Flame-retardant friction electronegative material as well as preparation method and application thereof

Abstract

The invention discloses a flame-retardant friction electronegative material and a preparation method and application thereof.The preparation method comprises the steps that liquid metal and nano-clay are evenly mixed to obtain composite nano-particles, and the mass part ratio of the liquid metal to the nano-clay is (1-4): 1; the composite nano particles are evenly dispersed into the organic silica gel precursor solution, a liquid metal / nano clay / organic silica gel mixed solution is obtained, and the mass fraction of the composite nano particles in the liquid metal / nano clay / organic silica gel mixed solution is 1-20%; and uniformly coating a substrate with the liquid metal / nano clay / organic silica gel mixed solution, and curing at 60-80 DEG C for 5-10 hours to obtain the flame-retardant friction electronegative material on the substrate. The flame-retardant friction electronegativity material has good flame retardance and thermal stability, and the flame retardance of the organic silica gel is greatly improved through the synergistic effect of the liquid metal and the nano clay.

Description

Technical Field

[0001] This invention belongs to the field of triboelectric nanogenerator technology, specifically relating to a flame-retardant triboelectric material, its preparation method, and its application. Background Technology

[0002] Energy harvesting technology aims to convert dissipated energy sources in the environment, such as solar, wind, thermal, and mechanical energy, into electrical energy, and is one of the emerging methods to address the inherent shortcomings of traditional energy architectures. Triboelectric nanogenerators (TENGs) are an emerging energy harvesting technology that can convert widely existing mechanical energy in the surrounding environment (such as vibration, waves, and human movement) into electrical energy. This technology has attracted much attention due to its advantages such as simple fabrication process, wide availability of materials, and strong ability to harvest low-frequency mechanical energy. In recent years, to improve the electrical output performance of TENGs and better meet the energy requirements of micro / nano power supplies and self-powered sensors, researchers have conducted extensive work from multiple perspectives, including structural design and physical / chemical surface modification.

[0003] Organosilicon materials (such as polydimethylsiloxane, PDMS) are often used as triboelectric materials for constructing triboelectric generators (TENGs) due to their strong electron-accepting ability. However, their low dielectric properties (PDMS has a dielectric constant of approximately 2.65) limit their triboelectric power generation performance, making it difficult to meet the power requirements of high-power devices. Furthermore, organosilicon materials are flammable under fire, which greatly restricts their application in high-temperature or fire-prone environments. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a method for preparing a flame-retardant triboelectric material based on liquid metal / nanoclay / organosilicon, which is low-cost and simple to implement.

[0005] Another object of the present invention is to provide a flame-retardant triboelectric material obtained by the above preparation method.

[0006] Another objective of this invention is to provide the use of a flame-retardant triboelectric material in a triboelectric nanogenerator, the resulting triboelectric nanogenerator exhibiting high output power density, long-term electrical stability, and excellent flame-retardant properties.

[0007] The objective of this invention is achieved through the following technical solution.

[0008] A method for preparing a flame-retardant triboelectric material includes the following steps:

[0009] Step 1: Mix liquid metal and nano-clay evenly to obtain composite nanoparticles. The ratio of liquid metal to nano-clay by mass is (1~4):1. The liquid metal includes eutectic gallium indium alloy and / or eutectic gallium indium tin alloy. The nano-clay is one or a mixture of kaolin, montmorillonite and bentonite.

[0010] Step 2: The composite nanoparticles are uniformly dispersed in the organosilicone precursor solution to obtain a liquid metal / nanoclay / organosilicone mixture, wherein the mass fraction of the composite nanoparticles in the liquid metal / nanoclay / organosilicone mixture is 1~20%;

[0011] In step 2, the silicone precursor solution is a two-component PDMS prepolymer.

[0012] Step 3: The liquid metal / nanoclay / organic silicone mixture is uniformly coated onto the substrate and cured at 60~80°C for 5~10 hours to obtain a flame-retardant triboelectric material on the substrate.

[0013] In step 3, the thickness of the flame-retardant triboelectric material is 0.1~1.0 mm.

[0014] In step 3, the substrate is made of polytetrafluoroethylene (PTFE).

[0015] In the above technical solution, the ratio of liquid metal to nano-clay is preferably (1.5~2.5):1 by mass, and the mass fraction of composite nanoparticles in the liquid metal / nanoclay / organic silica gel mixture is 2~8%, preferably 2~6%.

[0016] The flame-retardant triboelectric material obtained by the above preparation method.

[0017] The application of the above-mentioned flame-retardant triboelectrone materials (as triboelectrone materials) in triboelectric nanogenerators.

[0018] In the above technical solution, the triboelectric positive material is a polymer film, and the polymer film is made of nylon, cellulose or polyvinyl alcohol.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1. The flame-retardant triboelectric material of the present invention has good flame-retardant properties and thermal stability. The synergistic effect of liquid metal and nano-clay greatly improves the flame-retardant properties of silicone material, opening up a new path for TENG devices with both excellent flame-retardant properties and high electrical output performance.

[0021] 2. The flame-retardant triboelectric material of this invention is applied in a triboelectric nanogenerator, resulting in an output power density as high as 21.8 W / m³. -2 Under mechanical shock of 50N and 1Hz, after 10,000 cycles of testing, its open-circuit voltage remains stable (basically stable at 220V), demonstrating good cycle stability. Attached Figure Description

[0022] Figure 1 Images of the composite nanoparticles obtained in Examples 1-4;

[0023] Figure 2 The images show the morphology and elemental distribution of the composite nanoparticles obtained in Example 2, where (a) is a morphology image, (b) is a magnified view of a portion of (a), and (c) is an elemental distribution image.

[0024] Figure 3 The following are the (a) open-circuit voltage, (b) short-circuit current, and (c) transferred charge of the triboelectric nanogenerators obtained in Examples 1-4.

[0025] Figure 4 The output voltage and output current of the triboelectric nanogenerator obtained in Example 2 under different load resistances;

[0026] Figure 5 The power density of the triboelectric nanogenerator obtained in Example 2 under different load resistances;

[0027] Figure 6 The curves show the change of open-circuit voltage (voltage) of the triboelectric nanogenerator obtained in Example 2 with the number of cycle tests, where (a) is the open-circuit voltage (voltage) after 10,000 cycle tests, (b) is the open-circuit voltage (voltage) after the 1995th to 2000th cycle tests, and (c) is the open-circuit voltage (voltage) after the 9995th to 10000th cycle tests.

[0028] Figure 7 (a) Open-circuit voltage (voltage), (b) Short-circuit current (current), and (c) Transferred charge (charge) of the triboelectric nanogenerators obtained in Examples 2 and 5-7;

[0029] Figure 8 The following are the (a) open-circuit voltage, (b) short-circuit current, and (c) transferred charge of the triboelectric nanogenerators obtained in Examples 8-11;

[0030] Figure 9 (a) Open-circuit voltage (voltage), (b) Short-circuit current (current), and (c) Transfer charge (charge) of the triboelectric nanogenerators obtained in Examples 9 and 12-14.

[0031] Figure 10 (a) Open-circuit voltage, (b) Short-circuit current, and (c) Transfer charge of the triboelectric nanogenerators obtained in Examples 15-18;

[0032] Figure 11 (a) Open-circuit voltage (voltage), (b) Short-circuit current (current), and (c) Transferred charge (charge) of the triboelectric nanogenerators obtained in Examples 16 and 19-21.

[0033] Figure 12 (a) Open-circuit voltage (voltage), (b) Short-circuit current (current), and (c) Transferred charge (charge) of the triboelectric nanogenerators obtained in Comparative Examples 1-3.

[0034] Figure 13 The output voltage and output current of the triboelectric nanogenerator obtained in Comparative Example 1 are shown.

[0035] Figure 14 The power density of the triboelectric nanogenerator obtained in Comparative Example 1 is shown.

[0036] Figure 15 (a) Open-circuit voltage (voltage), (b) Short-circuit current (current), and (c) Transferred charge (charge) of the triboelectric nanogenerator obtained in Comparative Example 4.

[0037] Figure 16 The output voltage and output current of the triboelectric nanogenerator obtained in Comparative Example 4 are shown.

[0038] Figure 17 The power density of the triboelectric nanogenerator obtained in Comparative Example 4 is shown.

[0039] Figure 18 (a) Open-circuit voltage (voltage), (b) Short-circuit current (current), and (c) Transferred charge (charge) of the triboelectric nanogenerator obtained in Comparative Example 5;

[0040] Figure 19 The output voltage and output current of the triboelectric nanogenerator obtained in Comparative Example 5 are shown.

[0041] Figure 20 The power density of the triboelectric nanogenerator obtained in Comparative Example 5;

[0042] Figure 21 Thermogravimetric curves of the flame-retardant triboelectric material obtained in Example 2, the flame-retardant triboelectric material obtained in Example 9, the flame-retardant triboelectric material obtained in Example 16, and the triboelectric materials obtained in Comparative Examples 1 to 5 are shown.

[0043] Figure 22Flame retardant properties of the flame-retardant triboelectric material obtained in Example 2, Example 9, Example 16, and Comparative Examples 1-5 were tested. Detailed Implementation

[0044] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0045] Sources of materials used in this invention:

[0046] The eutectic gallium indium tin alloy was purchased from Dongguan Bingkai Metal Products Co., Ltd., and the mass fractions of Ga, In, and Sn in the eutectic gallium indium tin alloy were 68.5%, 21.5%, and 10%, respectively.

[0047] Kaolin (CAS No. 1332-58-7) was purchased from Tianjin Guangfu Fine Chemical Research Institute;

[0048] Montmorillonite (CAS No. 1318-93-0) was purchased from Shanghai Aladdin Reagent Co., Ltd.

[0049] Bentonite (CAS No. 1302-78-9) was purchased from Shanghai Aladdin Reagent Co., Ltd.

[0050] The silicone precursor liquids used in the following examples and comparative examples are two-component PDMS prepolymers. The two-component PDMS prepolymers (obtained by mixing components A and B at a mass ratio of 10:1, Sylgard 184) were purchased from Dow Corning Incorporated.

[0051] In the following figures, voltage represents open-circuit voltage (V). oc ), current represents short-circuit current (I) sc ) and charge represent transferred charge (Q) sc ).

[0052] Examples 1-21

[0053] A triboelectric nanogenerator (TENG) includes: a positive electrode, a polymer film, a triboelectric negative material, and a negative electrode arranged in parallel from bottom to top. The upper surface of the positive electrode is adhered with the polymer film (triboelectric positive material), and the lower surface of the negative electrode is adhered with the triboelectric negative material. The positive and negative electrodes are respectively fixed on a plate, and the polymer film and the triboelectric negative material can be in contact or separated. The positive electrode is a copper-nickel alloy cloth (3M China Co., Ltd., model 3MCEF-1), the polymer film is nylon, and the negative electrode is a copper-nickel alloy cloth (3M China Co., Ltd., model 3MCEF-1). A copper wire is welded to the lower surface of the positive electrode and the upper surface of the negative electrode. The triboelectric negative material is a flame-retardant triboelectric negative material.

[0054] A method for preparing a flame-retardant triboelectric material includes the following steps:

[0055] Step 1: Add liquid metal and nano-clay to a beaker and stir with a magnetic stirrer (500 rpm) for 30 minutes at room temperature to mix them evenly and obtain composite nanoparticles. The ratio of liquid metal to nano-clay by mass is X, and the liquid metal is a eutectic gallium indium tin alloy. The types of nano-clay and X in different embodiments are shown in Table 1.

[0056] Step 2: Add the composite nanoparticles to the silicone precursor solution and stir magnetically (500 rpm) for 30 minutes at room temperature to obtain a uniformly dispersed liquid metal / nanoclay / silicone mixture. The silicone precursor solution is a two-component PDMS prepolymer. The mass fraction of the composite nanoparticles in the liquid metal / nanoclay / silicone mixture is Y. Y in different embodiments is shown in Table 1.

[0057] Step 3: Pour the liquid metal / nanoclay / silicone mixture onto the substrate (the substrate is a polytetrafluoroethylene plate). Use a coater to spread the liquid metal / nanoclay / silicone mixture evenly onto the substrate. Then place the substrate in a vacuum drying oven at 60°C for 5 hours to cure (during this time, chemical cross-linking occurs in the liquid metal / nanoclay / silicone mixture to form polydimethylsiloxane, which encapsulates the composite nanoparticles inside the cross-linked structure, resulting in a liquid metal / nanoclay / silicone film). The film is then peeled off from the substrate to obtain a flame-retardant triboelectric material. The flame-retardant triboelectric material has a thickness of 0.5 mm and a length and width of 4 cm.

[0058] Table 1

[0059]

[0060] Figure 1 These are photographs of the composite nanoparticles obtained in Examples 1-4. Figure 1 It can be seen that as the content of liquid metal in the composite nanoparticles increases, the color of the composite nanoparticles obtained in Examples 1-4 gradually deepens. This indicates that the liquid metal and nanoclay have been successfully combined to form composite nanoparticles.

[0061] The composite nanoparticles obtained in Example 2 were subjected to SEM and EDS tests, and the results are as follows: Figure 2 As shown. (a) is a morphological diagram, (b) is a magnified view of a portion of (a), and (c) is an elemental distribution diagram. Figure 2 The morphology images show that the nanoclay is granular, while the liquid metal appears as a film coating the surface of the nanoclay, indicating that the liquid metal and nanoclay have successfully combined and further formed composite nanoparticles. Figure 2 As shown in (c), Al and Si elements from nano-clay (kaolin) and Ga, In and Sn elements from liquid metal (eutectic gallium indium tin alloy) are uniformly distributed in the composite nanoparticles.

[0062] Electrical output performance test: The positive electrode of the triboelectric nanogenerator was fixed to the slider of a linear motor (Linmot Q24IA, purchased from Suzhou Kerui Limo Motor Co., Ltd.). The linear motor allows the polymer film and the triboelectric negative material to contact and separate. A copper wire extending from each of the positive and negative electrodes of the triboelectric nanogenerator was connected to the two probes of an electrometer (Keithley 6514, purchased from Keithley Corporation, USA). The linear motor was started, and the electrical output performance of the triboelectric nanogenerator was tested. The open-circuit voltage (V) of the triboelectric nanogenerator was collected using the electrometer. oc ), short-circuit current (I) sc ) and transferred charge (Q) sc Among them, the triboelectric nanogenerator is one of the triboelectric nanogenerators obtained in Examples 1-21. The triboelectric nanogenerator operates in a vertical contact-separation mode, the linear motor applies a force of 50N, and the linear motor's motion frequency is 2Hz. The electrical output performance (open-circuit voltage (V)) of the triboelectric nanogenerators obtained in Examples 1-21 is recorded. oc ), short-circuit current (I) sc ) and transferred charge (Q) sc The curves of eight complete motion cycles (each motion cycle includes one contact and one separation) after stable operation are plotted as follows: Figure 3 , Figures 7-11 As shown.

[0063] Depend on Figure 3 , Figures 7-11 It can be seen that the triboelectric nanogenerators obtained in Examples 2, 9, and 16 have better electrical output performance. The open-circuit voltage (V) of the triboelectric nanogenerators obtained in Examples 2, 9, and 16 is... oc ), short-circuit current (I) sc ) and transferred charge (Q) sc The maximum values ​​of ) are shown in Table 2.

[0064] Table 2

[0065]

[0066] Load Characteristic Test: The triboelectric nanogenerator obtained in Example 2 was subjected to load characteristic test under a 50N, 2Hz mechanical impact from a linear motor. A copper wire extending from each of the positive and negative electrodes of the triboelectric nanogenerator obtained in Example 2 was connected to both ends of a load resistor. The voltage port of an electrometer was then connected in parallel with the load resistors, and the output voltage of each load resistor (R) was measured and recorded. The resistance values ​​of the load resistors were 1MΩ, 2MΩ, 4MΩ, 6MΩ, 8MΩ, 10MΩ, 20MΩ, 30MΩ, 40MΩ, 50MΩ, 60MΩ, 70MΩ, 80MΩ, 90MΩ, 100MΩ, 200MΩ, 500MΩ, or 1GΩ. The output voltages obtained from load resistors with different resistance values ​​are shown below. Figure 4 As shown.

[0067] The triboelectric nanogenerator obtained in Example 2 was subjected to load characteristic tests under a 50N, 2Hz mechanical impact from a linear motor. In this test, a copper wire extending from each of the positive and negative electrodes of the triboelectric nanogenerator was connected to both ends of a load resistor. An electrometer was connected in series between the load resistor and the triboelectric nanogenerator. The output current (I) of the load resistor (R) was measured using the electrometer. The resistance values ​​of the load resistors were 1MΩ, 2MΩ, 4MΩ, 6MΩ, 8MΩ, 10MΩ, 20MΩ, 30MΩ, 40MΩ, 50MΩ, 60MΩ, 70MΩ, 80MΩ, 90MΩ, 100MΩ, 200MΩ, 500MΩ, or 1GΩ. The output current obtained from load resistors with different resistance values ​​was as follows: Figure 4 As shown. Then, the power density is calculated based on the output current. The power density obtained for different load resistance values ​​is as follows. Figure 5 As shown. The formula for calculating power density is: PD = (I 2 ·R) / S, where PD represents power density, I represents output current, R represents load resistance, and S represents the effective contact area between the triboelectric positive material and the triboelectric negative material in the triboelectric nanogenerator.

[0068] Depend on Figure 4 It can be seen that the output voltage of the triboelectric nanogenerator obtained in Example 2 gradually increases with increasing resistance, while the output current gradually decreases with increasing resistance. Figure 5 It can be seen that the power density of the triboelectric nanogenerator obtained in Example 2 shows a trend of first increasing and then decreasing as the resistance of the external resistor gradually increases, with a maximum power density of 21.8 W / m². -2 This indicates that the synergistic effect of liquid metal and nanoclay can significantly enhance the electrical output and power density of silicone.

[0069] Cyclic stability test: The triboelectric nanogenerator obtained in Example 2 was subjected to 10,000 cycles. Each cycle was identical to one motion cycle in the "Electrical Output Performance Test," the only difference being that the linear motor's motion frequency was 1 Hz. Open circuit voltage (V) oc The curve showing how the number of cycles changes is as follows: Figure 6 As shown, (a) is the open-circuit voltage after 10,000 cycles, (b) is the open-circuit voltage after the 1995th to 2000th cycles, and (c) is the open-circuit voltage after the 9995th to 10,000th cycles. Figure 6 It can be seen that under the mechanical impact of a linear motor at 50N and 1Hz, the triboelectric nanogenerator obtained in Example 2, after undergoing 10,000 consecutive cycles of testing, exhibits a Vr oc The value remained relatively stable at 220V. This indicates that the triboelectric nanogenerator obtained in Example 2 has good long-term cycling stability. (The performance of the triboelectric nanogenerator is related to the accumulation of surface charge density. The higher the surface charge density, the higher the performance (open circuit voltage) of the triboelectric nanogenerator. As the test time increases, the surface charge density accumulation of the triboelectric nanogenerator's friction layer gradually increases, thus the open circuit voltage gradually increases and reaches a maximum value.) Figure 6 The open-circuit voltage of the triboelectric nanogenerator was measured after 1 hour of pre-running with a linear motor and then undergoing 10,000 cycle tests. Figure 3 The open-circuit voltage of the triboelectric nanogenerator was measured immediately after a 30-second pre-run of a linear motor, as the initial charge accumulation time was longer. Figure 6 The open-circuit voltage is generally slightly higher than Figure 3 ).

[0070] Comparative Example 1

[0071] A triboelectric nanogenerator (TENG) is basically the same as "a triboelectric nanogenerator" in Example 2, except that "flame-retardant triboelectric material" is replaced with "triboelectric material of nano-clay / organic silica gel".

[0072] In this comparative example, the method for obtaining the triboelectrone material of nano-clay / organosilicone includes: adding nano-clay (kaolin, 0.5g) to an organosilicone precursor solution (the organosilicone precursor solution is a two-component PDMS prepolymer), and magnetically stirring (500 rpm) for 30 minutes at room temperature to obtain a uniformly dispersed nano-clay / organosilicone mixture, wherein the mass fraction of nano-clay in the nano-clay / organosilicone mixture is 5%; pouring the nano-clay / organosilicone mixture onto a substrate (polytetrafluoroethylene plate), spreading the nano-clay / organosilicone mixture with a coater to uniformly coat it onto the substrate, and then placing the substrate in a vacuum drying oven at 60°C for 5 hours to cure it to obtain a film; peeling the film off the substrate to obtain the triboelectrone material of nano-clay / organosilicone (thickness of 0.5mm, length and width of 4cm).

[0073] Comparative Example 2

[0074] A triboelectric nanogenerator (TENG) is basically the same as the "triboelectric nanogenerator" in Comparative Example 1, except that "kaolin" is replaced with "montmorillonite" (the method for obtaining the triboelectric negative material of nano-clay / organosilicone is basically the same as the "method for obtaining the triboelectric negative material of nano-clay / organosilicone" in Comparative Example 1, except that the nano-clay is montmorillonite).

[0075] Comparative Example 3

[0076] A triboelectric nanogenerator (TENG) is basically the same as the "triboelectric nanogenerator" in Comparative Example 1, except that "kaolin" is replaced with "bentonite" (the method for obtaining the triboelectric negative material of nano-clay / organosilicone is basically the same as the "method for obtaining the triboelectric negative material of nano-clay / organosilicone" in Comparative Example 1, except that the nano-clay is bentonite).

[0077] The triboelectric nanogenerators obtained in Comparative Examples 1-3 were tested according to the "Electrical Output Performance Test". The open-circuit voltage (V) of the triboelectric nanogenerators obtained in Comparative Examples 1-3 was measured. oc ), short-circuit current (I) sc ) and transferred charge (Q) sc )like Figure 12 As shown, (a) is the open-circuit voltage, (b) is the short-circuit current, and (c) is the transferred charge; "kaolin / PDMS" corresponds to the triboelectric nanogenerator obtained in Example 1, "montmorillonite / PDMS" corresponds to the triboelectric nanogenerator obtained in Example 2, and "bentonite / PDMS" corresponds to the triboelectric nanogenerator obtained in Example 3. Figure 12It can be seen that the triboelectric nanogenerators obtained in Comparative Examples 1-3 do not have an advantage in electrical output performance compared with those obtained in Examples 2, 9, and 16. This may be because the composite nanoparticles of the present invention have high conductivity, enabling them to form a large number of microcapacitor models, enhancing the charge capture and storage capacity inside the flame-retardant triboelectric material, thereby improving the electrical output performance of the assembled TENG.

[0078] The triboelectric nanogenerator obtained in Comparative Example 1 was subjected to load characteristic testing according to the "Load Characteristic Test" procedure. Figure 13 and Figure 14 As shown, Figure 13 The output voltage and output current of the triboelectric nanogenerator obtained in Comparative Example 1 are shown. Figure 14 This represents the power density of the triboelectric nanogenerator obtained in Comparative Example 1. (From...) Figure 13 It can be seen that the output voltage of the triboelectric nanogenerator obtained in Comparative Example 1 gradually increases with the increase of resistance value, while the output current gradually decreases with the increase of resistance value, which is basically consistent with the trend of Example 2. Figure 14 It can be seen that the maximum power density of the triboelectric nanogenerator obtained in Comparative Example 1 is 5.0 W / m³. -2 This is far lower than the power density of the triboelectric nanogenerator obtained in Example 2 (21.8 W / m³). -2 The power density of the triboelectric nanogenerator obtained in Example 2 is 4.4 times that of Comparative Example 1.

[0079] Comparative Example 4

[0080] A triboelectric nanogenerator (TENG) is basically the same as the "triboelectric nanogenerator" in Example 2, except that the "flame-retardant triboelectric material" is replaced with "liquid metal / organosilicon triboelectric material". The liquid metal / organosilicon triboelectric material in this comparative example does not contain nano-clay.

[0081] In this comparative example, the method for obtaining a triboneonic material of liquid metal / organosilicon includes the following steps:

[0082] Step 1: Add liquid metal (0.5g) and silicone precursor solution (the silicone precursor solution is a two-component PDMS prepolymer) to a plastic beaker, then place the plastic beaker in a 0°C ice-water bath. Use an ultrasonic homogenizer to uniformly disperse the liquid metal into the silicone precursor solution to obtain a liquid metal / silicone mixture. The liquid metal is a eutectic gallium indium tin alloy, and the mass fraction of the liquid metal in the liquid metal / silicone mixture is 5%. The power of the ultrasonic homogenizer is 50 watts, and the ultrasonic homogenizer time is 30 minutes.

[0083] Step 2: Pour the liquid metal / organic silicone mixture onto the substrate (PTFE plate), spread the liquid metal / organic silicone mixture with a coater to evenly coat the substrate, and then place the substrate in a vacuum drying oven at 60°C for 5 hours to cure, thus obtaining a film; peel the film off the substrate to obtain the triboelectrone material of liquid metal / organic silicone (the thickness of the triboelectrone material is 0.5 mm, and its length and width are both 4 cm).

[0084] Comparative Example 5

[0085] A triboelectric nanogenerator (TENG) is basically the same as the "triboelectric nanogenerator" in Example 2, except that the "flame-retardant triboelectrone material" is replaced with "organosilicone triboelectrone material". The method for obtaining the organosilicone triboelectrone material includes: pouring 10g of organosilicone precursor liquid onto a substrate (polytetrafluoroethylene (PTFE) plate), spreading the organosilicone precursor liquid with a coater to uniformly coat it onto the substrate, and then placing the substrate in a vacuum drying oven at 60°C for 5 hours to cure it to obtain a film; peeling the film off the substrate to obtain the organosilicone triboelectrone material (the organosilicone triboelectrone material has a thickness of 0.5mm and a length and width of 4cm).

[0086] The triboelectric nanogenerators obtained in Comparative Examples 4-5 were tested according to the "Electrical Output Performance Test". The open-circuit voltage (V) of the triboelectric nanogenerators obtained in Comparative Examples 4-5 was measured. oc ), short-circuit current (I) sc ) and transferred charge (Q) sc )like Figure 15 and Figure 18 As shown, where, Figure 15 For the triboelectric nanogenerator obtained in Comparative Example 4, (a) open-circuit voltage, (b) short-circuit current, and (c) transferred charge, Figure 18 The figures show (a) open-circuit voltage, (b) short-circuit current, and (c) transferred charge of the triboelectric nanogenerator obtained in Comparative Example 5. Figure 15 and Figure 18 It can be seen that the electrical output performance of the triboelectric nanogenerators obtained in Comparative Examples 4 and 5 is significantly inferior to that of the triboelectric nanogenerators obtained in Examples 2, 9 and 16.

[0087] The triboelectric nanogenerators obtained in Comparative Examples 4 and 5 were subjected to load characteristic tests according to the "Load Characteristic Test" procedure. The results of the load characteristic test are as follows: Figures 16-17 and Figures 19-20 As shown, Figure 16 The output voltage and output current of the triboelectric nanogenerator obtained in Comparative Example 4 are shown. Figure 17 To show the power density of the triboelectric nanogenerator obtained in Comparative Example 4, Figure 19 The output voltage and output current of the triboelectric nanogenerator obtained in Comparative Example 5 are shown. Figure 20 The power density of the triboelectric nanogenerator obtained in Comparative Example 5 is shown.

[0088] Depend on Figure 16 and Figure 19 It can be seen that the output voltage of the triboelectric nanogenerators obtained in Comparative Examples 4 and 5 gradually increases with increasing resistance, while the output current gradually decreases with increasing resistance. Figure 17 and Figure 20 It can be seen that the maximum power density of the triboelectric nanogenerator obtained in Comparative Example 4 is 5.4 W / m³. -2 The triboelectric nanogenerator obtained in Comparative Example 5 has the highest power density of 1.7 W / m³. -2 This is far lower than the power density of the triboelectric nanogenerator obtained in Example 2 (21.8 W / m³). -2 The power density of the triboelectric nanogenerator obtained in Example 2 is 4.0 times and 12.8 times that of Comparative Example 4 and Comparative Example 5, respectively.

[0089] Flame retardant performance test method: The sample was cut and folded to a size of 3.5cm long × 1.0cm wide × 2mm thick, and then placed vertically on the outer flame of an alcohol lamp (with no gap between the sample and the flame). The sample was ignited and the time was recorded. After the sample was ignited, it was immediately removed from the flame, and the combustion phenomenon was observed and the duration of combustion was recorded. The sample was one of the following: the flame-retardant triboelectric material obtained in Example 2, the flame-retardant triboelectric material obtained in Example 9, the flame-retardant triboelectric material obtained in Example 16, and the triboelectric materials obtained in Comparative Examples 1-5. Images of the flame retardant performance test are shown below. Figure 22 As shown, (a) is the flame-retardant triboelectric material obtained in Example 2, (b) is the flame-retardant triboelectric material obtained in Example 9, (c) is the flame-retardant triboelectric material obtained in Example 16, (d) is the triboelectric material obtained in Comparative Example 1, (e) is the triboelectric material obtained in Comparative Example 2, (f) is the triboelectric material obtained in Comparative Example 3, (g) is the triboelectric material obtained in Comparative Example 4, and (h) is the triboelectric material obtained in Comparative Example 5.

[0090] Depend on Figure 22 It can be seen that the flame-retardant triboelectric materials obtained in Examples 2, 9, and 16 have better flame-retardant properties and are not easily ignited. Furthermore, the flame-retardant triboelectric materials obtained in Examples 2, 9, and 16 exhibit rapid self-extinguishing characteristics within 10 seconds, 12 seconds, and 18 seconds of the onset of combustion, respectively (e.g., ...). Figure 22As shown in (a) to (c). The triboelectrone materials obtained in Comparative Examples 1 to 3 are based on nano-clay and silicone, and the flames extinguish after 50, 55, and 58 seconds of combustion, respectively (as shown in (a) to (c)). Figure 22 As shown in (d) to (f); the triboelectrone material obtained in Comparative Example 4 is based on liquid metal and silicone, and its flame extinguishes 80 seconds after the start of combustion (as shown in (d) to (f)). Figure 22 (g) shown); the triboelectric material obtained in Comparative Example 5 was based on silicone rubber, which completely burned to ash after 100 seconds of combustion and did not exhibit self-extinguishing properties (as shown in the figure). Figure 22 As shown in (h). It can be seen that the synergistic effect of liquid metal and nano-clay can significantly enhance the flame retardant properties of silicone.

[0091] Thermal stability testing method: The thermal stability of the samples was tested using a thermogravimetric analyzer (model: SDT-Q600, purchased from TA Instruments, USA), and the char retention rate was calculated (a higher char retention rate indicates better thermal stability and flame retardant performance). The thermal stability test method involved heating the samples from room temperature to 800°C at a rate of 10°C / min under a nitrogen atmosphere. The samples were one of the following: the flame-retardant triboelectric material obtained in Example 2, the flame-retardant triboelectric material obtained in Example 9, the flame-retardant triboelectric material obtained in Example 16, and the triboelectric materials obtained in Comparative Examples 1-5. The obtained thermogravimetric curves are shown below. Figure 21 As shown, "liquid metal / kaolin / PDMS" corresponds to the flame-retardant triboelectric material obtained in Example 2, "liquid metal / montmorillonite / PDMS" corresponds to the flame-retardant triboelectric material obtained in Example 9, "liquid metal / bentonite / PDMS" corresponds to the flame-retardant triboelectric material obtained in Example 16, "kaolinite / PDMS" corresponds to the triboelectric material obtained in Example 1, "montmorillonite / PDMS" corresponds to the triboelectric material obtained in Example 2, "bentonite / PDMS" corresponds to the triboelectric material obtained in Example 3, "liquid metal / PDMS" corresponds to the triboelectric material obtained in Example 4, and "PDMS" corresponds to the triboelectric material obtained in Example 5.

[0092] Depend on Figure 21 It can be seen that the flame-retardant triboelectric materials obtained in Examples 2, 9, and 16 have high char retention rates at 800°C, at 69.9%, 68.4%, and 65.6%, respectively; while the char retention rates of the triboelectric materials obtained in Comparative Examples 1-5 are 57.3%, 55.6%, 54.3%, 50.0%, and 43.6%, respectively. It is noteworthy that the order of thermal stability of the triboelectric materials is consistent with the order of flame-retardant performance testing, further verifying that the synergistic effect of liquid metal and nano-clay can significantly enhance the flame-retardant properties of silicone rubber.

[0093] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing a flame-retardant triboelectric material, characterized in that, Includes the following steps: Step 1: Mix liquid metal and nano-clay evenly to obtain composite nanoparticles. The ratio of liquid metal to nano-clay by mass is (1~4):

1. The liquid metal includes eutectic gallium indium alloy and / or eutectic gallium indium tin alloy. The nano-clay is one or a mixture of kaolin, montmorillonite and bentonite. Step 2: The composite nanoparticles are uniformly dispersed in the organosilicone precursor solution to obtain a liquid metal / nanoclay / organosilicone mixture, wherein the mass fraction of the composite nanoparticles in the liquid metal / nanoclay / organosilicone mixture is 1~20%; Step 3: The liquid metal / nanoclay / organic silicone mixture is uniformly coated onto the substrate and cured at 60~80°C for 5~10 hours to obtain a flame-retardant triboelectric material on the substrate.

2. The preparation method according to claim 1, characterized in that, In step 3, the thickness of the flame-retardant triboelectric material is 0.1~1.0 mm.

3. The preparation method according to claim 1, characterized in that, In step 3, the substrate is made of polytetrafluoroethylene.

4. The preparation method according to claim 1, characterized in that, The silicone precursor is a two-component PDMS prepolymer.

5. The flame-retardant triboelectric material obtained by the preparation method according to any one of claims 1 to 4.

6. The use of the flame-retardant triboelectric material as described in claim 5 in triboelectric nanogenerators.

7. The use according to claim 6, characterized in that, In triboelectric nanogenerators, the triboelectric positive material is a polymer film.

8. The use according to claim 7, characterized in that, The polymer film is made of nylon, cellulose, or polyvinyl alcohol.

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