A method for preparing a triboelectric nanogenerator with an antibacterial hydrogel electrode and the product thereof.

Abstract

This invention discloses a method for preparing a triboelectric nanogenerator using an antibacterial hydrogel electrode. The method involves preparing chitosan carbon quantum dots, dissolving sodium dodecyl sulfate, lauryl methacrylate, and lithium chloride in deionized water and stirring, then adding acrylamide, 2wt%-3wt% agar, 0.5wt%-1wt% chitosan carbon quantum dots, a photoinitiator, and N-N-methylenebisacrylamide. The mixture is stirred at 95℃-100℃ in a light-protected environment to obtain a PAAm-CQDs hydrogel presol. At room temperature, polydimethyl... The polydimethylsiloxane film was immersed in a 10%–15% benzophenone solution dissolved in ethanol, washed with methanol, and completely dried with nitrogen. The treated polydimethylsiloxane film was placed at the bottom of an acrylic mold, and a pre-solution of PAAm-CQDs hydrogel was poured into the acrylic mold. The mold was then irradiated with 365 nm ultraviolet light to obtain a polydimethylsiloxane crosslinked PAAm-CQDs hydrogel. Copper wires were inserted into the bottom of the hydrogel to connect the electrodes, thus obtaining a triboelectric nanogenerator with an antibacterial hydrogel electrode.

Description

Technical Field

[0001] This invention belongs to the field of triboelectric nanogenerator materials, and relates to a method for preparing a triboelectric nanogenerator with an antibacterial hydrogel electrode and the product thereof. Background Technology

[0002] With the booming development of the electronics industry, wearable, portable, and flexible electronic products have rapidly entered people's lives, and their convenience makes people reluctant to separate them from their everyday belongings. However, the common use of bulky and rigid batteries to power wearable devices in daily life reduces wearing comfort and portability, and limits extended outdoor service. At the same time, the periodic charging or replacement of a single battery leads to increased maintenance time and costs, thus hindering portable / wearable applications. Therefore, self-powered operation is highly desirable when designing wearable sensors for real-world scenarios.

[0003] In 2012, Wang Zhonglin et al. first reported a triboelectric nanogenerator (TENG) based on the principle of triboelectricity. This TENG exhibits significantly high output voltage, current, and power density, as well as advantages such as light weight, ease of manufacture, and good reliability. Triboelectric nanogenerators are a promising, simple, cost-effective, high-performance, self-contained power source. They can be viewed as a self-powered strategy because they can effectively convert mechanical energy into electrical energy from frictional stimulation between various materials with different electron affinities and polarities, based on the coupling between contact charging and electrostatic induction.

[0004] Importantly, TENGs allow for the design and fabrication of flexible, elastic wearable devices through the materials used in their construction. However, a challenge for wearable flexible nanogenerators is the lack of high-performance elastic conductive electrodes for applications involving body stretching. Therefore, attention has focused on ultra-stretchable conductive electrodes to achieve various extreme deformations and good conductivity. Hydrogels, with their 3D polymer chain cross-linked network structure, offer ideal material for realizing flexible TENGs, as their 3D network structure endows devices with excellent mechanical properties, including high softness, flexibility, and elasticity.

[0005] For wearable biophysical and biomechanical sensing, TENGs require prolonged direct contact with human skin to continuously acquire signals, which can easily induce localized bacterial growth. Therefore, the antibacterial capability of TENGs is a crucial characteristic that cannot be ignored when designing them. Currently, TENG electrodes with antibacterial properties are typically fabricated by doping non-stretchable membrane substrates with conductive fillers such as silver nanowires, resulting in poor flexibility and stretchability. In contrast, conductive hydrogels or ionogels used as electrodes exhibit excellent flexibility, stretchability, and compliance. Summary of the Invention

[0006] In view of this, the present invention provides a method for preparing a triboelectric nanogenerator using an antibacterial hydrogel electrode and a product thereof. Specifically, the present invention provides the following technical solution:

[0007] 1. A method for preparing a triboelectric nanogenerator using an antibacterial hydrogel electrode, comprising the following steps:

[0008] 1) Preparation of chitosan carbon quantum dots;

[0009] 2) Dissolve sodium dodecyl sulfate, lauryl methacrylate and lithium chloride in deionized water, stir, add acrylamide and 2wt%-3wt% agar, add 0.5wt%-1wt% chitosan carbon quantum dots from step 1), then add photoinitiator and NN methylenebisacrylamide, stir at 95℃-100℃ for 15-20 minutes in the dark to obtain PAAm-CQDs hydrogel presol;

[0010] 3) At room temperature, immerse the polydimethylsiloxane film in a 10%–15% benzophenone solution dissolved in ethanol for 2–5 minutes, wash the polydimethylsiloxane film with methanol, and dry it completely with nitrogen.

[0011] 4) Place the polydimethylsiloxane film treated in step 3) at the bottom of the acrylic mold, pour the PAAm-CQDs hydrogel presol obtained in step 2) into the acrylic mold, and irradiate with 365nm ultraviolet light for 20-30 minutes to obtain polydimethylsiloxane crosslinked PAAm-CQDs hydrogel.

[0012] 5) Insert copper wire into the bottom of the hydrogel obtained in step 4) to connect the electrodes and obtain the antibacterial hydrogel electrode triboelectric nanogenerator, namely PAAm-CQDs hydrogel electrode triboelectric nanogenerator.

[0013] Further, the preparation method of step 1) is as follows: dissolve 0.5wt%-2.5wt% of chitosan in an acid solution and place it in a hydrothermal reactor to react at 180℃-200℃ for 5-6 hours. Filter the supernatant and freeze-dry it to obtain the product chitosan carbon quantum dots.

[0014] Furthermore, the agar in step 2) is 2 wt% or 3 wt%.

[0015] Further, in step 2), the concentrations of sodium dodecyl sulfate, lauryl methacrylate, lithium chloride, and acrylamide are 0.5 wt%-2.5 wt%, respectively; the stirring time is 5-6 hours; the concentrations of photoinitiator, N,N-methylenebisacrylamide are 0.5 wt%-2.5 wt%.

[0016] Furthermore, the photoinitiator mentioned in step 2) is I2959.

[0017] Further, the preparation method of the dimethylsiloxane film in step 3) is as follows: Dow Corning 184 silicone polymer Sylgard 184A and Dow Corning 184 silicone crosslinking agent Sylgard 184B are mixed at a mass ratio of 10:1. The mixed solution is placed in a vacuum drying oven and vacuumed to remove excess air bubbles. The solution is then used. The mixed solution of Sylgard 184A and Sylgard 184B is poured onto a silicon wafer and spin-coated at 500 rpm / min for 20 seconds on a semiconductor spin coater. The silicon wafer is then removed and heated at 70°C for 2 hours to obtain a polydimethylsiloxane film.

[0018] 2. The triboelectric nanogenerator prepared by the above method using an antibacterial hydrogel electrode.

[0019] Furthermore, under a pressure of 51 kPa, it can generate a maximum open-circuit voltage of 67.7-79.3 volts, a maximum short-circuit current of 1.68-2.5 microamps, and a transferred charge of 17.7-21.8 nanocoulombs.

[0020] The beneficial effects of this invention are as follows: This invention prepares a triboelectric nanogenerator based on an antibacterial hydrogel electrode, namely, a PAAm-CQDs hydrogel electrode triboelectric nanogenerator. The basic electrical output characteristics of the PAAm-CQDs hydrogel electrode triboelectric nanogenerator are adjusted by changing the concentration of added agar. When the agar concentration reaches 2wt%, it can generate an open-circuit voltage of 67.7V, a short-circuit current of 2.5µA, and a transferred charge of 17.7nanocoules at a pressure of 51kPa. Compared with the traditional method without agar (generating an open-circuit voltage of 52.5V, a short-circuit current of 1µA, and a transferred charge of 15.4nanocoules at a pressure of 51kPa), these figures are improved by 29.0%, 150.0%, and 14.9%, respectively. When the agar concentration reaches 3 wt%, an open-circuit voltage of 79.3 V, a short-circuit current of 1.68 μA, and a transferred charge of 21.8 nanocoulombs can be generated at a pressure of 51 kPa. These figures represent improvements of 51.0%, 68.0%, and 41.6% compared to the traditional method without agar (which generates an open-circuit voltage of 52.5 V, a short-circuit current of 1 μA, and a transferred charge of 15.4 nanocoulombs at a pressure of 51 kPa). Attached Figure Description

[0021] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided:

[0022] Figure 1 Figure 1 shows the basic electrical output characteristics of PAAm-CQDs hydrogel electrodes triboelectric nanogenerators with different agar concentrations.

[0023] Figure 2 Photograph of the inhibition zone of PAAm-CQDs hydrogel with 3wt% agar after 24 hours of incubation.

[0024] Figure 3 The electrical output characteristics of PAAm-CQDs hydrogel electrode triboelectric nanogenerator in contact with different triboelectric materials are shown in the figure.

[0025] Figure 4 A schematic diagram and charging curve of the capacitor charging of the PAAm-CQDs hydrogel electrode triboelectric nanogenerator. Detailed Implementation

[0026] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0027] Example 1

[0028] The steps for fabricating PAAm-CQDs hydrogel electrode triboelectric nanogenerators are as follows:

[0029] 1) Preparation of chitosan carbon quantum dots (CQDs)

[0030] 2 wt% of chitosan (CS) was dissolved in an acid solution and placed in a hydrothermal reactor at 200°C for 5 hours. The supernatant was filtered and freeze-dried to obtain the product CQDs.

[0031] 2) Preparation of PAAm-CQDs hydrogel presolution

[0032] 1 wt% sodium dodecyl sulfate (SDS), 1 wt% lauryl methacrylate (LMA), and 1 wt% lithium chloride (LiCl) were dissolved in deionized water and stirred for 5 hours. Then, 2 wt% acrylamide (Aam) and 2 wt%-3 wt% agar (Agar) were added, followed by 0.5 wt% CQDs, 0.5 wt% photoinitiator (I2959), and 0.5 wt% NN methylenebisacrylamide (MBA). The mixture was stirred in an oil bath at 95°C for 15 minutes in the dark to obtain a PAAm-CQDs hydrogel presol.

[0033] 3) Preparation of polydimethylsiloxane

[0034] Dow Corning 184 silicone polymer (Sylgard 184A) and Dow Corning 184 silicone crosslinking agent (Sylgard 184B) were mixed at a mass ratio of 10:1. The mixture was placed in a vacuum drying oven and vacuumed to remove excess air bubbles before use. The mixture of Sylgard 184A and Sylgard 184B was poured onto a silicon wafer and spin-coated at 500 rpm for 20 seconds using a spin coater from Suzhou Meitu Semiconductor. Finally, the silicon wafer was removed and heated at 70°C for 2 hours to obtain a polydimethylsiloxane film (PDMS film).

[0035] 4) Adhere the PAAm-CQDs hydrogel to the elastomer.

[0036] The surface of the PDMS membrane was thoroughly cleaned with methanol and deionized water, and then immersed in a 10% benzophenone solution dissolved in ethanol for 2 minutes at room temperature. Afterward, the PDMS membrane was washed three times with methanol and completely dried with nitrogen to obtain the benzophenone-treated PDMS membrane. The benzophenone-treated PDMS membrane was placed at the bottom of an acrylic mold (20mm*20mm*2mm), and then a PAAm-CQDs hydrogel pre-solution was poured into the acrylic mold. The PAAm-CQDs hydrogel pre-solution poured into the acrylic mold was irradiated with 365nm ultraviolet light for 20 minutes. During this period, the benzophenone-treated PDMS membrane surface covalently crosslinked and bonded with the polyacrylamide (PAAm) network, thereby preparing a PAAm-CQDs hydrogel crosslinked with PDMS.

[0037] 5) Preparation of single-electrode hydrogels:

[0038] Copper wires are inserted into the bottom of PAAm-CQDs hydrogel crosslinked with PDMS to form an electrode connection, thus forming a PDMS-hydrogel-copper wire structure, resulting in a triboelectric nanogenerator of antibacterial hydrogel electrode, namely PAAm-CQDs hydrogel electrode triboelectric nanogenerator.

[0039] Example 2

[0040] The study investigated the effect of changing the agar content on the basic electrical output performance of the PAAm-CQDs hydrogel electrode triboelectric nanogenerator. The agar content in step 2) of Example 1 was adjusted to 0%, 1%, 2%, 3%, and 4% to prepare PAAm-CQDs hydrogel electrode triboelectric nanogenerators, and their electrical performance was investigated to determine the optimal amount of agar added.

[0041] Test Example 1

[0042] Basic electrical output performance tests were conducted on PAAm-CQDs hydrogel electrode triboelectric nanogenerators.

[0043] The prepared series of PAAm-CQDs hydrogel electrode triboelectric nanogenerators were attached to a vertical block, and a nylon 66 film was attached to the linear motor at the other end to form a "contact-separation" structure. The separation interval of the linear motor was 10 mm, the applied pressure was 51 kPa, and the frequency was 1.7 Hz. The open circuit voltage, short circuit current, and transferred charge were measured using a Keithley 6517b electrometer. Figure 1 The graph shows the basic electrical output characteristics at different agar concentrations.

[0044] Figure 1 (a) represents the open-circuit voltage of PAAm-CQDs hydrogel electrodes triboelectric nanogenerators with different agar concentrations. Figure 1 (b) Short-circuit current of PAAm-CQDs hydrogel electrodes triboelectric nanogenerators with different agar concentrations. Figure 1 (c) represents the amount of transferred charge in the triboelectric nanogenerators of PAAm-CQDs hydrogel electrodes with different agar concentrations. Figure 1 (d) represents the maximum open-circuit voltage, maximum short-circuit current, and maximum transferred charge of PAAm-CQDs hydrogel electrode triboelectric nanogenerators with different agar concentrations.

[0045] from Figure 1As shown in (a)-(c), the addition of agar slightly increased the voltage (from 52.5 V to 52.7 V), while the current and transferred charge decreased compared to before the addition. The reverse current decreased from 1 μA to 0.39 μA, and the charge decreased from 15.4 nanocoulombs to 13.8 nanocoulombs. However, with increasing agar concentration, the voltage, current, and transferred charge all increased significantly. When the agar concentration reached 2 wt%, the reverse current reached its maximum value, increasing by 150% compared to before the addition of agar. When the agar concentration reached 3 wt%, the voltage and transferred charge reached their maximum values ​​of 79.3 V and 21.8 nanocoulombs, respectively, representing increases of 51.0% and 41.6% compared to before the addition of agar.

[0046] Test Example 2

[0047] The antibacterial properties of PAAm-CQDs hydrogel were tested.

[0048] The gel was cut into 1 cm diameter cylinders using a mold and sterilized under UV light for 2 hours. 50 μL of a 10⁵ CFU / mL Staphylococcus aureus suspension was evenly spread onto an agar plate. The sterilized gel was then pressed onto the plate and incubated at 37°C for 24 hours. The size of the inhibition zone was measured using a colony counter. The antibacterial activity of PAAm-CQDs hydrogel against Gram-negative Escherichia coli (E. coli) was tested by placing a 10 mm diameter paper composite sample in a ≈10⁵ CFU / mL E. coli suspension, evenly dispersing the suspension on a prepared agar plate, and observing the formation of inhibition zones. A larger inhibition zone diameter indicates stronger antibacterial activity.

[0049] Figure 2 Photograph of the inhibition zone after 24 hours of incubation with 3 wt% agar. From Figure 2As can be seen, distinct antibacterial zones were formed, with diameters of 20.7 mm, 21.7 mm, and 23.9 mm, and an average diameter of 22.1 mm. This indicates that the PAAm-CQDs hydrogel possesses excellent antibacterial properties. For wearable biophysical and biomechanical sensing, wearable TENGs require prolonged direct contact with human skin to continuously acquire signals, which can easily induce local bacterial growth. Since the hydrogel side of the PAAm-CQDs hydrogel electrode triboelectric nanogenerator needs to be in prolonged contact with the skin, the antibacterial properties of the PAAm-CQDs hydrogel hydrogel are particularly important. To enable the PAAm-CQDs hydrogel electrode triboelectric nanogenerator to possess antibacterial properties, it is only necessary for the PAAm-CQDs hydrogel hydrogel hydrogel to have antibacterial properties. The above results show that when the PAAm-CQDs hydrogel nanotriboelectric nanogenerator is used as a wearable device in prolonged contact with the skin, it can effectively inhibit bacterial growth, which provides a good basis for prolonged skin contact to continuously acquire signals.

[0050] Test Example 3

[0051] Electrical output tests were conducted on the PAAm-CQDs hydrogel electrode triboelectric nanogenerator.

[0052] A PAAm-CQDs hydrogel electrode triboelectric nanogenerator with an agar concentration of 3wt% was attached to a vertical block. Aluminum foil, A4 paper, thermoplastic polyurethane, nitrile rubber, and nylon 66 film were attached to the linear motor at the other end, forming a "contact-separation" structure. The separation interval of the linear motor was 10 mm, the applied pressure was 51 kPa, and the frequency was 1.7 Hz. The open circuit voltage, short circuit current, and transferred charge were measured using a Keithley 6517b electrometer.

[0053] Figure 3 (a) is the open-circuit voltage output of the PAAm-CQDs hydrogel electrode triboelectric nanogenerator. Figure 3 (b) represents the short-circuit current output by the PAAm-CQDs hydrogel electrode triboelectric nanogenerator. Figure 3 (c) represents the transferred charge output by the PAAm-CQDs hydrogel electrode triboelectric nanogenerator. Figure 3 (d) shows the maximum open-circuit voltage, maximum short-circuit current, and maximum transferred charge of the PAAm-CQDs hydrogel electrode triboelectric nanogenerator. The results show that the open-circuit voltage, short-circuit current, and transferred charge generated by using aluminum foil contact all reach their maximum values ​​of 90.5 V, 3.68 μA, and 32.0 nanocoulombs, respectively.

[0054] The nylon 66 friction layer and the polydimethylsiloxane film, as two independent components of MH-TENG, allow the nylon 66 film to be easily replaced with other common triboelectric materials while still generating a significant electrical signal output. Figure 3 As shown in (d), this demonstrates the wide applicability of the antibacterial hydrogel electrode triboelectric nanogenerator in different scenarios.

[0055] Test Example 4

[0056] Energy harvesting performance of PAAm-CQDs hydrogel electrode triboelectric nanogenerator.

[0057] A PAAm-CQDs hydrogel electrode triboelectric nanogenerator with an agar concentration of 3wt% was attached to a vertical block, and a nylon 66 film was attached to a linear motor at the other end, forming a "contact-separation" structure. The linear motor separation interval was 10 mm, the applied pressure was 255 kPa, and the frequency was 2.7 Hz. At the same operating frequency and applied pressure, 1 uF, 10 uF, and 22 uF capacitors were charged, and the voltage across the capacitors was measured using a Keithley 6517b.

[0058] Figure 4 (a) is a schematic diagram of the charging circuit for the PAAm-CQDs hydrogel electrode triboelectric nanogenerator. Figure 4 (b) shows the capacitance-charging curve of the PAAm-CQDs hydrogel electrode triboelectric nanogenerator. Figure 4 As shown in (b), it took 3.6 seconds, 18.8 seconds, and 46.5 seconds, respectively, to charge the 1uF, 10uF, and 22uF capacitors to 2 volts. The above experiments demonstrate that the triboelectric nanogenerator based on the antibacterial hydrogel electrode can effectively harvest energy generated by mechanical vibration.

[0059] Finally, it should be noted that the above preferred 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 through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A method for preparing an antibacterial hydrogel electrode triboelectric nanogenerator, characterized in that, The preparation steps are as follows: 1) Preparation of chitosan carbon quantum dots; 2) Dissolve sodium dodecyl sulfate, lauryl methacrylate, and lithium chloride in deionized water, stir, add acrylamide, agar, and chitosan carbon quantum dots obtained in step 1), then add photoinitiator and NN methylenebisacrylamide. Stir at 95°C-100°C in a light-protected environment to obtain a PAAm-CQDs hydrogel presol; the concentration of agar is 2 wt%–3 wt%; the concentration of lauryl methacrylate is 0.5 wt%–2.5 wt%; the concentration of acrylamide is 0.5 wt%–2.5 wt%; and the concentration of NN methylenebisacrylamide is 0.5 wt%–2.5 wt%. 3) At room temperature, immerse the polydimethylsiloxane film in a 10%–15% benzophenone solution dissolved in ethanol, wash the polydimethylsiloxane film with methanol, and dry it completely with nitrogen. 4) The polydimethylsiloxane film treated in step 3) is placed at the bottom of the acrylic mold. The PAAm-CQDs hydrogel presol obtained in step 2) is poured into the acrylic mold and irradiated with 365nm ultraviolet light to obtain polydimethylsiloxane crosslinked PAAm-CQDs hydrogel. 5) Insert copper wire into the bottom of the polydimethylsiloxane crosslinked PAAm-CQDs hydrogel obtained in step 4) to connect the electrodes and obtain a triboelectric nanogenerator with an antibacterial hydrogel electrode.

2. The method according to claim 1, wherein the method is characterized by, The preparation method of step 1) is as follows: dissolve 0.5 wt% to 2.5 wt% of chitosan in an acid solution and place it in a hydrothermal reactor to react at 180°C to 200°C for 5-6 hours. Filter the supernatant and freeze-dry it to obtain the product chitosan carbon quantum dots.

3. The method for preparing a triboelectric nanogenerator with an antibacterial hydrogel electrode according to claim 1, characterized in that, The agar concentration in step 2) is 2 wt% or 3 wt%.

4. The method for preparing a triboelectric nanogenerator with an antibacterial hydrogel electrode according to claim 1, characterized in that, In step 2), the concentration of chitosan carbon quantum dots is 0.5 wt% to 1 wt%, the concentration of sodium dodecyl sulfate is 0.5 wt% to 2.5 wt%, the concentration of lithium chloride is 0.5 wt% to 2.5 wt%, the stirring time is 5-6 hours, and the concentration of photoinitiator is 0.5 wt% to 2.5 wt%.

5. The method for preparing a triboelectric nanogenerator with an antibacterial hydrogel electrode according to claim 1, characterized in that, The photoinitiator mentioned in step 2) is I2959.

6. The method for preparing a triboelectric nanogenerator with an antibacterial hydrogel electrode according to claim 1, characterized in that, The stirring time in step 2) is 15 to 20 minutes.

7. The method according to claim 1, wherein the method is characterized by, Step 3) describes the preparation method of the polydimethylsiloxane film as follows: Dow Corning 184 silicone polymer Sylgard 184 A and Dow Corning 184 silicone crosslinking agent Sylgard 184 B are mixed at a mass ratio of 10:

1. The mixed solution is placed in a vacuum drying oven and vacuumed to remove excess air bubbles. The solution is then used. The mixed solution of Sylgard 184 A and Sylgard 184 B is poured onto a silicon wafer and spin-coated at 500 rpm / min for 20 seconds on a semiconductor spin coater. The silicon wafer is then removed and heated at 70°C for 2 hours to obtain the polydimethylsiloxane film.

8. The method according to claim 1, wherein the method is characterized by, The irradiation time in step 4) is 20 to 30 minutes.

9. A triboelectric nanogenerator prepared by the method for preparing an antibacterial hydrogel electrode according to any one of claims 1-8. 10.The friction nanogenerator according to claim 9, wherein, It generates a maximum open-circuit voltage of 67.7–79.3 V, a maximum short-circuit current of 1.68–2.5 μA, and a transferred charge of 17.7–21.8 nanocoulombs at a pressure of 51 kPa.

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