A pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescent composite material

Abstract

The present application relates to the technical field of fluorescent liquid crystal, and particularly relates to a liquid crystal polymer-aggregation induced emission molecule fluorescent composite material with pH response, which comprises an SLCP film and TPE-4amidine; amidine groups on the TPE-4amidine are responsive to pH, so that the fluorescence of the material changes; the SLCP film contains hydrogen bond structures with carboxyl groups, which are easily reversibly deconstructed under high temperature or alkaline solution treatment, forming regular transverse pore structures. With the help of the SLCP film as the main body, the electrostatic interaction in the SLCP film can be accurately controlled by adjusting the pH, the fluorescent molecules are adsorbed and self-assembly structures are formed, realizing the reversible change of the fluorescent color of the liquid crystal polymer-aggregation induced emission molecule fluorescent composite material from yellow green to blue, which not only breaks through the application limitation of the traditional liquid crystal unit, but also enhances the stimulus response of the material due to the porous structure, and has wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of fluorescent liquid crystal technology, and more particularly to a pH-responsive liquid crystal polymer-aggregation-induced emission molecule fluorescent composite material. Background Technology

[0002] Fluorescent compounds exhibit internal filtration and self-absorption; molecular aggregation easily induces fluorescence quenching, known as aggregation-induced fluorescence quenching (ACQ). Generally, the solution needs to be diluted to a concentration less than 10%. -5 Accurate spectra of fluorescent molecules can only be obtained at concentrations of mol / L, and low concentrations severely limit the practical application of fluorescence sensors. Researchers typically avoid molecular aggregation by selecting fluorophores with high fluorescence quantum efficiency, introducing flexible groups such as alkyl chains to address π-π stacking and material dissolution issues, and designing sterically hindered molecular structures such as dendrites to impede aggregation. In 2001, Tang Benzhong's research group first proposed the AIE (aggregation-induced emission) mechanism. They discovered that fluorescent substances containing groups such as 1-methyl-1,2,3,4,5-tetraphenylthiophene, substituted styrene, 9,10-stilbeneylanthracene, and tetraphenylethylene exhibit non-fluorescence or low fluorescence in solution. However, in the aggregated state, intramolecular motion is restricted, suppressing energy decay in non-radiative channels and eliminating torsional intramolecular charge transfer (TICT) and J-aggregation, thus producing strong fluorescence. Aggregation-induced emission expands the application range of fluorescence sensors from detection only in dilute solutions to detection of aggregates.

[0003] Significant progress has been made in the study of AIE small molecules, and research on polymer materials with AIE properties has become increasingly widespread. When AIE motifs are introduced into a polymer matrix, the polymer chains inhibit the molecular motion of AIE structural units, resulting in higher luminescence efficiency. Compared to AIE small molecules, AIE polymers exhibit better plasticity, heat resistance, and corrosion resistance. Furthermore, through various synthetic strategies, specific functional groups can be introduced into polymer chains, thereby obtaining polymer materials that exhibit fluorescence responses to external stimuli (light, force, acids, alkalis, heat), greatly expanding their applications in stimulus-responsive materials, metal ion detection, and biomedicine.

[0004] For example, patent document CN115677890A discloses a dendritic fluorescent liquid crystal polymer with aggregation-induced emission properties and its preparation method. First, a dendritic fluorescent monomer molecule I with AIE effect is synthesized, and then the corresponding dendritic fluorescent liquid crystal polymer II is synthesized by free radical polymerization. This type of dendritic fluorescent liquid crystal polymer material has high temperature resistance and good processing performance, but it cannot guarantee the sensitivity and reversibility of pH response.

[0005] Therefore, based on the relevant technologies mentioned above, there is an urgent need to develop a pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescent composite material. Summary of the Invention

[0006] In view of this, the purpose of this invention is to propose a pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescence composite material to solve the problems of pH sensitivity and reversibility of aggregation-induced emission molecular fluorescence composite materials in the prior art.

[0007] To achieve the above objectives, the present invention provides a pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescent composite material.

[0008] A pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescence composite material, comprising an SLCP film and TPE-4amidine;

[0009] The SLCP membrane has a hydrogen bond structure containing carboxyl groups;

[0010] The structural formula of TPE-4amidine is as follows:

[0011]

[0012] Preferably, the SLCP membrane is prepared as follows:

[0013] Step A1: Mix the monomer and crosslinking agent, then add the photoinitiator and polymerization inhibitor, dissolve them together in dichloromethane, and heat at 50-70℃ for 3-5 hours under light-protected conditions to obtain a liquid crystal monomer mixture;

[0014] Step A2: Fill the liquid crystal monomer mixture into the liquid crystal cell, let it stand at 90-100℃ for 3-8 minutes in a yellow light environment without ultraviolet light, then irradiate it with a point light source with a wavelength of 365nm for 3-8 minutes, and then further cure it at 135℃ for 2-5 hours to obtain the SLCP film.

[0015] Preferably, the structural formula of the monomer described in step A1 is as follows:

[0016]

[0017] The crosslinking agent has the following structural formula:

[0018]

[0019] The structural formula of the photoinitiator is as follows:

[0020]

[0021] The polymerization inhibitor is p-methoxyphenol.

[0022] Preferably, the ratio of monomer, crosslinking agent, photoinitiator, polymerization inhibitor and dichloromethane in step A1 is 0.8-1g: 0.1-0.2g: 8-12mg: 0.1-0.5mg: 10-12mL.

[0023] Preferably, the amount of the liquid crystal monomer mixture used in step A2 is 0.8-1.2g.

[0024] Preferably, the preparation method of TPE-4amidine is as follows:

[0025] Step B1: Add zinc powder and tetrahydrofuran to a 500mL flask, place the flask in an ice-salt bath and stir for 20-30 minutes. Under nitrogen protection and at 0-2℃, slowly add titanium tetrachloride dropwise to the flask, stir at room temperature for 8-10 minutes, and then reflux at 40-50℃ for 20-30 minutes to obtain the pretreated solution.

[0026] Step B2: Pyridine and 4,4'-diaminobenzophenone were added to the pretreatment solution and refluxed at 40-50℃ for 22-26 h. After cooling to room temperature, the mixture was evaporated at 110-115℃ for 20-30 min, dissolved in water, extracted twice with dichloromethane, and purified by column chromatography using dichloromethane and petroleum ether as eluents to obtain intermediate A.

[0027] Step B3: Intermediate A, 1,1-dimethoxy-N,N-dimethylethylamine and methanol are mixed and stirred at 60-80°C under a nitrogen atmosphere for 10-12 hours. After purification by silica gel column chromatography using dichloromethane and petroleum ether, the mixture is heated under vacuum at 60-80°C for 6-8 hours to obtain TPE-4amidine.

[0028] Preferably, the ratio of zinc powder, tetrahydrofuran, and titanium tetrachloride used in step B1 is 10-15g: 300-350mL: 8-10mL.

[0029] Preferably, the ratio of pyridine, 4,4'-diaminobenzophenone and pretreatment solution in step B2 is 3-5 mL: 4-6 g: 300-350 mL;

[0030] The volume ratio of dichloromethane to petroleum ether in step B2 is 1:3;

[0031] The structural formula of intermediate A is as follows:

[0032]

[0033] Preferably, the ratio of intermediate A, 1,1-dimethoxy-N,N-dimethylethylamine, and methanol in step B3 is 0.08-0.3 g : 0.1-0.4 g : 0.1-0.3 mL;

[0034] The volume ratio of dichloromethane to petroleum ether in step B3 is 3:1.

[0035] Preferably, the preparation method of the pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescence composite material is as follows:

[0036] After adding 2-5 mL of pH 12 phosphate buffer to the SLCP membrane, rinse the SLCP membrane with distilled water. Prepare a 10% concentration of TPE-4amidine solution. -4 A mol / L solution was coated onto an SLCP membrane and allowed to stand for 6-8 hours to obtain a pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescent composite material.

[0037] The beneficial effects of this invention are:

[0038] This invention designs and synthesizes a novel aggregation-induced emission molecule, TPE-4amidine, containing four amidine groups, as a guest, and integrates it into the network of a hydrogen-bonded SLCP membrane to achieve self-assembly, forming a pH-responsive smectic liquid crystal polymer-aggregation-induced emission molecule fluorescent composite material.

[0039] This invention provides a pH-responsive liquid crystal polymer-aggregation-induced emission (ALPE) fluorescent composite material. The amidine group on TPE-4amidine responds to pH, resulting in a change in the material's fluorescence. The SLCP membrane contains a carboxyl group hydrogen bond structure, which readily and reversibly deconstructs under high temperature or alkaline solution treatment, forming a regular transverse porous structure. Using this SLCP membrane as the host, the electrostatic interactions within the SLCP membrane can be precisely controlled by adjusting the pH, adsorbing fluorescent molecules and forming a self-assembled structure. This achieves a reversible change in fluorescence color from yellow-green to blue in the pH-responsive liquid crystal polymer-aggregation-induced emission (ALPE) fluorescent composite material. This not only overcomes the application limitations of traditional liquid crystal units, but its porous structure also enhances the material's stimulus responsiveness, showing broad application prospects. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a synthetic route diagram of TPE-4amidine in this invention;

[0042] Figure 2 This is the hydrogen nuclear magnetic resonance spectrum of intermediate A in this invention;

[0043] Figure 3 This is the carbon NMR spectrum of intermediate A in this invention;

[0044] Figure 4 The 1H NMR spectrum of TPE-4amidine in this invention;

[0045] Figure 5 This is the carbon NMR spectrum of TPE-4amidine in this invention;

[0046] Figure 6 Different water contents (10) in Example 1 of the present invention -4 Fluorescence spectrum of mol / L LTPE-4amidine solution;

[0047] Figure 7 This is a differential scanning calorimetry (DSC) curve of the liquid crystal monomer mixture in Embodiment 1 of the present invention;

[0048] Figure 8 These are photographs of the pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescent composite material in Example 1 of the present invention after being treated with phosphate buffer solutions at different pH values.

[0049] Figure 9 This is a patterned application diagram of the SLCP film in Embodiment 1 of the present invention. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0051] The sources and properties of some of the raw materials used in this invention are as follows:

[0052] 4,4'-Diaminobenzophenone was purchased from Shanghai Hansi Chemical Co., Ltd.; 1,1-Dimethoxy-N,N-Dimethylethylamine was purchased from Hubei Xinhongli Chemical Co., Ltd.

[0053] Example 1: A pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescent composite material, comprising the following steps:

[0054] S1: Mix 0.8-1g of monomer and 0.1-0.2g of crosslinking agent, then add 8-12mg of photoinitiator and 0.1-0.5mg of polymerization inhibitor, dissolve them together in 10-12mL of dichloromethane, and heat at 50-70℃ for 3-5h under light-protected conditions to obtain a liquid crystal monomer mixture;

[0055] S2: 0.8g of liquid crystal monomer mixture was filled into the liquid crystal cell, and after standing at 90°C for 3 minutes in a yellow light environment without ultraviolet light, it was irradiated with a point light source with a wavelength of 365nm for 3 minutes, and then further cured at 135°C for 2 hours to obtain the SLCP film.

[0056] S3: In a 500mL flask, add 10g of zinc powder and 300mL of tetrahydrofuran. Place the flask in an ice-salt bath and stir for 20min. Under nitrogen protection and at 0℃, slowly add 8mL of titanium tetrachloride dropwise to the flask. Stir at room temperature for 8min, then reflux at 40℃ for 20min to obtain the pretreated solution.

[0057] S4: Add 3 mL of pyridine and 4 g of 4,4'-diaminobenzophenone to 300 mL of pretreatment solution, reflux at 40 °C for 22 h, cool to room temperature, evaporate at 110 °C for 20 min, dissolve in water, extract twice with dichloromethane, and purify by column chromatography using dichloromethane and petroleum ether as eluents to obtain intermediate A, wherein the volume ratio of dichloromethane to petroleum ether is 1:3;

[0058] S5: Mix 0.08 g intermediate A, 0.1 g 1,1-dimethoxy-N,N-dimethylethylamine and 0.1 mL methanol, stir at 60 °C under nitrogen atmosphere for 10 h, purify by silica gel column chromatography using dichloromethane and petroleum ether, and heat at 60 °C under vacuum for 6 h to obtain TPE-4amidine, wherein the volume ratio of dichloromethane to petroleum ether is 3:1;

[0059] S6: Add 2 mL of pH 12 phosphate buffer to the SLCP membrane, then rinse the SLCP membrane with distilled water. Prepare TPE-4amidine to a concentration of 10. -4 A mol / L solution was coated onto an SLCP membrane and allowed to stand for 8 hours to obtain a pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescent composite material.

[0060] Example 2: A pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescent composite material, comprising the following steps:

[0061] S1: Mix 0.8-1g of monomer and 0.1-0.2g of crosslinking agent, then add 8-12mg of photoinitiator and 0.1-0.5mg of polymerization inhibitor, dissolve them together in 10-12mL of dichloromethane, and heat at 50-70℃ for 3-5h under light-protected conditions to obtain a liquid crystal monomer mixture;

[0062] S2: 0.9g of liquid crystal monomer mixture was filled into the liquid crystal cell, and after standing at 94°C for 5 minutes in a yellow light environment without ultraviolet light, it was irradiated with a point light source with a wavelength of 365nm for 5 minutes, and then further cured at 135°C for 3 hours to obtain the SLCP film.

[0063] S3: In a 500mL flask, add 12g of zinc powder and 320mL of tetrahydrofuran. Place the flask in an ice-salt bath and stir for 24min. Under nitrogen protection, slowly add 8.5mL of titanium tetrachloride dropwise to the flask at 0.5℃. Stir at room temperature for 8.5min, then reflux at 44℃ for 24min to obtain the pretreated solution.

[0064] S4: Add 3.5 mL of pyridine and 4.5 g of 4,4'-diaminobenzophenone to 320 mL of pretreatment solution, reflux at 44 °C for 23 h, cool to room temperature, evaporate at 112 °C for 24 min, dissolve in water, extract twice with dichloromethane, and purify by column chromatography using dichloromethane and petroleum ether as eluents to obtain intermediate A, wherein the volume ratio of dichloromethane to petroleum ether is 1:3;

[0065] S5: Mix 0.1g intermediate A, 0.2g 1,1-dimethoxy-N,N-dimethylethylamine and 0.15mL methanol, stir at 60-80℃ under nitrogen atmosphere for 10.5h, purify by silica gel column chromatography using dichloromethane and petroleum ether, and heat at 64℃ under vacuum for 6.5h to obtain TPE-4amidine, wherein the volume ratio of dichloromethane to petroleum ether is 3:1;

[0066] S6: Add 3 mL of pH 12 phosphate buffer to the SLCP membrane, then rinse the SLCP membrane with distilled water. Prepare TPE-4amidine to a concentration of 10. -4 A mol / L solution was coated onto an SLCP membrane and allowed to stand for 6.5 h to obtain a pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescent composite material.

[0067] Example 3: A pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescence composite material, comprising the following steps:

[0068] S1: Mix 0.8-1g of monomer and 0.1-0.2g of crosslinking agent, then add 8-12mg of photoinitiator and 0.1-0.5mg of polymerization inhibitor, dissolve them together in 10-12mL of dichloromethane, and heat at 50-70℃ for 3-5h under light-protected conditions to obtain a liquid crystal monomer mixture;

[0069] S2: 1.1g of liquid crystal monomer mixture was filled into the liquid crystal cell, and after standing at 98°C for 7 minutes in a yellow light environment without ultraviolet light, it was irradiated with a point light source with a wavelength of 365nm for 7 minutes, and then further cured at 135°C for 4 hours to obtain the SLCP film.

[0070] S3: In a 500mL flask, add 14g of zinc powder and 340mL of tetrahydrofuran. Place the flask in an ice-salt bath and stir for 28min. Under nitrogen protection, at 1℃, slowly add 9mL of titanium tetrachloride dropwise to the flask. Stir at room temperature for 9min, then reflux at 48℃ for 28min to obtain the pretreated solution.

[0071] S4: Add 4 mL of pyridine and 5 g of 4,4'-diaminobenzophenone to 340 mL of pretreatment solution, reflux at 48 °C for 25 h, cool to room temperature, evaporate at 114 °C for 28 min, dissolve in water, extract twice with dichloromethane, and purify by column chromatography using dichloromethane and petroleum ether as eluents to obtain intermediate A, wherein the volume ratio of dichloromethane to petroleum ether is 1:3;

[0072] S5: Mix 0.2g intermediate A, 0.3g 1,1-dimethoxy-N,N-dimethylethylamine and 0.2mL methanol, stir at 68℃ under nitrogen atmosphere for 11h, purify by silica gel column chromatography using dichloromethane and petroleum ether, and heat at 78℃ under vacuum for 7h to obtain TPE-4amidine, wherein the volume ratio of dichloromethane to petroleum ether is 3:1;

[0073] S6: Add 4 mL of pH 12 phosphate buffer to the SLCP membrane, then rinse the SLCP membrane with distilled water. Prepare TPE-4amidine to a concentration of 10. -4 A mol / L solution was coated onto an SLCP membrane and allowed to stand for 7 hours to obtain a pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescent composite material.

[0074] Example 4: A pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescent composite material, comprising the following steps:

[0075] S1: Mix 1g of monomer and 0.2g of crosslinking agent, then add 12mg of photoinitiator and 0.5mg of polymerization inhibitor, dissolve them together in 12mL of dichloromethane, heat at 70℃ for 5h under light-protected conditions to obtain a liquid crystal monomer mixture;

[0076] S2: 1.2g of liquid crystal monomer mixture was filled into the liquid crystal cell, and after standing at 100°C for 8 minutes in a yellow light environment without ultraviolet light, it was irradiated with a point light source with a wavelength of 365nm for 8 minutes, and then further cured at 135°C for 5 hours to obtain the SLCP film.

[0077] S3: In a 500mL flask, add 15g of zinc powder and 350mL of tetrahydrofuran. Place the flask in an ice-salt bath and stir for 30min. Under nitrogen protection, at 2℃, slowly add 10mL of titanium tetrachloride dropwise to the flask. Stir at room temperature for 10min, then reflux at 50℃ for 30min to obtain the pretreated solution.

[0078] S4: Add 5 mL of pyridine and 6 g of 4,4'-diaminobenzophenone to 350 mL of pretreatment solution, reflux at 50 °C for 26 h, cool to room temperature, evaporate at 115 °C for 30 min, dissolve in water, extract twice with dichloromethane, and purify by column chromatography using dichloromethane and petroleum ether as eluents to obtain intermediate A, wherein the volume ratio of dichloromethane to petroleum ether is 1:3;

[0079] S5: Mix 0.3g intermediate A, 0.4g 1,1-dimethoxy-N,N-dimethylethylamine and 0.3mL methanol, stir at 80℃ under nitrogen atmosphere for 12h, purify by silica gel column chromatography using dichloromethane and petroleum ether, and heat at 80℃ under vacuum for 8h to obtain TPE-4amidine, wherein the volume ratio of dichloromethane to petroleum ether is 3:1;

[0080] S6: Add 2-5 mL of pH 12 phosphate buffer to the SLCP membrane, then rinse the SLCP membrane with distilled water. Prepare TPE-4amidine to a concentration of 10. -4 A mol / L solution was coated onto an SLCP membrane and allowed to stand for 6-8 hours to obtain a pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescent composite material.

[0081] Performance testing:

[0082] Fluorescence tests at different water contents:

[0083] The TPE-4amidine prepared in Example 1 was dissolved in dimethylformamide to prepare a solution with a concentration of 10. - 2A stock solution of mol / L was prepared. Then, the stock solution was mixed with different proportions of dimethylformamide and water to prepare concentrations of 10 with different water contents (0%, 10%...80%, 90%, 99%). -4 A mol / L solution was prepared and its fluorescence properties were tested.

[0084] When the water content is between 0% and 60%, the fluorescence of TPE-4amidine is very weak and almost imperceptible. However, as the water content gradually increases from 70% to 99%, the fluorescence intensity of the solution increases significantly, with a maximum emission wavelength of 468 nm, and the overall fluorescence appears blue.

[0085] When the SLCP membrane treated with alkali was added to a TPE-4amidine solution with strong fluorescence, the fluorescence intensity of the solution decreased by 10 times, and the SLCP membrane changed from a non-fluorescent state to a thin film with strong green fluorescence.

[0086] Phase transition test:

[0087] Take 20 mg of the liquid crystal monomer mixture from Example 1, preheat the differential scanning calorimeter to the operating temperature, and ensure accurate instrument calibration. Place the liquid crystal monomer mixture from Example 1 and the reference material into the sample crucible of the differential scanning calorimeter, set the heating rate to 10 °C / min, heat to 150 °C, and start the differential scanning calorimeter. The instrument will heat the sample according to the preset temperature program, while monitoring and recording the heat difference between the sample and the reference material.

[0088] Differential scanning calorimetry (DSC) analysis showed that the prepared liquid crystal mixture underwent a phase transformation into a smectic liquid crystal at 88℃, transformed into a nematic phase at 104.64℃, and finally reached an isotropic state upon further heating.

[0089] Fluorescence reversibility test:

[0090] Two drops of alkaline phosphate buffer were added to the pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescence composite material prepared in Example 1, and its fluorescence color was observed. Then, the surface of the pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescence composite material was wiped clean, two drops of acidic phosphate buffer were added, and its fluorescence color was observed. The test was repeated 8 times.

[0091] The test results show that after adding alkaline phosphate buffer, the fluorescence color changed from green to yellow-green; while when adding acidic phosphate buffer, the fluorescence color turned blue. After multiple cycles of introducing acid and alkali, the fluorescence color continued to cycle between yellow-green and blue. This may be because TPE-4amidine exhibits fluorescence quenching under alkaline conditions, resulting in a decrease in fluorescence intensity. However, the SLCP film in the pH-responsive liquid crystal polymer-aggregation-induced emission molecular fluorescence composite material can accurately control the electrostatic interactions within the SLCP film by adjusting the pH, adsorbing fluorescent molecules and forming self-assembled structures, which can enhance the fluorescence intensity and emit green fluorescence. Based on this, by adjusting the pH value of different parts of the fluorescent molecule composite material, information conversion applications of different fluorescence signals in the same sample can be realized.

[0092] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

[0093] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A pH-responsive liquid crystal polymer-aggregation induced emission molecule fluorescent composite material, characterized in that, The SLCP film and the TPE-4amidine are included; The SLCP film is a hydrogen bond structure containing a carboxyl group; The structure of the TPE-4amidine is as follows: ； The preparation method of the SLCP film is as follows: Step A1: mix the monomer and the crosslinking agent, then add the photoinitiator and the polymerization inhibitor, and dissolve them in dichloromethane, heat at 50-70 DEG C for 3-5 h in the dark, and obtain a liquid crystal monomer mixture; Step A2: fill the liquid crystal monomer mixture into a liquid crystal cell, irradiate it with a point light source with a wavelength of 365 nm for 3-8 min in a yellow light environment without ultraviolet light, and then further cure it at 135 DEG C for 2-5 h, and obtain a SLCP film; The structure of the monomer in step A1 is as follows: ； The structure of the crosslinking agent is as follows: ； The structure of the photoinitiator is as follows: ； The polymerization inhibitor is p-methoxyphenol.

2. The pH-responsive liquid crystal polymer-aggregation induced emission molecule fluorescent composite material according to claim 1, characterized in that, The amount ratio of the monomer, the crosslinking agent, the photoinitiator, the polymerization inhibitor and dichloromethane in step A1 is 0.8-1 g: 0.1-0.2 g: 8-12 mg: 0.1-0.5 mg: 10-12 mL.

3. The pH-responsive liquid crystalline polymer-aggregation-induced emission molecule fluorescent composite material of claim 1, wherein, The amount of the liquid crystal monomer mixture in step A2 is 0.8-1.2 g.

4. The pH-responsive liquid crystal polymer-aggregation-induced emission molecule fluorescent composite material according to any one of claims 1-3, characterized in that, The preparation method of the liquid crystal polymer-aggregation-induced emission molecule fluorescent composite material with pH response is as follows: After 2-5 mL of phosphate buffer solution with pH=12 was dropped on the SLCP film, the SLCP film was washed with distilled water, a TPE-4 amidine solution with a concentration of 10 -4 mol / L was coated on the SLCP film, and was left for 6-8 h to obtain a liquid crystal polymer-aggregation-induced emission molecule fluorescent composite material with pH response.

Images