A composite nanogenerator for an intelligent monitoring system, its preparation method and application

Abstract

The present invention relates to a nanogenerator, specifically to a composite nanogenerator for an intelligent monitoring system, its preparation method and application, which include the following steps: S1: Prepare barium titanate nanowires by a two-step hydrothermal method and carry out hydroxylation treatment to obtain hydroxylated barium titanate nanowires; S2: Mix the hydroxylated barium titanate nanowires obtained in step S1 with carboxylated carbon nanotubes, PVDF and PDMS, and prepare a PVDF / PDMS-BTO-CNT nanofiber film by electrospinning; S3: Bond a PI film, a copper tape and the PVDF / PDMS-BTO-CNT nanofiber film obtained in step S2 in sequence, and paste the PI film inside a rubber hose to assemble the composite nanogenerator. Compared with the prior art, the present invention solves the problem that most of the composite nanogenerators in the prior art cannot be put into practical application due to complex structures and low output performance.

Description

Technical Field

[0001] The invention relates to a nanogenerator, in particular to a composite nanogenerator for an intelligent monitoring system and a preparation method and application thereof. Background Art

[0002] From the earliest invention of the steam engine to the later invention of electricity, it has long been proven that energy is the fundamental force for the progress of human civilization. However, the non-renewable nature of fossil fuels has put humans in the dilemma of energy depletion. In recent years, the development of piezoelectric nanogenerators (PENG) and triboelectric nanogenerators (TENG) has provided new solutions for wearable electronics, health monitoring, the Internet of Things and other fields. PENG and TENG can effectively convert the widespread irregular and easily ignored mechanical energy into electrical energy. Although related research has been widely discussed by many scholars, low output power and complex structure have severely limited its application.

[0003] Nanogenerators come in a variety of forms, including one-dimensional linear structures, two-dimensional fabric structures, and three-dimensional structures. In these structures, the functional layers (friction layer and piezoelectric layer) are mainly in the form of thin films. Electrospinning is a mature preparation process. The films prepared by this process are widely used to prepare the functional layers of nanogenerators due to their high porosity, neat micromorphology, and high β-phase content. Most of the nanogenerators studied by scholars are single piezoelectric nanogenerators or triboelectric nanogenerators, and their output power is usually low.

[0004] Improving the performance of composite nanogenerators can be done from two perspectives, namely, improving the performance of piezoelectric nanogenerators and triboelectric nanogenerators. Piezoelectric nanogenerators mainly rely on piezoelectric effect and electrostatic induction. Its common materials include inorganic ceramics such as barium titanate, zinc oxide, lead zirconate titanate, and organic polymers PVDF and its copolymers. Researchers usually combine the two to obtain piezoelectric nanogenerators that are both flexible and have considerable piezoelectric output performance. In piezoelectric materials, since the β phase has a higher net dipole moment than the α phase, more β phase content can promote the improvement of its piezoelectric performance. The working mechanism of triboelectric nanogenerators is mainly friction electrification and electrostatic induction. Its internal porous structure, rough surface and high dielectric constant are the main factors to improve performance. If the dielectric constant of the film can be improved by designing the microscopic form of nanofillers inside the polymer, and a high β phase content is obtained to prepare a composite nanogenerator, its output performance will be greatly improved and its structure will be simplified.

[0005] Chinese Patent CN202210186422.7 discloses a preparation method and application of a piezoelectric-triboelectric coupled induction material, which prepares a nanogenerator with both piezoelectric and triboelectric coupling effects, having excellent mechanical properties and signal conversion performance. However, the output performance of the prepared nanogenerator is weak and it has not been applied in specific scenarios. Chinese Patent CN202010578455.7 discloses a self-powered nanosensor based on piezoelectric-triboelectric coupling effect. The configuration of the nanosensor from top to bottom is a piezoelectric-triboelectric structure layer, an electrode layer, a support layer, an electrode layer, and a protective layer in sequence. The piezoelectric-triboelectric nanostructure layer is a nanowire structure on a flexible substrate. However, due to its complex structure, it is difficult to be applied.

[0006] In summary, most of the current composite nanogenerators cannot be put into practical applications due to their complex structures and low output performance. Therefore, it is an urgent problem to be solved to simplify the structure of the composite nanogenerator while improving its output performance to make it more convenient to apply in real life. Summary of the Invention

[0007] The purpose of the present invention is to provide a composite nanogenerator for an intelligent monitoring system, its preparation method and application to solve at least one of the above problems, so as to solve the problem that most of the existing composite nanogenerators cannot be put into practical applications due to their complex structures and low output performance, and achieve the goal of simplifying the structure of the composite nanogenerator while improving its output performance to make it more convenient to apply in real life.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] The first aspect of the present invention discloses a preparation method of a composite nanogenerator for an intelligent monitoring system, including the following steps:

[0010] S1: Prepare barium titanate nanowires by a two-step hydrothermal method and perform hydroxylation treatment to obtain hydroxylated barium titanate nanowires;

[0011] S2: Mix the hydroxylated barium titanate nanowires obtained in step S1 with carboxylated carbon nanotubes, PVDF, and PDMS, and prepare a PVDF / PDMS-BTO-CNT nanofiber film by electrospinning;

[0012] S3: Bond a PI film, a copper tape, and the PVDF / PDMS-BTO-CNT nanofiber film obtained in step S2 in sequence, and paste the PI film inside a rubber hose to assemble the composite nanogenerator.

[0013] Preferably, in step S1, it specifically includes the following steps:

[0014] S11: Disperse titanium dioxide in an alkaline solution, stir and then carry out a hydrothermal reaction. After washing and drying the reaction product, Na2Ti3O7 is obtained.

[0015] S12: Immerse the Na2Ti3O7 obtained in step S11 in an acidic solution, and then obtain H2Ti3O7 after washing and drying.

[0016] S13: Place the H2Ti3O7 obtained in step S12 in a barium hydroxide octahydrate solution, stir and then carry out a hydrothermal reaction. After washing and drying the reaction product, barium titanate nanowires are obtained.

[0017] S14: Add the barium titanate nanowires obtained in step S13 to hydrogen peroxide and reflux. After washing and drying the reaction product, hydroxylated barium titanate nanowires are obtained.

[0018] Preferably,

[0019] In step S11, the concentration of hydroxide ions in the alkaline solution is 9 - 12 mol / L, and the dosage ratio of titanium dioxide to the alkaline solution is 3 g:60 mL; the stirring time is 10 - 14 h; the temperature of the hydrothermal reaction is 170 - 230 °C, and the time is 60 - 84 h; the washing is successively carried out with deionized water and ethanol until the washing liquid is neutral; the drying is vacuum drying, the temperature is 60 - 80 °C, and the time is 12 - 24 h.

[0020] In step S12, the concentration of hydrogen ions in the acidic solution is 0.1 - 0.3 mol / L, and the volume ratio of the acidic solution to the alkaline solution is 220 - 260:60; the immersion time is 20 - 28 h; the washing is successively carried out with deionized water and ethanol until the washing liquid is neutral; the drying is vacuum drying, the temperature is 60 - 80 °C, and the time is 12 - 24 h.

[0021] In step S13, the concentration of barium hydroxide octahydrate is 1.8 - 2.2 g:100 - 140 mL; the mass ratio of H2Ti3O7 to barium hydroxide octahydrate is 0.2 - 0.4:1.8 - 2.2; the temperature of the hydrothermal reaction is 170 - 230 °C, and the time is 2 - 4 h; the washing is successively carried out with dilute hydrochloric acid and deionized water until neutral; the drying is vacuum drying, the temperature is 60 - 80 °C, and the time is 12 - 24 h.

[0022] In step S14, the dosage ratio of the barium titanate nanowires to hydrogen peroxide is 2 - 4 g:20 - 50 mL; the reflux temperature is 95 - 115 °C, and the time is 3 - 5 h; the washing is successively carried out with deionized water and ethanol until the washing liquid is neutral; the drying is vacuum drying, the temperature is 60 - 80 °C, and the time is 12 - 24 h.

[0023] Preferably, in step S2, it specifically includes the following steps:

[0024] S21: Disperse the carboxylated carbon nanotubes and the hydroxylated barium titanate nanowires obtained in step S1 in a mixed solution formed by mixing DMF and acetone, and then stir and ultrasonically treat to obtain a mixed solution A;

[0025] S22: Add PVDF to the mixed solution A obtained in step S21, and then stir and ultrasonically treat to obtain a mixed solution B;

[0026] S23: Add PDMS to the mixed solution B obtained in step S22, and then stir and ultrasonically treat to obtain a mixed solution C;

[0027] S24: Electrospun the mixed solution C obtained in step S23 to obtain a PVDF / PDMS-BTO-CNT nanofiber film.

[0028] Preferably,

[0029] In step S21, the addition amount of the carboxylated carbon nanotubes is 0 - 5 wt% of the mixed solution C, and not 0 wt%; the addition amount of the hydroxylated barium titanate nanowires is 0 - 25 wt% of the mixed solution C, and not 0 wt%; in the mixed solution, the mass ratio of DMF to acetone is 0.2 - 5:1; the stirring time is 20 - 60 minutes; the ultrasonic time is 1 - 2 hours;

[0030] In step S22, the addition amount of PVDF is 10 - 20 wt% of the mixed solution C; the stirring time is 40 - 90 minutes, and the temperature is 50 - 70 °C; the ultrasonic time is 1 - 2 hours;

[0031] In step S23, the PDMS is a mixture of polydimethylsiloxane and a curing agent mixed at a mass ratio of 10:1, and the addition amount of PDMS is 40 - 80 wt% of the addition amount of PVDF; the stirring time is 40 - 90 minutes; the ultrasonic time is 0.5 - 2 hours;

[0032] In step S24, the process parameters of the electrospinning are: a single-hole needle of 14 - 22G; a syringe of 5 - 10 mL; a spinning distance of 10 - 20 cm; a spinning voltage of 12 - 20 kV; a spinning speed of 0.5 - 1.5 mL / h; the spinning temperature is 20 - 40 °C; the spinning time is 1 - 3 h.

[0033] Preferably, in step S3,

[0034] The rubber hose described above is a hollow semi-circular hose with a length of 3 - 8 cm;

[0035] The width of the PI film described above is 4 - 6 cm, and the length is 5 - 8 cm;

[0036] The width of the copper tape described above is 2 - 5 cm, and the length is 2 - 5 cm;

[0037] The size of the PVDF / PDMS - BTO - CNT nanofiber film described above is larger than that of the copper tape.

[0038] The second aspect of the present invention discloses a composite nanogenerator for an intelligent monitoring system, which is prepared by any of the methods described above.

[0039] The third aspect of the present invention discloses an application of the composite nanogenerator described above in an intelligent monitoring system.

[0040] Preferably, the monitoring system includes a composite nanogenerator, an Arduino data board, and a user terminal;

[0041] The composite nanogenerator is connected to the Arduino data board through a signal receiver, and the Arduino data board is connected to the user terminal through a transmission module to form a monitoring system;

[0042] A control program is burned on the Arduino data board.

[0043] Preferably, the transmission module includes a wifi module or a bluetooth module; the user terminal includes a mobile phone or a computer; the control program executes a monitoring function.

[0044] Briefly speaking, the present invention is to use an electrospinning machine to prepare a nanofiber film with a triboelectric - piezoelectric coupling effect, and then assemble it into an integrated piezoelectric - triboelectric composite nanogenerator, which can be used in an artificial intelligence monitoring system in remote areas with inconvenient power supply.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] By simultaneously introducing carbon nanotubes and barium titanate nanowires into the PVDF / PDMS system, the present invention obtains a composite nanogenerator with an internal micro - capacitance structure (barium titanate nanowires and carbon nanotubes form a micro - capacitance inside the PVDF / PDMS film, enhancing the dielectric performance). The prepared film not only has a high β - phase content but also exhibits excellent dielectric performance, greatly improving its output performance.

[0047] In addition, the charges generated by triboelectrification can enhance the polarization degree of piezoelectric dipoles in the device, thus enhancing its piezoelectric output performance, that is, enhancing the performance of the composite nanogenerator.

[0048] The present invention can realize the functions of the piezoelectric layer and the negative friction layer only through the nanofiber monolayer film prepared by electrospinning, greatly simplifying its structure.

[0049] In addition to designing the material composition and structural form of the composite nanogenerator, the present invention also hypothetically applies it to the intelligent monitoring system in remote and power-supply-inconvenient areas by experimental methods. The actual application is stable, sensitive, and accurate, showing strong application potential in the future.

[0050] The composite nanogenerator prepared by the present invention has excellent output performance, good stability, controllable operation, and is green and environmentally friendly. When used in an intelligent monitoring system, it has high reliability and strong practicability, and can provide a new choice for the portable power supply of self-powered devices in the Internet of Things era. Description of the Drawings

[0051] Figure 1 It is the transmission electron microscope image of the barium titanate nanowires prepared by the hydrothermal synthesis method in Example 1;

[0052] Figure 2 It is the XRD pattern of the barium titanate nanowires prepared by the hydrothermal synthesis method in Example 1;

[0053] Figure 3 It is the FTIR spectra of the barium titanate nanowires prepared by the hydrothermal synthesis method in Example 1 before and after hydroxylation;

[0054] Figure 4 It is the SEM image of the electrospun nanofiber film in Example 1 at 3 μm;

[0055] Figure 5 It is the SEM image of the electrospun nanofiber film in Example 1 at 0.4 μm;

[0056] Figure 6 It is the TEM image of the barium titanate and carbon nanotube system in Example 1;

[0057] Figure 7 It is the Raman spectrum of the barium titanate, carbon nanotubes and electrospun nanofiber film in Example 1;

[0058] Figure 8 It is the FTIR spectra of the electrospun nanofiber films in Examples 1, 2, 3 and Comparative Examples 1, 2;

[0059] Figure 9 It is the β-phase content diagram of the electrospun nanofiber films in Examples 1, 2, 3 and Comparative Examples 1, 2;

[0060] Figure 10 Dielectric constant diagrams of the electrospun nanofiber films in Examples 1, 2, 3 and Comparative Examples 1, 2;

[0061] Figure 11 Dielectric loss diagrams of the electrospun nanofiber films in Examples 1, 2, 3 and Comparative Examples 1, 2;

[0062] Figure 12 Composite voltage diagrams of the electrospun nanofiber films in Examples 1, 2, 3 and Comparative Examples 1, 2;

[0063] Figure 13 Composite current diagrams of the electrospun nanofiber films in Examples 1, 2, 3 and Comparative Examples 1, 2;

[0064] Figure 14 Comparison diagrams of the sum of the composite voltage and the piezo - triboelectric values of the electrospun nanofiber films in Examples 1, 2, 3 and Comparative Examples 1, 2;

[0065] Figure 15 Schematic diagram of the enhancement of dipole polarization inside the triboelectric charge - enhanced nanofiber film;

[0066] Figure 16 Schematic diagram of the structure of the assembled composite nanogenerator in Example 1;

[0067] Figure 17 Schematic diagram of the structure of the intelligent monitoring system in Example 1. Detailed implementation manners

[0068] The present invention will be described in detail below with reference to the accompanying drawings and specific examples.

[0069] In the following examples, if not otherwise specified, the reagents used can be conventional reagents in the art or commercially available reagents, and the methods used can be conventional means in the art or well - known methods.

[0070] The general steps of the following examples are as follows:

[0071] (1) Prepare barium titanate nanowires by a two - step hydrothermal method and perform hydroxylation treatment;

[0072] (2) Prepare PVDF / PDMS - BTO - CNT nanofiber films by an electrospinning process;

[0073] (3) Assemble the electrospun nanofiber films into a composite nanogenerator;

[0074] (4) Apply the composite nanogenerator to an intelligent monitoring system.

[0075] Specifically:

[0076] The method for preparing barium titanate nanowires by the two-step hydrothermal method and performing hydroxylation treatment in step (1) is as follows:

[0077] a. Disperse titanium dioxide in an alkaline solution and stir, then carry out a hydrothermal reaction. After the reaction product is washed and dried, Na2Ti3O7 is obtained;

[0078] b. Immerse the Na2Ti3O7 obtained in step a in an acidic solution, and then obtain H2Ti3O7 after washing and drying;

[0079] c. Stir the H2Ti3O7 obtained in step b in an aqueous solution of barium hydroxide octahydrate, and then carry out a hydrothermal reaction. After the reaction product is washed and dried, barium titanate nanowires are obtained;

[0080] d. Add the barium titanate nanowires obtained in step c to hydrogen peroxide and reflux. After the reaction product is washed and dried, hydroxylated barium titanate is obtained.

[0081] Preferably,

[0082] In step a, the dosage ratio of titanium dioxide to the alkaline solution is 3 g: 60 mL; the alkaline solution is an alkaline solution with a hydroxide ion concentration of 9 - 12 mol / L; the stirring time is 10 - 14 h; the temperature of the hydrothermal reaction is 170 - 230 °C, and the time is 60 - 84 h; the washing is successively washing with deionized water and ethanol until the washing liquid is neutral; the drying environment is a vacuum oven, the drying temperature is 60 - 80 °C, and the drying time is 12 - 24 h;

[0083] In step b, the amount of Na2Ti3O7 is all the products in step a; the acidic solution is an acidic solution with a hydrogen ion concentration of 0.1 - 0.3 mol / L, the volume is 220 - 260 mL, and the soaking time is 20 - 28 h; the washing is successively washing with deionized water and ethanol until the washing liquid is neutral; the drying environment is a vacuum oven, the temperature is 60 - 80 °C, and the time is 12 - 24 h;

[0084] In step c, the concentration of barium hydroxide octahydrate is 1.8 - 2.2 g: 100 - 140 mL; the mass ratio of H2Ti3O7 to barium hydroxide octahydrate is 0.2 - 0.4: 1.8 - 2.2; the temperature of the hydrothermal reaction is 170 - 230 °C, and the time is 2 - 4 h; the washing is successively washing with dilute hydrochloric acid and deionized water until neutral; the drying environment is a vacuum oven, the drying temperature is 60 - 80 °C, and the drying time is 12 - 24 h;

[0085] In step d, the mass of the barium titanate nanowires is 2-4 g; the volume of the hydrogen peroxide is 20-50 mL; the reflux temperature is 95-115 °C, and the reflux time is 3-5 h; the washing is carried out by washing with deionized water and ethanol in sequence until the washing liquid is neutral; the drying environment is a vacuum oven, the temperature is 60-80 °C, and the time is 12-24 h;

[0086] The electrospinning process described in step (2) is as follows:

[0087] a. Dispersing the carboxylated carbon nanotubes and the hydroxylated barium titanate nanowires obtained in step (1) in a mixed solution of DMF and acetone, and then performing stirring and ultrasonic treatment;

[0088] b. Adding PVDF to the mixed solution obtained in step a, and then performing stirring and ultrasonic treatment;

[0089] c. Adding PDMS to the mixed solution obtained in step b, and then performing stirring and ultrasonic treatment;

[0090] d. Electrospinning the solution obtained in step c to obtain a nanofiber film.

[0091] Preferably,

[0092] In step a, the mass fraction of the carboxylated carbon nanotubes in the solution obtained in step c is 0-5%; the mass fraction of the hydroxylated barium titanate nanowires in the solution obtained in step c is 0-20%; the mass ratio of DMF to acetone is 0.2-5; the stirring time is 20-60 minutes; the ultrasonic time is 1-2 hours;

[0093] In step b, the mass fraction of PVDF in the solution obtained in step c is 10-20%; the stirring time is 40-90 minutes; the ultrasonic time is 1-2 hours;

[0094] In step c, PDMS is a mixture of polydimethylsiloxane and a curing agent in a ratio of 10:1, and its total mass is 40-80% of the PVDF added in step b; the stirring time is 40-90 minutes; the ultrasonic time is 0.5-2 hours;

[0095] The process parameters of the electrospinning in step d are as follows: a single-hole needle of 14-22 G; a syringe of 5-10 mL; a spinning distance of 10-20 cm; a spinning voltage of 12-20 kV; a spinning speed of 0.5-1.5 mL / h; the spinning temperature is 20-40 °C; the spinning time is 1-3 h.

[0096] The method for assembling the nanogenerator described in step (3) is as follows:

[0097] a. Cut the rubber hose into small segments;

[0098] b. Paste the PI film inside the hose obtained in step a;

[0099] c. Paste the copper tape on the surface of the PI film pasted in step b;

[0100] d. Cut the nanofiber film obtained in step (2) into small pieces of film and paste them on the surface of the copper tape pasted in step c.

[0101] Preferably,

[0102] The rubber hose described in step a is a hollow semi-circular or other-shaped hose, and the length of the small segment is 3 - 8 cm;

[0103] The width of the PI film described in step b is 4 - 6 cm, and the length is 5 - 8 cm;

[0104] The width of the copper tape described in step c is 2 - 5 cm, and the length is 2 - 5 cm;

[0105] The size of the small piece of nanofiber film described in step d is larger than the size of the copper tape described in step c.

[0106] Preferably, the method of using the composite nanogenerator in the intelligent monitoring system described in step (4) is as follows:

[0107] a. Connect the nanogenerator obtained in step (3) and the signal receiver;

[0108] b. Connect the signal receiver described in step a and the Arduino data board;

[0109] c. Upload the control program to the Arduino data board described in step b;

[0110] d. Connect the Arduino data board described in step b and the transmission module;

[0111] e. Receive the data of the transmission module described in step d on the mobile terminal.

[0112] Preferably,

[0113] The signal receiver described in step a is a device that can sense the output signal of the nanogenerator obtained in step (3) and can transmit data to the Arduino data board;

[0114] The control program described in step c is programmed by a computer and can perform specific monitoring functions;

[0115] The transmission module described in step d includes but is not limited to a wifi module or a bluetooth module;

[0116] The mobile device described in step e includes but is not limited to mobile phones or computers.

[0117] Example 1

[0118] Step (1): Prepare barium titanate nanowires by a two-step hydrothermal method and perform hydroxylation treatment

[0119] (1-1) Disperse 3 g of titanium dioxide into 60 mL of 10 mol / L sodium hydroxide solution and stir for 12 h, then add it to a 200 mL hydrothermal synthesis reactor and react at 200 °C for 72 h. Wash the obtained precipitate successively with deionized water and ethanol. When the washing solution is neutral, dry the product in a vacuum oven at 70 °C to obtain Na2Ti3O7.

[0120] (1-2) Immerse the obtained Na2Ti3O7 in 240 mL of 0.1 mol / L HCl solution for 24 h, wash it with deionized water and ethanol. When the washing solution is neutral, dry the product in a vacuum oven at 70 °C to obtain H2Ti3O7.

[0121] (1-3) Add 0.14 g of H2Ti3O7 and 1.025 g of barium hydroxide octahydrate to 60 mL of deionized water, stir for 24 h, then add it to a 200 mL hydrothermal synthesis reactor and react at 200 °C for 3 h. Wash the obtained product successively with dilute hydrochloric acid and deionized water. When the washing solution is neutral, dry the product in a vacuum oven at 70 °C to obtain barium titanate nanowires.

[0122] (1-4) Add 3 g of barium titanate nanowires to 30 mL of hydrogen peroxide solution and reflux at 105 °C for 4 h. Wash the product with deionized water. When the washing solution is neutral, dry the product in a vacuum oven at 70 °C for 24 h to obtain hydroxy barium titanate nanowires.

[0123] Step (2): Prepare PVDF / PDMS-BTO-CNT nanofiber film by electrospinning process

[0124] (2-1) Disperse 0.015 g of carboxylated carbon nanotubes and 0.225 g of hydroxy barium titanate nanowires in a mixed solution of 6.8 g of DMF and 1.7 g of acetone, then stir for 0.5 h and finally perform ultrasonic treatment for 1 h;

[0125] (2-2) Add 1.26 g of PVDF to the mixed solution obtained in step a, then stir at 60 °C for 1 h and finally perform ultrasonic treatment for 1 h;

[0126] (2-3) Add 0.9 g of DC184 PDMS and its curing agent with a mass ratio of 10:1 to the mixed solution obtained in step b, then stir for 1 h, and finally perform ultrasonic treatment for 0.5 h;

[0127] (2-4) Electrospin the solution obtained in step (2-3) to obtain a nanofiber membrane, using a 20G single-hole needle; a 5 mL syringe; a spinning distance of 15 cm; a spinning voltage of 18 kV; a spinning speed of 1 mL / h; the spinning temperature is 25 °C; the spinning time is 2 h.

[0128] Step (3): Assemble the electrospun nanofiber membrane into a composite nanogenerator

[0129] (3-1) Cut the semi-circular hollow rubber hose into small segments with a length of 5 cm;

[0130] (3-2) Paste a PI film with a length and width of 5 cm inside the hose obtained in step (3-1);

[0131] (3-3) Paste a copper tape with a length and width of 3 cm on the surface of the PI film pasted in step (3-2);

[0132] (3-4) Cut the nanofiber membrane obtained in step (2) into small pieces with a length and width of 3.2 cm, and paste them on the surface of the copper tape pasted in step (3-3).

[0133] Step (4): Use the composite nanogenerator in an intelligent monitoring system

[0134] (4-1) Connect the nanogenerator obtained in step (3) to the signal receiver part of the semi-ceramic vibration simulation sensor produced by Shenzhen Kobe Microelectronics Co., Ltd.;

[0135] (4-2) Connect the signal receiver part of the semi-ceramic vibration simulation sensor to the Arduino data board;

[0136] (4-3) Upload the intelligent monitoring program (obtained by computer programming and can perform specific monitoring functions) to the Arduino data board described in step (4-2);

[0137] (4-4) Connect the Arduino data board described in step (4-3) to the HC-05 Bluetooth module of Xintai Microelectronics Co., Ltd.;

[0138] (4-5) Receive the data of the transmission module (Bluetooth module) described in step (4-4) on the mobile phone side.

[0139] Among them, the intelligent monitoring program in step (4-3) is:

[0140] #include<SoftwareSerial.h>

[0141] #define TX 2

[0142] #define RX 3

[0143] SoftwareSerial BT(TX, RX);

[0144] void setup() {

[0145] / / put your setup code here, to run once:

[0146] BT.begin(9600);

[0147] Serial.begin(9600);

[0148] }

[0149] void loop() {

[0150] / / put your main code here, to run repeatedly:

[0151] if (analogRead(A0) > 10) {

[0152] BT.write(1);

[0153] Serial.print(analogRead(A0));

[0154] Serial.println("");

[0155] delay(1000);

[0156] if (analogRead(A1) > 10) {

[0157] BT.write(2);

[0158] Serial.print(analogRead(A1));

[0159] Serial.println("");

[0160] delay(1000);

[0161] }

[0162] if(analogRead(A2)>10){

[0163] BT.write(3);

[0164] Serial.print(analogRead(A2));

[0165] Serial.println("");

[0166] delay(1000);

[0167] }

[0168] }

[0169] Figure 1 It is proved that the barium titanate nanowires prepared by the hydrothermal synthesis method in Example 1 have a uniform structure and are pure substances without impurities; Figure 2 It is proved that the barium titanate nanowires prepared by the hydrothermal synthesis method in Example 1 have a perovskite structure and are completely matched with the absorption peaks of the standard card PDF#75 - 0212, proving that the prepared barium titanate nanowires do not contain impurities; Figure 3 It is proved that after the barium titanate nanowires prepared in Example 1 are hydroxylated, the absorption peak intensity of their FTIR becomes higher, the peak band range becomes wider, and the absorption peak wavenumber becomes smaller, proving that the hydroxylation treatment is successful; Figure 4 It is proved that the electrospun nanofiber film prepared in Example 1 has a uniform microstructure; Figure 5 It is proved that the barium titanate nanowires in the electrospun nanofiber film prepared in Example 1 are arranged around the carbon nanotubes; Figure 6 It is proved that there is a phenomenon that the barium titanate nanowires and carbon nanotubes in Example 1 tend to be coaxially arranged; Figure 7 It is proved that the Raman absorption peaks of the barium titanate nanowires in the electrospun nanofiber film prepared in Example 1 are from 278, 309, 516 cm -1 shifted to 276, 296, 494 cm -1 , and the Raman absorption peaks of the carbon nanotubes are from 1344, 1578 cm -1 shifted to 1353, 1592 cm -1 , indicating that hydrogen bonds are formed between the barium titanate nanowires and carbon nanotubes in the nanofiber film and they have a micro - capacitor structure; Figure 16 Figure of the physical object of the nanogenerator assembled in Example 1, proving that the physical object has a simple structure; Figure 17It is a physical diagram of the intelligent monitoring system in Example 1. Nanogenerators at different positions collect abnormal signals during operation, transmit the signals to the Arduino board through a ceramic vibration simulation sensor, and then transmit the signals to the mobile phone through a Bluetooth module. By applying artificial interference signals to the nanogenerators at different positions and observing the signal changes in the corresponding areas on the mobile phone, it is proved that the system can achieve sensitive and reliable real-time monitoring functions and is expected to be applied to real-time monitoring scenarios in remote and power-inconvenient areas in the future.

[0170] Example 2

[0171] Step (1): Prepare barium titanate nanowires by a two-step hydrothermal method and perform hydroxylation treatment.

[0172] (1-1) Disperse 3 g of titanium dioxide into 60 mL of 10 mol / L sodium hydroxide solution and stir for 12 h, then add it to a 200 mL hydrothermal synthesis reactor and react at 200 °C for 72 h. Wash the obtained precipitate successively with deionized water and ethanol. When the washing solution is neutral, dry the product in a vacuum oven at 70 °C to obtain Na2Ti3O7.

[0173] (1-2) Immerse the obtained Na2Ti3O7 in 240 mL of 0.1 mol / L HCl solution for 24 h, wash it with deionized water and ethanol. When the washing solution is neutral, dry the product in a vacuum oven at 70 °C to obtain H2Ti3O7.

[0174] (1-3) Add 0.14 g of H2Ti3O7 and 1.025 g of barium hydroxide octahydrate to 60 mL of deionized water, stir for 24 h, then add it to a 200 mL hydrothermal synthesis reactor and react at 200 °C for 3 h. Wash the obtained product successively with dilute hydrochloric acid and deionized water. When the washing solution is neutral, dry the product in a vacuum oven at 70 °C to obtain barium titanate nanowires.

[0175] (1-4) Add 3 g of barium titanate nanowires to 30 mL of hydrogen peroxide solution and reflux at 105 °C for 4 h. Wash the product with deionized water. When the washing solution is neutral, dry the product in a vacuum oven at 70 °C for 24 h to obtain hydroxy barium titanate nanowires.

[0176] Step (2): Prepare a PVDF / PDMS-BTO-CNT nanofiber film by an electrospinning process.

[0177] (2-1) Disperse 0.0075 g of carboxylated carbon nanotubes and 0.225 g of hydroxy barium titanate nanowires in a mixed solution of 6.8 g of DMF and 1.7 g of acetone, then stir for 0.5 h and finally perform ultrasonic treatment for 1 h.

[0178] (2-2) Add 1.2675 g of PVDF to the mixed solution obtained in step a, then stir at 60 °C for 1 h, and finally perform ultrasonic treatment for 1 h;

[0179] (2-3) Add 0.9 g of DC184 PDMS and its curing agent with a mass ratio of 10:1 to the mixed solution obtained in step b, then stir for 1 h, and finally perform ultrasonic treatment for 0.5 h;

[0180] (2-4) Electrospun the solution obtained in step (2-3) to obtain a nanofiber film, using a 20G single-hole needle; a 5 mL syringe; a spinning distance of 15 cm; a spinning voltage of 18 kV; a spinning speed of 1 mL / h; the spinning temperature is 25 °C; the spinning time is 2 h.

[0181] The processes of step (3) and step (4) are the same as those in Example 1.

[0182] Example 3

[0183] Step (1): Prepare barium titanate nanowires by a two-step hydrothermal method and perform hydroxylation treatment

[0184] (1-1) Disperse 3 g of titanium dioxide into 60 mL of 10 mol / L sodium hydroxide solution and stir for 12 h, then add it to a 200 mL hydrothermal synthesis reaction kettle and react at 200 °C for 72 hours. Wash the obtained precipitate with deionized water and ethanol successively. When the washing liquid is neutral, dry the product in a vacuum oven at 70 °C to obtain Na2Ti3O7.

[0185] (1-2) Immerse the obtained Na2Ti3O7 in 240 mL of 0.1 mol / L HCl solution for 24 hours, wash it with deionized water and ethanol successively. When the washing liquid is neutral, dry the product in a vacuum oven at 70 °C to obtain H2Ti3O7.

[0186] (1-3) Add 0.14 g of H2Ti3O7 and 1.025 g of barium hydroxide octahydrate to 60 mL of deionized water, stir for 24 hours, then add it to a 200 mL hydrothermal synthesis reaction kettle and react at 200 °C for 3 hours. Wash the obtained product with dilute hydrochloric acid and deionized water successively. When the washing liquid is neutral, dry the product in a vacuum oven at 70 °C to obtain barium titanate nanowires.

[0187] (1-4) Add 3 g of barium titanate nanowires to 30 mL of hydrogen peroxide solution and reflux at 105 °C for 4 h. Wash the product with deionized water. When the washing liquid is neutral, dry the product in a vacuum oven at 70 °C for 24 h to obtain hydroxylated barium titanate nanowires.

[0188] Step (2): Prepare the PVDF / PDMS-BTO-CNT nanofiber film through the electrospinning process

[0189] (2-1) Disperse 0.0225 g of carboxylated carbon nanotubes and 0.225 g of barium titanate hydroxide nanowires in a mixed solution of 6.8 g of DMF and 1.7 g of acetone, then stir for 0.5 h, and finally perform ultrasonic treatment for 1 h;

[0190] (2-2) Add 1.2525 g of PVDF to the mixed solution obtained in step a, then stir at 60 °C for 1 h, and finally perform ultrasonic treatment for 1 h;

[0191] (2-3) Add 0.9 g of DC184 PDMS and its curing agent with a mass ratio of 10:1 to the mixed solution obtained in step b, then stir for 1 h, and finally perform ultrasonic treatment for 0.5 h;

[0192] (2-4) Electrospin the solution obtained in step (2-3) to obtain a nanofiber film, using a 20G single-hole needle; a 5 mL syringe; a spinning distance of 15 cm; a spinning voltage of 18 kV; a spinning speed of 1 mL / h; the spinning temperature is 25 °C; the spinning time is 2 h.

[0193] The processes of steps (3) and (4) are the same as those in Example 1.

[0194] Example 4

[0195] Step (1): Prepare barium titanate nanowires through a two-step hydrothermal method and perform hydroxylation treatment

[0196] (1-1) Disperse 3 g of titanium dioxide in 60 mL of 10 mol / L sodium hydroxide solution and stir for 12 h, then add it to a 200 mL hydrothermal synthesis reactor and react at 200 °C for 60 hours. Wash the obtained precipitate successively with deionized water and ethanol. When the washing solution is neutral, dry the product in a vacuum oven at 60 °C to obtain Na2Ti3O7.

[0197] (1-2) Immerse the obtained Na2Ti3O7 in 240 mL of 0.1 mol / L HCl solution for 20 hours, wash it with deionized water and ethanol. When the washing solution is neutral, dry the product in a vacuum oven at 70 °C to obtain H2Ti3O7.

[0198] (1-3) 0.14 g of H2Ti3O7 and 1.025 g of barium hydroxide octahydrate were added to 60 mL of deionized water and stirred for 24 hours. Then, the mixture was added to a 200 mL hydrothermal synthesis autoclave and reacted at 170 °C for 4 hours. The product obtained from the reaction was washed successively with dilute hydrochloric acid and deionized water. When the washing solution was neutral, the product was dried in a vacuum oven at 60 °C to obtain barium titanate nanowires.

[0199] (1-4) 3 g of barium titanate nanowires were added to 20 mL of hydrogen peroxide solution and refluxed at 100 °C for 3 h. The product was washed with deionized water. When the washing solution was neutral, the product was dried in a vacuum oven at 70 °C for 18 h to obtain barium titanate hydroxide nanowires.

[0200] Step (2): Prepare PVDF / PDMS-BTO-CNT nanofiber film by electrospinning process

[0201] (2-1) 0.0225 g of carboxylated carbon nanotubes and 0.225 g of barium titanate hydroxide nanowires were dispersed in a mixed solution of 6.8 g of DMF and 1.7 g of acetone, then stirred for 40 min, and finally ultrasonically treated for 1.5 h;

[0202] (2-2) 1.2525 g of PVDF was added to the mixed solution obtained in step a, then stirred at 60 °C for 1 h, and finally ultrasonically treated for 1 h;

[0203] (2-3) 0.9 g of DC184 PDMS and its curing agent with a mass ratio of 10:1 were added to the mixed solution obtained in step b, then stirred for 1 h, and finally ultrasonically treated for 0.5 h;

[0204] (2-4) The solution obtained in step (2-3) was electrospun to obtain a nanofiber film, using an 18G single-hole needle; a 10 mL syringe; a spinning distance of 18 cm; a spinning voltage of 12 kV; a spinning speed of 0.7 mL / h; a spinning temperature of 30 °C; and a spinning time of 3 h.

[0205] The processes of step (3) and step (4) are the same as those in Example 1.

[0206] Example 5

[0207] Step (1): Prepare barium titanate nanowires by a two-step hydrothermal method and perform hydroxylation treatment

[0208] (1-1) Disperse 3 g of titanium dioxide into 60 mL of 10 mol / L sodium hydroxide solution and stir for 14 h. Then add it to a 200 mL hydrothermal synthesis reactor and react at 220 °C for 84 h. Wash the obtained precipitate successively with deionized water and ethanol. When the washing liquid is neutral, dry the product in a vacuum oven at 60 °C to obtain Na2Ti3O7.

[0209] (1-2) Immerse the obtained Na2Ti3O7 in 240 mL of 0.1 mol / L HCl solution for 28 h, wash it with deionized water and ethanol. When the washing liquid is neutral, dry the product in a vacuum oven at 80 °C to obtain H2Ti3O7.

[0210] (1-3) Add 0.14 g of H2Ti3O7 and 1.025 g of barium hydroxide octahydrate to 60 mL of deionized water, stir for 24 h, then add it to a 200 mL hydrothermal synthesis reactor and react at 230 °C for 4 h. Wash the obtained product successively with dilute hydrochloric acid and deionized water. When the washing liquid is neutral, dry the product in a vacuum oven at 80 °C to obtain barium titanate nanowires.

[0211] (1-4) Add 3 g of barium titanate nanowires to 50 mL of hydrogen peroxide solution and reflux at 110 °C for 3 h. Wash the product with deionized water. When the washing liquid is neutral, dry the product in a vacuum oven at 80 °C for 24 h to obtain barium titanate hydroxide nanowires.

[0212] Step (2): Prepare PVDF / PDMS-BTO-CNT nanofiber film by electrospinning process

[0213] (2-1) Disperse 0.0225 g of carboxylated carbon nanotubes and 0.225 g of barium titanate hydroxide nanowires in a mixed solution of 6.8 g of DMF and 1.7 g of acetone, then stir for 1 h and finally ultrasonically treat for 1 h;

[0214] (2-2) Add 1.2525 g of PVDF to the mixed solution obtained in step a, then stir at 60 °C for 1.5 h and finally ultrasonically treat for 1 h;

[0215] (2-3) Add 0.9 g of DC184 PDMS and its curing agent with a mass ratio of 10:1 to the mixed solution obtained in step b, then stir for 1.5 h and finally ultrasonically treat for 0.5 h;

[0216] (2-4) Electrospin the solution obtained in step (2-3) to obtain a nanofiber film, using a 22G single-hole needle; a 10 mL syringe; a spinning distance of 20 cm; a spinning voltage of 20 kV; a spinning speed of 1.5 mL / h; a spinning temperature of 40 °C; and a spinning time of 1 h.

[0217] The processes of step (3) and step (4) are the same as those in Example 1.

[0218] Comparative Example 1

[0219] Step (1): Prepare barium titanate nanowires by a two-step hydrothermal method and perform hydroxylation treatment.

[0220] (1-1) Disperse 3 g of titanium dioxide into 60 mL of 10 mol / L sodium hydroxide solution and stir for 12 h, then add it to a 200 mL hydrothermal synthesis reactor and react at 200 °C for 72 hours. Wash the obtained precipitate successively with deionized water and ethanol. When the washing liquid is neutral, dry the product in a vacuum oven at 70 °C to obtain Na2Ti3O7.

[0221] (1-2) Immerse the obtained Na2Ti3O7 in 120 mL of 0.1 mol / L HCl solution for 24 hours, wash it with deionized water and ethanol. When the washing liquid is neutral, dry the product in a vacuum oven at 70 °C to obtain H2Ti3O7.

[0222] (1-3) Add 0.14 g of H2Ti3O7 and 1.025 g of barium hydroxide octahydrate to 60 mL of deionized water, stir for 24 hours, then add it to a 200 mL hydrothermal synthesis reactor and react at 200 °C for 3 hours. Wash the obtained product successively with dilute hydrochloric acid and deionized water. When the washing liquid is neutral, dry the product in a vacuum oven at 70 °C to obtain barium titanate nanowires.

[0223] (1-4) Add 3 g of barium titanate nanowires to 30 mL of hydrogen peroxide solution and reflux at 105 °C for 4 h. Wash the product with deionized water. When the washing liquid is neutral, dry the product in a vacuum oven at 70 °C to obtain hydroxylated barium titanate nanowires.

[0224] Step (2): Prepare PVDF / PDMS-BTO nanofiber film by electrospinning process.

[0225] (2-1) Disperse 0.225 g of hydroxylated barium titanate nanowires in a mixed solution of 6.8 g of DMF and 1.7 g of acetone, then stir for 0.5 h, and finally perform ultrasonic treatment for 1 h;

[0226] (2-2) Add 1.275 g of PVDF to the mixed solution obtained in step a, then stir at 60 °C for 1 h, and finally perform ultrasonic treatment for 1 h;

[0227] (2-3) Add 0.9 g of PDMS and its curing agent with a mass ratio of 10:1 to the mixed solution obtained in step b, then stir for 1 h, and finally perform ultrasonic treatment for 0.5 h;

[0228] (2-4) Electrospin the solution obtained in step (2-3) to obtain a nanofiber film, using a 20G single-hole needle; a 5 mL syringe; a spinning distance of 15 cm; a spinning voltage of 18 kV; a spinning speed of 1 mL / h; a spinning temperature of 25 °C; and a spinning time of 2 h.

[0229] Comparative Example 2

[0230] Prepare a PVDF / PDMS nanofiber film through an electrospinning process

[0231] a. Disperse 1.5 g of PVDF in a mixed solution of 6.8 g of DMF and 1.7 g of acetone, then stir at 60 °C for 1 h, and finally perform ultrasonic treatment for 1 h;

[0232] b. Add 0.9 g of PDMS and its curing agent with a mass ratio of 10:1 to the mixed solution obtained in step a, then stir for 1 h, and finally perform ultrasonic treatment for 0.5 h;

[0233] c. Electrospin the solution obtained in step b to obtain a nanofiber film, using a 20G single-hole needle; a 5 mL syringe; a spinning distance of 15 cm; a spinning voltage of 18 kV; a spinning speed of 1 mL / h; a spinning temperature of 25 °C; and a spinning time of 2 h.

[0234] Figure 8 and Figure 9 It shows that the presence of α-phase and β-phase can be observed in the electrospun nanofiber films prepared in the above Examples 1-3 and Comparative Examples 1 and 2. Among them, the electrospun nanofiber film prepared in Example 3 has the highest β-phase content because carbon nanotubes and barium titanate act as nucleating agents in the nanofiber film, which is beneficial to the nucleation of PVDF to form more β-phase; Figure 10 It shows that Example 3 has the highest dielectric constant, followed by Example 1, because with the addition of carbon nanotubes, more micro-capacitors are formed inside the nanofiber film and the dielectric constant increases; Figure 11 It shows that the dielectric losses of Example 1, Example 2, and Example 3 are comparable; Figure 12 and Figure 13 It shows that the composite nanogenerator prepared in Example 1 has the highest voltage output and current output. On the one hand, this is the result of the competition between the dielectric constant and the dielectric loss for the output performance; on the other hand, as the carbon nanotube content increases, the electronegativity of the electrospun nanofiber membrane decreases, resulting in a decrease in the amount of charge generated when it contacts the copper electrode, so the electrical performance output will be reduced, thus showing that Example 1 has the highest electrical performance output; Figure 14It is illustrated that the performance of the prepared nanofiber film as a composite nanogenerator (measured under a force of 30 N with contact-separation) is better than the sum of the performance when used as a triboelectric nanogenerator (measured with contact-separation under a force of 5 N) and a piezoelectric nanogenerator (measured under a force of 30 N without contact-separation). Figure 15 It is illustrated that the charges generated by triboelectrification contribute to promoting the dipole polarization inside the nanofiber film, thus enhancing the piezoelectric performance, that is, enhancing the output performance of the composite nanogenerator. Therefore, the Figure 14 presented results occur.

[0235] The above description of the embodiments is to enable those of ordinary skill in the art to understand and use the invention. Obviously, those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A preparation method of a composite nanogenerator for an intelligent monitoring system, characterized in that It includes the following steps: S1: Prepare barium titanate nanowires by a two-step hydrothermal method and perform hydroxylation treatment to obtain hydroxylated barium titanate nanowires; S2: Mix the hydroxylated barium titanate nanowires obtained in step S1 with carboxylated carbon nanotubes, PVDF, and PDMS, and prepare a PVDF / PDMS-BTO-CNT nanofiber film by electrospinning; S3: Bond a PI film, a copper tape, and the PVDF / PDMS-BTO-CNT nanofiber film obtained in step S2 in sequence, and paste the PI film inside a rubber hose to assemble the composite nanogenerator.

2. The preparation method of a composite nanogenerator for an intelligent monitoring system according to claim 1, characterized in that, In step S1, it specifically includes the following steps: S11: Disperse titanium dioxide in an alkaline solution, stir and then perform a hydrothermal reaction. After the reaction product is washed and dried, Na2Ti3O7 is obtained; S12: Immerse the Na2Ti3O7 obtained in step S11 in an acidic solution, and then obtain H2Ti3O7 after washing and drying; S13: Place the H2Ti3O7 obtained in step S12 in an aqueous solution of barium hydroxide octahydrate, stir and then perform a hydrothermal reaction. After the reaction product is washed and dried, barium titanate nanowires are obtained; S14: Add the barium titanate nanowires obtained in step S13 to hydrogen peroxide and reflux. After the reaction product is washed and dried, hydroxylated barium titanate nanowires are obtained.

3. The preparation method of a composite nanogenerator for an intelligent monitoring system according to claim 2, wherein in step S11, the concentration of hydroxide ions in the alkaline solution is 9-12 mol / L, and the dosage ratio of titanium dioxide to the alkaline solution is 3 g: 60 mL; the stirring time is 10-14 h; the temperature of the hydrothermal reaction is 170-230 °C, and the time is 60-84 h; the washing is to wash with deionized water and ethanol in sequence until the washing liquid is neutral; the drying is vacuum drying, the temperature is 60-80 °C, and the time is 12-24 h; in step S12, the concentration of hydrogen ions in the acidic solution is 0.1-0.3 mol / L, and the volume ratio of the acidic solution to the alkaline solution is 220-260: 60; the immersion time is 20-28 h; the washing is to wash with deionized water and ethanol in sequence until the washing liquid is neutral; the drying is vacuum drying, the temperature is 60-80 °C, and the time is 12-24 h; in step S13, the concentration of barium hydroxide octahydrate is 1.8-2.2 g: 100-140 mL; the mass ratio of H2Ti3O7 to barium hydroxide octahydrate is 0.2-0.4: 1.8-2.2; the temperature of the hydrothermal reaction is 170-230 °C, and the time is 2-4 h; the washing is to wash with dilute hydrochloric acid and deionized water in sequence until neutral; the drying is vacuum drying, the temperature is 60-80 °C, and the time is 12-24 h; In step S14, the dosage ratio of the barium titanate nanowires to hydrogen peroxide is 2-4 g: 20-50 mL; the reflux temperature is 95-115 °C, and the time is 3-5 h; the washing is successively washing with deionized water and ethanol until the washing liquid is neutral; the drying is vacuum drying, the temperature is 60-80 °C, and the time is 12-24 h.

4. The preparation method of a composite nanogenerator for an intelligent monitoring system according to claim 1, characterized in that, In step S2, it specifically includes the following steps: S21: Disperse the carboxylated carbon nanotubes and the hydroxylated barium titanate nanowires obtained in step S1 in a mixed solution formed by mixing DMF and acetone, and then perform stirring and ultrasonic treatment to obtain a mixed solution A; S22: Add PVDF to the mixed solution A obtained in step S21, and then perform stirring and ultrasonic treatment to obtain a mixed solution B; S23: Add PDMS to the mixed solution B obtained in step S22, and then perform stirring and ultrasonic treatment to obtain a mixed solution C; S24: Perform electrospinning on the mixed solution C obtained in step S23 to obtain a PVDF / PDMS-BTO-CNT nanofiber film.

5. The preparation method of a composite nanogenerator for an intelligent monitoring system according to claim 4, wherein In step S21, the addition amount of the carboxylated carbon nanotubes is 0-5 wt% of the mixed solution C, and is not 0 wt%; the addition amount of the hydroxylated barium titanate nanowires is 0-25 wt% of the mixed solution C, and is not 0 wt%; in the mixed solution, the mass ratio of DMF to acetone is 0.2-5: 1; the stirring time is 20-60 minutes; the ultrasonic time is 1-2 hours; In step S22, the addition amount of PVDF is 10-20 wt% of the mixed solution C; the stirring time is 40-90 minutes, and the temperature is 50-70 °C; the ultrasonic time is 1-2 hours; In step S23, the PDMS is a mixture of polydimethylsiloxane and a curing agent mixed at a mass ratio of 10: 1, and the addition amount of PDMS is 40-80 wt% of the addition amount of PVDF; the stirring time is 40-90 minutes; the ultrasonic time is 0.5-2 hours; In step S24, the process parameters of the electrospinning are: a single-hole needle of 14-22G; a syringe of 5-10 mL; a spinning distance of 10-20 cm; a spinning voltage of 12-20 kV; a spinning speed of 0.5-1.5 mL / h; the spinning temperature is 20-40 °C; the spinning time is 1-3 h.

6. The preparation method of a composite nanogenerator for an intelligent monitoring system according to claim 1, characterized in that In step S3, The rubber hose is a hollow semi-circular hose with a length of 3-8 cm; The width of the PI film is 4-6 cm, and the length is 5-8 cm; The width of the copper tape is 2-5 cm, and the length is 2-5 cm; The size of the PVDF / PDMS-BTO-CNT nanofiber film is larger than the size of the copper tape.

7. A composite nanogenerator for an intelligent monitoring system, characterized in that, Prepared by the method according to any one of claims 1-6.

8. An application of a composite nanogenerator according to claim 7 in an intelligent monitoring system.

9. The application of a composite nanogenerator for an intelligent monitoring system according to claim 8, characterized in that, The described intelligent monitoring system includes a composite nanogenerator, an Arduino data board, and a user terminal; The composite nanogenerator is connected to the Arduino data board through a signal receiver, and the Arduino data board is connected to the user terminal through a transmission module to form a monitoring system; A control program is burned on the Arduino data board.

10. The application of a composite nanogenerator for an intelligent monitoring system according to claim 9, wherein, The transmission module includes a wifi module or a bluetooth module; the user terminal includes a mobile phone or a computer; and the control program executes a monitoring function.

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