Preparation method of super-hydrophobic pressure-temperature dual-mode sensing sponge capable of resisting liquid interference

Abstract

The invention discloses a preparation method of a super-hydrophobic pressure-temperature dual-mode sensing sponge capable of resisting liquid interference, which comprises the following steps: soaking a polyurethane sponge in an ethanol mixed solution of graphene and ascorbic acid, then soaking in a mixed solution containing pyrrole, SDBS (Sodium Dodecyl Benzene Sulfonate) and ferric trichloride, and drying to obtain the super-hydrophobic pressure-temperature dual-mode sensing sponge. And soaking the sponge in an n-hexane solution of PDMS, and curing to obtain the conductive sponge with the super-hydrophobic surface. The conductive sponge with the super-hydrophobic surface is prepared by adopting a simple solution soaking method, and the method has the advantages that the process is simple and easy to operate, reaction conditions are controllable, raw materials are wide in source and low in cost, and the obtained product is easy to degrade, has lasting and stable super-hydrophobic self-cleaning performance and excellent conductivity and can be applied to various occasions.

Description

Technical Field

[0001] This invention belongs to the field of flexible electronic materials technology, specifically relating to a method for preparing a superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference. Background Technology

[0002] Flexible wearable electronic devices, with their portability, wearability, and real-time monitoring capabilities, have demonstrated enormous development potential in the fields of smart wearables and artificial intelligence. The core of these devices lies in utilizing functional nanomaterials to convert external mechanical, thermal, and chemical stimuli into measurable electrical signals. However, the biggest weakness of traditional flexible sensors is their poor environmental stability. Humidity, sweat, rain, and acidic or alkaline liquids can all corrode them, and conductive functional materials are prone to degradation or failure in harsh environments such as moisture, acidity, or alkalinity. This not only severely damages the sensor's conductivity, sensitivity, and stability but also poses potential risks to user safety. Therefore, developing new high-performance flexible sensors with resistance to liquid interference has become an urgent need to advance this field.

[0003] Introducing superhydrophobic interfaces into flexible conductive materials holds promise for overcoming the performance instability issues of wearable sensors in humid and corrosive environments. By constructing micro / nano structures on the sensor surface, its surface energy can be reduced, enabling it to repel various liquids. This fundamentally improves the sensor's robustness and service life, thereby significantly expanding the boundaries of sensor applications and enhancing its reliability. However, the greatest challenge lies in how to integrate the inherent roughness of the conductive material with the superhydrophobic structure to achieve perfect performance compatibility, ensuring that the final sensor, while possessing superhydrophobic capabilities, does not compromise its intrinsic conductivity and sensitivity. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference. This method employs simple solution immersion, in-situ loading, and surface modification to prepare a conductive sponge with a superhydrophobic surface, solving problems such as easy surface corrosion, decreased conductivity of conductive materials, and poor long-term stability in traditional sensors. The prepared superhydrophobic pressure-temperature dual-mode sensing sponge exhibits durable environmental resistance, excellent resistance to environmental interference, and excellent conductivity, and is expected to be widely used in marine exploration and underwater operations, high-performance motion and physiological monitoring, and long-term medical and rehabilitation engineering.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference is prepared by the following steps: (1) Mix the graphene aqueous dispersion with ascorbic acid in ethanol, then soak the cut polyurethane sponge in the mixture, rinse the sponge with a large amount of deionized water to remove surface impurities, and then dry it in an oven. (2) Dissolve pyrrole and sodium dodecylbenzenesulfonate (SDBS) in deionized water, stir evenly at 4 °C, then slowly add anhydrous ferric chloride, then add the sponge treated in step (1) to the resulting mixed solution for soaking, then rinse with a large amount of deionized water, and then place it in an oven to dry. (3) Soak the sponge treated in step (2) in a hexane solution of PDMS, then take out the sponge, gently squeeze it until no obvious solution seeps out, and put it in an oven for curing to obtain a conductive sponge with a superhydrophobic surface.

[0006] Further, the concentration of the graphene aqueous dispersion in step (1) is 1-5 mg·mL. -1 .

[0007] Further, in the mixed solution described in step (1), the content of graphene is 0.5-2.5 mg / mL, and the amount of ascorbic acid used is 10% of the mass of the graphene used.

[0008] Furthermore, the soaking temperature in step (1) is 70°C.

[0009] Furthermore, the soaking time in step (1) is 1-5 h.

[0010] Furthermore, in the mixed solution described in step (2), the content of pyrrole is 22.4 mmol / L, and the molar ratio of pyrrole, sodium dodecylbenzenesulfonate and anhydrous ferric chloride is 1:2:1.

[0011] Furthermore, the soaking time in step (2) is 2 hours.

[0012] Further, the PDMS content in the hexane solution of PDMS in step (3) is 1-10 mg·ml. -1 .

[0013] Furthermore, the soaking time in step (3) is 10-60 min.

[0014] Furthermore, the curing temperature in step (3) is 60-120 °C and the time is 10 min.

[0015] The advantages of this invention are: (1) The present invention uses a simple soaking method to obtain superhydrophobic reduced graphene oxide / polypyrrole sponge. Its preparation process is simple and easy to operate. The prepared superhydrophobic reduced graphene oxide / polypyrrole sponge has long-lasting surface stability, good conductivity and good environmental durability. It solves many problems such as complex preparation process, long time consumption, poor surface stability and easy interference of traditional sponge flexible sensor.

[0016] (2) Surface roughness and low surface energy are the factors that determine the superhydrophobicity of materials. The method of the present invention can prepare a superhydrophobic self-cleaning surface for polypyrrole sponge in a short time. The mechanism of forming a superhydrophobic surface is: the in-situ deposition of graphene and polypyrrole forms a micro / nano structure with the sponge fabric itself, which makes the surface rough. The surface is modified by polydimethylsiloxane with low surface energy, and a superhydrophobic conductive sponge is prepared simply and quickly.

[0017] (3) The superhydrophobic reduced graphene oxide / polypyrrole sponge prepared in this invention exhibits good resistance to liquid interference and excellent pressure-temperature sensing properties. By testing the superhydrophobic surface stability and sensing properties of the superhydrophobic reduced graphene oxide / polypyrrole sponge, it is demonstrated that the prepared superhydrophobic conductive sponge has a wide range of resistance to liquid interference, exhibiting a water contact angle value of over 150° in various liquid environments. Moreover, the conductive sponge has sensitive temperature response and rapid resistance response in the temperature range of 35-80℃. It also has a stable monitoring capability for small pressures. Therefore, it has advantages such as durable environmental resistance, excellent resistance to environmental interference, and excellent conductivity. It can solve the problems of easy corrosion of traditional sensor surfaces, degradation of conductive material performance, and poor long-term stability. It is expected to be widely used in marine exploration and underwater operations, high-performance motion and physiological monitoring, long-term medical and rehabilitation engineering, etc. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a schematic diagram of the process for preparing the superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference according to the present invention. Figure 2 The image shows the Raman spectra of the reduced graphene oxide sponges prepared in Example 4 at different reduction times. Figure 3Scanning electron microscope (SEM) images of the polyurethane sponge (a) used in Example 4, and the prepared reduced graphene oxide sponge (b), reduced graphene oxide / polypyrrole sponge (c), and superhydrophobic pressure-temperature dual-mode sensing sponge (d). Figure 4 The mechanical properties test diagram of the superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference prepared in Example 4; Figure 5 The test diagram shows the anti-liquidity performance of the superhydrophobic pressure-temperature dual-mode sensing sponge prepared in Example 4. Figure 6 Temperature sensing curve of the superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference prepared in Example 4; Figure 7 Pressure sensing curve of the superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference prepared in Example 4. Detailed Implementation

[0019] This invention provides a method for preparing a superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference, comprising the following steps: (1) Preparation of reduced graphene oxide sponge; (2) Preparation of reduced graphene oxide / polypyrrole sponge; (3) Construction of superhydrophobic surfaces.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to specific embodiments.

[0021] Step 1: Preparation of reduced graphene oxide sponge Take a concentration of 1-5 mg·mL -1 30 mL of graphene aqueous dispersion and 0.3-1.5 mg of ascorbic acid were added to 30 mL of anhydrous ethanol and mixed evenly. The cut polyurethane sponge was then placed in the mixture and soaked at 70 °C for 1-5 h. After that, the sponge was taken out, rinsed with plenty of deionized water to remove surface impurities, and then placed in an oven to dry.

[0022] Step 2: Preparation of reduced graphene oxide / polypyrrole sponge Weigh out 3.36 mmol of pyrrole, 6.72 mmol of sodium dodecylbenzenesulfonate and 3.36 mmol of anhydrous ferric chloride (molar ratio 1:2:1). Dissolve the weighed pyrrole and SDBS in 150 mL of deionized water and stir at 4 °C for 30 min. Then slowly add anhydrous ferric chloride. Place the reduced graphene oxide sponge in the mixed solution and stir for 2 h. Remove the sponge, rinse it with plenty of deionized water and dry it in an oven.

[0023] Step 3: Construction of Superhydrophobic Surfaces The prepared reduced graphene oxide / polypyrrole sponge was then subjected to a concentration of 1-10 mg·ml. -1 Immerse the PDMS in a hexane solution for 10-60 min, then remove it, gently squeeze until no obvious solution seeps out, and then place it in an oven at 60-120 ℃ for 10 min to cure.

[0024] Figure 1 This is a schematic diagram illustrating the process of preparing the superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference according to the present invention. As shown in the figure, the polyurethane sponge is coated in graphene / ascorbic acid solution and polypyrrole / Fe2O3 solution respectively. 3+ Superhydrophobic reduced graphene oxide / polypyrrole conductive sponge can be obtained by immersion in the solution and PDMS solution.

[0025] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments. However, the present invention is not limited to the listed embodiments, but should also include any other known modifications within the scope of the claims of the present invention.

[0026] First, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0027] Secondly, this invention is described in detail using structural diagrams, etc. When detailing the embodiments of this invention, for ease of explanation, the diagrams may be partially enlarged, deviating from the general scale. Furthermore, the diagrams are merely examples and should not limit the scope of protection of this invention. In addition, actual manufacturing should include three-dimensional space with length, width, and depth.

[0028] Example 1 This embodiment prepares a superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference according to the following steps: Step 1: Preparation of reduced graphene oxide sponge Measure out a mass concentration of 1 mg·mL -1 30 mL of graphene aqueous dispersion was prepared, and 0.3 mg of ascorbic acid was weighed out. The two were dissolved in 30 mL of anhydrous ethanol and mixed evenly. The cut polyurethane sponge was then placed in the mixture and soaked at 70 °C for 1 h. After that, the sponge was taken out and rinsed with plenty of deionized water to remove surface impurities. Then it was placed in an oven to dry.

[0029] Step 2: Preparation of reduced graphene oxide / polypyrrole sponge Weigh out 3.36 mmol of pyrrole, 6.72 mmol of sodium dodecylbenzenesulfonate and 3.36 mmol of anhydrous ferric chloride, respectively. Then dissolve the weighed pyrrole and SDBS in 150 mL of deionized water and stir at 4 °C for 30 min. Then slowly add anhydrous ferric chloride. Place the reduced graphene oxide sponge in the mixed solution and stir for 2 h. Remove the sponge, rinse it with plenty of deionized water and dry it in an oven.

[0030] Step 3: Construction of Superhydrophobic Surfaces The prepared reduced graphene oxide / polypyrrole sponge was then subjected to a concentration of 1 mg·ml. -1 After soaking the PDMS in a hexane solution for 10 min, remove it, gently squeeze until no obvious solution seeps out, and then place it in an 80 ℃ oven to cure for 10 min.

[0031] Example 2 This embodiment prepares a superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference according to the following steps: Step 1: Preparation of reduced graphene oxide sponge Measure out a mass concentration of 1 mg·mL -1 30 mL of graphene aqueous dispersion and 0.3 mg of ascorbic acid were weighed and dissolved in 30 mL of anhydrous ethanol. After mixing evenly, the cut polyurethane sponge was placed in the mixed solution and soaked at 70°C for 2 h. After that, the sponge was taken out, rinsed with plenty of deionized water to remove surface impurities, and then placed in an oven to dry.

[0032] Step 2: Preparation of reduced graphene oxide / polypyrrole sponge Weigh out 3.36 mmol of pyrrole, 6.72 mmol of sodium dodecylbenzenesulfonate and 3.36 mmol of anhydrous ferric chloride, respectively. Then dissolve the weighed pyrrole and SDBS in 150 mL of deionized water and stir at 4 °C for 30 min. Then slowly add anhydrous ferric chloride and place the reduced graphene oxide sponge in the mixed solution and stir for 2 h. Remove the sponge, rinse it with plenty of deionized water and dry it in an oven.

[0033] Step 3: Construction of Superhydrophobic Surfaces The prepared reduced graphene oxide / polypyrrole sponge was then subjected to a concentration of 1 mg·ml. -1 After soaking the PDMS in a hexane solution for 10 min, remove it, gently squeeze until no obvious solution seeps out, and then place it in an 80 ℃ oven to cure for 10 min.

[0034] Example 3 This embodiment prepares a superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference according to the following steps: Step 1: Preparation of reduced graphene oxide sponge Measure out a mass concentration of 1 mg·mL -1 30 mL of graphene aqueous dispersion and 0.3 mg of ascorbic acid were weighed and dissolved in 30 mL of anhydrous ethanol. After mixing evenly, the cut polyurethane sponge was placed in the mixed solution and soaked at 70°C for 4 h. After that, the sponge was taken out, rinsed with a large amount of deionized water to remove surface impurities, and then placed in an oven to dry.

[0035] Step 2: Preparation of reduced graphene oxide / polypyrrole sponge Weigh out 3.36 mmol of pyrrole, 6.72 mmol of sodium dodecylbenzenesulfonate and 3.36 mmol of anhydrous ferric chloride, respectively. Then dissolve the weighed pyrrole and SDBS in 150 mL of deionized water and stir at 4 °C for 30 min. Then slowly add anhydrous ferric chloride and place the reduced graphene oxide sponge in the mixed solution and stir for 2 h. Remove the sponge, rinse it with plenty of deionized water and dry it in an oven.

[0036] Step 3: Construction of Superhydrophobic Surfaces The prepared reduced graphene oxide / polypyrrole sponge was then subjected to a concentration of 1 mg·ml. -1 After soaking the PDMS in a hexane solution for 10 min, remove it, gently squeeze until no obvious solution seeps out, and then place it in an 80 ℃ oven to cure for 10 min.

[0037] Example 4 This embodiment prepares a superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference according to the following steps: Step 1: Preparation of reduced graphene oxide sponge Measure out a mass concentration of 1 mg·mL -1 30 mL of graphene aqueous dispersion was prepared, and 0.3 mg of ascorbic acid was weighed out. The two were dissolved in 30 mL of anhydrous ethanol and mixed evenly. The cut polyurethane sponge was then placed in the mixed solution and soaked at 70°C for 3 h. After that, the sponge was taken out and rinsed with plenty of deionized water to remove surface impurities. Then it was placed in an oven to dry.

[0038] Step 2: Preparation of reduced graphene oxide / polypyrrole sponge Weigh out 3.36 mmol of pyrrole, 6.72 mmol of sodium dodecylbenzenesulfonate and 3.36 mmol of anhydrous ferric chloride, respectively. Then dissolve the weighed pyrrole and SDBS in 150 mL of deionized water and stir at 4 °C for 30 min. Then slowly add anhydrous ferric chloride and place the reduced graphene oxide sponge in the mixed solution and stir for 2 h. Remove the sponge, rinse it with plenty of deionized water and dry it in an oven.

[0039] Step 3: Construction of Superhydrophobic Surfaces The prepared reduced graphene oxide / polypyrrole sponge was then subjected to a concentration of 1 mg·ml. -1 After soaking the PDMS in a hexane solution for 10 min, remove it, gently squeeze until no obvious solution seeps out, and then place it in an 80 ℃ oven to cure for 10 min.

[0040] Figure 2 The figures show the Raman spectra of reduced graphene oxide sponges prepared in Examples 1-4 after different reduction times. As can be seen from the figures, after 3 hours of reduction, the intensity ratio of the D and G band peaks of the resulting reduced graphene oxide reaches its maximum value, indicating that the reduction process, while restoring the conductive network, also introduces structural disorder, which can increase the number of interaction sites.

[0041] Figure 3 The images show scanning electron microscope (SEM) images of the polyurethane sponge used in Example 4, as well as the prepared reduced graphene oxide sponge, reduced graphene oxide / polypyrrole sponge, and superhydrophobic pressure-temperature dual-mode sensing sponge. The images demonstrate that both reduced graphene oxide and polypyrrole were successfully and uniformly loaded onto the sponge.

[0042] The superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference prepared in Example 4 was subjected to compression deformation tests at different degrees. The results are shown in [Figure 4]. Figure 4 .like Figure 4 As shown, the prepared superhydrophobic pressure-temperature dual-mode sensing sponge can withstand 80% compression, proving that it has excellent compressive strength.

[0043] The superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference prepared in Example 4 was immersed in solutions of different pH values ​​(acidic aqueous solution of hydrochloric acid, neutral solution of NaCl, and alkaline solution of NaOH). After 24 h, the water contact angle of its surface was measured, and the results are shown in [Figure 4]. Figure 5 .like Figure 5 As shown, the water contact angle of the prepared superhydrophobic pressure-temperature dual-mode sensing sponge after different pH treatments is greater than 150°, indicating that it has broad resistance to liquid interference and a stable superhydrophobic surface.

[0044] The superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference prepared in Example 4 was placed in an oven, and a Keithley source meter was connected to both ends of the sponge sensor. The oven was continuously heated (35~80℃), and the resistance of the sponge was measured simultaneously. The resulting temperature sensing curve is shown in [Figure number missing]. Figure 6 .Depend on Figure 6 As can be seen, the sponge resistance gradually decreases with the increase of oven temperature, indicating that the prepared superhydrophobic pressure-temperature dual-mode sensing sponge sensor has fast and highly linear temperature sensing performance.

[0045] A Keithley digital source meter was connected to both ends of the superhydrophobic pressure-temperature dual-mode sensing sponge prepared in Example 4, which is resistant to liquid interference. Different pressures were then applied to the surface of the sponge, and the resistance of the sponge was measured. The resulting pressure sensing curves are shown in the figure. Figure 7 .Depend on Figure 7 It can be seen that the prepared superhydrophobic pressure-temperature dual-mode sensing sponge sensor has sensitive monitoring capability for different pressures (a), and has stable and uniform monitoring capability for small changes in fixed pressure (b).

[0046] In summary, this invention prepares a superhydrophobic reduced graphene oxide / polypyrrole sponge through simple solution immersion, in-situ loading, and surface modification, thereby obtaining a superhydrophobic pressure-temperature dual-mode sensing sponge with resistance to liquid interference. The reaction conditions are mild, the process is simple and easy to operate, and the resulting sensing sponge exhibits excellent conductivity, strong resistance to external interference, excellent environmental stability, and no environmental pollution. It has promising application prospects and can be widely used in marine exploration and underwater operations, high-performance motion and physiological monitoring, and long-term medical and rehabilitation engineering.

[0047] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

[0048] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included in the scope of the present invention.

Claims

1. A method for preparing a superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference, characterized in that, Includes the following steps: (1) Mix graphene aqueous dispersion with ascorbic acid in ethanol, then soak polyurethane sponge in the mixture, rinse the sponge with a large amount of deionized water and dry it; (2) Dissolve pyrrole and sodium dodecylbenzenesulfonate in deionized water, stir evenly at 4 °C, then slowly add anhydrous ferric chloride, then add the sponge treated in step (1) to the resulting mixed solution for soaking, then rinse with a large amount of deionized water and dry. (3) Soak the sponge treated in step (2) in a hexane solution of PDMS, then take out the sponge, gently squeeze it until no obvious solution seeps out, and put it in an oven for curing to obtain a conductive sponge with a superhydrophobic surface.

2. The method for preparing the superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference according to claim 1, characterized in that: In the mixture described in step (1), the content of graphene is 0.5-2.5 mg / mL, and the amount of ascorbic acid used is 10% of the mass of graphene used.

3. The method for preparing the superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference according to claim 1, characterized in that: The soaking time in step (1) is 1-5 hours.

4. The method for preparing the superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference according to claim 1, characterized in that: In the mixed solution described in step (2), the content of pyrrole is 22.4 mmol / L, and the molar ratio of pyrrole, sodium dodecylbenzenesulfonate, and anhydrous ferric chloride is 1:2:

1.

5. The method for preparing the superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference according to claim 1, characterized in that: The soaking time in step (2) is 2 hours.

6. The method for preparing the superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference according to claim 1, characterized in that: The PDMS content in the hexane solution of PDMS in step (3) is 1-10 mg·ml. -1 .

7. The method for preparing the superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference according to claim 1, characterized in that: The soaking time in step (3) is 10-60 min.

8. The method for preparing the superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference according to claim 1, characterized in that: The curing temperature in step (3) is 60-120 ℃ and the time is 10 min.

9. A superhydrophobic pressure-temperature dual-mode sensing sponge resistant to liquid interference, prepared by the method described in claim 1.

Images