measured on a Bruker AVANCE III 400 MHz NMR instrument with tetramethylsilane (TMS) as the internal standard and DMSO-d6 as the solvent.

[0111] Fourier Transform Infrared Test (FT-IR): FT-IR spectrum was obtained using VERTEX70 at 4000cm -1 Up to 400cm -1 The wavelength range was tested.

[0112] Fluorescence spectrum test: The fluorescence spectrum was tested on a FS920 (450W xenon lamp) fluorescence spectrum instrument.

[0113] Gel Permeation Chromatography (GPC): GPC was tested on a Waters 1515 gel permeation chromatograph with tetrahydrofuran (THF) as the mobile phase.

[0114] Differential Scanning Calorimetry (DSC): The measurements were performed using a Q20 in a nitrogen atmosphere at a heating rate of 10 K / min.

[0115] Thermogravimetric (TG) loss was measured using a STA449C analyzer in a nitrogen atmosphere at a heating rate of 10 K / min.

[0116] According to one embodiment of the present application, a method for preparing a phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid responsive data encryption material comprises:

[0117] (1) 1,10-phenanthroline-2,9-dicarboxylic acid and o-phenylenediamine are reacted in polyphosphorus to prepare 2,9-Bis(1H-benzimidazol-2-yl)-1,10-phenanthro line;

[0118] (2) 2,9-bis(1-(4-nitro-2-(trifluorometh yl)-phenyl)-1H-benzo[d]imidazol-2-yl)-1,10-phenanthroline and 1-fluoro-4-nitro-2-trifluoromethylbenzene are used as monomers to prepare a dinitro compound 2,9-bis(1-(4-nitro-2-trifluoromethyl)-phenyl)-1H-benzo[d]imidazol-2-yl)-1,10-phenanthroline through a nucleophilic substitution reaction in the presence of a catalyst;

[0119] (3) subjecting the dinitro compound 2,9-bis(1-(4-nitro-2-trifluoromethyl)-phenyl)-1H-benzimidazole-2-yl-1,10-phenanthroline to a reduction reaction in the presence of a catalyst and a reducing agent to prepare a diamine monomer 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1H-benzimidazole-yl))bis(3-(trifluoromethyl)aniline);

[0120] (4) under an inert atmosphere, a diamine monomer 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1H-benzo[d]imidazole-2,1-diyl))bis(3-(trifluoromethyl)aniline), a dianhydride monomer containing an Ar structure, and a diamine monomer containing an M structure are mixed in an organic solvent, and a polymerization reaction is carried out under the action of a catalyst to obtain the phenanthroline benzimidazole structure polyimide;

[0121] (5) Under an inactive atmosphere, reacting a rare earth metal chloride salt and a small molecule ligand of a β-diketone structure in an alkaline mixed solution to prepare a small molecule rare earth complex;

[0122] (6) Under an inactive atmosphere, the small molecule rare earth metal complex obtained in step 5 and the polyimide polymer containing a phenanthroline benzimidazole structure obtained in step 4 are coordinated in an organic solvent to prepare the phenanthroline benzimidazole structure polyimide single rare earth ion coordinated acid responsive data encryption material.

[0123] Example 1

[0124] Steps S1 to S3 The synthesis of 4,4′-((1,10-phenanthroline-2,9-diyl)bis(1-hydrogen-benzimidazol-yl))bis(3-(trifluoromethyl)aniline is as follows.

[0125] Step S1: Under an inert gas atmosphere, 1.34 g of 1,10-phenanthroline-2,9-diacid and 1.135 g of o-phenylenediamine were added to 12.5 ml of polyphosphoric acid, and the mixture was reacted at 220° C. for 6 h. After the reaction was completed, the mixture was cooled to 120° C., and the reaction solution was poured into 200 ml of an ice-water mixture. The mixture was adjusted to pH 9 with ammonia water, and the precipitate was filtered to obtain a precipitate, which was washed three times with hexane and dried in a vacuum drying oven at 80° C. for 6 h to obtain a product of 2,9-bis(1-hydrogen-benzimidazol-2-yl)-1,10-phenanthroline, and the NMR spectrum was as follows: Figure 1 As shown;

[0126] Step S2: Under an inert gas atmosphere, 2.01 g of 2,9-bis(1-hydrogen-benzimidazol-2-yl)-1,10-phenanthroline prepared in step (S1), 1.38 g of anhydrous potassium carbonate and 2.195 g of 1-fluoro-4-nitro-2-trifluoromethylbenzene were added to 20 ml of DMF, and the mixture was reacted at 95° C. for 15 h. After the reaction was completed, the mixture was cooled to room temperature, and the reaction solution was poured into 150 ml of deionized water. The precipitate was filtered to obtain a precipitate, which was washed three times with hexane and dried in a vacuum drying oven at 80° C. for 6 h to obtain a product, which was a dinitro compound 2,9-bis(1-(4-nitro-2-trifluoromethyl)-phenyl)-1-hydrogen-benzimidazol-2-yl-1,10-phenanthroline, and the NMR spectrum was as follows: Figure 2 As shown;

[0127] Step S3: Under an inert gas atmosphere, 0.50 g of a dinitro compound 2,9-bis(1-(4-nitro-2-trifluoromethyl)-phenyl)-1 hydrogen-benzimidazol-2-yl-1,10 phenanthroline and 0.05 g of a 10% Pd / C catalyst (Pd loading is 10%) are added to 20 ml of ethanol, and then 0.4 ml of hydrazine hydrate is added dropwise to the above reaction system, and the reaction is carried out at 85° C. for 12 h. After the reaction is completed, the reaction is cooled to room temperature, and the catalyst is filtered to remove the catalyst. The solvent is removed from the obtained liquid by rotary evaporation to obtain a solid powder, which is dried in a vacuum drying oven at 80° C. for 6 h to obtain a product of a diamine monomer 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1 hydrogen-benzimidazol-yl))bis(3-(trifluoromethyl)aniline, and the NMR spectrum is as follows: Figure 3 shown.

[0128] Step S4: Synthesis of phenanthroline benzimidazole structured polyimide polymer

[0129] In an inert gas atmosphere, 0.30 g of 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1 hydrogen-benzimidazole-yl))bis(3-(trifluoromethyl)aniline and 0.08 g of 4,4'-diaminodiphenyl ether (ODA) were quickly added to a three-necked flask, and then about 5.5 ml of m-cresol was added as a solvent, and the reactants were dissolved by stirring at 80 ° C for 1 hour under a nitrogen atmosphere. 0.29 g of 3,3,4,4-diphenylsulfone tetracarboxylic acid dianhydride was added to the above mixture. The reaction temperature was raised to 150 ° C and stirred continuously. After 3 hours, 0.30 mL of isoquinoline was added to the reaction system as a dehydrating agent and catalyst. Then, the temperature was raised to 200 ° C, and the reaction was continued for 12 hours under stirring. After cooling, the reaction solution was gradually poured into ethanol to generate a large amount of fibrous precipitates. After filtering, the dried product was washed with a large amount of water and ethanol and recorded as PI-1. The nuclear magnetic spectrum is as follows Figure 4 As shown, the GPC test results are as follows Figure 5 shown.

[0130] Step S5: Synthesis of small molecule rare earth complexes

[0131] Under an inert gas atmosphere, acetylacetone (0.06 g, 6 mmol) was dissolved in 30 mL of anhydrous ethanol, and then 6 mL of an aqueous solution of NaOH (1N) and 10 mL of anhydrous ethanol solution of Eu Cl3·6H2O (2 mmol) were added to the anhydrous ethanol solution of acetylacetone in sequence, and then 200 mL of distilled water was added, the mixture was heated to 60°C, and cooled to room temperature under stirring. A precipitate was precipitated and filtered. The obtained solid was dissolved in 60 mL of benzene, and 200 mL of n-hexane was added. The mixture was allowed to stand at room temperature overnight, filtered, and dried in vacuo at 60°C for 48 h to obtain a light yellow solid recorded as a small molecule rare earth complex Eu(acac)3·2H2O.

[0132] Step S6: Synthesis of single rare earth ion coordinated acid responsive data encryption material of phenanthroline benzimidazole structure polyimide

[0133] 0.20 g of polymer PI-1 was dissolved in 10 ml of tetrahydrofuran (THF). A small molecule rare earth complex containing Ln(acac)3·2H2O was added to the reaction mixture at a molar ratio of 10% of the phenanthroline imidazole group, and the reaction system was continuously stirred at a stable temperature of 60°C for 15 hours. After the reaction was completed, the reaction solution was concentrated by rotary evaporation and then slowly added dropwise to ethanol to induce the formation of a precipitate. The precipitate was washed with water and ethanol and the dried product was recorded as PI-Ligand-Eu 3+ -10%.

[0134] Example 2

[0135] Steps S1 to S5 are the same as those in Example 1, except that step S6 is:

[0136] 0.20 g of polymer PI-1 was dissolved in 10 ml of tetrahydrofuran (THF). A small molecule rare earth complex containing Ln(acac)3·2H2O was added to the reaction mixture at a molar ratio of 20% of the phenanthroline imidazole group, and the reaction system was continuously stirred at a stable temperature of 60°C for 15 hours. After the reaction was completed, the reaction solution was concentrated by rotary evaporation and then slowly added dropwise to ethanol to induce the formation of a precipitate. The precipitate was washed with water and ethanol and the dried product was recorded as PI-Ligand-Eu 3+ -20%.

[0137] Example 3

[0138] Steps S1 to S5 are the same as those in Example 1, except that step S6 is:

[0139] 0.20 g of polymer PI-1 was dissolved in 10 ml of tetrahydrofuran (THF). A small molecule rare earth complex containing Ln(acac)3·2H2O was added to the reaction mixture at a molar ratio of 30% of the phenanthroline imidazole group, and the reaction system was continuously stirred at a stable temperature of 60°C for 15 hours. After the reaction was completed, the reaction solution was concentrated by rotary evaporation and then slowly added dropwise to ethanol to induce the formation of a precipitate. The precipitate was washed with water and ethanol and the dried product was recorded as PI-Ligand-Eu 3+ -30%.

[0140] Example 4

[0141] Steps S1-S3 and S5-S6 are the same as those in Example 1, except that step S4 is:

[0142] Under an inert gas atmosphere, 0.30 g of 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1 hydrogen-benzimidazole-yl))bis(3-(trifluoromethyl)aniline and 0.022 g of p-phenylenediamine were quickly added to a three-necked flask, and then about 5 ml of m-cresol was added as a solvent, and the reactants were dissolved by stirring at 80°C under a nitrogen atmosphere for 1 hour. 0.36 g of hexafluoroisopropylphthalic anhydride (6FDA) was added to the above mixture. The reaction temperature was raised to 150°C and stirred continuously. After 3 hours, 0.30 mL of isoquinoline was added to the reaction system as a dehydrating agent and catalyst. Then, the temperature was raised to 200°C and the reaction was continued for 12 hours under stirring. After cooling, the reaction solution was gradually poured into ethanol to generate a large amount of fibrous precipitates. After filtering, the dried product was washed with a large amount of water and ethanol and recorded as PI-2.

[0143] Example 5

[0144] Steps S1-S3 and S5-S6 are the same as those in Example 1, except that step S4 is:

[0145] Under an inert gas atmosphere, 0.30 g of 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1 hydrogen-benzimidazole-yl))bis(3-(trifluoromethyl)aniline and 0.064 g of 4,4'-diaminobiphenyl were quickly added to a three-necked flask, and then about 7 ml of m-cresol was added as a solvent. The reactants were dissolved by stirring at 80°C for 1 hour under a nitrogen atmosphere. 0.42 g of bisphenol A type diether dianhydride was added to the above mixture. The reaction temperature was raised to 150°C and stirred continuously. After 3 hours, 0.30 mL of isoquinoline was added to the reaction system as a dehydrating agent and catalyst. Then, the temperature was raised to 200°C and the reaction was continued for 12 hours under stirring. After cooling, the reaction solution was gradually poured into ethanol to generate a large amount of fibrous precipitates. After filtering, the dried product was washed with a large amount of water and ethanol and recorded as PI-3.

[0146] Test Example 1 Encryption process of single rare earth ion coordination acid response data encryption material of phenanthroline benzimidazole structure polyimide

[0147] like Figure 6 As shown, PI-Ligand-Eu was prepared at a concentration of 20 mg / ml. 3+ -10% tetrahydrofuran solution and 20mg / ml tetrahydrofuran solution of Eu(acac)3·2H2O. Taking advantage of their different photoluminescent properties, we use these compounds as basic pixels, where red represents "1" and blue represents "0". Deploying this color coding strategy can perform data storage and encryption within a 3×8 matrix. Acetic acid is added during the decryption process, where the equimolar addition of acetic acid achieves the decryption of the data string "01000011, 01000001, 01010011", which is subsequently translated into the ASCII representation "CAS". PI-Ligand-Eu with different acetic acid addition amounts 3+ -10% of the fluorescence emission spectrum as Figure 7 As shown, PI-Ligand-Eu with different acetic acid contents 3+ -10% color change as shown Figure 8 As shown, (a) is PI-Ligand-Eu 3+ -10%, (b) PI-Ligand-Eu 3+ -10% plus 5% acetic acid, (c) is PI-Ligand-Eu 3+ -10% plus 10% acetic acid.

[0148] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid response data encryption material, It is characterized in that It includes phenanthroline benzimidazole structure polyimide, rare earth ions, and β-diketone structure organic small molecule ligands combined by coordination; The phenanthroline benzimidazole structure polyimide has a general structure shown in Formula I: wherein Ar is the residue of a dianhydride monomer; M is selected from C 6 -C 40 At least one of the arylene groups; 0.5<n≤1,n+m=1; The organic small molecule ligand of the β-diketone structure has a structure of the general formula shown in Formula Ia:

2. The phenanthroline benzimidazole structure polyimide single rare earth ion coordinated acid responsive data encryption material according to claim 1, It is characterized in that The phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid responsive data encryption material has a general structure shown in Formula II: Among them, Ln represents rare earth ions, and Ligand represents organic small molecule ligands; Ar is the residue of a dianhydride monomer; M is selected from C 6 -C 40 At least one of the arylene groups; 0.5<n≤1,n+m=1.

3. The phenanthroline benzimidazole structure polyimide single rare earth ion coordinated acid responsive data encryption material according to claim 1, It is characterized in that The rare earth ion is selected from at least one element ion of Tb, Eu, Ce, Yb, Sm, and Gd; Preferably, the molar ratio of the rare earth ions to the N atoms in the phenanthroline benzimidazole structure polyimide is 0.025 to 0.5:1; Preferably, the organic small molecule ligand of the β-diketone structure is selected from at least one of α-thienyltrifluoroacetone, acetylacetone, dibenzoylmethane, benzoylacetone, benzoyltrifluoroacetone, and β-naphthoyltrifluoroacetone.

4. The phenanthroline benzimidazole structure polyimide single rare earth ion coordinated acid responsive data encryption material according to claim 1, It is characterized in that Ar is selected from any one of the groups of the structure shown in formula III; 5. The phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid response data encryption material according to claim 1, It is characterized in that M is selected from any one of the groups of the structure shown in formula IV; 6. The phenanthroline benzimidazole structure polyimide single rare earth ion coordinated acid responsive data encryption material according to claim 1, It is characterized in that The glass transition temperature of the phenanthroline benzimidazole structure polyimide is greater than or equal to 290° C. Preferably, the initial decomposition temperature of the phenanthroline benzimidazole structure polyimide is greater than or equal to 504° C.; Preferably, the residual carbon rate of the phenanthroline benzimidazole structure polyimide is greater than or equal to 50%; Preferably, the molecular weight of the phenanthroline benzimidazole structure polyimide is greater than or equal to 20000 g / mol; Preferably, the glass transition temperature of the phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid responsive data encryption material is greater than or equal to 250° C.; Preferably, the initial decomposition temperature of the phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid responsive data encryption material is greater than or equal to 350° C.; Preferably, the residual carbon rate of the phenanthroline benzimidazole structure polyimide single rare earth ion coordination acid response data encryption material is greater than or equal to 55%.

7. A method for preparing a phenanthroline benzimidazole structured polyimide single rare earth ion coordinated acid responsive data encryption material according to any one of claims 1 to 6, It is characterized in that The steps include: S1, adding a monomer mixture containing 1,10-phenanthroline-2,9-diacid and o-phenylenediamine to polyphosphorus, and performing reaction I to obtain 2,9-bis(1-hydrogen-benzimidazole-2-yl)-1,10-phenanthroline; S2, reacting a mixture containing 2,9-bis(1-hydrogen-benzimidazol-2-yl)-1,10-phenanthroline and 1-fluoro-4-nitro-2-trifluoromethylbenzene, catalyst I, and solvent I with II to obtain a dinitro compound 2,9-bis(1-(4-nitro-2-trifluoromethyl)-phenyl)-1-hydrogen-benzimidazol-2-yl-1,10-phenanthroline; S3, under an inert atmosphere, reacting a mixture containing a dinitro compound 2,9-bis(1-(4-nitro-2-trifluoromethyl)-phenyl)-1 hydrogen-benzimidazol-2-yl-1,10-phenanthroline, a catalyst II, a reducing agent, and a solvent II with III to obtain a diamine monomer 4,4'-((1 10-phenanthroline-2 9-diyl)bis(1 hydrogen-benzimidazol-yl))bis(3-(trifluoromethyl)aniline; S4, under an inert atmosphere, reacting a mixture containing a diamine monomer 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1 hydrogen-benzimidazole-yl))bis(3-(trifluoromethyl)aniline, a dianhydride monomer containing an Ar structure, a diamine monomer containing an M structure, and a solvent III, and then adding a catalyst III to the product, continuing to react IV-b, and then adding ethanol to the product to form a precipitate to obtain the phenanthroline benzimidazole structure polyimide; S5, adding rare earth metal chloride and an organic small molecule ligand with a β-diketone structure to the alkaline mixed solution, reacting IV, and obtaining a small molecule rare earth complex; S6, mixing the phenanthroline benzimidazole structure polyimide and the small molecule rare earth complex in solvent IV, and coordinating them to obtain the phenanthroline benzimidazole structure polyimide single rare earth ion coordinated acid responsive data encryption material.

8. The preparation method according to claim 7, It is characterized in that In step S1, the molar ratio of 1,10-phenanthroline-2,9-diacid to o-phenylenediamine is 1:2.0-2.2; Preferably, in step S1, the conditions of reaction I include: reaction temperature of 200-240° C., reaction time of 5-8 h; Preferably, in step S2, the molar ratio of 2,9-bis(1-hydrogen-benzimidazol-2-yl)-1,10-phenanthroline to 1-fluoro-4-nitro-2-trifluoromethylbenzene is 1:2.0-2.2; Preferably, in step S2, the conditions of reaction II include: reaction temperature of 80 to 120° C., reaction time of 12 to 24 h; Preferably, in step S2, the catalyst I is selected from at least one of potassium carbonate, cesium carbonate and calcium carbonate; Preferably, in step S2, solvent I is selected from at least one of N-methylpyrrolidone, NN-dimethylformamide, and NN-dimethylacetamide; Preferably, in step S3, catalyst II is a 5% dry palladium carbon catalyst (Pb / C catalyst, Pd loading is 5%); Preferably, in step S3, the amount of catalyst II used is 8 to 12% by weight of the dinitro compound; Preferably, in step S3, the reducing agent is 85% hydrazine hydrate (85% N 2 H 4 ·H 2 O); Preferably, in step S3, the amount of the reducing agent is 5 to 10 times the weight of the dinitro compound; Preferably, in step S3, the conditions of reaction III include: reaction temperature of 80 to 120° C., reaction time of 12 to 24 h; Preferably, in step S3, solvent II is selected from at least one of ethanol, NN-dimethylformamide, and NN-dimethylacetamide; Preferably, in step S4, the ratio of the diamine monomer 4,4'-((1,10-phenanthroline-2,9-diyl)bis(1-hydrogen-benzimidazole-yl))bis(3-(trifluoromethyl)aniline, the dianhydride monomer containing the Ar structure, and the diamine monomer containing the M structure is 1:1:1; Preferably, in step S4, the catalyst III is selected from isoquinoline; Preferably, in step S4, the conditions of reaction IV-a include: reaction time at 80°C to 90°C for 1 to 2 h; Preferably, in step S4, the conditions of reaction IV-b include: reaction time at 150°C to 160°C for 2 to 4 hours, then heating to 190°C to 200°C for 12 to 18 hours; Preferably, in step S4, the solvent III is selected from at least one of m-cresol, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; Preferably, in step S5, the molar ratio of the rare earth metal chloride salt to the organic small molecule ligand of the compound β-diketone structure is 1:3 to 3.1; Preferably, in step S5, the conditions for reaction V include: heating to 60° C., reacting at this temperature for 0.5 to 4 hours, and cooling naturally under continuous stirring after the reaction until precipitation is complete; Preferably, in step S5, the pH of the alkaline mixed solution is greater than or equal to 8, and the alkaline mixed solution includes a mixed solution of ethanol and water, and the volume ratio of the ethanol to water is 1:8-20; Preferably, in step S6, the molar ratio of the small molecule rare earth metal complex to the phenanthroline imidazole group in the phenanthroline benzimidazole structure polyimide is 0.1 to 0.3:1; Preferably, in step S6, the conditions of reaction VI include: reaction temperature of 50 to 120° C., reaction time of 8 to 15 h; Preferably, solvent IV is selected from at least one of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone.

9. Use of the phenanthroline benzimidazole structure polyimide single rare earth ion coordinated acid responsive data encryption material according to any one of claims 1 to 6, or the phenanthroline benzimidazole structure polyimide single rare earth ion coordinated acid responsive data encryption material prepared according to the preparation method according to any one of claims 7 to 9 in polymer acid responsive data encryption materials.

10. The use according to claim 9, It is characterized in that The phenanthroline benzimidazole structure polyimide single rare earth ion coordinated acid response data encryption material realizes acid response data encryption under the action of proton acid; By adjusting the amount of proton acid added, the interaction between proton acid and the imidazole group and the β-diketone organic small molecule ligand in the phenanthroline benzimidazole structure polyimide is controlled to affect the sensitization characteristics of rare earth ions, and different fluorescence emission spectra of the data encryption material that responds to the single rare earth ion coordination acid of the phenanthroline benzimidazole structure polyimide are achieved; The acid response data encryption method is shown in Formula V: Among them, H + It is a protonic acid, and the protonic acid is selected from organic acids and inorganic acids.

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