Preparation method of polyvinylidene fluoride piezoelectric film surface electrodeTechnical Field
The invention belongs to the technical field of functional materials, relates to a preparation method of a film surface electrode, and particularly relates to a preparation method of a polyvinylidene fluoride piezoelectric film surface electrode.
Background
The polyvinylidene fluoride piezoelectric film is a material with wide application and can be made into various sensors. The polyvinylidene fluoride piezoelectric film has the advantages of high sensitivity, thin thickness, impact resistance, wide frequency response range, low acoustic impedance, good stability and the like, and is particularly widely applied to the fields of underwater acoustic monitoring and medicine.
At present, polyvinylidene fluoride piezoelectric film surface electrodes are all prepared by a vacuum evaporation method, and are generally metal aluminum or gold electrodes. The method needs an expensive vacuum coating machine, the vacuum coating process is complex and is not easy to operate, the number of films to be coated by vaporization each time is limited, and a large number of films cannot be coated by vaporization simultaneously.
Disclosure of Invention
The invention aims to solve the technical problem of providing a novel method for preparing a metal electrode on the surface of a polyvinylidene fluoride piezoelectric film.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a preparation method of a polyvinylidene fluoride piezoelectric film surface electrode comprises the following operation steps:
1) preparing a polyvinylidene fluoride piezoelectric film;
2) treating the surface of the polyvinylidene fluoride piezoelectric film by a physical method to enable the surface to be flat and uniform in hydrophilicity, cleaning and then airing;
3) treating the polyvinylidene fluoride piezoelectric film with fluoroplastic treatment fluid for 4-8 minutes, cleaning and airing;
4) sequentially passing the polyvinylidene fluoride piezoelectric film through an alkaline solution and K with the concentration of (30-50) g/L2CrO4The solution and 98wt% sulfuric acid are mixed according to the weight ratio of (2-5) liter: 1 liter of coarsening solution prepared in proportion, and 1-4 g/liter of SnCl2The solution, 37wt% hydrochloric acid and tin particles are mixed according to the weight ratio of (120-350) liters: 1 liter: (30-50) g of sensitizing solution and AgNO with the concentration of (2-6) g/L3The solution and ammonia water are mixed according to the weight ratio of (120-300) liter: 1 liter of activating solution and 10-30 percent formaldehyde aqueous solution are prepared, and operations such as deoiling cleaning, coarsening, sensitizing, activating, reducing and the like are carried out;
5) anhydrous CuSO4, sodium potassium tartrate, NaOH and deionized water, wherein the weight percentages of (4-7), (10-40), (6-9) and (3-7) g: preparing a solution according to the proportion of 1 liter, and mixing the solution with a formaldehyde solution with the concentration of (1-2)% according to the weight ratio of (30-100 liters: preparing chemical plating solution according to the proportion of 1 liter, placing the polyvinylidene fluoride piezoelectric film in the chemical plating solution for copper plating, and preparing the polyvinylidene fluoride piezoelectric film surface electrode after the copper plating is finished.
The invention relates to a preparation method of a polyvinylidene fluoride piezoelectric film surface electrode, which is characterized by comprising the following steps: the physical method is a method for grinding the surface of the polyvinylidene fluoride piezoelectric film by using water grinding sand paper or grinding fluid.
The invention relates to a preparation method of a polyvinylidene fluoride piezoelectric film surface electrode, which is characterized by comprising the following steps: the water-milled sand paper is A600 or A1000; the grinding fluid is green silicon carbide water grinding fluid with 1000 meshes or 1200 meshes.
The invention relates to a preparation method of a polyvinylidene fluoride piezoelectric film surface electrode, which is characterized by comprising the following steps: the fluoroplastic treatment fluid is a polytetrafluoroethylene surface treatment agent or a sodium naphthalene solution.
The invention relates to a preparation method of a polyvinylidene fluoride piezoelectric film surface electrode, which is characterized by comprising the following steps: the alkaline solution is prepared from NaOH particles and Na2CO3Particles, Na3PO4Granules and water, in an amount of 8 g: 15 g: 30 g: prepared by 1 liter.
The invention relates to a preparation method of a polyvinylidene fluoride piezoelectric film surface electrode, which is characterized by comprising the following steps: the coarsening solution consists of K with the concentration of 40 g/L2CrO4Solution and 98wt% sulfuric acid solution, in a ratio of 1: 0.3 volume ratio.
The invention relates to a preparation method of a polyvinylidene fluoride piezoelectric film surface electrode, which is characterized by comprising the following steps: the sensitizing solution is composed of SnCl with the concentration of 3 g/L2The solution, 37wt% hydrochloric acid solution and deionized water were mixed in a ratio of 1: 0.005: 1 in a volume ratio.
The invention relates to a preparation method of a polyvinylidene fluoride piezoelectric film surface electrode, which is characterized by comprising the following steps: the activating solution is prepared from AgNO with the concentration of 4g/L3Deionized water solution and ammonia water according to a ratio of 1: 1 in a volume ratio.
The invention relates to a preparation method of a polyvinylidene fluoride piezoelectric film surface electrode, which is characterized by comprising the following steps: the copper plating solution is prepared from CuSO with the concentration of 5g/L4The solution, 345g/L potassium sodium tartrate solution, 6.8g/L NaOH solution and 1.6 percent formaldehyde deionized water solution are mixed according to the weight ratio of 2: 1: 1.5: 1 in a volume ratio.
The preparation method of the polyvinylidene fluoride piezoelectric film surface electrode effectively solves the problem that expensive vacuum coating equipment is required in the traditional method, and greatly reduces the manufacturing cost; the chemical copper plating solution can be recycled for many times, and the purpose of saving resources is achieved; but also can chemically plate a plurality of films at one time, and is particularly suitable for large-batch industrial production. The polyvinylidene fluoride piezoelectric film electrode prepared by the method has good electrical property, surface resistance below 1 omega, good electrode adhesion, adhesive force measured by an adhesive tape method, and no electrode falling phenomenon. In addition, the method of the invention also has the advantages of simplicity, convenience, easy operation and high efficiency.
Detailed Description
The technical solutions related to the present invention are described in detail below with reference to examples, but the technical solutions related to the present invention are not limited thereto.
Example one
6 pieces of polyvinylidene fluoride piezoelectric film with area of 40mm multiplied by 40mm and thickness of 50 μm are prepared.
Surface mechanical treatment: the grinding fixture comprises two stainless steel metal plates which are vertically arranged and have smooth surfaces, the size is 60mm multiplied by 3mm, A600 abrasive paper is flatly adhered to the lower surface of the upper metal plate by a double-faced adhesive tape, four corners of a polyvinylidene fluoride piezoelectric film are adhered to the upper surface of the lower metal plate by glue, water is added under the pressure of 0.1MPa and is uniformly ground at the speed of 0.01m/s until no dispersed water drops exist on the surface of the film, namely the surface of the film has uniform hydrophilicity.
And grinding the other surface of the polyvinylidene fluoride piezoelectric film by the same method.
And (3) placing the ground film into a cleaning tank of an ultrasonic cleaning machine, ultrasonically cleaning the ground film for 20 minutes at the room temperature by using the frequency of 45Hz, taking out the film, and naturally drying the film at the room temperature.
Chemical treatment: putting the dried polyvinylidene fluoride piezoelectric film into a beaker filled with a polytetrafluoroethylene surface treating agent, soaking for 7 minutes, taking out, putting into the beaker filled with ethanol for washing, washing a reaction product of the ethanol and metal sodium in the surface treating agent by using a large amount of warm water, finally scrubbing the surface of the film by using the ethanol, and drying.
Before chemical copper plating of the polyvinylidene fluoride piezoelectric film, preparation work such as oil removal cleaning, chemical coarsening, sensitization, activation, reduction and the like is sequentially carried out.
Deoiling and cleaning: 500 ml of water, 40 g of NaOH and 7.5 g of Na are added to a beaker in this order2CO3And 15 g of Na3PO4Preparing a cleaning solution, heating to 45 ℃ while stirring, putting the dried polyvinylidene fluoride piezoelectric film into the solution, stirring for 20 minutes, taking out, washing for 3 times at normal temperature, and naturally drying.
Chemical coarsening: by K2CrO4K is prepared with water to a concentration of 30 g/l2CrO4Measuring 120 ml of solution, mixing with 60 ml of 98wt% sulfuric acid to prepare a coarsening solution, heating to 55 ℃ while stirring, putting the polyvinylidene fluoride piezoelectric film into the solution, stirring for 15 minutes, taking out, washing for 5 times at normal temperature, and washing for 3 times with deionized water。
Sensitization: with SnCl2The particles and deionized water are prepared into SnCl with the concentration of 1 g/L2And (3) measuring 100 ml of the solution, mixing the solution with 1 ml of 37wt% hydrochloric acid, heating to 30 ℃ while stirring, adding 0.03 g of tin particles, stirring until the tin particles are dissolved to prepare a sensitized solution, and putting the polyvinylidene fluoride piezoelectric film into the solution and stirring for 10 minutes.
And (3) activation: by AgNO3The particles and deionized water are prepared into AgNO with the concentration of 2 g/L3And (3) measuring 120 ml of solution, slowly dropping 1 ml of ammonia water while stirring, changing the solution from turbid to transparent and clear, heating to 30 ℃ while stirring, and putting the polyvinylidene fluoride piezoelectric film into the solution and stirring for 20 minutes.
Reduction: in order to prevent residual activating solution on the surface of the polyvinylidene fluoride piezoelectric film from being brought into chemical plating solution to influence the effect of chemical plating, after the activating operation, the activated polyvinylidene fluoride piezoelectric film is put into 10% formaldehyde water solution to be soaked for 10 minutes.
After the preparation was complete, 1 g of anhydrous CuSO was added4The particles, 2.5 g of potassium sodium tartrate particles and 1.5 g of NaOH particles are put into 250 ml of deionized water to be stirred and mixed, after the mixture is uniform, 120 ml of the solution is measured, 4 ml of formaldehyde with the concentration of 1% is added to prepare a chemical plating solution, the chemical plating solution is heated to 50 ℃ while stirring, a polyvinylidene fluoride piezoelectric film is put into the solution to be plated with copper for 20 minutes, the polyvinylidene fluoride piezoelectric film is turned over once every 10 seconds during the process, the polyvinylidene fluoride piezoelectric film is washed by the deionized water for 10 times after being taken out, and the polyvinylidene fluoride piezoelectric film is dried at normal temperature.
The thickness of the metal copper plated on the surface of the polyvinylidene fluoride piezoelectric film by the method is measured by a film thickness gauge to be within the range of 0.7-1 mu m.
The polyvinylidene fluoride piezoelectric thin film electrode prepared by the method has good conductivity, the surface resistance is below 1 omega, the electrode adhesion is good, the adhesion is measured by using a tape method, and the electrode falling phenomenon is avoided. After high-voltage polarization is carried out for 5min at the voltage of 17-17.5 Kv, the piezoelectric property d of the material is measured33=20～21pC/N。
Example two
The difference from the first embodiment is that: when the polyvinylidene fluoride piezoelectric film is subjected to surface mechanical treatment, A1000 water grinding sand paper is adopted.
EXAMPLE III
The polyvinylidene fluoride piezoelectric film has an area of 30mm multiplied by 30mm and a thickness of 65 mu m, and 8 blocks.
Surface mechanical treatment: the grinding fixture comprises two stainless steel metal plates which are vertically arranged and have smooth surfaces, the size is 60mm multiplied by 3mm, four corners of the polyvinylidene fluoride piezoelectric film are adhered to the upper surface of the lower metal plate by double-faced adhesive, 10 milliliters of uniformly mixed 1000-mesh green silicon carbide and aqueous solution are poured into the upper surface of the polyvinylidene fluoride piezoelectric film, water is added under the pressure of 0.2MPa to be ground at a constant speed of 0.01m/s until no dispersed water drops exist on the surface of the film, namely the surface of the film has uniform hydrophilicity.
And grinding the other surface of the polyvinylidene fluoride piezoelectric film by the same method.
And (3) placing the ground film into a cleaning tank of an ultrasonic cleaning machine, ultrasonically cleaning the film for 20 minutes at the room temperature by using the frequency of 45HZ, taking out the film, and naturally drying the film at the room temperature.
Chemical treatment: scrubbing the surface of an air-dried polyvinylidene fluoride piezoelectric film with ethanol to remove impurities, drying the air-dried polyvinylidene fluoride piezoelectric film, putting the air-dried polyvinylidene fluoride piezoelectric film into a beaker filled with a polytetrafluoroethylene surface treating agent, soaking the glass for 10 minutes, taking the glass out, putting the glass into the beaker filled with ethanol for washing, then washing a reaction product of the ethanol and metal sodium in the surface treating agent with a large amount of warm water, finally scrubbing the surface of the film with the ethanol and drying the film.
Before chemical copper plating of the polyvinylidene fluoride piezoelectric film, preparation work such as oil removal cleaning, chemical coarsening, sensitization, activation, reduction and the like is sequentially carried out.
Deoiling and cleaning: 500 ml of water, 40 g of NaOH pellets and 7.5 g of Na were added to a beaker in this order2CO3Granules and 15 g Na3PO4Preparing particles into a cleaning solution, heating to 45 ℃ while stirring, putting the dried polyvinylidene fluoride piezoelectric film into the solution, stirring for 20 minutes, taking out, washing for 3 times at normal temperature, and naturally drying.
Chemical coarsening: by K2CrO4The granules were formulated with water to give a K concentration of 40 g/l2CrO4And (3) weighing 200 ml of the solution, mixing the solution with 60 ml of 98wt% sulfuric acid to prepare a coarsening solution, heating the solution to 55 ℃ while stirring, putting the polyvinylidene fluoride piezoelectric film into the solution, stirring for 15 minutes, taking out the solution, washing for 5 times at normal temperature, and washing for 5 times with deionized water.
Sensitization: with SnCl2The particles and deionized water are prepared into SnCl with the concentration of 3 g/L2The solution was measured 250 ml, mixed with 1.25 ml of 37wt% hydrochloric acid, heated to 30 ℃ with stirring, added with 0.05 g of tin particles, stirred until the tin particles were dissolved to prepare a sensitized solution, and the polyvinylidene fluoride piezoelectric film was put into the solution and stirred for 10 minutes.
And (3) activation: by AgNO3The particles and deionized water are prepared into AgNO with the concentration of 4g/L3And (3) measuring 250 ml of solution, slowly dripping 1.2 ml of ammonia water while stirring, changing the solution from turbid to transparent and clear, heating to 30 ℃ while stirring, and putting the polyvinylidene fluoride piezoelectric film into the solution and stirring for 20 minutes.
Reduction: and (3) putting the activated polyvinylidene fluoride piezoelectric film into 20% formaldehyde water solution to soak the film for 10 minutes.
After the preparation was complete, 1.25 g of anhydrous CuSO was added48.5 g of potassium sodium tartrate and 1.7 g of NaOH are put into 250 ml of deionized water to be stirred and mixed, after the mixture is uniform, 4 ml of formaldehyde is added to prepare a chemical plating solution, the chemical plating solution is heated to 50 ℃ while stirring, a polyvinylidene fluoride piezoelectric film is put into the solution to be plated with copper for 22 minutes, the polyvinylidene fluoride piezoelectric film is turned over once every 10 seconds during the chemical plating solution, and the polyvinylidene fluoride piezoelectric film is washed by the deionized water for 10 times after being taken out and is dried at normal temperature.
A layer of metallic copper is chemically plated on the surface of the polyvinylidene fluoride piezoelectric film by the method, and the thickness of the metallic copper is measured by a film thickness gauge to be within the range of 0.6-0.9 mu m.
The polyvinylidene fluoride piezoelectric thin film electrode prepared by the method has good conductivity, surface resistance below 1 omega, good electrode adhesion, and no electrode falling phenomenon when tested by an adhesive tape strip. After the film sample is polarized for 5min under the high pressure of 19.5-20 Kv, the film sample is measuredTesting their piezoelectric properties, d33=20～21pC/N。
Example four
The difference from the second embodiment is that:
when the polyvinylidene fluoride piezoelectric film is subjected to surface mechanical treatment, 10 ml of 1200-mesh green silicon carbide and water solution which are uniformly mixed are adopted.
Chemical roughening solution with K2CrO4K is prepared with water to a concentration of 50 g/l2CrO4The solution is prepared by measuring 300 ml and mixing with 60 ml of 98wt% sulfuric acid.
Sensitizing solution with SnCl2The particles and deionized water are prepared into SnCl with the concentration of 4g/L2And (3) weighing 350 ml of solution, mixing with 1 ml of 37wt% hydrochloric acid, heating to 30 ℃ while stirring, adding 0.045 g of tin particles, and stirring until the tin particles are dissolved to prepare the solution.
Activating the solution with AgNO3The particles and deionized water are prepared into AgNO with the concentration of 6 g/L3The solution is prepared by measuring 300 ml of ammonia water and slowly dripping 1 ml of ammonia water while stirring.
The reducing solution was a 30% aqueous formaldehyde solution.
Electroless plating solution, 1.75 g of anhydrous CuSO4The particles, 10 g of potassium sodium tartrate particles and 2.2.5 g of NaOH particles are put into 250 ml of deionized water to be stirred and mixed, 400 ml of the solution is measured after the mixture is uniform, and 4 ml of formaldehyde with the concentration of 1 percent is added to prepare the sodium potassium tartrate-formaldehyde aqueous solution.
The method is used for chemically plating the surface of the polyvinylidene fluoride piezoelectric film with metal copper, and the thickness of the metal copper is measured by a film thickness gauge to be within the range of 0.7-1 mu m.
The polyvinylidene fluoride piezoelectric thin film electrode prepared by the method has good conductivity, surface resistance below 0.9 omega, good electrode adhesion, and no electrode falling phenomenon when tested by an adhesive tape strip. Testing the piezoelectric performance of the film samples after polarizing for 5min at high voltage of 9-9.5 Kv, d33=19～21pC/N。