Antibacterial composite film for flexible piezoelectric sensor as well as preparation method and application of antibacterial composite film

Abstract

The invention discloses a preparation method of an antibacterial composite film for a flexible piezoelectric sensor. The preparation method specifically comprises the following steps: step 1, preparing Ag2O nanoparticles; step 2, preparing Ag2O / CB composite nanoparticles according to the product obtained in the step 1; step 3, preparing an Ag2O / CB / PVDF spinning solution; and step 4, preparing the Ag2O / CB / PVDF flexible film according to directional electrostatic spinning. The invention further discloses an antibacterial composite film for the flexible piezoelectric sensor and application. The problems that a PVDF piezoelectric material for the wearable flexible piezoelectric sensor is prone to bacterial infection in a use environment and low in sensitivity are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of piezoelectric sensing, relates to a method for preparing an antibacterial composite film for a flexible piezoelectric sensor, and also relates to an antibacterial composite film for a flexible piezoelectric sensor and an application thereof. Background Art

[0002] In recent years, people's emphasis on their own health and the change in health concepts have led to the widespread use of wearable devices in daily health tests such as heart rate, blood pressure, body temperature and blood oxygen concentration. Flexible piezoelectric pressure sensors are the key to wearable devices. They monitor and capture the required signals and convert the signals into observable results through digital signal processing. Polyvinylidene fluoride (PVDF) is a semi-crystalline polymer piezoelectric material with the advantages of high flexibility, high mechanical strength, high electromechanical coupling, good biocompatibility, easy processing and integrated drive and sensing. It has become an ideal piezoelectric material for flexible piezoelectric pressure sensors. However, the piezoelectric coefficient of PVDF is relatively low, and it has the disadvantages of low sensitivity and small response range. In addition, wearable devices are in direct contact with human skin. Long-term wearing can easily create a humid environment, which is easy to breed bacteria and cause skin infections. Therefore, it is urgent to develop an antibacterial and highly sensitive PVDF-based composite film for flexible piezoelectric sensors.

[0003] Modification of PVDF piezoelectric film and introduction of antibacterial agents and highly conductive materials can make it antibacterial and enhance its electronic conductivity, thereby improving the sensing sensitivity. Silver and its compounds have the strongest antibacterial ability among inorganic antibacterial agents, among which Ag2O nanoparticles have become widely used silver compound antibacterial agents due to their unique electronic structure, good stability and high safety. Conductive carbon black (CB) nanoparticles are one of the most commonly used conductive fillers in conductive polymer composites because of their easy availability, light weight, good dispersibility and excellent conductivity. If PVDF can be modified with Ag2O nanoparticles and CB nanoparticles, antibacterial properties can be introduced and conductivity can be improved. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing an antibacterial composite film for a flexible piezoelectric sensor, so as to solve the problem that PVDF piezoelectric materials used in wearable flexible piezoelectric sensors are prone to bacterial infection and have low sensitivity in the use environment.

[0005] The second object of the present invention is to provide an antibacterial composite film for flexible piezoelectric sensors.

[0006] The third object of the present invention is to provide an application of an antibacterial composite film for flexible piezoelectric sensors.

[0007] The first technical solution adopted by the present invention is a method for preparing an antibacterial composite film for a flexible piezoelectric sensor, which specifically comprises the following steps:

[0008] Step 1, preparing Ag2O nanoparticles;

[0009] Step 2, preparing Ag2O / CB composite nanoparticles according to the product obtained in step 1;

[0010] Step 3, preparing Ag2O / CB / PVDF spinning solution;

[0011] Step 4: Prepare the Ag2O / CB / PVDF flexible film by directional electrospinning.

[0012] The first technical solution of the present invention is also characterized in that:

[0013] The specific process of step 1 is:

[0014] A silver nitrate solution with a concentration of 0.1 to 0.2 mol / L and a sodium hydroxide solution with a concentration of 0.4 to 1.0 mol / L are stirred and mixed evenly, wherein the volume ratio of the silver nitrate solution to the sodium hydroxide solution is 1:1.5 to 2, the reaction temperature is 40 to 60°C, the reaction is stirred for 1.5 to 3 hours, and then repeatedly washed, vacuum filtered, and dried to obtain Ag2O nanoparticles.

[0015] The specific process of step 2 is:

[0016] The Ag2O nanoparticles and CB nanoparticles obtained in step 1 were added into a planetary ball mill at a mass ratio of 4:1, anhydrous ethanol was used as the ball milling medium, the ball-to-material mass ratio was 6:1, the ball milling was performed for 1 hour and then stopped for 30 minutes, and the cycle was repeated three times to obtain Ag2O / CB composite nanoparticles.

[0017] The specific process of step 3 is:

[0018] The Ag2O / CB composite nanoparticles and PVDF obtained in step 2 are added to an organic solvent containing acetone, wherein PVDF accounts for 20wt.% to 24wt.% of the total content of the solution, and the Ag2O / CB composite nanoparticles account for 5wt.% to 10wt.% of the total content. The mixed solution is heated in a water bath at 40 to 60°C for 2 to 4h to obtain an Ag2O / CB / PVDF spinning solution.

[0019] In step 3, the organic solvent is at least one of N,N-dimethylformamide, N-methylpyrrolidone or N,N-dimethylacetamide.

[0020] The specific process of step 4 is:

[0021] The Ag2O / CB / PVDF spinning solution obtained in step 3 is added to the propulsion pump of the electrospinning equipment, and directional electrospinning is carried out under the conditions of a spinning voltage of 20 to 26 kV, a receiving distance of 12 cm to 15 cm, a spinning temperature of 20°C to 35°C, a humidity of 30% to 40%, a spinning solution propulsion speed of 0.2 mL / h to 0.5 mL / h, and a drum speed of 100 to 200 r / min. After the spinning is completed, the film is removed and dried at 70°C for 2 to 3 hours to remove the residual organic solvent, thereby obtaining an antibacterial Ag2O / CB / PVDF flexible piezoelectric film.

[0022] The second technical solution adopted by the present invention is that the antibacterial composite film for flexible piezoelectric sensors is prepared by the above-mentioned preparation method of the antibacterial composite film for flexible piezoelectric sensors.

[0023] The third technical solution adopted by the present invention is the application of the antibacterial composite film for flexible piezoelectric sensors in flexible piezoelectric sensors.

[0024] The beneficial effects of the present invention are that the flexible piezoelectric material of the sensor in the present invention is Ag2O / CB composite nanoparticles / PVDF piezoelectric polymer composite film, and the antibacterial function of the sensor is given by the antibacterial property of Ag2O nanoparticles, and it can be used in an E. coli environment; the introduction of CB nanoparticles with strong conductivity and low cost can increase the electrical signal amplification effect of the sensor film, greatly improving the sensitivity of the sensor; the PVDF-based film is prepared by electrospinning, so that the PVDF piezoelectric material self-polarizes and converts a large number of highly electrically active β-phase crystals under high-voltage stretching, significantly improving the piezoelectric performance and piezoresistance change sensitivity of the sensor film, and having a wide detection range; and the method has a simple preparation process, a simple sensor structure, and low cost, and is suitable for large-scale production applications. Therefore, the prepared antibacterial Ag2O / CB / PVDF composite film has important application prospects in the fields of wearable flexible sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1( a ) is a SEM image of an antibacterial Ag2O / CB / PVDF flexible piezoelectric film prepared in Example 1 of the method for preparing an antibacterial composite film for a flexible piezoelectric sensor of the present invention;

[0026] FIG1( b ) is a C element surface distribution energy spectrum diagram of the antibacterial Ag2O / CB / PVDF flexible piezoelectric film prepared in Example 1 of the method for preparing an antibacterial composite film for a flexible piezoelectric sensor of the present invention;

[0027] FIG1(c) is a diagram showing the F element surface distribution energy spectrum of the antibacterial Ag2O / CB / PVDF flexible piezoelectric film prepared in Example 1 of the method for preparing an antibacterial composite film for a flexible piezoelectric sensor of the present invention;

[0028] FIG1(d) is a graph showing the surface distribution energy spectrum of the Ag element of the antibacterial Ag2O / CB / PVDF flexible piezoelectric film prepared in Example 1 of the method for preparing an antibacterial composite film for a flexible piezoelectric sensor of the present invention;

[0029] FIG1(e) is a surface distribution energy spectrum of the O element of the antibacterial Ag2O / CB / PVDF flexible piezoelectric film prepared in Example 1 of the method for preparing an antibacterial composite film for a flexible piezoelectric sensor of the present invention;

[0030] Figure 2 This is the XRD spectrum of the antibacterial Ag2O / CB / PVDF flexible piezoelectric film prepared in Example 2 of the method for preparing the antibacterial composite film for the flexible piezoelectric sensor of the present invention;

[0031] FIG3( a ) is a graph showing the growth results of Escherichia coli in a control group that was not treated with the antibacterial composite film for the flexible piezoelectric sensor of the present invention;

[0032] FIG3( b ) is a graph showing the growth results of Escherichia coli after being treated with the antibacterial Ag2O / CB / PVDF flexible piezoelectric film prepared by Example 3 of the method for preparing an antibacterial composite film for a flexible piezoelectric sensor of the present invention;

[0033] Figure 4 It is a schematic diagram of the structure of the antibacterial Ag2O / CB / PVDF flexible piezoelectric film assembled sensor in Example 1 of the method for preparing the antibacterial composite film for the flexible piezoelectric sensor of the present invention;

[0034] Figure 5 This is the sensing test result of the antibacterial Ag2O / CB / PVDF flexible piezoelectric film assembled sensor prepared in Example 1 of the method for preparing the antibacterial composite film for flexible piezoelectric sensors of the present invention. DETAILED DESCRIPTION

[0035] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] The method for preparing the antibacterial composite film for the flexible piezoelectric sensor of the present invention is specifically implemented according to the following steps:

[0037] Step 1, mixing a silver nitrate solution with a concentration of 0.1-0.2 mol / L and a sodium hydroxide solution with a concentration of 0.4-1.0 mol / L in a volume ratio of 1:1.5-2 under stirring, and reacting vigorously at 40-60° C. for 1.5-3 hours, then washing, vacuum filtering, and drying in the dark to obtain Ag2O nanoparticles.

[0038] Step 2, the Ag2O nanoparticles obtained in step 1 and the conductive carbon black (CB) nanoparticles are added into a planetary ball mill at a mass ratio of 4:1, anhydrous ethanol is used as the ball milling medium, the ball-to-material mass ratio is 6:1, the ball milling is performed for 1 hour and then stopped for 30 minutes, and the process is repeated three times to obtain Ag2O / CB composite nanoparticles.

[0039] Step 3, adding the Ag2O / CB composite nanoparticles and PVDF obtained in step 2 to an organic solvent containing 30% or 40% acetone, wherein the organic solvent is at least one of N,N-dimethylformamide (DMF), N-methylpyrrolidone (NMP) or N,N-dimethylacetamide (DMA), wherein PVDF accounts for 20wt.% to 24wt.% of the total content of the solution, and the Ag2O / CB composite nanoparticles account for 5wt.% to 10wt.% of the total content, and the mixed solution is heated in a water bath at 40 to 60°C for 2 to 4h to obtain Ag2O / CB / PVDF spinning solution.

[0040] Step 4, adding the Ag2O / CB / PVDF spinning solution obtained in step 3 to the propulsion pump of the electrospinning equipment, performing directional electrospinning under the conditions of a spinning voltage of 20 to 26 kV, a receiving distance of 12 cm to 15 cm, a spinning temperature of 20°C to 35°C, a humidity of 30% to 40%, a spinning solution propulsion speed of 0.2 mL / h to 0.5 mL / h, and a drum speed of 100 to 200 r / min. After spinning, the film is removed and dried at 70°C for 2 to 3 hours to remove residual organic solvents, thereby obtaining an antibacterial Ag2O / CB / PVDF flexible piezoelectric film.

[0041] Example 1

[0042] The method for preparing the antibacterial composite film for the flexible piezoelectric sensor of the present invention specifically comprises the following steps:

[0043] Step 1, mixing a silver nitrate solution with a concentration of 0.1 mol / L and a sodium hydroxide solution with a concentration of 0.4 mol / L at a volume ratio of 1:1.5 under stirring, and reacting vigorously at 40° C. for 1.5 hours, and then washing, vacuum filtering, and drying in the dark to obtain Ag2O nanoparticles;

[0044] Step 2: Take the Ag2O nanoparticles and CB nanoparticles prepared in step 1 and add them into a planetary ball mill at a mass ratio of 4:1. Use anhydrous ethanol as the ball milling medium. Mill for 1 hour at a ball-to-material mass ratio of 6:1 and then stop for 30 minutes. Repeat this three times to obtain Ag2O / CB composite nanoparticles.

[0045] Step 3, add the Ag2O / CB composite nanoparticles and PVDF of step 2 to a mixed organic solvent of N,N-dimethylformamide (DMF) and acetone in a volume ratio of 6:4, wherein PVDF accounts for 20wt.% of the total content of the solution, and Ag2O / CB particles account for 5wt.% of the total content, and heat the mixed solution in a water bath at 40°C for 2h to obtain Ag2O / CB / PVDF spinning solution.

[0046] Step 4, add the Ag2O / CB / PVDF spinning solution of step 3 into the propulsion pump, and carry out directional electrospinning under the conditions of spinning voltage 20kV, receiving distance 12cm, spinning temperature 20℃, humidity 30%, spinning solution propulsion speed 0.2mL / h, and drum speed 100r / min. After spinning, dry the film at 70℃ for 2h to obtain the antibacterial Ag2O / CB / PVDF flexible piezoelectric film.

[0047] Example 2

[0048] The method for preparing the antibacterial composite film for the flexible piezoelectric sensor of the present invention specifically comprises the following steps:

[0049] Step 1, mixing a silver nitrate solution with a concentration of 0.2 mol / L and a sodium hydroxide solution with a concentration of 1.0 mol / L at a volume ratio of 1:2 under stirring, and reacting vigorously at 60° C. for 3 hours, and then washing, vacuum filtering, and drying in the dark to obtain Ag2O nanoparticles.

[0050] Step 2: Take the Ag2O nanoparticles and CB nanoparticles prepared in step 1 and add them into a planetary ball mill at a mass ratio of 4:1. Use anhydrous ethanol as the ball milling medium. Mill for 1 hour at a ball-to-material mass ratio of 6:1 and then stop for 30 minutes. Repeat this three times to obtain Ag2O / CB composite nanoparticles.

[0051] Step 3, adding the Ag2O / CB composite nanoparticles and PVDF obtained in step 2 to a mixed solvent of N-methylpyrrolidone (NMP) and acetone in a volume ratio of 7:3, wherein PVDF accounts for 24wt% of the total content of the solution, and the Ag2O / CB composite nanoparticles account for 10wt.% of the total content, and heating the mixed solution in a water bath at 60°C for 4h to obtain Ag2O / CB / PVDF spinning solution.

[0052] Step 4, add the Ag2O / CB / PVDF spinning solution of step 3 into the propulsion pump, and carry out directional electrospinning under the conditions of spinning voltage 26 kV, receiving distance 15 cm, spinning temperature 35°C, humidity 40%, spinning solution propulsion speed 0.5 mL / h, and drum speed 200 r / min. After spinning, the film is dried at 70°C for 3 hours to obtain an antibacterial Ag2O / CB / PVDF flexible piezoelectric film.

[0053] Example 3

[0054] The method for preparing the antibacterial composite film for the flexible piezoelectric sensor of the present invention specifically comprises the following steps:

[0055] Step 1: First, a 0.15 mol / L silver nitrate solution and a 1.0 mol / L sodium hydroxide solution are mixed at a volume ratio of 1:2 under stirring, and react vigorously at 60° C. for 2.5 hours, and then washed, vacuum filtered, and dried in the dark to obtain Ag2O nanoparticles.

[0056] Step 2: Take the Ag2O nanoparticles and CB nanoparticles prepared in step 1 and add them into a planetary ball mill at a mass ratio of 4:1. Use anhydrous ethanol as the ball milling medium. Mill for 1 hour at a ball-to-material mass ratio of 6:1 and then stop for 30 minutes. Repeat this three times to obtain Ag2O / CB composite nanoparticles.

[0057] Step 3, adding the Ag2O / CB composite nanoparticles and PVDF obtained in step 2 to a mixed solvent of N,N-dimethylformamide (DMF) and acetone in a volume ratio of 6:4, wherein PVDF accounts for 22wt.% of the total content of the solution, and Ag2O / CB composite nanoparticles account for 8wt.% of the total content, and heating the mixed solution in a 60°C water bath for 2h to obtain Ag2O / CB / PVDF spinning solution.

[0058] Step 4, add the Ag2O / CB / PVDF spinning solution of step 3 into the propulsion pump, and carry out directional electrospinning under the conditions of spinning voltage 22kV, receiving distance 13cm, spinning temperature 30℃, humidity 40%, spinning solution propulsion speed 0.5mL / h, and drum speed 100r / min. After spinning, the film is dried at 70℃ for 3h to obtain an antibacterial Ag2O / CB / PVDF flexible piezoelectric film.

[0059] Example 4

[0060] The method for preparing the antibacterial composite film for the flexible piezoelectric sensor of the present invention specifically comprises the following steps:

[0061] Step 1: First, a 0.2 mol / L silver nitrate solution and a 0.8 mol / L sodium hydroxide solution are mixed at a volume ratio of 1:2 under stirring, and react vigorously at 60° C. for 2 h, followed by washing, vacuum filtration, and light-proof drying to finally obtain Ag2O nanoparticles.

[0062] Step 2, add the Ag2O nanoparticles and CB particles in step 1 into a planetary ball mill at a mass ratio of 4:1, use anhydrous ethanol as the ball milling medium, ball mill for 1 hour under the condition of a ball-to-material mass ratio of 6:1, then stop for 30 minutes, repeat three times, and obtain Ag2O / CB composite nanoparticles.

[0063] Step 3, adding the Ag2O / CB composite nanoparticles and PVDF of step 2 to a mixed solvent of N,N-dimethylacetamide (DMA) and acetone in a volume ratio of 7:3, wherein PVDF accounts for 24wt.% of the total content of the solution, and the Ag2O / CB composite nanoparticles account for 6wt.% of the total content, and heating the mixed solution in a 60°C water bath for 3h to obtain Ag2O / CB / PVDF spinning solution.

[0064] Step 4, add the Ag2O / CB / PVDF spinning solution into the propulsion pump, and carry out directional electrospinning under the conditions of spinning voltage 24kV, receiving distance 15cm, spinning temperature 30℃, humidity 35%, spinning solution propulsion speed 0.4mL / h, and drum speed 150r / min. After spinning, the film is dried at 70℃ for 3h to obtain the antibacterial Ag2O / CB / PVDF flexible piezoelectric film.

[0065] Figure 1(a) is a SEM image magnified 1500 times. As can be seen from the figure, the fiber fineness is relatively uniform, and a small amount of agglomerated bright particles are found on the fiber. Figure 1(b) is the C element surface distribution energy spectrum; Figure 1(c) is the F element surface distribution energy spectrum; Figure 1 is (d) the Ag element surface distribution energy spectrum; Figure 1 is (e) the O element surface distribution energy spectrum. As can be seen from Figures 1(b) and 1(c), C and F elements are distributed in large quantities on the entire film surface, indicating that the main component of the film is PVDF; as can be seen from Figures 1(d) and 1(e), Ag and O elements are uniformly dispersed in the film in the form of dots, indicating that Ag2O particles are uniformly dispersed in the fibers and at the fiber interlacing.

[0066] Figure 2 This is the XRD spectrum of the antibacterial flexible piezoelectric film prepared by the method of the present invention in Example 2. The spectrum obtained by the test was compared with the JCPDF standard card, and it was found that the flexible piezoelectric film prepared by electrospinning was composed of multiple phases, namely cubic Ag2O, conductive CB and β-phase PVDF, indicating that the antibacterial Ag2O / CB / PVDF flexible piezoelectric film was successfully prepared by electrospinning.

[0067] Figure 3(a) shows the colony growth result of E. coli without antibacterial film after 1 day of culture, and Figure 3(b) shows the colony growth result of E. coli co-cultured with the antibacterial flexible piezoelectric film prepared in Example 3 of the present invention for 1 day. It can be seen from the figure that the addition of the antibacterial Ag2O / CB / PVDF flexible piezoelectric film has a strong bactericidal effect, and the bactericidal rate of E. coli reaches 99.76%.

[0068] When the antibacterial flexible piezoelectric film prepared in Example 4 of the present invention is used, the sensor film without the copper sticker is directly connected to the multimeter with a wire. When measuring without pressing but just close to the pulse, the resistance is large. When pressing with the index finger, the internal electrons are arranged more closely due to squeezing, and the PVDF piezoelectric effect is added, so that the resistance becomes smaller, indicating that the antibacterial Ag2O / CB / PVDF flexible piezoelectric film has good sensing performance.

[0069] Figure 4 The figure is a schematic diagram of the structure of the antibacterial Ag2O / CB / PVDF flexible piezoelectric film assembly sensor prepared by the method of the present invention. First, three 20×20 mm sensing films of the same size and thickness are cut, and then two copper stickers of the same size are cut, and then the copper stickers are respectively attached to the top and bottom of the three films, and then the electrical wires are respectively connected to the upper and lower copper stickers and led out, so as to obtain the antibacterial flexible piezoelectric sensor.

[0070] Figure 5 This is the sensing performance test result of the antibacterial Ag2O / CB / PVDF flexible piezoelectric film assembled sensor prepared in Example 1 of the method of the present invention. By regularly changing the pressure and monitoring the response time and corresponding resistance change rate of the sensor in real time, it can be seen that the sensor can respond quickly to pressure changes and the resistance change rate increases with the increase of pressure.

[0071] Example 5

[0072] The method for preparing the antibacterial composite film for the flexible piezoelectric sensor of the present invention specifically comprises the following steps:

[0073] Step 1: First, a 0.2 mol / L silver nitrate solution and a 0.8 mol / L sodium hydroxide solution are mixed at a volume ratio of 1:1.8 under stirring, and react vigorously at 50°C for 2 hours, followed by washing, vacuum filtration, and light-proof drying to finally obtain Ag2O nanoparticles.

[0074] Step 2, add the Ag2O nanoparticles and CB particles in step 1 into a planetary ball mill at a mass ratio of 4:1, use anhydrous ethanol as the ball milling medium, ball mill for 1 hour under a ball-to-material ratio of 6:1, then stop for 30 minutes, repeat three times, and obtain Ag2O / CB composite nanoparticles.

[0075] Step 3, adding the Ag2O / CB composite nanoparticles and PVDF in step 2 to a mixed solvent of N,N-dimethylacetamide (DMA) and acetone in a volume ratio of 7:3, wherein PVDF accounts for 24wt.% of the total content of the solution, and the Ag2O / CB composite nanoparticles account for 6wt.% of the total content, and heating the mixed solution in a 50°C water bath for 3h to obtain Ag2O / CB / PVDF spinning solution.

[0076] Step 4, add the Ag2O / CB / PVDF spinning solution into the propulsion pump, and carry out directional electrospinning under the conditions of spinning voltage 24kV, receiving distance 15cm, spinning temperature 30℃, humidity 35%, spinning solution propulsion speed 0.4mL / h, and drum speed 150r / min. After spinning, the film is dried at 70℃ for 2.5h to obtain the antibacterial Ag2O / CB / PVDF flexible piezoelectric film.

[0077] Example 6

[0078] The method for preparing the antibacterial composite film for the flexible piezoelectric sensor of the present invention specifically comprises the following steps:

[0079] Step 1: First, a 0.2 mol / L silver nitrate solution and a 0.8 mol / L sodium hydroxide solution are mixed at a volume ratio of 1:2 under stirring, and react vigorously at 50° C. for 2 hours, followed by washing, vacuum filtration, and light-proof drying to finally obtain Ag2O nanoparticles.

[0080] Step 2, add the Ag2O nanoparticles and CB particles in step 1 into a planetary ball mill at a mass ratio of 4:1, use anhydrous ethanol as the ball milling medium, ball mill for 1 hour under a ball-to-material ratio of 6:1, then stop for 30 minutes, repeat three times, and obtain Ag2O / CB composite nanoparticles.

[0081] Step 3, adding the Ag2O / CB composite nanoparticles and PVDF in step 2 to a mixed solvent of N,N-dimethylacetamide (DMA) and acetone in a volume ratio of 7:3, wherein PVDF accounts for 24wt.% of the total content of the solution, and the Ag2O / CB composite nanoparticles account for 6wt.% of the total content, and heating the mixed solution in a 50°C water bath for 3h to obtain Ag2O / CB / PVDF spinning solution.

[0082] Step 4, add the Ag2O / CB / PVDF spinning solution into the propulsion pump, and carry out directional electrospinning under the conditions of spinning voltage 24kV, receiving distance 15cm, spinning temperature 30℃, humidity 35%, spinning solution propulsion speed 0.4mL / h, and drum speed 150r / min. After spinning, the film is dried at 70℃ for 2.5h to obtain the antibacterial Ag2O / CB / PVDF flexible piezoelectric film.

Claims

1. A method for preparing an antibacterial composite film for a flexible piezoelectric sensor, characterized in that: The specific steps include: Step 1, preparing Ag2O nanoparticles; Step 2, preparing Ag2O / CB composite nanoparticles according to the product obtained in step 1; Step 3, preparing Ag2O / CB / PVDF spinning solution; Step 4: Prepare the Ag2O / CB / PVDF flexible film by directional electrospinning.

2. The method for preparing the antibacterial composite film for flexible piezoelectric sensors according to claim 1, characterized in that: The specific process of step 1 is as follows: A silver nitrate solution with a concentration of 0.1 to 0.2 mol / L and a sodium hydroxide solution with a concentration of 0.4 to 1.0 mol / L are stirred and mixed evenly, wherein the volume ratio of the silver nitrate solution to the sodium hydroxide solution is 1:1.5 to 2, the reaction temperature is 40 to 60°C, the reaction is stirred for 1.5 to 3 hours, and then repeatedly washed, vacuum filtered, and dried to obtain Ag2O nanoparticles.

3. The method for preparing the antibacterial composite film for flexible piezoelectric sensors according to claim 2, characterized in that: The specific process of step 2 is: The Ag2O nanoparticles and CB nanoparticles obtained in step 1 were added into a planetary ball mill at a mass ratio of 4:1, anhydrous ethanol was used as the ball milling medium, the ball-to-material mass ratio was 6:1, the ball milling was performed for 1 hour and then stopped for 30 minutes, and the cycle was repeated three times to obtain Ag2O / CB composite nanoparticles.

4. The method for preparing the antibacterial composite film for flexible piezoelectric sensors according to claim 3, characterized in that: The specific process of step 3 is as follows: The Ag2O / CB composite nanoparticles and PVDF obtained in step 2 are added to an organic solvent containing acetone, wherein PVDF accounts for 20wt.% to 24wt.% of the total content of the solution, and the Ag2O / CB composite nanoparticles account for 5wt.% to 10wt.% of the total content. The mixed solution is heated in a water bath at 40 to 60°C for 2 to 4h to obtain an Ag2O / CB / PVDF spinning solution.

5. The method for preparing the antibacterial composite film for flexible piezoelectric sensors according to claim 4, characterized in that: In the step 3, the organic solvent is at least one of N,N-dimethylformamide, N-methylpyrrolidone or N,N-dimethylacetamide.

6. The method for preparing an antibacterial composite film for a flexible piezoelectric sensor according to claim 4, characterized in that: The specific process of step 4 is as follows: The Ag2O / CB / PVDF spinning solution obtained in step 3 is added to the propulsion pump of the electrospinning equipment, and directional electrospinning is carried out under the conditions of a spinning voltage of 20 to 26 kV, a receiving distance of 12 cm to 15 cm, a spinning temperature of 20°C to 35°C, a humidity of 30% to 40%, a spinning solution propulsion speed of 0.2 mL / h to 0.5 mL / h, and a drum speed of 100 to 200 r / min. After the spinning is completed, the film is removed and dried at 70°C for 2 to 3 hours to remove the residual organic solvent, thereby obtaining an antibacterial Ag2O / CB / PVDF flexible piezoelectric film.

7. An antibacterial composite film for a flexible piezoelectric sensor, prepared by the method for preparing an antibacterial composite film for a flexible piezoelectric sensor as claimed in any one of claims 1 to 6.

8. Application of antibacterial composite film for flexible piezoelectric sensors in flexible piezoelectric sensors.

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