CN113943425B - Application of double-network organogel in preparation of oxygen sensor - Google Patents
Application of double-network organogel in preparation of oxygen sensor Download PDFInfo
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Abstract
The invention discloses a double-network organogel and a preparation method and application thereof, wherein acrylamide and chitosan are utilized to prepare the double-network organogel, the gel contains a large amount of hydroxyl and amino functional groups and can react with oxygen, the oxygen sensor is prepared by utilizing the double-network organogel, oxygen can be captured to a three-phase interface of a gel-electrode-external environment, an electrochemical reaction is generated under the action of applied voltage, an electrical signal is generated, the response of the gel to oxygen concentration is formed, and meanwhile, the sensitivity to oxygen is improved.
Description
Technical Field
The invention relates to the technical field of sensors, in particular to a double-network organogel and a preparation method and application thereof.
Background
With the rapid development of 5G and the Internet of things, the world of everything interconnection is coming, and more sensors gradually enter the lives of people. In the aspect of monitoring objects by actual sensors, gas detection, especially oxygen detection, becomes more important, because people cannot leave oxygen, which is closely related to the health of people, and when the oxygen concentration in the environment is too high or too low, the oxygen sensor can cause harm to human bodies, so that the oxygen sensor plays an important role in monitoring whether the oxygen concentration around the environment where the human bodies are located is normal or not in real time, and a higher-quality living environment is provided for people. In addition, the oxygen sensor in the wearable electronic device, the electronic skin, and other devices needs to be attached to an object with an irregular surface topography for use, and may be deformed such as bent and stretched during use, so that the oxygen sensor is also required to have good flexibility and stretchability. In addition, in a daily application, since the sensor moves along with a human body or a robot, the sensor is likely to be detached or damaged. Therefore, it also needs a certain self-adhesion and self-healing property so that it can be better applied to practical situations.
Conventional flexible gas sensors are typically made by integrating a non-flexible sensing element, such as MoS, on a flexible substrate, such as Polydimethylsiloxane (PDMS), polybutylene adipate/terephthalate (Ecoflex), and Polyimide (PI) 2 、CeO 2 And the self stretchability of the sensor is limited by the flexible substrate, and meanwhile, the separation of the sensitive element and the substrate may occur, so that the stability of the device is reduced, and the biocompatibility and the self-adhesion of the flexible substrate materials are generally poor, so that the flexible substrate materials are not suitable for being directly attached to human skin, and even if the flexible substrate materials can be attached to the human skin, the self-adhesion is not high enough. For example, chinese patent CN110183688 discloses a method for preparing a flexible strain sensor based on nanocellulose-carbon nanotube-polyacrylamide conductive hydrogel, which can be used to prepare a flexible oxygen sensor without a substrate, but has low sensitivity and poor self-adhesion and biocompatibility because the gel cannot adsorb oxygen in the environment.
Disclosure of Invention
The invention aims to solve the technical problems of low sensitivity, poor self-adhesion performance and poor biocompatibility of the existing oxygen sensor by using gel, and provides a preparation method of double-network organogel.
The above purpose of the invention is realized by the following technical scheme:
a preparation method of a double-network organogel comprises the following steps:
firstly, mixing acrylamide, a cross-linking agent, an initiator, chitosan, a cosolvent and a solvent, carrying out cross-linking polymerization to prepare a single-network hydrogel, then soaking the single-network hydrogel in an electrolyte salt solution, and carrying out salting-out to prepare a double-network organogel, wherein the mass ratio of the acrylamide to the cross-linking agent to the initiator to the chitosan to the cosolvent is 500-3000:0.5-3:20-100:100-1000:20-100.
The invention utilizes acrylamide and chitosan to prepare double-network organogel, wherein polyacrylamide in a network structure contains-CONH 2 Chitosan is an alkaline polysaccharide containing a large amount of-OH, -NH 2 Endowing the double-network organic gel with a large number of functional groups. The oxygen sensor is prepared by utilizing the double-network organogel, the functional groups can capture oxygen and water molecules in the environment to a three-phase interface of gel-electrode-external environment through the interaction of hydrogen bonds and the like, and generate electrochemical reaction under the action of applied voltage so as to generate an electrical signal, the active adsorption capacity to oxygen is favorable for forming the response of the gel to the oxygen concentration, and the sensitivity of the sensor is greatly improved. In addition, when the double-network organogel is contacted with other external objects, the functional groups can form hydrogen bonds or ionic interaction with the contacted objects, so that the double-network organogel can be tightly adhered to the contacted objects and has good self-adhesion. The mechanical strength and biocompatibility of the gel can be enhanced by adding the chitosan, so that the gel is less prone to damage and the like, the durability of the sensor is further improved, and the sensor is more suitable for being in a human body or being in contact with the human body. The double-network organic gel is used as an oxygen sensor, and when the oxygen sensor is in an environment containing O 2 In the method, because the functional group is contained in the double-network organic gel, the double-network organic gel can be in contact with O in the surrounding environment 2 The molecules interact through hydrogen bonds or the like, O 2 Is adsorbed and trapped, O 2 Molecules can obtain electrons at the cathode of the oxygen sensor and are reduced, and reduction reaction is carried out; the metal electrode can lose electrons at the anode of the oxygen sensor and be oxidized to generate oxidation reaction, so that Faraday current is formed in the whole electrochemical reaction process, and when the concentration of oxygen is higher, the more oxygen participating in the electrochemical reaction in the same time is, the higher the Faraday current is; conversely, the lower the oxygen concentration, the lower the faraday current generated. By observing the change of the current flowing through the sensor, the change of the oxygen concentration in the environment can be known, in addition, the double-network organic gel is used as the oxygen sensor, the oxygen sensor can also have excellent flexibility and stretchability, and the chitosan has good biocompatibility, so the gel has high safety and can be widely applied to wearable devices and electronic skins.
Preferably, the mass ratio of the acrylamide to the cross-linking agent to the initiator to the chitosan to the cosolvent to the solvent is 1500-2000:1-2:40-70:300-500:40-70.
Preferably, the electrolyte salt is one or more of potassium chloride, calcium chloride and sodium chloride. The existence of electrolyte salt can shield electrostatic repulsion between chitosan chains, and salting-out action is helpful for dehydration of chitosan chains, and interaction between hydrophobic chains is increased, so that loose chitosan chains form a chitosan network.
Preferably, the cross-linking agent is N, N' -methylenebisacrylamide.
Preferably, the initiator is a photoinitiator or a thermal initiator.
Preferably, the photoinitiator is photoinitiator 2959.
Preferably, the thermal initiator is ammonium persulfate.
Preferably, the solvent is water or water and a polyhydric alcohol having 1 to 10 carbon atoms. The solvent provides an environment conducive to the movement of anions and cations and a sufficient number of water molecules to participate in the electrochemical reaction.
When the solvent is water, the hydrogel is soaked in the electrolyte salt solution and then soaked in the polyhydric alcohol with 1-10 carbon atoms, and part of water in the double-network gel is treatedThe molecules are replaced by organic solvent molecules, so that the gel is converted into the organogel, and the double-network organogel is obtained. The introduction of the alcohol organic solvent brings a large amount of-OH groups, so that hydrogen bond interaction can be formed between the alcohol organic solvent and a gel network, and the gel is toughened; and hydrogen bonds can be formed between the gel and free water molecules, so that the content of the free water molecules in the gel is reduced, and the content of bound water molecules is increased, so that the problem that water in the gel is easy to evaporate is solved, the freezing point of a solvent can be reduced, the frost resistance and the moisture retention performance of the gel are improved, and the sensor can normally work within a wider temperature range. In addition, the-OH groups introduced by the polyol can react with O 2 、H 2 O molecules form hydrogen bonds, promoting O 2 、H 2 The adsorption of O further improves the sensitivity of oxygen detection. Furthermore, the-OH introduced by the polyalcohol can also be connected with the-CONH of polyacrylamide and chitosan network 2 -OH and-NH 2 A large number of hydrogen bonds are formed between the two layers, the original loose double-network structure is toughened, and the tensile property is improved.
Preferably, the solvent is propylene glycol. The freezing point of the mixed solution of the propylene glycol and the water can reach below-120 ℃, and the frost resistance of the gel can be improved.
Preferably, the cosolvent is one or more of acetic acid, citric acid and diluted hydrochloric acid.
The invention protects the double-network organogel prepared by the preparation method.
The invention also protects the application of the double-network organogel in preparing the oxygen sensor.
Preferably, the oxygen sensor further comprises an electrode.
Preferably, the electrode is a silver electrode.
The oxygen sensor prepared based on the polyacrylamide-chitosan double-network organogel can be applied to portable oxygen sensing devices, wearable oxygen sensing devices, oxygen sensing electronic skins, human-computer interfaces, flexible robots, medical equipment or plant growth monitoring equipment. The device can further comprise a flexible substrate and an alarm, wherein the oxygen sensor can be arranged on the surface of the flexible substrate in a stacking mode, and the alarm is triggered when the oxygen sensor senses that the oxygen concentration is lower than a set value or exceeds the set value.
Compared with the prior art, the invention has the beneficial effects that:
the invention uses acrylamide and chitosan to prepare single network hydrogel through cross-linking polymerization, and then prepares double network organogel through salting-out action under the action of electrolyte salt, the gel system contains a large amount of hydroxyl and amino functional groups which can react with oxygen, the oxygen sensor is prepared by using the double network organogel, the oxygen is captured to the three-phase interface of gel-electrode-external environment, and electrochemical reaction is generated under the action of applied voltage, thereby generating electric signals, forming the response of the gel to the oxygen concentration, and simultaneously improving the sensitivity. In addition, the functional groups in the double-network organic gel also improve the self-adhesion performance of the gel. The double-network organogel is used as the oxygen sensor, so that the sensor has excellent stretchability, flexibility, self-adhesion performance and self-repairing performance, the sensitivity is high, and the biocompatibility of the chitosan is good, so that the prepared oxygen sensor has better safety, is more suitable for equipment in contact with human skin, such as oxygen sensing electronic skin, and can be directly attached to the human skin to monitor O in the environment in real time 2 The content of the gas is changed, so that the oxygen sensor can be widely applied to wearable devices.
Drawings
FIG. 1 is a schematic diagram of the synthesis process and structure of a double-network organogel according to example 1 of the present invention; wherein the reference numbers are as follows: chitosan 1, a photoinitiator 2959, acrylamide 3, N' -methylene bisacrylamide 4, acetic acid 5, polyacrylamide 6, a chitosan network 7, sodium chloride 8, propylene glycol 9 and a hydrogen bond 10.
FIG. 2 shows polyacrylamide, chitosan, propylene glycol, and water molecules and O in the external environment in the double-network organogel of example 1 of the present invention 2 A molecular binding scheme; wherein the reference numbers are: o is 2 11, electrons 12, water molecules 13, a metal cathode 14 and a metal anode 15.
Fig. 3 is a schematic diagram of the working principle of the double-network organogel as an oxygen sensor in embodiment 1 of the present invention.
FIG. 4 is a graph showing the flexibility and tensile properties of the double-network organogel of example 1.
FIG. 5 is a self-adhesive property test chart of the double-network organogel of example 1 of the present invention.
FIG. 6 is a self-healing characteristic test chart of the double-network organogel of example 1.
FIG. 7a is a diagram of a pair 1%O as oxygen sensors when a dual-network organogel is not deformed in example 1 of the present invention 2 Three times of cycle test dynamic response curve of the gas; FIG. 7b shows a pair of 1%O as oxygen sensor when the dual-network organogel is not deformed in accordance with embodiment 1 of the present invention 2 Response results of three-cycle testing of gas; FIG. 7c shows an embodiment of the present invention as an oxygen sensor pair 1%O when the dual-network organogel is not deformed 2 A response time and recovery time test curve in the test of one period of gas; FIG. 7d shows the exposure of the double-network organogel of example 1 of the present invention to different concentrations of O as an oxygen sensor without deformation 2 Dynamic response curve in gas; FIG. 7e shows the oxygen sensor pair O when the double-network organogel is not deformed in example 1 of the present invention 2 A gas concentration response linear fitting curve; as shown in FIG. 7f, the performance of the oxygen sensor prepared from the polyacrylamide-chitosan double-network organogel in all aspects is far better than that of most of the oxygen sensors based on metal oxide semiconductors reported at present.
FIG. 8a shows the twin-network hydrogel and the twin-network organogel pair 1%O in example 1 of the present invention 2 The response curve of the gas; FIG. 8b is a graph of the single network organogel and dual network organogel pair 1%O of example 1 of the present invention 2 Response curve of gas.
FIG. 9a shows the same concentration of O in an undeformed and 86% stretched dual network organogel of example 1 in accordance with the present invention 2 The response curve of the gas; FIG. 9b is a diagram of example 1 of the present invention showing the double-network organogel pair 1%O in an undeformed and 180 degree bent state 2 The response curve of the gas; FIG. 9c is the pair 1%O of the dual-network organogel of example 1 after fracture and self-repair 2 Response of gasA curve; FIG. 9d is the drawing of example 1 of the present invention showing the double-network organogel pair 1%O under different deformation states 2 Response results of the gas.
Detailed Description
The present invention will be further described with reference to specific embodiments, but the present invention is not limited to the embodiments in any way. The starting reagents used in the examples of the present invention are those conventionally purchased, unless otherwise specified.
Example 1
A preparation method of a double-network organogel comprises the following steps:
s1, mixing acrylamide 3, chitosan 1, N' -methylene bisacrylamide 4, a photoinitiator 2959, acetic acid 5 and deionized water in proportion, magnetically stirring at 900rpm until the mixture is uniform to obtain a mixed solution, and then carrying out photoinitiation for 1 hour under the irradiation of ultraviolet light to carry out cross-linking polymerization to form polyacrylamide network gel; wherein the mass ratio of acrylamide, N' -methylene bisacrylamide, photoinitiator, chitosan and acetic acid is 1800:1:58:400:58;
s2, soaking the polyacrylamide gel in sodium chloride 8 for 30min, and forming a chitosan network 7 by using the dispersed chitosan chains through salting out effect to obtain polyacrylamide/chitosan double-network gel;
s3, soaking the polyacrylamide/chitosan double-network gel in propylene glycol 9 for 7h to obtain the polyacrylamide-chitosan double-network-based organic gel, wherein the preparation process is shown in the figure 1.
As shown in figure 2, because the polyacrylamide 6, the chitosan network 7 and the propylene glycol 9 in the gel contain functional groups, the functional groups can be respectively matched with water molecules 13 and O in the external environment 2 11, hydrogen bonds 10 are formed, so that the sensitivity of the gel to oxygen detection can be improved.
Example 2
The difference between the embodiment and the embodiment 1 is that the mass ratio of acrylamide, N' -methylene-bisacrylamide, photoinitiator, chitosan and acetic acid is replaced by 1500:1:40:300:40.
example 3
The difference between the embodiment and the embodiment 1 is that the mass ratio of acrylamide, N' -methylene-bis-acrylamide, photoinitiator, chitosan and acetic acid is replaced by 2000:2:70:500:70.
comparative examples 1 to 3
Comparative example 1 was prepared substantially in the same manner as in example 1 except that step S3 was not performed.
Comparative example 2 is prepared substantially in the same manner as in example 1, except that chitosan powder, acetic acid, and step S2 are not added.
Comparative example 3 was prepared in substantially the same manner as in example 1, except that chitosan was replaced with sodium alginate.
Performance testing
1. Flexibility and stretchability of gels
The double network organogel prepared in example 1 was subjected to bending, twisting, and stretching experiments, and the gel was bent to 180 ° (results are shown in fig. 4 a) and twisted to 720 ° (results are shown in fig. 4 b) by hand, and after the external force was removed, the gel was rapidly restored to its original shape. The results show that the gel stretches up to 1400% of its original length (as shown in FIG. 4c, d), indicating that the double-network organogel has excellent flexibility and stretchability. The double-network organogels prepared in examples 2 to 3 were subjected to the bending, twisting and stretching experiments, and the results show that the double-network organogels also have excellent flexibility and stretchability.
2. Self-adhesive properties
The double-network organic gel prepared in example 1 is adhered to different substrates including metal, plastic and glass, and still can bear the weight of 80g, 40g and 100g respectively (as shown in fig. 5 a), and the adhesion strength of the organic gel to the metal, the plastic and the glass can be calculated to be 20 kPa, 9.1 kPa and 10kPa respectively. This excellent adhesion is in addition to-CONH on polyacrylamide 2 In addition to this, the large amount of-NH groups on the chitosan chains 2 . When chitosan was not present (comparative example 2) or replaced by another polymer network (comparative example 3), the adhesion properties decreased. Comparative example 2 gel to goldThe adhesive strength of the metal, plastic and glass is 1.5, 3.5 and 2.2kPa respectively, and the adhesive strength of the gel prepared in the comparative example 3 to the metal, plastic and glass is 0.7, 0.6 and 1.4kPa respectively, which is far lower than that of the polyacrylamide-chitosan double-network organic gel prepared in the example 1 (as shown in figure 5 b). The polyacrylamide-chitosan double-network organogel has larger peel strength to various substrates (as shown in figure 5 c) through 180-degree peeling experiments, and the peel strength of the double-network organogel on glass and aluminum sheets is similar and is about 35N/m. This indicates that the double network organogel has good self-adhesive properties.
3. Self-repairing property
The LED bulb and the double-network organogel prepared in example 1 were combined to form a closed loop, and a 3V power supply was applied to the closed loop, which indicated that the double-network organogel had good conductivity (as shown in fig. 6 a). The double network organogel was cut with scissors, the closed current loop was opened and the LED bulb was immediately extinguished (as shown in fig. 6 b). And then the double-network organic gel cut into two sections is butted, the self-repairing of the double-network organic gel is realized, the conductivity of the double-network organic gel is restored again, and the LED bulb is lighted (as shown in figure 6 c). The electrical device tests the resistance of the fractured double-network organogel after being butted and re-separated, so that the resistance of the butted double-network organogel can be quickly restored to the original resistance value (as shown in fig. 6 d). These all indicate that the electrical properties thereof have good self-repairing properties. The butted and repaired double-network organogel is heated for 10min at 100 ℃ in a sealed state, and the double-network organogel can realize more than 250% of stretching (as shown in figure 6e, f), so that the good mechanical property of the double-network organogel is shown, and the good self-repairing property of the double-network organogel is also shown.
4. Gas-sensitive characteristics
The organogel prepared in example 1 was exposed sequentially to pure N 2 And a specific concentration of O 2 Connecting electrodes at both ends of the organogel to an electrical test device in a gas atmosphere, and monitoring the relative current change (Δ I/I) through the organogel 0 % and. DELTA.I is the change in current, I 0 Is initially in pure N 2 Current under atmosphere) The gas sensitive characteristics of the sensor were evaluated. The ventilator is at "O" in FIG. 7 for each test cycle 2 When the valve is opened, the O begins to be introduced 2 Gas up to "O 2 Off, end, O 2 When closed, nitrogen was started.
As shown in figure 7a, b, the organogel was exposed to 1% O repeatedly for cycles as an oxygen sensor 2 The dynamic response curve of the gas and the response magnitude of the cycle test. When the organogel is exposed to O 2 The current increases immediately when the gas is in motion, at which time O 2 Gas and H 2 The O molecules participate in the electrochemical reaction at the cathode to generate faradic current, causing an increase in the current flowing through the organogel. In the three-cycle test, the organogel pair 1%O 2 The response of (a) is substantially constant, indicating good repeatability.
As shown in FIG. 7c, organogel as oxygen sensor pair 1%O 2 The response time and the recovery time of the catalyst are respectively 39.9s and 63.7s, which are shorter than those based on ZnO and SnO 2 The oxygen sensor made of the traditional metal oxide material shows that the oxygen sensor has higher response speed and recovery speed.
As shown in FIG. 7d, organogels as oxygen sensors for different concentrations of O 2 Have different responses, and the smaller the concentration the smaller the response.
As shown in FIG. 7e, organogel as oxygen sensor pair O 2 The gas concentration response presents positive correlation, the detection range is from 0 percent to 100 percent, and the gas concentration response has the characteristic of detection in the full concentration range. And the gas sensor has good linearity under the concentration of 0-20%. The sensitivity of the gas sensor is 0.2%/ppm at a concentration of 0% to 20%, the theoretical detection limit is as low as 5.7ppm, and the sensitivity is very high.
As shown in FIG. 7f, the performance of each aspect of the oxygen sensor prepared from the polyacrylamide-chitosan double-network organogel is far better than that of most of the oxygen sensors based on metal oxide semiconductors reported at present.
As shown in FIGS. 8a, b, the polyacrylamide-chitosan double network organogel prepared in example 1 was prepared relative to comparative example 1The polyacrylamide-chitosan double-network hydrogel, the polyacrylamide single-network hydrogel prepared in the comparative example 2 and the polyacrylamide-calcium alginate prepared in the comparative example 3 have higher response and sensitivity when being used as gas sensors. Under the same conditions, the polyacrylamide-chitosan double-network hydrogel pair 1%O prepared in comparative example 1 2 The response was 1968%, much higher than 564% for comparative example 2 and 498% for comparative example 3, suggesting that the introduction of chitosan as a second polymer network into the gel brought a large amount of-NH to the gel 2 and-OH, the response sensitivity of the sensor is greatly improved; also for 1%O 2 Example 1 prepared bis-network organogel pair 1%O relative to comparative example 1 2 The response of the sensor is improved from 1968% to 3200% by 1.6 times, and the result shows that after the sensor is soaked in propylene glycol, the double-network hydrogel is successfully modified into double-network organogel, and the propylene glycol is introduced into the gel, so that a large amount of-OH is increased, and the sensitivity of the sensor is further improved.
5. Influence of different states of the gel on gas sensitivity
As shown in FIG. 9a, the organic hydrogel still responded to oxygen when the tensile strain was 86%, and the magnitude of the response increased from 2065% to 5139% for the same concentration of oxygen; as shown in FIGS. 9b, c, d, the sensor is sensitive to 1% concentration of O under 180 deg. bending conditions 2 3136%, in the post-self-repaired state, the sensor is sensitive to O at a concentration of 1% 2 The response of (c) was 3240%, which is substantially consistent with the response in the original state, i.e., unbent compared to 3200% without fracture. This indicates that the organogel-based gas sensor can still function properly in a bent state or after it has broken and healed naturally again; even in the tensile deformation state, the device can still work as usual through the calibration of an external device. The characteristics make it very suitable for the flexible electronic device field, help to expand its application range.
The oxygen sensor comprises electrodes for participating in an electrochemical reaction and for measuring a parameter reflecting the rate of the electrochemical reaction, the parameter being selected from the group consisting of the current flowing through the gel at a bias voltage, the currentA metal with good conductivity, such as silver, is highly selected. The oxygen sensor may further include detection means electrically connected to the two electrodes, respectively, for measuring a current flowing through the oxygen sensor through the electrodes. When in an oxygen atmosphere, oxygen can participate in electrochemical reactions at the electrodes of the sensor, thereby generating a faraday current. The higher the concentration of the oxygen is, the more the oxygen participating in the electrochemical reaction in the same time is, and the larger the generated Faraday current is; conversely, the lower the oxygen concentration, the lower the faraday current generated. By observing the change in current flowing through the sensor, the change in oxygen concentration in the environment can be known. The schematic diagram of the oxygen sensor prepared by the double-network organic hydrogel is shown in figure 3, and when the gas O to be detected in the external environment 2 The molecules 11 get electrons 12 at the metal cathode 14 of the oxygen sensor, and undergo a reduction reaction in the presence of water molecules 13: o is 2 +2H 2 O+4e - →4OH - . The metal anode is a silver electrode, and the silver is oxidized at the metal anode 15: ag-e - →Ag + ，Ag + +Cl - ≈ AgCl. The oxygen sensor detects a change in concentration of oxygen in the environment by detecting a change in the rate of electrochemical reactions occurring at the gel-electrode-external environment three-phase interface.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.
Claims (6)
1. The application of the double-network organogel in preparing the oxygen sensor is characterized in that the preparation method of the double-network organogel comprises the following steps:
firstly, mixing acrylamide, a cross-linking agent, an initiator, chitosan, a cosolvent and water, carrying out cross-linking polymerization to prepare a single-network hydrogel, then soaking the single-network hydrogel in an electrolyte salt solution, carrying out salting-out action, and then soaking the single-network hydrogel in a polyhydric alcohol with the carbon atom number of 1-10 to prepare the double-network organogel, wherein the mass ratio of the acrylamide, the cross-linking agent, the initiator, the chitosan and the cosolvent is 500-3000:0.5-3:20-100:100-1000:20-100.
2. The use of claim 1, wherein the electrolyte salt is one or more of potassium chloride, calcium chloride and sodium chloride.
3. The use according to claim 1, wherein the mass ratio of the acrylamide, the cross-linking agent, the initiator, the chitosan and the cosolvent is 1500-2000:1-2:40-70:300-500:40-70.
4. Use according to claim 1, characterized in that the crosslinking agent is N, N' -methylenebisacrylamide.
5. Use according to claim 1, wherein the initiator is a photoinitiator or a thermal initiator.
6. The use of claim 1, wherein the cosolvent is one or more of acetic acid, citric acid and diluted hydrochloric acid.
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| CN104693382A (en) * | 2015-02-15 | 2015-06-10 | 青岛大学 | Method for preparing high-strength hydrogel |
| CN109134762A (en) * | 2018-09-13 | 2019-01-04 | 长春工业大学 | A kind of high intensity, freeze proof, conductive chitosan/acrylamide double-network hydrogel and preparation method thereof |
| CN109490380A (en) * | 2018-12-27 | 2019-03-19 | 中山大学 | Humidity sensor and its preparation method of application, equipment and humidity sensor |
| CN109490379A (en) * | 2018-12-27 | 2019-03-19 | 中山大学 | Gas sensor and its preparation method of application, equipment and gas sensor |
| CN110591002A (en) * | 2019-07-11 | 2019-12-20 | 郑州轻工业学院 | Multifunctional chitosan composite hydrogel and preparation method and application thereof |
| CN111234262A (en) * | 2020-01-07 | 2020-06-05 | 湖北大学 | CS/Al3+-PAM double-network ionic hydrogel and preparation method and application thereof |
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104693382A (en) * | 2015-02-15 | 2015-06-10 | 青岛大学 | Method for preparing high-strength hydrogel |
| CN109134762A (en) * | 2018-09-13 | 2019-01-04 | 长春工业大学 | A kind of high intensity, freeze proof, conductive chitosan/acrylamide double-network hydrogel and preparation method thereof |
| CN109490380A (en) * | 2018-12-27 | 2019-03-19 | 中山大学 | Humidity sensor and its preparation method of application, equipment and humidity sensor |
| CN109490379A (en) * | 2018-12-27 | 2019-03-19 | 中山大学 | Gas sensor and its preparation method of application, equipment and gas sensor |
| CN110591002A (en) * | 2019-07-11 | 2019-12-20 | 郑州轻工业学院 | Multifunctional chitosan composite hydrogel and preparation method and application thereof |
| CN111234262A (en) * | 2020-01-07 | 2020-06-05 | 湖北大学 | CS/Al3+-PAM double-network ionic hydrogel and preparation method and application thereof |
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