Anti-swelling hydrogel humidity-sensitive material and preparation method thereof
By polymerizing to form an anti-swelling hydrogel humidity-sensitive material, the problems of complex preparation and high cost of existing humidity-sensitive materials are solved, achieving efficient and low-cost humidity sensing effect, which is suitable for flexible humidity sensors.
Patent Information
- Application Number
- CN202411764790.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-03
- Publication Date
- 2025-12-12
AI Technical Summary
Existing methods for preparing humidity-sensitive materials are too complex and costly, which prevents them from effectively utilizing the performance of humidity sensors in practical applications. Furthermore, existing materials are susceptible to environmental influences, resulting in unstable performance, and their large size makes them inconvenient to carry and transport.
A combination of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, acrylic acid, crosslinking agent, metal ions and initiator is used to form an anti-swelling hydrogel moisture-sensitive material through heating polymerization. This material forms a multi-layer network structure to improve flexibility and moisture sensitivity, and enhances electrical conductivity through hydrogen bonds and hydrophilic groups.
The prepared anti-swelling hydrogel humidity-sensitive material has good humidity sensing ability, fast response speed, low cost, and is suitable for flexible humidity sensors, making it suitable for humidity monitoring in special environments such as data centers and archives.
Smart Images
Figure CN121108412A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of high polymer material preparation, in particular to an anti-swelling hydrogel humidity-sensitive material and a preparation method thereof. BACKGROUND
[0002] Flexible humidity sensors have the characteristics of flexibility, fast response, high precision, low power consumption, etc., and have become the most suitable humidity measurement electronic devices for various fields, especially in the complex environment of special equipment such as data rooms and archives that need to closely monitor humidity. As an important component of flexible humidity sensors, humidity-sensitive materials are the key factor affecting the performance of flexible humidity sensors. As humidity-sensitive materials for humidity sensing, the moisture absorption rate, air permeability, heat resistance, dielectricity, stability, and preparation cost of the materials need to be considered comprehensively. Therefore, how to prepare humidity-sensitive materials with excellent performance has become a problem to be solved.
[0003] Currently, different preparation materials and processes can be used to prepare humidity-sensitive materials with different characteristics for different application scenarios. For example, humidity-sensitive materials based on room temperature ionic liquids, humidity-sensitive sensing films prepared based on reduced graphene oxide and cellulose, humidity-sensitive materials prepared based on two-dimensional materials / lithium chloride LiCl coating and paper-based substrate materials, and poly-ionic liquid humidity-sensitive materials prepared based on ceramic substrates and graphite carbon interdigital electrodes, etc. However, the existing preparation methods of the above humidity-sensitive materials are too complex, and the preparation requirements are harsh. Moreover, due to the high preparation cost, it is not easy to replace them regularly in actual application scenarios, which leads to the inability to better play the performance of the humidity sensor. SUMMARY
[0004] To solve the existing technical problems, the present application provides an anti-swelling hydrogel humidity-sensitive material and a preparation method thereof.
[0005] To achieve the above-mentioned purposes, the technical solutions of the embodiments of the present application are as follows:
[0006] In a first aspect, the present application provides a preparation method of an anti-swelling hydrogel humidity-sensitive material, which comprises: adding poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate and acrylic acid into deionized water to obtain a mixed solution; wherein the ratio of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, acrylic acid and deionized water is (3-5) g:(4-9) g:(10-15) g;
[0007] A pre-configured crosslinking agent solution and a metal ion solution are added to the mixed solution to form a reaction solution A after being uniformly dispersed; wherein the ratio of the added crosslinking agent solution and the metal ion solution is (1.5-2.5):1;
[0008] The pre-configured initiator solution and tetramethyl ethylenediamine are added into the reaction liquid A in a ratio of 1:1 and uniformly dispersed to obtain a reaction liquid B.
[0009] The reaction liquid B is heated to polymerize and form an anti-swelling hydrogel humidity-sensitive material.
[0010] In the above scheme, the crosslinking agent solution is obtained by ultrasonic dissolution of the crosslinking agent and deionized water in a mass ratio of 0.18:1 for 5-20 minutes, and the ultrasonic frequency is 20-40 kHz.
[0011] In the above scheme, the metal ion solution is obtained by dissolving the metal ion and deionized water in a mass ratio of (0.06-0.3):1, and the metal ion is aluminum ion, zinc ion or iron ion.
[0012] In the above scheme, the initiator solution is obtained by dissolving the initiator and deionized water in a mass ratio of 0.018:1.
[0013] In the above scheme, the crosslinking agent is N,N-methylene bisacrylamide.
[0014] In the above scheme, the initiator is ammonium persulfate.
[0015] In the above scheme, the pre-configured crosslinking agent solution and metal ion solution are added to the mixed liquid to uniformly disperse and form the reaction liquid A, which includes: after the pre-configured crosslinking agent solution and metal ion solution are added to the mixed liquid, cell disruption stirring is performed for 3-10 minutes to obtain the uniformly dispersed reaction liquid A.
[0016] In the above scheme, the pre-configured initiator solution and tetramethyl ethylenediamine are added to the reaction liquid A in a ratio of 1:1 and uniformly dispersed to obtain the reaction liquid B, which includes: after the pre-configured initiator solution and tetramethyl ethylenediamine are added to the reaction liquid A, ultrasonic dispersion is performed for 15-30 minutes, and the ultrasonic power is 20-40 kHz to obtain the reaction liquid B.
[0017] In the above scheme, the reaction temperature of the polymerization and formation is 38-48 degrees Celsius, and the reaction time is 20-40 hours.
[0018] In a second aspect, the present application provides an anti-swelling hydrogel humidity-sensitive material prepared by the above preparation method.
[0019] The anti-swelling hydrogel humidity-sensitive material and the preparation method thereof provided by the embodiment of the application, in the first aspect, by adding poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate and metal ions, the effect of enhanced bonding can be introduced to form a multi-layer network structure, thereby improving the tensile property, i.e., flexibility, of the hydrogel humidity-sensitive material; in the second aspect, by adding poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate and acrylic acid, the PEDOT:PSS chains formed are crosslinked with the polyacrylic acid (PAA, Poly Acrylic Acid) chains, thereby improving the anti-swelling property of the hydrogel humidity-sensitive material; in the third aspect, by mixing PEDOT:PSS, AA and metal ions, a large number of hydrogen bonds and hydrophilic groups can be generated, which greatly improves the humidity sensitivity, and when the humidity in the environment increases, the gel network of the hydrogel can adsorb water molecules in the air to increase the water content and improve the conductivity, thereby achieving the improvement of humidity sensing; in the fourth aspect, the preparation method of the hydrogel humidity-sensitive material of the embodiment of the application is relatively simple, the preparation conditions are loose, and the preparation cost is greatly reduced. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 It is a flowchart of the preparation method of the anti-swelling hydrogel humidity-sensitive material of the embodiment of the application.
[0021] Figure 2 It is a schematic diagram of the relationship between the relative humidity and the conductivity of the hydrogel humidity-sensitive material of the embodiment of the application.
[0022] Figure 3 It is a schematic diagram of the relationship between the relative humidity and the resistance change rate of the hydrogel humidity-sensitive material of the embodiment of the application. DETAILED DESCRIPTION
[0023] The application will be further described in detail below with reference to the drawings and specific embodiments.
[0024] It should be understood that the term "and / or" herein merely describes the association relationship of the associated objects, and indicates that there can be three relationships, for example, A and / or B can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.
[0025] The terms "first", "second", and the like in the specification and claims of the application are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented in an order other than those illustrated or described herein.
[0026] Before the preparation method of the hydrogel embodiment of the present application is described in detail, the related art is briefly described first.
[0027] At present, an existing ion liquid type humidity sensitive material is prepared from room temperature ionic liquid, ion liquid carrier and at least two electrodes, the room temperature ionic liquid is one or more than one of alkyl imidazole, alkyl pyridine, quaternary ammonium salt, quaternary phosphonium salt or benzimidazole ionic liquid; the ion liquid carrier as the container of the ion liquid can be the membrane or gel of the immobilized ion liquid, the flocculent carrier or semiconductor substrate that can adsorb the ion liquid; the electrode is a metal electrode or a non-metal electrode (such as a carbon electrode or a silicon electrode).
[0028] The ion liquid type humidity sensitive material prepared by the above method can use room temperature ionic liquid as the sensitive component of humidity, and through the interaction between water molecules and room temperature ionic liquid material, the viscosity, conductivity and other physical and chemical properties of the ion liquid are affected, so as to realize humidity detection.
[0029] Although this kind of liquid type humidity sensitive material has obvious humidity detection characteristics, it also has obvious disadvantages, so that its effect in the actual application scene is not ideal. The disadvantages are: the liquid type humidity sensitive material is easily affected by the environment, resulting in unstable performance; the liquid type humidity sensitive material has large volume, which is not convenient for carrying and transportation, and is easy to leak or damage during transportation; the production and maintenance cost of the liquid type humidity sensitive material is high, and the compatibility changes easily during use, affecting its performance and service life.
[0030] In addition, an existing preparation method of a humidity sensitive sensing film is as follows: pentanoyl chloride is used as a modifier to modify cellulose in an ionic liquid solution 1-ethyl-3-methyl imidazole acetate, to prepare water-soluble cellulose acetate; the water-soluble cellulose acetate is configured into a cellulose aqueous solution, graphene oxide is configured into a graphene oxide aqueous solution, the configured graphene oxide aqueous solution is added into the cellulose solution to obtain a uniform mixture of cellulose and graphene oxide; a reducing agent is added into the above mixture of cellulose and graphene oxide, and reduction is carried out under the condition that the water-soluble cellulose acetate is a dispersion system, to obtain a water solution of reduced graphene oxide (rGO) and cellulose; the water solution of reduced graphene oxide and cellulose is subjected to ultrasonic vibration treatment, and then is subjected to filtration and drying treatment to obtain a flexible humidity sensitive sensing film.
[0031] Although the humidity-sensitive sensing film prepared by the above preparation method has high sensitivity, fast response speed and good humidity detection effect, the humidity-sensitive sensing film needs to be prepared at a temperature of 55-70 degrees Celsius (℃), the reaction time needs to be 6-12 hours, and the reduction reaction needs to be stirred at an oil bath temperature of 80℃ for 3 hours while keeping the stirring speed at 800 revolutions per minute (RPM, Revolutions Per Minute), the drying temperature is 60℃, and the drying time is 30 minutes. It can be seen that the preparation method of the humidity sensing film is too complex, the preparation condition is too harsh, and the preparation cost is too high.
[0032] Based on this, the anti-swelling hydrogel for leakage and humidity monitoring and the preparation method thereof are provided, Figure 1 The flowchart of the preparation method of the anti-swelling hydrogel humidity-sensitive material of the embodiments of the present application is shown as follows: Figure 1 The preparation method of the anti-swelling hydrogel includes the following steps:
[0033] Step 101: poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate and acrylic acid are added to deionized water to obtain a mixed solution; wherein the ratio of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, acrylic acid and deionized water is (3-5) g:(4-9) g:(10-15) g;
[0034] Step 102: a pre-configured crosslinking agent solution and a metal ion solution are added to the mixed solution to uniformly disperse to form a reaction liquid A; wherein the ratio of the added crosslinking agent solution and the metal ion solution is (1.5-2.5):1;
[0035] Step 103: a pre-configured initiator solution and tetramethyl ethylenediamine are added to the reaction liquid A in a ratio of 1:1 to uniformly disperse to obtain a reaction liquid B;
[0036] Step 104: the reaction liquid B is heated to polymerize and form an anti-swelling hydrogel humidity-sensitive material.
[0037] Here, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (also known as PEDOT:PSS) is composed of two substances, polymer PEDOT of 3,4-ethylenedioxythiophene monomer (EDOT) and polystyrene sulfonate (PSS), which is a high molecular conductive polymer and has good conductivity, high light transmittance and flexibility; acrylic acid (also known as AA, Acrylic Acid) is an organic compound that is easy to polymerize and miscible with water; deionized water is pure water after removing ionic impurities, which is used to eliminate the interference of other ions in the dissolution process.
[0038] In the embodiment, the PEDOT:PSS, AA and deionized water are mixed in a ratio of (3-5):(4-9):(10-15) g, so that O-H in hydroxyl or carboxyl, O=S in sulfonic acid group, SO-H in sulfonic acid group and O-H in hydroxyl or carboxyl, SO-H in sulfonic acid group and O=C in carboxyl in the mixed solution generate a large number of hydrogen bonds and hydrophilic groups with hydrophilicity, thereby greatly improving the moisture sensitivity of the material.
[0039] It should be noted that, in order to make the prepared hydrogel moisture-sensitive material have excellent moisture-sensitive effect, it is necessary to ensure that the mass of the added PEDOT:PSS accounts for 5%-30% of the total mass of the added raw materials (i.e. including PEDOT:PSS, AA, and metal ions, cross-linking agent, initiator and tetramethyl ethylenediamine in the following steps).
[0040] In the embodiment, after the PEDOT:PSS, AA and deionized water are mixed in a certain ratio to obtain a mixed solution, the volumes of the pre-configured cross-linking agent solution and metal ion solution are added to the mixed solution in a ratio of (1.5-2.5):1, so as to accelerate the physical cross-linking reaction of the mixed solution by the cross-linking agent solution and enhance the conductivity by the metal ion solution. It should be noted that the role of the cross-linking agent is to generate chemical bonds between linear molecules, so as to connect the linear molecules together to form a network structure, so as to improve the strength and elasticity of the polymer material.
[0041] In some embodiments, the cross-linking agent solution is obtained by ultrasonic dissolution of the cross-linking agent and deionized water in a mass ratio of 0.18:1 for 5-20 minutes, and the ultrasonic frequency is 20-40 kHz.
[0042] In the embodiment, the cross-linking agent is added to the deionized water in a mass ratio of 0.18:1 in advance, and the cross-linking agent solution is obtained by ultrasonic dissolution. The ultrasonic dissolution time is preferably 5-20 minutes (min), and the ultrasonic frequency is preferably 20-40 kHz, so as to use the micro-mechanical effect generated by high-frequency vibration to promote the rapid dissolution of the cross-linking agent.
[0043] In some embodiments, the cross-linking agent is N,N-methylene bisacrylamide.
[0044] In the embodiment, the cross-linking agent used to configure the cross-linking agent solution can be N,N-methylene bisacrylamide (also known as MBA). MBA is used as a cross-linking agent for polymers, participates in the reaction in the form of a short-chain free radical, and can control the polymerization degree by changing the reaction conditions, thereby controlling the structure and morphology of the polymer.
[0045] In some embodiments, the metal ion solution is obtained by dissolving the metal ion and deionized water in a mass ratio of (0.06-0.3):1, and the metal ion is aluminum ion, zinc ion or iron ion.
[0046] In this embodiment, the metal ion is added to the deionized water in advance and dissolved sufficiently in a mass ratio of (0.06-0.3):1 to obtain the metal ion solution. Preferably, the metal ion is aluminum ion (chemical formula: Al 3+ ), and then it can be zinc ion (chemical formula: Zn 2+ ) or iron ion (chemical formula: Fe 3+ ).
[0047] In some embodiments, the step 102 comprises: after the pre-configured crosslinking agent solution and the metal ion solution are added to the mixed solution, performing cell disruption stirring for 3-10 minutes to obtain a uniformly dispersed reaction liquid A.
[0048] In this embodiment, after the pre-configured MBA solution and the metal ion solution are added to the mixed solution, the mixed solution is put into a cell disrupter for cell disruption stirring to improve the mixing uniformity of the mixed solution, thereby obtaining a uniformly dispersed mixed pre-polymer solution (i.e., reaction liquid A). Preferably, the cell disruption time is 3-10 minutes, and the cell disruption stirring can be performed at a certain time interval during the process.
[0049] In this embodiment, after the crosslinking agent solution and the metal ion solution are mixed in a certain proportion to obtain the reaction liquid A, the pre-configured initiator solution and tetramethyl ethylenediamine are added to the reaction liquid in a volume ratio of 1:1 to obtain a uniformly dispersed reaction liquid B. Tetramethyl ethylenediamine (also known as TEMED) is a water-miscible organic compound in liquid form, which has the function of catalyzing the crosslinking polymerization reaction.
[0050] In some embodiments, the initiator solution is obtained by dissolving the initiator and deionized water in a mass ratio of 0.018:1.
[0051] In this embodiment, the initiator is added to the deionized water in advance and dissolved sufficiently in a mass ratio of 0.018:1 to obtain the initiator solution for subsequent initiation of the polymerization reaction.
[0052] In some embodiments, the initiator is ammonium persulfate.
[0053] In this embodiment, the initiator used to prepare the initiator solution can be ammonium persulfate (also known as APS), which is an inorganic compound used as a polymer initiator. The polymerization reaction of monomers can be initiated by free radicals generated by the decomposition of ammonium persulfate.
[0054] In some embodiments, the step 103 comprises: after adding the pre-configured initiator solution and tetramethyl ethylenediamine into the reaction liquid A, performing ultrasonic dispersion for 15-30 minutes, and the ultrasonic power is 20-40 kHz, to obtain the reaction liquid B.
[0055] In this embodiment, after adding the pre-configured APS solution and TEMED into the reaction liquid in a mass ratio of 1:1, ultrasonic degassing treatment is needed to obtain a uniformly dispersed mixture pre-polymer liquid (i.e. reaction liquid B). The ultrasonic duration is preferably 15-30 min, and the ultrasonic power is preferably 20-40 kHz, so as to improve the mixing uniformity of the reaction liquid and avoid air entering.
[0056] In this embodiment, after obtaining the reaction liquid B, the reaction liquid B is placed in a mold for thermal initiation, and through chemical cross-linking reaction, a hydrogel humidity-sensitive material with a specified shape is formed in the mold.
[0057] It should be noted that, in order to avoid air entering and affecting the polymerization effect of the reaction liquid in the mold, a closed cylindrical mold is preferably used, and the opening of the closed mold is always kept upward and as vertical as possible during the polymerization process, so as to obtain a cylindrical anti-swelling hydrogel humidity-sensitive material.
[0058] In some embodiments, the reaction temperature for polymerization molding is 38-48 degrees Celsius, and the reaction time is 20-40 hours.
[0059] In this embodiment, after placing the reaction liquid B in the closed mold, the closed mold should be placed in a constant temperature box to ensure that the temperature of the thermal initiation is constant, so as to accelerate the polymerization reaction, improve the solidification molding speed of the hydrogel, and further improve the humidity sensing ability. The temperature of the thermal initiation is preferably 38-48 degrees Celsius. Within this temperature range, the higher the temperature of the thermal initiation, the shorter the time required for polymerization molding, so that the polymerization molding time can be controlled between 20-40 hours (h).
[0060] In the embodiment, in the first aspect, the addition of PEDOT:PSS and metal ions can introduce the effect of enhanced bonding to form a multi-layer network structure, thereby improving the tensile property, i.e., flexibility, of the hydrogel humidity-sensitive material; in the second aspect, the addition of PEDOT:PSS and AA enables the PEDOT:PSS chains and PAA chains to be crosslinked with each other, thereby improving the anti-swelling property of the hydrogel humidity-sensitive material; in the third aspect, the mixing of PEDOT:PSS, AA and metal ions can generate a large number of hydrogen bonds and hydrophilic groups, which greatly improve the humidity sensitivity, and when the humidity in the environment increases, the gel network of the hydrogel can adsorb water molecules in the air to increase the water content and improve the conductivity, thereby achieving the improvement of humidity sensing; in the fourth aspect, the preparation method of the hydrogel humidity-sensitive material of the embodiment is relatively simple, the preparation conditions are loose, and the preparation cost is greatly reduced.
[0061] The application will be further described in detail through a plurality of specific embodiments.
[0062] Embodiment 1
[0063] The preparation method of the anti-swelling hydrogel humidity-sensitive material of the application specifically comprises the following steps:
[0064] Step 201: 0.12 g of APS, 0.012 g of MBA and 0.4 g of aluminum ions are weighed and dissolved in 10 g of deionized water to obtain a pre-prepared APS solution, MBA solution and aluminum ion solution, wherein, in the process of preparing the MBA solution, ultrasonic dissolution is performed in an ultrasonic dispersion machine with an ultrasonic frequency of 30 kHz for 10 min;
[0065] Step 202: 4 g of PEDOT:PSS, 6 g of AA and 10 g of deionized water are weighed, 4 g of PEDOT:PSS is mixed with 10 g of deionized water, and then 6 g of AA is added to obtain a uniformly dispersed mixture;
[0066] Step 203: 3 milliliters (ml) of the MBA solution and 2 ml of the aluminum ion solution are weighed from the pre-prepared MBA solution and aluminum ion solution, and the two solutions are sequentially added to the above mixture;
[0067] Step 204: After the MBA solution and the aluminum ion solution are added to the above mixture, the mixture is subjected to cell disruption stirring in a cell disrupter, wherein the stirring is performed every 3 seconds for 3 seconds, until a cell disruption time of 3 min is reached, to obtain a uniformly dispersed reaction liquid A;
[0068] Step 205: 1ml of APS solution and 1ml of TEMED are weighed in the above-mentioned pre-configured APS solution, and the two solutions are sequentially added to the above-mentioned reaction liquid A, and ultrasonic debubbling is performed in an ultrasonic dispersion machine with an ultrasonic frequency of 30kHz for 15min to obtain a uniformly dispersed reaction liquid B;
[0069] Step 206: The reaction liquid B is placed in a sealed cylindrical mold, and polymerization molding is performed in a thermostat with a thermal initiation temperature of 45 degrees Celsius for 24h to obtain an anti-swelling hydrogel humidity-sensitive material for leakage and humidity monitoring.
[0070] Example 2:
[0071] The preparation method of the anti-swelling hydrogel humidity-sensitive material of the present application specifically comprises the following steps:
[0072] Step 301: 0.12g of APS, 0.012g of MBA and 0.6g of aluminum ions are weighed and dissolved in 10g of deionized water respectively to obtain pre-configured APS solution, MBA solution and aluminum ion solution, wherein during the preparation of the MBA solution, ultrasonic dissolution is performed in an ultrasonic dispersion machine with an ultrasonic frequency of 30kHz for 10min;
[0073] Step 302: 4g of PEDOT:PSS, 6g of AA and 10g of deionized water are weighed, 4g of PEDOT:PSS is mixed with 10g of deionized water, and then 6g of AA is added to obtain a uniformly dispersed mixture liquid;
[0074] Step 303: In the above-mentioned pre-configured MBA solution and aluminum ion solution, 3ml of MBA solution and 2ml of aluminum ion solution are weighed, and the two solutions are sequentially added to the above-mentioned mixture liquid;
[0075] Step 304: After the MBA solution and the aluminum ion solution are added to the above-mentioned mixture liquid, the mixture liquid is subjected to cell disruption stirring in a cell disruptor, wherein the stirring is performed every 3 seconds for 3 seconds, until a cell disruption time of 3min is reached, to obtain a uniformly dispersed reaction liquid A;
[0076] Step 305: 1ml of APS solution and 1ml of TEMED are weighed in the above-mentioned pre-configured APS solution, and the two solutions are sequentially added to the above-mentioned reaction liquid A, and ultrasonic debubbling is performed in an ultrasonic dispersion machine with an ultrasonic frequency of 30kHz for 15min to obtain a uniformly dispersed reaction liquid B;
[0077] Step 306: Put the reaction liquid B into a sealed cylindrical mold, and perform polymerization molding in a thermostat with a thermal initiation temperature of 45 degrees Celsius for 24 hours to obtain the anti-swelling hydrogel humidity-sensitive material for leakage and humidity monitoring.
[0078] Example 3:
[0079] The preparation method of the anti-swelling hydrogel humidity-sensitive material comprises the following steps:
[0080] Step 401: Weigh 0.12g of APS, 0.012g of MBA and 0.8g of aluminum ions, respectively dissolved in 10g of deionized water to obtain pre-configured APS solution, MBA solution and aluminum ion solution, wherein, in the process of configuring the MBA solution, ultrasonic dissolution needs to be performed in the ultrasonic dispersion machine with an ultrasonic frequency of 30kHz for 10min;
[0081] Step 402: Weigh 4g of PEDOT:PSS, 6g of AA and 10g of deionized water, mix 4g of PEDOT:PSS with 10g of deionized water first, then add 6g of AA to obtain a uniformly dispersed mixture;
[0082] Step 403: In the pre-configured MBA solution and aluminum ion solution, weigh 3ml of MBA solution and 2ml of aluminum ion solution, and add the two solutions to the above mixture in sequence;
[0083] Step 404: After adding the MBA solution and the aluminum ion solution to the above mixture, perform cell disruption stirring on the mixture in the cell disrupter, wherein, stir every 3 seconds for 3 seconds, until the cell disruption time reaches 3min, to obtain a uniformly dispersed reaction liquid A;
[0084] Step 405: Weigh 1ml of APS solution in the pre-configured APS solution, and weigh 1ml of TEMED at the same time, add the two solutions to the above reaction liquid A in sequence, and perform ultrasonic debubbling in the ultrasonic dispersion machine with an ultrasonic frequency of 30kHz for 15min to obtain a uniformly dispersed reaction liquid B;
[0085] Step 406: Put the reaction liquid B into a sealed cylindrical mold, and perform polymerization molding in a thermostat with a thermal initiation temperature of 45 degrees Celsius for 24 hours to obtain the anti-swelling hydrogel humidity-sensitive material for leakage and humidity monitoring.
[0086] Example 4:
[0087] The preparation method of the anti-swelling hydrogel humidity-sensitive material comprises the following steps:
[0088] Step 501: 0.12 g of APS, 0.012 g of MBA and 1.0 g of aluminum ions are weighed and dissolved in 10 g of deionized water respectively to obtain a pre-configured APS solution, an MBA solution and an aluminum ion solution, wherein, in the process of configuring the MBA solution, ultrasonic dissolution needs to be performed in an ultrasonic disperser with an ultrasonic frequency of 30 kHz for 10 min;
[0089] Step 502: 4 g of PEDOT:PSS, 6 g of AA and 10 g of deionized water are weighed, 4 g of PEDOT:PSS is mixed with 10 g of deionized water first, and then 6 g of AA is added to obtain a uniformly dispersed mixed solution;
[0090] Step 503: 3 ml of the MBA solution and 2 ml of the aluminum ion solution are weighed from the pre-configured MBA solution and aluminum ion solution, and the two solutions are sequentially added to the above-mentioned mixed solution;
[0091] Step 504: After the MBA solution and the aluminum ion solution are added to the above-mentioned mixed solution, the mixed solution is subjected to cell crushing stirring in a cell crusher, wherein the stirring is performed every 3 seconds for 3 seconds, until a cell crushing time length of 3 min is reached, to obtain a uniformly dispersed reaction solution A;
[0092] Step 505: 1 ml of the APS solution is weighed from the pre-configured APS solution, 1 ml of TEMED is weighed at the same time, the two solutions are sequentially added to the above-mentioned reaction solution A, and ultrasonic debubbling is performed in an ultrasonic disperser with an ultrasonic frequency of 30 kHz for 15 min to obtain a uniformly dispersed reaction solution B;
[0093] Step 506: The reaction solution B is placed in a sealed cylindrical mold, and polymerization molding is performed in a thermostat with a thermal initiation temperature of 45 degrees Celsius for 24 h to obtain an anti-swelling hydrogel humidity-sensitive material for leakage and humidity monitoring.
[0094] It should be noted that the differences between the above-mentioned embodiments 1 to 4 are only that the mass of aluminum ions added is adjusted to be 0.4 g, 0.6 g, 0.8 g and 1.0 g respectively, and other preparation steps and preparation conditions are the same, which are only used to illustrate the preparation method of the anti-swelling hydrogel humidity-sensitive material in the embodiments of the present application, and there are multiple possibilities in the mass of the added metal ions, and not all the possibilities of the preparation method are completely reflected. In addition, in addition to the multiple possibilities of the mass of the added metal ions, the mass of other raw materials added can also have multiple possibilities, for example, the mass of the added PEDOT:PSS can be 0.1 or 0.4, etc.
[0095] Based on the preparation method of the anti-swelling hydrogel humidity-sensitive material in the embodiments of the present application, different masses of Al 3+The anti-swelling hydrogel humidity-sensitive material prepared by PEDOT:PSS was applied to a flexible humidity sensor, and its conductivity (K, in Siemens per meter (S / m)) and resistivity change rate (ΔR / R0 (%)) were tested under different humidity environments. Figure 2 This is a schematic diagram illustrating the relationship between relative humidity and electrical conductivity of the hydrogel humidity-sensitive material according to an embodiment of the present invention; as shown below. Figure 2 As shown, with other preparation methods remaining unchanged, 1.5g Al was used respectively. 3+ and 0.1g PEDOT:PSS, 1.5g Al 3+ And 0.4g PEDOT:PSS, 2.0g Al 3+ And 0.1g PEDOT:PSS and 2.0g Al 3+ Four hydrogel humidity-sensitive materials prepared with 2.0g Al and 0.4g PEDOT:PSS all exhibited increased conductivity with increasing relative humidity in measurement environments ranging from 20% to 98%, indicating that all four hydrogel humidity-sensitive materials possessed relatively fast response speeds. 3+ The hydrogel humidity-sensitive material prepared with 0.1g PEDOT:PSS exhibited the fastest response speed.
[0096] Figure 3 This is a schematic diagram illustrating the relationship between relative humidity and resistivity change rate of the hydrogel humidity-sensitive material according to an embodiment of the present invention; as shown below. Figure 3 As shown, with other preparation methods remaining unchanged, 1.5g Al was used respectively. 3+ and 0.1g PEDOT:PSS, 1.5g Al 3+ And 0.4g PEDOT:PSS, 2.0g Al 3+ And 0.1g PEDOT:PSS and 2.0g Al 3+ Four hydrogel humidity-sensitive materials prepared with 0.4 g PEDOT:PSS all exhibited good humidity sensitivity. In measurement environments with relative humidity ranging from 20% to 98%, the rate of change in resistivity increased with increasing relative humidity. This indicates that all four hydrogel humidity-sensitive materials possess good humidity sensitivity. Among them, the material with 2.0 g Al... 3+ The hydrogel humidity-sensitive material prepared with 0.1g PEDOT:PSS exhibited the best humidity sensitivity.
[0097] In summary, the hydrogel humidity-sensitive material prepared by the method for preparing the anti-swelling hydrogel humidity-sensitive material based on the embodiments of the present invention, when applied to the field of humidity sensing, has good humidity sensing ability and faster response speed in high humidity environments.
[0098] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A method for preparing an anti-swelling hydrogel humidity-sensitive material, characterized in that, The method includes: Poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate and acrylic acid were added to deionized water to obtain a mixture; wherein the ratio of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, acrylic acid and deionized water was (3-5) g:(4-9) g:(10-15) g. The pre-prepared crosslinking agent solution and metal ion solution are added to the mixture and dispersed evenly to form reaction solution A; wherein the ratio of the added crosslinking agent solution to the metal ion solution is (1.5~2.5):1; The pre-prepared initiator solution and tetramethylethylenediamine were added to reaction solution A in a 1:1 ratio and dispersed evenly to obtain reaction solution B; The reaction solution B was heated to polymerize and mold, resulting in an anti-swelling hydrogel moisture-sensitive material.
2. The method according to claim 1, characterized in that, The crosslinking agent solution is obtained by ultrasonically dissolving the crosslinking agent and deionized water at a mass ratio of 0.18:1 for 5 to 20 minutes, with an ultrasonic frequency of 20 to 40 kHz.
3. The method according to claim 1, characterized in that, The metal ion solution is obtained by dissolving metal ions and deionized water at a mass ratio of (0.06-0.3):1, and the metal ions used are aluminum ions, zinc ions, or iron ions.
4. The method according to claim 1, characterized in that, The initiator solution is obtained by dissolving the initiator and deionized water at a mass ratio of 0.018:
1.
5. The method according to claim 2, characterized in that, The crosslinking agent is N,N-methylenebisacrylamide.
6. The method according to claim 4, characterized in that, The initiator used is ammonium persulfate.
7. The method according to claim 1, characterized in that, The step of adding a pre-prepared crosslinking agent solution and a metal ion solution to a mixture and dispersing them evenly to form reaction solution A includes: After adding the pre-prepared crosslinking agent solution and metal ion solution to the mixture, the cells are broken down and stirred for 3 to 10 minutes to obtain a uniformly dispersed reaction solution A.
8. The method according to claim 1, characterized in that, The step of adding a pre-prepared initiator solution and tetramethylethylenediamine in a 1:1 ratio to reaction solution A and dispersing them evenly to obtain reaction solution B includes: After adding the pre-prepared initiator solution and tetramethylethylenediamine to reaction solution A, the mixture is ultrasonically dispersed for 15–30 minutes at an ultrasonic power of 20–40 kHz to obtain reaction solution B.
9. The method according to claim 1, characterized in that, The reaction temperature for polymerization is 38–48 degrees Celsius, and the reaction time is 20–40 hours.
10. A swelling-resistant hydrogel humidity-sensitive material, characterized in that, The anti-swelling hydrogel humidity-sensitive material is prepared by the preparation method described in any one of claims 1 to 9.