Wood-based hygrometer device

Abstract

The invention firstly discloses a wood-based hygrometer device which comprises a phosphorescent wood film, a polymer type protective shell and a pop-up switch, wherein the phosphorescent wood film is used for detecting environment humidity; the polymer type protective shell is made of an epoxy resin type solid film and can be used for storing a plurality of phosphorescent wood films, so that the phosphorescent wood films in the structure are protected from being influenced by the external environment; when testing is needed, one phosphorescent wood film can be popped up through the pop-up switch and is used for detecting the environment humidity. Compared with a traditional hygrometer, the wood-based hygrometer is low in cost and simple in preparation process. Wherein the phosphorescent wood film can sensitively reflect the change of environment humidity by utilizing the dry shrinkage and wet expansion characteristics of wood, and the change can be visually displayed through the intensity or color change of phosphorescence. In addition, the hygrometer has the advantages of being reusable, diversified in form, adjustable in breadth size, attractive in finished product and the like, can be customized according to actual requirements, and is very suitable for monitoring environment humidity for a long time.

Description

Technical Field

[0001] The invention belongs to the technical field of temperature sensing materials, and in particular relates to a wood-based hygrometer device. Background Art

[0002] As a capillary limited expansion colloidal material with significant hygroscopicity, wood has a unique multi-level pore structure, excellent mechanical properties, a natural rigid network three-dimensional nanostructure, and is easy to form hydrogen bonds. The polar groups contained in the chemical components of its cell wall enable it to shrink and swell with changes in air humidity, providing a unique template for chemical and physical modifications for specific functional targets. The three main components of wood are cellulose, hemicellulose and lignin. Although lignin can cause room temperature phosphorescence (RTP), the emission curve of lignin is not adjustable, which seriously limits the practical application of performance improvement of RTP materials derived from natural wood. Therefore, delignified wood film can be obtained by removing lignin from natural wood film. The delignified wood film can maintain the original pore structure of natural wood. The rigid environment provided by the pore structure can load and constrain organic room temperature phosphorescent small molecules, providing a template structure for enhancing the room temperature phosphorescence of phosphorescent small molecules. This feature provides a solid theoretical basis for the design of wood-based hygrometers.

[0003] However, traditional humidity indicators, such as wet and dry bulb thermometers, hair hygrometers, and lithium chloride hygrometers, all have their own limitations, such as low indication efficiency, insensitivity, susceptibility to environmental factors, or high cost. Although there are cases in the prior art that use the shrinkage and swelling characteristics of wood to prepare hygrometers, their indication stability may be affected by a variety of environmental factors, such as temperature fluctuations, changes in light, etc., resulting in unstable humidity indication results and affecting measurement accuracy. Secondly, some cases of using phosphorescent materials to prepare hygrometers also have certain defects, including: during long-term use, the luminescence performance of phosphorescent materials may gradually decay, resulting in a weakened indication effect of the hygrometer after long-term monitoring, requiring regular replacement or calibration, which increases the cost of use and difficulty of maintenance. Compared with some electronic hygrometers, finally, some hygrometers based on physical change indication methods may have the problem of slow response speed and cannot respond quickly to rapid changes in humidity, which may not be ideal for application scenarios that require real-time monitoring.

[0004] Based on the above analysis, the present invention proposes an innovative design and preparation scheme for a wood-based hygrometer, which is unique in that the humidity conditions are displayed through changes in phosphorescence. Compared with traditional hygrometers, this wood-based hygrometer not only has low raw material costs (only wood and long afterglow materials), but also has a simple preparation process and high production efficiency. More importantly, it utilizes the shrinkage and swelling characteristics of wood to sensitively reflect changes in ambient humidity and intuitively display them through changes in the intensity or color of phosphorescence. In addition, the hygrometer also has the advantages of being reusable, diverse in form, adjustable in size, and beautiful in finished product. It can be customized according to actual needs and is very suitable for long-term monitoring of ambient humidity. Summary of the invention

[0005] In view of the above shortcomings, this technology proposes a new preparation scheme for a hygrometer based on the shrinkage and swelling characteristics of wood and the luminescence characteristics of phosphorescent materials. It cleverly utilizes the deformation of wood with changes in air humidity, combined with the luminescence characteristics of phosphorescent materials that are sensitive to humidity, to achieve a direct display of humidity changes. This hygrometer has the advantages of low cost, simple process, and easy portability, providing a new idea for environmental humidity measurement.

[0006] The present invention is achieved by the following technical means:

[0007] The present invention first discloses a wood-based moisture meter device, comprising:

[0008] Phosphorescent wood film (1), polymer protective shell (2), and pop-up switch (3); wherein:

[0009] The phosphorescent wood film (1) is used to detect environmental humidity;

[0010] The polymer protective shell (2) is made of an epoxy resin consolidation film and can be used to store multiple phosphorescent wood films (1) to protect the phosphorescent wood films (1) inside the structure from being affected by the external environment; when testing is required, a phosphorescent wood film (1) can be ejected using a pop-up switch (3) to detect environmental humidity.

[0011] Furthermore, the size of the phosphorescent wood film (1) is 2 cm×1 cm.

[0012] Furthermore, the phosphorescent wood film (1) comprises:

[0013] A wood matrix and phosphorescent molecules; wherein:

[0014] The mass ratio of the wood substrate to the phosphorescent molecule is 14 to 100:1;

[0015] 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;

[0016] The phosphorescent molecule is 1-pyreneboronic acid.

[0017] Furthermore, the phosphorescent wood film (1) is prepared by the following method:

[0018] (1) Wood matrix pretreatment:

[0019] 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;

[0020] (2) Introduction of phosphorescent molecules:

[0021] 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;

[0022] (3) Preparation of phosphorescent wood film:

[0023] 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.

[0024] Furthermore, the wood film raw material in step (1) is selected from any one of basswood, silver oak, balsa wood and maple;

[0025] Furthermore, the deep purification in step (1) comprises:

[0026] 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;

[0027] The benzene solution is selected from: any one of toluene, super dry chlorobenzene, chlorobenzene, o-dichlorobenzene and m-dichlorobenzene.

[0028] Furthermore, in step (3), the drying temperature is 70° C. or 75° C.; and the drying time is 5 minutes.

[0029] The present invention also discloses a method for using any of the above-mentioned wood-based moisture meter devices, comprising:

[0030] (1) When in use, the ejection switch (3) is pressed to eject the phosphorescent wood film (1) stored inside the polymer protective shell (2);

[0031] (2) Place the wood-based hygrometer device in the test environment, then irradiate it with ultraviolet light for 2 minutes, record the intensity of the phosphorescence, and compare it with an accurate phosphorescence-humidity card to read the actual humidity of the environment.

[0032] Furthermore, the time of being placed in the test environment in step (2) is not less than 10 minutes.

[0033] Furthermore, the wavelength of the ultraviolet light in step (2) is 365 nm.

[0034] The beneficial effects of the present invention are:

[0035] 1. Significantly improve the sensitivity and stability of humidity detection: The phosphorescent wood film used in the present invention is purified by delignification treatment and solvent immersion, the cellulose structure in the wood film is optimized, and the pore structure is more uniform, thereby improving the sensitivity of the material to humidity changes. At the same time, the introduction of 1-pyreneboric acid gives the material unique phosphorescent emission characteristics, and its reversible phosphorescent changes are closely related to humidity changes, making humidity detection more accurate and reliable. Experimental data show that the humidity sensing material of the present invention exhibits extremely high sensitivity within the range of relative humidity changes and good long-term stability.

[0036] 2. Reduce production and maintenance costs: Compared with traditional humidity sensing materials, the raw materials (such as wood) used in the present invention are widely available and low-cost, and the preparation process is relatively simple, without the need for complex equipment and high energy consumption processes, thereby effectively reducing production costs. In addition, since the material itself has good stability and durability, the need for regular replacement or calibration is reduced, further reducing maintenance costs.

[0037] 3. Environmentally friendly and sustainable: The main raw material of the present invention, wood, not only has a naturally formed multi-level pore structure and excellent mechanical properties, but also has excellent properties such as low density and low thermal conductivity. Wood is also an environmentally friendly and sustainable renewable material. The final product of the present invention is environmentally friendly and degradable, which conforms to the concepts of green chemistry and sustainable development. At the same time, by recycling resources such as waste wood, the recycling of resources is achieved, reducing the pressure on the natural environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the structure of the wood-based moisture meter device of the present invention;

[0039] Figure 2 is a phosphorescence intensity calibration diagram of the wood-based hygrometer of the present invention;

[0040] Figure 3 This is a color chart for comparing humidity and phosphorescence intensity of the wood-based hygrometer of the present invention. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] Example 1

[0043] A wood-based moisture meter device, comprising:

[0044] Phosphorescent wood film (1), polymer protective shell (2), and pop-up switch (3); wherein:

[0045] The phosphorescent wood film (1) is used to detect environmental humidity;

[0046] The polymer protective shell (2) is made of an epoxy resin consolidation film and can be used to store multiple phosphorescent wood films (1) to protect the phosphorescent wood films (1) inside the structure from being affected by the external environment; when testing is required, a phosphorescent wood film (1) can be ejected using a pop-up switch (3) to detect the environmental humidity;

[0047] The size of the phosphorescent wood film (1) is 2 cm×1 cm.

[0048] Example 2

[0049] Preparation method of phosphorescent wood film:

[0050] (1) Wood matrix pretreatment:

[0051] The wood film raw material is treated chemically to remove lignin to obtain delignified wood, the delignified wood is soaked in deionized water for 5 minutes, then soaked in ethanol and acetone for 5 minutes respectively, and finally the wood film is immersed in a benzene solution for 1-5 minutes; until the wood film is completely transparent in the solution, the pretreated wood matrix is ​​obtained; wherein the wood film raw material is selected from: any one of basswood, silver oak, balsa wood and maple; the benzene solution is selected from: any one of toluene, super dry chlorobenzene, chlorobenzene, o-dichlorobenzene and m-dichlorobenzene;

[0052] (2) Introduction of phosphorescent molecules:

[0053] 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;

[0054] (3) Preparation of phosphorescent wood film:

[0055] 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.

[0056] Example 3

[0057] A method of using a wood-based moisture meter device, comprising:

[0058] (1) When in use, the ejection switch (3) is pressed to eject the phosphorescent wood film (1) stored inside the polymer protective shell (2);

[0059] (2) Place the wood-based hygrometer device in the test environment for more than 10 minutes, then irradiate it with ultraviolet light with a wavelength of 365 nm for 2 minutes, record the intensity of phosphorescence, and compare it with an accurate phosphorescence-humidity card to read the actual humidity of the environment.

[0060] Test Example 1

[0061] Design of wood-based hygrometer and calibration of phosphorescence intensity

[0062] Seal the beaker with tin foil, place the prepared phosphorescent wood film that has room temperature phosphorescence after testing on a beaker filled with water, and place the probe of the hygrometer in the large beaker. Then seal the large beaker with tin foil, heat it on a heating table, evaporate the water in the small beaker, read the humidity on the hygrometer, test the humidity environment in the large beaker, and mark the phosphorescence intensity in the room temperature phosphorescent wood film at any time. Correlate the phosphorescence intensity with the humidity on the hygrometer to prepare an accurate phosphorescence-humidity card (such as Figure 2 shown).

[0063] The specific tests are:

[0064] 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, record the correlation between the phosphorescence intensity of the phosphorescent wood film and humidity at different humidities, and prepare accurate phosphorescence-humidity cards.

[0065] Finally, the prepared room temperature phosphorescent wood film is sealed with a vacuum plastic sealing machine for sealed storage. When used, a single piece of room temperature phosphorescent wood film is taken out and then placed in the test environment for more than 10 minutes. Its phosphorescent properties can be observed and recorded under the irradiation of ultraviolet light. According to the accurate phosphorescence-humidity card, the actual humidity of the environment (such as Figure 3shown).

[0066] Regarding the above-mentioned technical solution of humidity-sensitive material based on chemical reaction of delignified wood film and 1-pyrene boric acid, there are indeed a variety of alternative solutions that can also achieve the purpose of the invention, that is, to prepare a material with humidity sensitivity and potential information encryption / anti-counterfeiting function. The following are some possible alternative solutions:

[0067] 1. Alternative chemical reactants

[0068] 1.1 Replacement of phosphorescent groups: In addition to 1-pyreneboronic acid, other organic molecules with phosphorescent or fluorescent properties (such as certain fluorescent dyes, quantum dots, etc.) can also be introduced into delignified wood films to produce similar humidity response properties. These molecules may need to chemically react or physically adsorb with cellulose or other components in the wood film to achieve stable binding.

[0069] 1.2 Use of other reactive functional groups: Consider using molecules with different reactive functional groups that can form more stable chemical bonds with cellulose, thereby enhancing the durability and humidity responsiveness of the material. For example, molecules containing aldehyde, carboxyl or amino groups can bind to cellulose through condensation reactions.

[0070] 2. Alternative material substrate

[0071] 2.1 Different types of wood: Although the present invention takes specific wood as an example, other types of wood or natural cellulose materials (such as bamboo, cotton stalks, etc.) can also be used as base materials and used to prepare moisture-sensitive materials after appropriate delignification treatment and purification.

[0072] 2.2 Synthetic cellulose materials: Synthetic cellulose materials (such as regenerated cellulose membranes, cellulose nanofibers, etc.) have a more uniform fiber structure and higher controllability, and can be used as alternative substrate materials to introduce phosphorescent groups or other functional molecules through similar methods.

[0073] 3. Alternative preparation methods

[0074] 3.1 Different solvent systems: In addition to the sequential immersion of deionized water, ethanol, acetone, and o-dichlorobenzene, other solvent systems or solvent combinations can also be explored to optimize the delignification effect and purification process.

[0075] 3.2 Combination of physical methods: In addition to chemical reactions, physical methods (such as ion implantation, plasma treatment, laser etching, etc.) can also be considered to introduce functional molecules into the wood film to form a moisture-sensitive layer.

[0076] 3.3 Multilayer structure design: Construct a multilayer structure of humidity-sensitive materials, in which each layer has different functions (such as moisture absorption layer, sensing layer, protective layer, etc.), and the overall function is achieved through layer-by-layer assembly.

[0077] The above alternatives demonstrate multiple possibilities for achieving the purpose of the present invention. At the same time, these alternatives also provide more ideas and directions for subsequent research and development.

[0078] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0079] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wood-based moisture meter device, comprising: Phosphorescent wood film (1), polymer protective shell (2), and pop-up switch (3); wherein: The phosphorescent wood film (1) is used to detect environmental humidity; The polymer protective shell (2) is made of an epoxy resin consolidation film and can be used to store multiple phosphorescent wood films (1) to protect the phosphorescent wood films (1) inside the structure from being affected by the external environment; when testing is required, a phosphorescent wood film (1) can be ejected using a pop-up switch (3) to detect environmental humidity.

2. The wood-based moisture meter device according to claim 1, wherein: The size of the phosphorescent wood film (1) is 2 cm×1 cm.

3. The wood-based moisture meter device according to claim 1, wherein: The phosphorescent wood film (1) comprises: 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.

4. The wood-based moisture meter device according to claim 3, wherein: The phosphorescent wood film is prepared by the following method: (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.

5. The wood-based moisture meter device according to claim 4, wherein: The wood film raw material of step (1) is selected from any one of basswood, silver oak, balsa wood and maple wood.

6. The wood-based moisture meter device according to claim 4, 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.

7. The wood-based moisture meter device according to claim 4, wherein: The drying temperature in step (3) is 70° C. or 75° C.; the drying time is 5 minutes.

8. A method for using any one of the wood-based moisture meter devices according to claims 1 to 7, comprising: (1) When in use, the ejection switch (3) is pressed to eject the phosphorescent wood film (1) stored inside the polymer protective shell (2); (2) Place the wood-based hygrometer device in the test environment, then irradiate it with ultraviolet light for 2 minutes, record the intensity of the phosphorescence, and compare it with an accurate phosphorescence-humidity card to read the actual humidity of the environment.

9. The method of use according to claim 8, wherein: The time of being placed in the test environment in step (2) is not less than 10 minutes.

10. The method of use according to claim 8, wherein: The wavelength of the ultraviolet light in step (2) is 365 nm.

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