Preparation and application of hydrothermal stimulation responsive room-temperature phosphorescent wood film

Abstract

The invention discloses preparation and application of a hydrothermal stimulus-responsive room-temperature phosphorescent wood film. The wood film is prepared by the following steps: preparing a wood substrate from the wood substrate and phosphorescent molecules according to a mass ratio of (14-100): 1; carrying out special treatment on the wood substrate to remove lignin and purifying to obtain a delignification wood film; the phosphorescent molecule is 1-pyrene boronic acid. The room-temperature phosphorescent wood film prepared by the invention has remarkably enhanced environmental responsiveness and rich selectivity, and successfully realizes high sensitivity to humidity and water vapor. Meanwhile, the phosphorescence efficiency and stability are effectively improved, the phosphorescence emission efficiency is improved by about 50% compared with that of a traditional material, and the long-term stability is also greatly enhanced. Even after multiple environmental response cycles, the phosphorescence performance of the material can still be kept at a high level, and the actual application requirements are met. The room-temperature phosphorescent wood film prepared by the invention is wide in application field, and has wide application prospects in multiple fields such as humidity detection, information security, artwork protection, product authentication, security and counterfeiting prevention and the like.

Description

Technical Field

[0001] The present application relates to the technical field of luminescent materials, and in particular to the preparation and application of a hydrothermal stimulus responsive room temperature phosphorescent wood film. Background Art

[0002] In the field of materials science, stimuli-responsive functional materials have attracted much attention because they can show specific changes in physical or chemical properties when the external environment (such as light, heat, humidity, etc.) changes. Such materials have broad application potential in many fields such as sensors, information storage, anti-counterfeiting technology, and smart packaging. Among them, room temperature phosphorescent materials, as a special material that can emit phosphorescence at room temperature, have become a research hotspot in recent years due to their unique optical properties and long-life luminescence characteristics.

[0003] Traditional phosphorescent materials are often based on inorganic or organic compounds and are made by specific synthesis methods. Although these materials have phosphorescent properties, they often need to be stable at low temperatures to emit light, and their responsiveness to environmental stimuli is limited. In addition, inorganic phosphorescent materials usually have problems such as high cost and difficult processing, while organic phosphorescent materials may face challenges such as poor stability and high toxicity. In recent years, researchers have begun to try to use natural materials (such as cellulose, lignin, etc.) as matrices and give them phosphorescent properties by introducing functional molecules. This method not only reduces costs, but also improves the biocompatibility and sustainability of materials. However, most of the current phosphorescent modification research based on natural materials is still in the laboratory stage, and the phosphorescent efficiency is low, and the responsiveness to environmental stimuli also needs to be further improved. Humidity-sensitive materials are a type of material that can respond to changes in environmental humidity and exhibit specific property changes. In the prior art, a variety of humidity-sensitive materials based on polymers, ceramics or metal oxides have been developed. These materials have been widely used in humidity sensors, environmental monitoring and other fields. However, these materials often do not have phosphorescent properties, and their humidity response mechanisms are significantly different from the hydrothermal stimulus responsive room temperature phosphorescent wood film described in the present invention.

[0004] As a renewable resource, wood has excellent physical and mechanical properties and biocompatibility. In recent years, researchers have successfully transformed wood into materials with specific functionalities through chemical modification and physical treatment. For example, delignification can improve the transparency and mechanical strength of wood; the introduction of functional molecules can give wood new optical, electrical or magnetic properties. However, there are no reports on the modification of wood into materials with hydrothermal stimulus responsive room temperature phosphorescence properties.

[0005] In summary, although the prior art has made some progress in the preparation of phosphorescent materials, the development of humidity-sensitive materials, and the modification of wood-based materials, there are still many shortcomings. The "hydrothermal stimulus responsive room temperature phosphorescent wood film" of the present invention came into being in this context, aiming to realize a new type of functional material through innovative preparation methods and material design to meet the growing application needs. Summary of the invention

[0006] In view of the above shortcomings, the purpose of the present invention is to provide an environmentally responsive phosphorescent wood film based on a wood matrix and a preparation method thereof, so as to solve the problems of insufficient environmental responsiveness, limited matrix selection, low phosphorescence efficiency and poor stability, high cost, etc. in the prior art. The present invention is achieved by the following technical means:

[0007] A hydrothermal stimulus responsive room temperature phosphorescent wood film, comprising:

[0008] A wood matrix and phosphorescent molecules; wherein:

[0009] The mass ratio of the wood substrate to the phosphorescent molecule is 14 to 100:1;

[0010] The wood substrate is specially treated to remove lignin and purified to obtain a delignified wood film;

[0011] The phosphorescent molecule is 1-pyreneboronic acid.

[0012] Furthermore, the thickness of the delignified wood film is 0.1-0.7 mm.

[0013] Furthermore, when the 1-pyrene boric acid is taken at 2.5 mg, the amount of delignified wood film can be 35 mg, 50 mg, 60 mg, 100 mg, 150 mg, 200 mg, or 250 mg.

[0014] A method for preparing a hydrothermal stimulus responsive room temperature phosphorescent wood film, comprising:

[0015] (1) Wood matrix pretreatment

[0016] Selecting basswood, silver oak, balsa wood and maple wood films as raw materials, removing lignin through chemical treatment (such as treatment with a composite solution formed by a sodium chlorite solution and an acid) to obtain delignified wood;

[0017] The delignified wood is deeply purified by soaking it in deionized water for 5 minutes to remove the chemical substances remaining in the pores of the wood film during the delignification process, and then soaking it in ethanol and acetone for 5 minutes respectively to fully fill the pores of the wood film with organic solvents, and finally immersing the wood film in toluene / ultra-dry chlorobenzene / chlorobenzene / o-dichlorobenzene / m-dichlorobenzene for 1-5 minutes until the wood film completely reaches a transparent state in the solution, thereby obtaining a pretreated wood matrix;

[0018] (2) Introduction of phosphorescent molecules

[0019] Dissolve 2.5 mg (or adjust the amount as needed) of 1-pyreneboronic acid (Py-BOH) in a mixed solvent consisting of 4 mL of ethanol and 1 mL of aqueous ammonia, and stir to form a reaction solution;

[0020] The pretreated wood substrate (e.g., with a thickness of 0.2 mm and a size of 1.5*1.5 cm) is placed in a reaction solution and subjected to an ultrasonic reaction, and the reaction conditions are controlled (ultrasonic temperature 45° C., reaction time 15 min) so that the 1-pyreneboric acid molecules react chemically with the cellulose in the wood substrate to form a stable chemical bond, thereby obtaining a semi-finished wood film;

[0021] After the reaction is completed, the semi-finished wood film is repeatedly washed with deionized water to remove unreacted phosphorescent molecules, and heated on a heating table at 60-80°C for 3-10 minutes to remove the solvent in the pores of the wood film. Generally, the wood film can be removed from the heating table when it turns uniformly white under naked eye observation, thus obtaining a hydrothermal stimulus responsive room temperature phosphorescent wood film.

[0022] Furthermore, the drying temperature is 70° C. or 75° C.; and the drying time is 5 minutes.

[0023] The invention also discloses a hydrothermal stimulation responsive room temperature phosphorescent wood film prepared according to any one of the above preparation methods.

[0024] The invention also discloses an application of the hydrothermal stimulation responsive room temperature phosphorescent wood film in the preparation of a high-sensitivity humidity sensor.

[0025] Furthermore, the highly sensitive humidity sensor can be used for humidity detection in the fields of environmental monitoring, agricultural irrigation, smart home, etc.

[0026] The present invention also discloses an application of the above-mentioned hydrothermal stimulation responsive room temperature phosphorescent wood film in the field of information security. In the fields of artwork protection, product authentication, security and anti-counterfeiting, information can be unlocked or hidden through specific environmental stimulation (such as humidity changes), thereby realizing encryption and decryption of information.

[0027] The beneficial effects of the present invention are:

[0028] 1. The room temperature phosphorescent wood film prepared by the present invention has significantly enhanced environmental responsiveness: by introducing the phosphorescent molecule 1-pyreneboric acid into the wood matrix in a chemically bonded manner, the present invention successfully achieves high sensitivity to humidity and water vapor. Experimental results show that when the material is in different humidity environments, its phosphorescent emission intensity can change significantly, and this change is reversible. This feature makes the material of the present invention have extremely high application value in the fields of humidity monitoring and environmental monitoring, and can accurately respond to environmental changes and provide reliable data support for related fields. Compared with traditional materials, the environmental responsiveness of the present invention is improved by at least 30%, and the response speed is faster and the stability is higher.

[0029] 2. The material matrix of the room temperature phosphorescent wood film prepared by the present invention has rich selectivity: The present invention innovatively uses wood as the matrix material, breaking the limitations of traditional phosphorescent materials in matrix selection. Wood, as a natural renewable resource, is not only low-cost, but also has good biocompatibility and environmental friendliness. This choice not only enriches the types of phosphorescent wood films, but also promotes the green and sustainable development of materials. In addition, the porous structure of wood provides abundant binding sites for the introduction of phosphorescent molecules, which helps to improve the overall performance of the material.

[0030] 3. The phosphorescence efficiency and stability of the room temperature phosphorescent wood film prepared by the present invention are effectively improved: by optimizing the selection and introduction method of phosphorescent molecules, and deeply pretreating and purifying the wood matrix, the present invention significantly improves the dispersion uniformity and binding stability of phosphorescent molecules in the matrix. This improvement makes the phosphorescence emission efficiency of the material of the present invention about 50% higher than that of traditional materials, and the long-term stability is also greatly enhanced. Even after multiple environmental response cycles, the phosphorescence performance of the material can still maintain a high level, meeting the needs of practical applications.

[0031] 4. The room temperature phosphorescent wood film prepared by the present invention has lower cost: The present invention uses relatively cheap wood as the matrix material, and combines simple solvent immersion and chemical reaction steps to achieve phosphorescent functionalization. This technical solution not only maintains the high performance of the material, but also effectively reduces the preparation cost. Compared with the traditional high-cost phosphorescent wood film, the cost of the present invention is reduced by about 30%, which provides strong support for large-scale production and wide application.

[0032] 5. The room temperature phosphorescent wood film prepared by the present invention has a wide range of applications: Based on the above excellent properties, the material of the present invention shows broad application prospects in humidity detection, information security, artwork protection, product authentication, security and anti-counterfeiting and other fields. Its highly sensitive environmental responsiveness and reversible phosphorescence conversion characteristics provide new solutions and technical support for these fields, which helps to promote the technological progress and development of related industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The phosphorescent wood film image prepared by the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of the phosphorescent wood film prepared by the present invention;

[0035] Figure 3 This is a schematic diagram of the environmental responsiveness test of the phosphorescent wood film prepared in the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0037] Example 1

[0038] Select a 0.5 mm thick, 1.5 cm*1.5 cm basswood film as the raw material, add it to 400 mL of 20% sodium chlorite solution, add an appropriate amount of glacial acetic acid, adjust the pH of the solution to between 4 and 5, and accurately remove the lignin in the wood film. The mass of the delignified wood film is about 50 mg.

[0039] Then, 2.5 mg of 1-pyreneboronic acid was dissolved in a mixed solvent consisting of 4 mL of ethanol and 1 mL of ammonia water, and stirred to form a reaction solution;

[0040] The pre-treated delignified basswood film was added into the reaction solution and subjected to ultrasonic reaction at a temperature of 45°C for 15 minutes, so that the 1-pyrene boric acid molecules reacted chemically with the cellulose in the film to form a stable chemical bond.

[0041] After the reaction is completed, the basswood film that has reacted with the phosphorescent molecules is repeatedly washed with deionized water to remove the unreacted phosphorescent molecules, and heated on a heating table at 70°C for 5 minutes to remove the solvent in the pores of the wood film, thereby obtaining a dry whitish wood film, i.e., a hydrothermal stimulus responsive room temperature phosphorescent wood film. The phosphorescent wood film diagram is different from the schematic diagram of the phosphorescent wood film structure. Figure 1 and Figure 2 shown.

[0042] Example 2

[0043] A silver oak wood film with a thickness of 0.5 mm and a size of 1.5 cm*1.5 cm was selected as the raw material, and it was added to 400 mL of a sodium chlorite solution with a mass fraction of 20%, and an appropriate amount of glacial acetic acid was added to adjust the pH of the solution to between 4 and 5, and the lignin in the wood film was accurately removed. The mass of the delignified wood film obtained was about 50 mg;

[0044] Then, 2.5 mg of 1-pyreneboronic acid was dissolved in a mixed solvent consisting of 4 mL of ethanol and 1 mL of ammonia water, and stirred to form a reaction solution;

[0045] The pre-treated delignified silver oak wood film was added into the reaction solution and subjected to ultrasonic reaction at a temperature of 45°C for 15 min, so that the 1-pyrene boric acid molecules reacted chemically with the cellulose in the wood film to form a stable chemical bond.

[0046] After the reaction is completed, the silver oak wood film that has reacted with the phosphorescent molecules is repeatedly washed with deionized water to remove unreacted phosphorescent molecules, and is heated on a heating table at 70°C for 5 minutes to remove the solvent in the pores of the wood film to obtain a dry whitish wood film, that is, a hydrothermal stimulus responsive room temperature phosphorescent wood film.

[0047] Example 3

[0048] A balsa wood film with a thickness of 0.5 mm and a size of 1.5 cm*1.5 cm was selected as the raw material, and it was added to 400 mL of a sodium chlorite solution with a mass fraction of 20%, and an appropriate amount of glacial acetic acid was added to adjust the pH of the solution to between 4 and 5, and the lignin in the wood film was accurately removed. The mass of the delignified wood film obtained was about 50 mg;

[0049] Then, 2.5 mg of 1-pyreneboronic acid was dissolved in a mixed solvent consisting of 4 mL of ethanol and 1 mL of ammonia water, and stirred to form a reaction solution;

[0050] The pre-treated delignified balsa wood film was added into the reaction solution and subjected to ultrasonic reaction at a temperature of 45°C for 15 min, so that the 1-pyrene boric acid molecules reacted chemically with the cellulose in the wood film to form a stable chemical bond.

[0051] After the reaction is completed, the balsa wood film that has reacted with the phosphorescent molecules is repeatedly washed with deionized water to remove unreacted phosphorescent molecules, and is heated on a heating table at 70°C for 5 minutes to remove the solvent in the pores of the wood film, thereby obtaining a dry whitish wood film, that is, a hydrothermal stimulus responsive room temperature phosphorescent wood film.

[0052] Example 4

[0053] A maple wood film with a thickness of 0.5 mm and a size of 1.5 cm*1.5 cm was selected as the raw material, and it was added to 400 mL of a sodium chlorite solution with a mass fraction of 20%, and an appropriate amount of glacial acetic acid was added to adjust the pH of the solution to between 4 and 5, and the lignin in the wood film was accurately removed. The mass of the delignified wood film obtained was about 50 mg;

[0054] Then, 2.5 mg of 1-pyreneboronic acid was dissolved in a mixed solvent consisting of 4 mL of ethanol and 1 mL of ammonia water, and stirred to form a reaction solution;

[0055] The pre-treated delignified maple wood film was added into the reaction solution and subjected to ultrasonic reaction at a temperature of 45°C for 15 min, so that the 1-pyrene boric acid molecules reacted chemically with the cellulose in the wood film to form a stable chemical bond.

[0056] After the reaction is completed, the maple wood film that has reacted with the phosphorescent molecules is repeatedly washed with deionized water to remove unreacted phosphorescent molecules, and is heated on a heating table at 70°C for 5 minutes to remove the solvent in the pores of the wood film, thereby obtaining a dry whitish wood film, that is, a hydrothermal stimulus responsive room temperature phosphorescent wood film.

[0057] Example 5

[0058] Select a 0.5 mm thick, 2.5 cm*2.5 cm basswood film as the raw material, add it to 400 mL of 20% sodium chlorite solution, add an appropriate amount of glacial acetic acid, adjust the pH of the solution to between 4 and 5, and accurately remove the lignin in the wood film. The mass of the delignified wood film obtained is about 80 mg;

[0059] Then, 2.5 mg of 1-pyreneboronic acid was dissolved in a mixed solvent consisting of 4 mL of ethanol and 1 mL of ammonia water, and stirred to form a reaction solution;

[0060] The pre-treated delignified basswood film was added into the reaction solution and subjected to ultrasonic reaction at a temperature of 45°C for 15 minutes, so that the 1-pyrene boric acid molecules reacted chemically with the cellulose in the film to form a stable chemical bond.

[0061] After the reaction is completed, the basswood film that has reacted with the phosphorescent molecules is repeatedly washed with deionized water to remove unreacted phosphorescent molecules, and is heated on a heating table at 75°C for 3 minutes to remove the solvent in the pores of the wood film, thereby obtaining a dry whitish wood film, that is, a hydrothermal stimulus responsive room temperature phosphorescent wood film.

[0062] Comparative Example 1

[0063] The preparation method and raw material ratio are the same as in Example 1, except that the heating temperature in the last step is different, specifically:

[0064] Select a 0.5 mm thick, 1.5 cm*1.5 cm basswood film as the raw material, add it to 400 mL of 20% sodium chlorite solution, add an appropriate amount of glacial acetic acid, adjust the pH of the solution to between 4 and 5, and accurately remove the lignin in the wood film. The mass of the delignified wood film is about 50 mg.

[0065] Then, 2.5 mg of 1-pyreneboronic acid was dissolved in a mixed solvent consisting of 4 mL of ethanol and 1 mL of ammonia water, and stirred to form a reaction solution;

[0066] The pre-treated delignified basswood film was added into the reaction solution and subjected to ultrasonic reaction at a temperature of 45°C for 15 minutes, so that the 1-pyrene boric acid molecules reacted chemically with the cellulose in the film to form a stable chemical bond.

[0067] After the reaction is completed, the basswood film that has reacted with the phosphorescent molecules is repeatedly washed with deionized water to remove unreacted phosphorescent molecules, and is heated on a heating table at 25°C for 30 minutes to remove the solvent in the pores of the wood film, thereby obtaining a dry whitish wood film, that is, a hydrothermal stimulus responsive room temperature phosphorescent wood film.

[0068] Comparative Example 2

[0069] The preparation method and raw material ratio are the same as in Example 1, except that the heating temperature in the last step is different, specifically:

[0070] Select a 0.5 mm thick, 1.5 cm*1.5 cm basswood film as the raw material, add it to 400 mL of 20% sodium chlorite solution, add an appropriate amount of glacial acetic acid, adjust the pH of the solution to between 4 and 5, and accurately remove the lignin in the wood film. The mass of the delignified wood film is about 50 mg.

[0071] Then, 2.5 mg of 1-pyreneboronic acid was dissolved in a mixed solvent consisting of 4 mL of ethanol and 1 mL of ammonia water, and stirred to form a reaction solution;

[0072] The pre-treated delignified basswood film was added into the reaction solution and subjected to ultrasonic reaction at a temperature of 45°C for 15 minutes, so that the 1-pyrene boric acid molecules reacted chemically with the cellulose in the film to form a stable chemical bond.

[0073] After the reaction is completed, the basswood film that has reacted with the phosphorescent molecules is repeatedly washed with deionized water to remove unreacted phosphorescent molecules, and is heated on a heating table at 30°C for 25 minutes to remove the solvent in the pores of the wood film, thereby obtaining a dry whitish wood film, that is, a hydrothermal stimulus responsive room temperature phosphorescent wood film.

[0074] Comparative Example 3

[0075] The preparation method and raw material ratio are the same as in Example 1, except that the heating temperature in the last step is different, specifically:

[0076] Select a 0.5 mm thick, 1.5 cm*1.5 cm basswood film as the raw material, add it to 400 mL of 20% sodium chlorite solution, add an appropriate amount of glacial acetic acid, adjust the pH of the solution to between 4 and 5, and accurately remove the lignin in the wood film. The mass of the delignified wood film is about 50 mg.

[0077] Then, 2.5 mg of 1-pyreneboronic acid was dissolved in a mixed solvent consisting of 4 mL of ethanol and 1 mL of ammonia water, and stirred to form a reaction solution;

[0078] The pre-treated delignified basswood film was added into the reaction solution and subjected to ultrasonic reaction at a temperature of 45°C for 15 minutes, so that the 1-pyrene boric acid molecules reacted chemically with the cellulose in the film to form a stable chemical bond.

[0079] After the reaction is completed, the basswood film that has reacted with the phosphorescent molecules is repeatedly washed with deionized water to remove unreacted phosphorescent molecules, and is heated on a heating table at 35°C for 20 minutes to remove the solvent in the pores of the wood film, thereby obtaining a dry whitish wood film, that is, a hydrothermal stimulus responsive room temperature phosphorescent wood film.

[0080] Comparative Example 4

[0081] The preparation method and raw material ratio are the same as in Example 1, except that the heating temperature in the last step is different, specifically:

[0082] Select a 0.5 mm thick, 1.5 cm*1.5 cm basswood film as the raw material, add it to 400 mL of 20% sodium chlorite solution, add an appropriate amount of glacial acetic acid, adjust the pH of the solution to between 4 and 5, and accurately remove the lignin in the wood film. The mass of the delignified wood film is about 50 mg.

[0083] Then, 2.5 mg of 1-pyreneboronic acid was dissolved in a mixed solvent consisting of 4 mL of ethanol and 1 mL of ammonia water, and stirred to form a reaction solution;

[0084] The pre-treated delignified basswood film was added into the reaction solution and subjected to ultrasonic reaction at a temperature of 45°C for 15 minutes, so that the 1-pyrene boric acid molecules reacted chemically with the cellulose in the film to form a stable chemical bond.

[0085] After the reaction is completed, the basswood film that has reacted with the phosphorescent molecules is repeatedly washed with deionized water to remove unreacted phosphorescent molecules, and is heated on a heating table at 90°C for 2 minutes to remove the solvent in the pores of the wood film, thereby obtaining a dry whitish wood film, that is, a hydrothermal stimulus responsive room temperature phosphorescent wood film.

[0086] Test Example 1

[0087] Environmental responsiveness test

[0088] An environmental responsiveness test was designed and implemented, and the phosphorescent wood films prepared in Example 1 and Comparative Examples 1 to 4 were placed under different humidity conditions to observe and record changes in their phosphorescent emission characteristics.

[0089] Seal the beaker with tin foil, place the prepared and tested phosphorescent wood film on the beaker filled with water, and seal the two in one space. The specific test is:

[0090] Fill a 100mL small beaker with deionized water, wrap the beaker with tin foil, poke small holes on the surface of the tin foil, and then place the phosphorescent wood film on the surface of the tin foil with holes. Then place the small beaker in a 1000ml beaker and fix the probe of the hygrometer to the large beaker. Put the whole set of equipment on the heating table and heat it. Water vapor penetrates into the phosphorescent wood film through the pores of the paper. Control the heating temperature to maintain 60°C and record whether the phosphorescence of the phosphorescent wood film disappears under different humidity. The experiment found that as the humidity increased, the phosphorescence gradually weakened and disappeared at 90% humidity.

[0091] Then the wood film whose phosphorescence disappeared was heated on a heating table for 5 minutes, and the phosphorescence of the wood film quickly recovered. After the phosphorescent wood film was fumigated with water vapor, when the humidity reached more than 90%, the phosphorescence of the phosphorescent wood film disappeared again, and the phosphorescence recovered quickly after heating, and the phosphorescence intensity did not decrease basically. The phosphorescent wood film could respond to repeated stimulation for more than dozens of times, and its phosphorescence intensity did not change much.

[0092] The experimental results are as follows Figure 3 As shown, the phosphorescence emission characteristics of the material prepared in Example 1 will be temporarily weakened or disappear when it comes into contact with water vapor, and the phosphorescence can be quickly restored after heating treatment, showing good reversibility. For the materials prepared in Comparative Examples 1 to 4, when the heating temperature changes from 25°C to 65°C, it is found that the phosphorescence intensity of the obtained wood film is slightly lower when the heating time is long; and when the heating temperature is higher than 75°C, although the heating time is short and the room temperature phosphorescent wood film is obtained quickly, if the control is not good, the wood film is easy to turn yellow, resulting in a decrease in the intensity of the obtained room temperature phosphorescent wood film.

[0093] The present application has been described by the above-mentioned relevant embodiments, but the above-mentioned embodiments are only examples for implementing the present invention. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, modifications and equivalent settings contained in the spirit and scope of the claims are all included in the scope of the present invention.

Claims

1. A hydrothermal stimulus responsive room temperature phosphorescent wood film, comprising: A wood matrix and phosphorescent molecules; wherein: The mass ratio of the wood substrate to the phosphorescent molecule is 14 to 100:1; The wood substrate is a delignified wood film having a thickness of 0.1 to 0.7 mm obtained by special treatment to remove lignin and purify; The phosphorescent molecule is 1-pyreneboronic acid.

2. The method for preparing the hydrothermal stimulus responsive room temperature phosphorescent wood film according to claim 1, comprising: (1) Wood matrix pretreatment: The wood film raw material is treated chemically to remove lignin, thereby obtaining delignified wood, and the delignified wood is deeply purified until the wood film reaches a completely transparent state in the solution, thereby obtaining a pretreated wood matrix; (2) Introduction of phosphorescent molecules: 2.5 mg of 1-pyreneboric acid was dissolved in a mixed solvent consisting of 4 mL of ethanol and 1 mL of ammonia water, and stirred to form a reaction solution; the pretreated wood substrate was placed in the reaction solution and subjected to ultrasonic reaction to obtain a semi-finished wood film; (3) Preparation of phosphorescent wood film: After the reaction is completed, the semi-finished wood film is repeatedly washed with deionized water to remove unreacted phosphorescent molecules, and heated on a heating table at 60-80° C. for 3-10 minutes to obtain a hydrothermal stimulus responsive room temperature phosphorescent wood film.

3. The preparation method according to claim 2, wherein: The wood film raw material of step (1) is selected from any one of basswood, silver oak, balsa wood and maple wood.

4. The preparation method according to claim 2, wherein: The deep purification in step (1) comprises: The delignified wood was soaked in deionized water for 5 minutes, then soaked in ethanol and acetone for 5 minutes respectively, and finally the wood film was immersed in benzene solution for 1-5 minutes; The benzene solution is selected from: any one of toluene, super dry chlorobenzene, chlorobenzene, o-dichlorobenzene and m-dichlorobenzene.

5. The preparation method according to claim 2, wherein: The drying temperature in step (2) is 70° C. or 75° C.; the drying time is 5 minutes.

6. A hydrothermal stimulus responsive room temperature phosphorescent wood film prepared according to the preparation method according to any one of claims 2 to 5.

7. Use of the hydrothermal stimulus responsive room temperature phosphorescent wood film according to claim 1 or 6 in the preparation of a highly sensitive humidity sensor.

8. The use according to claim 7, wherein: The highly sensitive humidity sensor includes humidity detection for environmental monitoring, agricultural irrigation, and smart home.

9. Application of the hydrothermal stimulus responsive room temperature phosphorescent wood film according to claim 1 or 6 in the field of information security.

10. The use according to claim 9, comprising: The information security field includes: in the fields of artwork protection, product authentication and security anti-counterfeiting, information can be unlocked or hidden through specific environmental stimulation to achieve encryption and decryption of information.

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