CN113943425A

CN113943425A - Double-network organogel and preparation method and application thereof

Info

Publication number: CN113943425A
Application number: CN202110893560.4A
Authority: CN
Inventors: 吴进; 梁誉苧; 吴子轩; 周子敬
Original assignee: Sun Yat Sen University
Current assignee: Sun Yat Sen University
Priority date: 2021-08-04
Filing date: 2021-08-04
Publication date: 2022-01-18
Anticipated expiration: 2041-08-04
Also published as: CN113943425B

Abstract

The invention discloses a double-network organogel and a preparation method and application thereof, the double-network organogel is prepared by utilizing acrylamide and chitosan, the gel contains a large amount of hydroxyl and amino functional groups, can react with oxygen, the oxygen sensor is prepared by utilizing the double-network organogel, the oxygen can be captured to the three-phase interface of the gel-electrode-external environment, under the action of applied voltage, electrochemical reaction is generated to generate an electric signal, the response of gel to oxygen concentration is formed, meanwhile, the sensitivity to oxygen is improved, in addition, the self-adhesive property of the gel is strong, and the chitosan has good biocompatibility, therefore, the oxygen sensor prepared by the invention has excellent stretchability and flexibility, self-adhesion performance, self-repairing performance and safety, and is more suitable for equipment in contact with human skin, so that the oxygen sensor can be widely applied to wearable devices.

Description

Double-network organogel and preparation method and application thereof

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 fabricated by integrating non-flexible sensing elements, such as MoS, on flexible substrates, such as Polydimethylsiloxane (PDMS), poly (ethylene adipate terephthalate) (Ecoflex), and Polyimide (PI)₂、CeO₂And 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 flexible application of conductive hydrogel based on nano-cellulose-carbon nanotube-polyacrylamideThe preparation method of the variable sensor utilizes the nanocellulose-carbon nanotube/polyacrylamide to prepare the conductive hydrogel, and the conductive hydrogel can be used for preparing the flexible oxygen sensor without a substrate, but the sensitivity is not high because the gel cannot adsorb oxygen in the environment, and the self-adhesion performance and the biocompatibility are still not good enough.

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, preparing a single-network hydrogel through cross-linking polymerization, then soaking the single-network hydrogel in an electrolyte salt solution, and preparing a double-network organogel through salting out, 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-CONH₂Chitosan is an alkaline polysaccharide containing a large amount of-OH, -NH₂Endowing 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 an electrochemical reaction is generated under the action of applied voltage, so that the oxygen sensor is producedAn electrical signal is generated, and the active adsorption capacity to oxygen contributes to the response of the formed gel to the oxygen concentration, so that 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. Uses double-network organic gel as oxygen sensor, when in environment containing O₂When the double-network organic gel contains functional groups, the functional groups can react with O in the surrounding environment₂The molecules interact through hydrogen bonds or the like, O₂Is adsorbed and trapped, O₂Molecules can obtain electrons at the cathode of the oxygen sensor to be 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-: 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 polyhydric alcohol with 1-10 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.

And when the solvent is water, soaking the hydrogel in an electrolyte salt solution, and then soaking the hydrogel in polyhydric alcohol with 1-10 carbon atoms, replacing part of water molecules in the double-network gel with organic solvent molecules, so that the gel is converted into 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 O₂、H₂O molecules form hydrogen bonds, promoting O₂、H₂The adsorption of O further improves the sensitivity of oxygen detection. In addition, the-OH introduced by the polyalcohol can also react with polyacrylamide and-CONH of a chitosan network₂-OH and-NH₂A 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, 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 electrical signals, forming the response of the gel to 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 bodyReal-time monitoring of O in an environment on skin₂The content of the gas varies, which enables the oxygen sensor to 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 29592, acrylamide 3, N, 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 invention₂A molecular binding scheme; wherein the reference numbers are: o is₂11, 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 graph of the oxygen sensor vs. 1% O when the dual-network organogel is undeformed in accordance with example 1 of the present invention₂Testing a dynamic response curve of the gas in three cycles; FIG. 7b shows the oxygen sensor pair of 1% O when the dual-network organogel of example 1 is undeformed₂Response results of three-cycle testing of gas; FIG. 7c shows the oxygen sensor pair at 1% O when the dual-network organogel is undeformed according to an embodiment of the present invention₂Test curves of response time and recovery time in a 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 deformation₂Dynamic 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 invention₂Gas concentration response linear fitting curve(ii) a 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.

FIG. 8a shows the dual network hydrogel and dual network organogel with 1% O according to example 1 of the present invention₂The response curve of the gas; FIG. 8b shows the single network organogel and double network organogel vs. 1% O of example 1 of the present invention₂Response 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 invention₂The response curve of the gas; FIG. 9b is a graph of dual network organogel of example 1 according to the present invention for 1% O when undeformed and bent 180₂The response curve of the gas; FIG. 9c is a graph showing the results of the non-fractured and self-repaired dual-network organogels vs. 1% O in example 1 of the present invention₂The response curve of the gas; FIG. 9d shows that the double-network organogel of example 1 of the present invention can react to 1% O under different deformation conditions₂The response result 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 examples in any way. The starting reagents employed in the examples of the present invention are, unless otherwise specified, those that are conventionally purchased.

Example 1

s1, mixing acrylamide 3, chitosan 1, N' -methylene bisacrylamide 4, a photoinitiator 29592, acetic acid 5 and deionized water in proportion, magnetically stirring at the rotating speed of 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 ₂11, 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 present example and example 1 is that the mass ratio of acrylamide, N' -methylenebisacrylamide, photoinitiator, chitosan, and acetic acid was replaced with 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 maximum gel elongation can be up to 1400% of the original length (as shown in fig. 4c, d), indicating that the double-network organogel has excellent flexibility and stretchability. The bending, twisting and stretching experiments of the double-network organogel prepared in the examples 2-3 show that the double-network organogel also has 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 polyacrylamide₂In addition, it is derived from a large amount of-NH groups on the chitosan chains₂. When chitosan was not present (comparative example 2) or replaced by another polymer network (comparative example 3), the adhesion properties decreased. The adhesion strength of the gel prepared in comparative example 2 to metal, plastic and glass is 1.5, 3.5 and 2.2kPa respectively, and the adhesion strength of the gel prepared in comparative example 3 to 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 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 power supply of 3V 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 resistance of the fractured double-network organogel after being butted and after being re-separated is tested by electrical equipment, and it can be seen that the resistance of the butted double-network organogel can be rapidly 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 fig. 6e and f), so that the good mechanical property and the good self-repairing property are shown.

4. Gas-sensitive characteristics

The organogel prepared in example 1 was exposed sequentially to pure N₂And a specific concentration of O₂Connecting 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 organogel₀% and. DELTA.I is the change in current, I₀Is initially in pure N₂Current under atmosphere) to evaluate the gas sensing characteristics of the sensor. The ventilator is at "O" in FIG. 7 for each test cycle₂When the valve is opened, the O begins to be introduced₂Gas up to "O₂Off, end, O₂When closed, nitrogen was started.

As shown in fig. 7a, b, for the cyclic repeated exposure of organogel as oxygen sensor to 1% O₂The dynamic response curve of the gas and the response magnitude of the cycle test. When the organogel is exposed to O₂The current increases immediately when the gas is in contact with the gas, at which point O₂Gas and H₂The O molecules participate in the electrochemical reaction at the cathode to generate faradic current, causing an increase in the current flowing through the organogel. Organogels to 1% O in three cycles₂The response of (a) is substantially constant, indicating good repeatability.

As shown in FIG. 7c, organogels as oxygen sensors for 1% O₂The 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 SnO₂The 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 O₂Have different responses, and the smaller the concentration the smaller the response.

As shown in FIG. 7e, organogel as oxygen sensor pair O₂The gas concentration response presents a positive correlation, the detection range is from 0 percent to 100 percent, and the gas concentration response has the characteristic of full concentration range detection. 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 fig. 8a and b, the polyacrylamide-chitosan double-network organogel prepared in example 1 has higher response and sensitivity as a gas sensor than the polyacrylamide-chitosan double-network hydrogel prepared in comparative example 1, the polyacrylamide single-network hydrogel prepared in comparative example 2 and the polyacrylamide-calcium alginate prepared in comparative example 3. Under the same conditions, the polyacrylamide-chitosan double-network hydrogel prepared in comparative example 1 was aligned to 1% O₂The 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 gel₂and-OH, the response sensitivity of the sensor is greatly improved; also for 1% O₂Comparative example 1, the double-network organogel prepared in example 1 is at 1% O₂The 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 its tensile strain was 86%, and the magnitude of the response was from 2065% for the same concentration of oxygenIs lifted to 5139%; as shown in FIGS. 9b, c, d, the sensor is aligned to 1% concentration of O under 180 degree bend₂Response of 3136%, in the post-self-repaired state, the sensor is paired with 1% concentration of O₂The 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 under the stretching deformation state, the device can 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 to be the current flowing through the gel at a certain bias voltage, the electrodes being selected to be a metal of good electrical conductivity, such as silver. 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 environment₂The 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 is₂+2H₂O+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. Oxygen sensors detect the environment by detecting changes in the rate of electrochemical reactions occurring at the gel-electrode-ambient three-phase interfaceThe concentration of oxygen in (c) varies.

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

1. The preparation method of the double-network organogel is characterized by comprising the following steps:

2. The preparation method as claimed in claim 1, wherein the mass ratio of the acrylamide, the cross-linking agent, the initiator, the chitosan, the cosolvent and the solvent is 1500-: 1-2: 40-70: 300-500: 40-70.

3. The preparation method according to claim 1, wherein the electrolyte salt is one or more of potassium chloride, calcium chloride and sodium chloride.

4. The preparation method as claimed in claim 1, wherein the mass ratio of the acrylamide, the cross-linking agent, the initiator, the chitosan and the cosolvent is 1500-: 1-2: 40-70: 300-500: 40-70.

5. The method according to claim 1, wherein the crosslinking agent is N, N' -methylenebisacrylamide.

6. The method of claim 1, wherein the initiator is a photoinitiator or a thermal initiator.

7. The method according to claim 1, wherein the solvent is water or water and a polyhydric alcohol having 1 to 10 carbon atoms.

8. The preparation method according to claim 1, wherein the cosolvent is one or more of acetic acid, citric acid and diluted hydrochloric acid.

9. The double-network organogel prepared by the preparation method of any one of claims 1 to 8.

10. Use of the dual network organogel of claim 9 in the preparation of an oxygen sensor.