CN112125660A

CN112125660A - Zinc oxide polyether-ether-ketone piezoresistor and preparation method thereof

Info

Publication number: CN112125660A
Application number: CN202010900909.8A
Authority: CN
Inventors: 郭靖; 汪宏; 司明明; 郝建宇; 赵恩达; 李晓萌
Original assignee: Xian Jiaotong University
Current assignee: Xian Jiaotong University
Priority date: 2020-08-31
Filing date: 2020-08-31
Publication date: 2020-12-25
Anticipated expiration: 2040-08-31
Also published as: CN112125660B

Abstract

The invention discloses a zinc oxide polyether-ether-ketone piezoresistor and a preparation method thereof, wherein the piezoresistor comprises the following components in percentage by mass of 60-99.95 wt%: 40-0.05 wt% of component Z and PEEK, wherein the component Z comprises 90-99 mol% of ZnO and 1-10 mol% of metal oxide dopant. The preparation method 1 comprises the following steps of mixing the components in percentage by weight of 60-99.95%: mixing 40-0.05 wt% of powder Z and PEEK; 2. and sintering the mixed powder by a cold sintering technology to obtain the piezoresistor with the required shape. The ZnO-based piezoresistor with the high-molecular polymer and the metal oxide as the synergistic additives is sintered at the extremely low temperature (270 ℃ minus 340 ℃), the nonlinear coefficient, the breakdown field strength and the highest breakdown field strength performance of the ZnO-based piezoresistor are improved, and the physical volume of the ZnO-based piezoresistor is reduced.

Description

Zinc oxide polyether-ether-ketone piezoresistor and preparation method thereof

Technical Field

The invention belongs to the field of electric power and electronic information devices, and relates to a zinc oxide polyether-ether-ketone piezoresistor and a preparation method thereof.

Background

Semiconductor ceramics having a resistance value in a nonlinear ohmic relationship with an applied voltage are called piezoresistors. The ZnO-added oxide-based voltage-sensitive ceramic is the most representative voltage-sensitive resistor with the best performance and the most extensive application at present. The high-nonlinearity-coefficient-of-self-body is commonly used for inhibiting transient overvoltage and surge current generated in electronic circuits and power systems, and plays a role in protecting the service safety of electronic circuit components and power system equipment.

For example: the ZnO piezoresistor is used in a power supply circuit of Internet of things electronic products such as a household intelligent television, the voltage-sensitive voltage of the ZnO resistor used here is 470V, when the maximum value (non-effective value) of transient surge voltage exceeds 470V, the piezoresistor utilizes the clamping characteristic to pull down the overhigh voltage, so that a rear-stage circuit works in a safe range, and the Internet of things electronic products such as the household intelligent television are protected.

At present, the nonlinear coefficient alpha of the commercial ZnO-added oxide-based piezoresistor is between 20 and 100, and the breakdown field intensity E is_b(@1mA/mm²) In the range of 100-3400V/mm. According to the existing documents, the breakdown field strength is 3400V/mm at most, so that the physical volume of the piezoresistor using the system is larger, especially in application scenes such as large lightning arresters and the like, the occupied area of equipment is large, and the waste of land resources is caused.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides the zinc oxide polyether-ether-ketone voltage dependent resistor and the preparation method thereof, which improve the nonlinear coefficient, the breakdown field strength and the highest breakdown field strength performance of the voltage dependent resistor, thereby reducing the physical volume of the voltage dependent resistor.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

the zinc oxide polyether-ether-ketone piezoresistor comprises the following components in percentage by weight of 60-99.95%: 40-0.05 wt% of component Z and PEEK, wherein the component Z comprises 90-99 mol% of ZnO and 1-10 mol% of metal oxide dopant.

A preparation method of a zinc oxide polyether-ether-ketone piezoresistor comprises the following steps;

step one, mixing the mass fraction of 60 wt% -99.95 wt%: 40-0.05 wt% of powder Z and PEEK are mixed, wherein the powder Z comprises 90-99 mol% of ZnO and 1-10 mol% of metal oxide dopant by molar mass fraction;

and step two, sintering the mixed powder to obtain the piezoresistor with the required shape.

Preferably, in the second step, cold sintering is adopted for sintering, the load during cold sintering is 300-480MPa, and the heat preservation temperature is 270-340 ℃.

Preferably, in the step one, a tetrahydrofuran solution with the purity of 99% and a pure toluene solution with the purity of 99% are mixed according to the volume ratio of 0.8-1.5 to obtain a solution A, the solution A is pre-stirred for 60-120 min, the temperature is gradually increased, the temperature increase speed is 5-10 ℃/s, the temperature is increased to 55-90 ℃, and the solution is uniformly stirred; weighing 0.1g-10g of PEEK powder, dissolving in the solution A, and uniformly stirring;

dissolving the powder Z and the powder PEEK in the mass fraction ratio in the step one in the solution A, preserving heat at 55-90 ℃, and uniformly stirring; stirring the mixed solution for 240-450 min, drying the stirred mixed solution at 80-95 ℃, sieving the dried powder by a sieve of 200-800 meshes, and continuously sieving for 1-3 times.

Preferably, in the first step, the powder Z and the powder PEEK in the mass fraction ratio in the first step are dissolved in 99% alcohol solution, and are uniformly stirred; mechanically grinding and stirring the mixed solution for 240-450 min, drying the stirred mixed solution at 90-95 ℃, and sieving the dried powder by a sieve of 200-800 meshes for 1-3 times; then carrying out heat treatment on the sieved powder, keeping the temperature at 360 ℃ for 18-24h, increasing the temperature rate at 5-10 ℃/min, and cooling along with the furnace; then sieving with 200-800 mesh sieve for 1-3 times.

Preferably, in the first step, the powder Z and the powder PEEK in the mass fraction ratio in the first step are dissolved in 99% alcohol solution, and are uniformly stirred; mechanically grinding and stirring the mixed solution for 240-450 min, drying the stirred mixed solution at 90-95 ℃, and sieving the dried powder by a sieve of 200-800 meshes for 1-3 times continuously.

Preferably, in the second step, 1g to 2g of sieved powder is selected and placed in a mortar with the diameter phi of 100mm to phi of 200mm, the mixture is ground for 2 to 3 minutes, 0.06g to 0.4g of acetic acid aqueous solution with the concentration of 1mol/L to 2mol/L is taken, the acetic acid aqueous solution is dropwise added into the mortar, the stirring is carried out until the acetic acid aqueous solution is dropwise added, and the grinding is carried out for 10 minutes.

Preferably, after the second step is completed, the quartz sand paper with 600 meshes is adopted for rough grinding for 5 to 10 minutes, the sand paper with 1200 meshes is adopted for fine grinding for 10 to 20 minutes, and the sand paper with 2000 meshes is adopted for fine grinding for 10 to 20 minutes.

Preferably, after the second step is completed, the piezoresistor is prepared into an electrode by adopting a gold spraying process or brushing conductive silver paste on the surface.

Compared with the prior art, the invention has the following beneficial effects:

the breakdown field intensity E of the piezoresistor is at normal temperature_b(@0.10mA/mm²) Over 6000V/mm and up to 14000V/mm, the highest physical breakdown field strength of 23000V/mm, the nonlinear coefficient alpha of 20-300, typical 'switching effect' and currentThe switching ratio Ion/Ioff maximum value is 300. At-90 deg.C, breakdown field strength E_b(@0.10mA/mm²) The maximum value is 15000V/mm, the maximum nonlinear coefficient alpha can reach 1000, namely the maximum value of the current switching ratio Ion/Ioff is 1000. At a temperature of 280 ℃, the breakdown field strength E_b(@0.10mA/mm²) The maximum is 12000V/mm, and the maximum nonlinear coefficient alpha can reach 450. On the basis of keeping the nonlinear coefficient, the breakdown field intensity is greatly improved, the electrical performance of the piezoresistor is improved, the improvement of the breakdown field intensity means that the voltage reaches the same size, the required thickness is smaller, the area is smaller, the miniaturization can be realized, and the physical volume of the piezoresistor is reduced.

According to the preparation method of the piezoresistor, the powder Z and the powder PEEK are mixed, so that the preparation of the powder raw material of the ceramic matrix composite material is realized, and the electrical property of the prepared piezoresistor is improved.

Furthermore, the densification sintering of the ceramic-high molecular polymer composite material is realized at extremely low temperature by adopting cold sintering, so that the high molecular polymer can be dispersed in the ZnO ceramic matrix, the electrical property of the piezoresistor is improved, the sintering temperature is greatly reduced, the energy loss in the production and preparation process is further reduced, and the effects of energy conservation and emission reduction are achieved.

Drawings

FIG. 1 is a schematic representation of the liquid phase assisted mixing of powder Z and powder PEEK of the present invention;

FIG. 2 is a schematic view of the fusion coating powder Z of PEEK powder according to the present invention;

FIG. 3 is a schematic representation of the solid phase mixing of powder Z and powder PEEK of the present invention;

FIG. 4 is a flow chart of the cold sintering process of the present invention.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings:

the piezoresistor comprises the following components in percentage by weight of 60-99.95%: 40-0.05 wt% of component Z and PEEK, wherein the component Z comprises 90-99 mol% of ZnO and 1-10 mol% of metal oxide dopant.

Breakdown field strength E at normal temperature_b(@0.10mA/mm²) Over 6000V/mm and up to 14000V/mm, the highest physical breakdown field strength is 23000V/mm, the nonlinear coefficient alpha is 20-300, the typical 'switching effect' is realized, and the maximum value of the current switching ratio Ion/Ioff is 300. At-90 deg.C, breakdown field strength E_b(@0.10mA/mm²) The maximum value is 15000V/mm, the maximum nonlinear coefficient alpha can reach 1000, namely the maximum value of the current switching ratio Ion/Ioff is 1000. At a temperature of 280 ℃, the breakdown field strength E_b(@0.10mA/mm²) The maximum is 12000V/mm, and the maximum nonlinear coefficient alpha can reach 450.

The preparation method of the piezoresistor comprises the following steps:

the purity of ZnO powder is higher than 99%, and the average particle diameter is 50nm-1 ч m. The purity of the powder PEEK (polyether-ether-ketone) is higher than 99 percent, the average particle diameter is 600-1200 meshes, and the melting temperature of the powder PEEK is 330-360 ℃.

Powder ZP is mixed by powder Z and powder PEEK, and the preparation method has three kinds, and the preparation method is as follows:

(1) liquid phase assisted mixing of powder Z and powder PEEK.

(2) Powder PEEK was melt coated over powder Z.

(3) Powder Z and powder PEEK were solid phase mixed.

(1) As shown in fig. 1, the powder P in the figure is the powder PEEK, and the mixing manner of the powder Z and the powder PEEK in liquid phase assisted mixing is as follows:

mixing the tetrahydrofuran solution and the pure toluene solution to obtain solution A, adopting a magnetic stirring device to pre-stir for 60min-120min, gradually heating up to 55 ℃ -90 ℃ at the heating rate of 5 ℃/s-10 ℃/s, and continuously stirring for 40min at the stirring rate of 200r/min-1200 r/min. Weighing 0.1g-10g of powder P, dissolving in the solution A, and continuously stirring for 120min at the stirring speed of 200r/min-1200 r/min.

In the solution A, the purity of a tetrahydrofuran solution is higher than 99%, the purity of a toluene solution is higher than 99%, and the volume ratio of the two solutions is as follows: 0.8-1.5.

And according to the mass fraction ratio of the powder Z to the powder PEEK, dissolving the powder Z and the powder PEEK in the solution A, preserving heat at 55-90 ℃, and simultaneously uniformly stirring and mixing for 40min at the stirring speed of 200-1200 r/min.

And pouring the mixed solution into a Teflon tank, and mechanically grinding by adopting a planetary ball mill mixer, wherein the stirring speed of the mechanical grinding is 400-600 r/min, and the continuous stirring time is 300-450 min.

Pouring the mixed solution after mechanical grinding into a beaker, placing the beaker in a vacuum oven for 24 hours at the temperature of 80-95 ℃, and drying to obtain the varistor powder raw material powder ZP 1.

And taking out the dried mixed powder ZP1, sieving by a sieve of 200-800 meshes for 1-3 times, and sealing and storing the powder ZP1 for later use.

(2) As shown in fig. 2, the powder Z and the powder PEEK were mixed in such a manner that the powder PEEK was melted to cover the powder Z as follows:

according to the mass fraction ratio of the powder Z and the powder PEEK, the powder Z and the powder PEEK are dissolved in 99 percent alcohol solution, and are uniformly stirred and mixed for 40min, wherein the stirring speed is 200r/min-1200 r/min.

And pouring the mixed solution into a Teflon tank, and mechanically grinding by adopting a planetary ball mill mixer, wherein the stirring speed of the mechanical grinding is 400-600 r/min, and the continuous stirring time is 240-360 min.

Pouring the mixed solution after mechanical grinding into a beaker, and placing the beaker in a vacuum oven for 24 hours, wherein the temperature of the oven is 90-95 ℃.

And taking out the dried mixed powder, and continuously sieving for 1-3 times by adopting a sieve with 200-800 meshes.

And placing the powder in a crucible, and placing the crucible in a muffle furnace for heat treatment. Keeping the temperature at 360 ℃ for 18-24h, heating at a rate of 5-10 ℃/min, and cooling with the furnace.

Taking out the mixed powder ZP2, grinding, sieving with 200-800 mesh sieve for 1-3 times, and sealing and storing powder ZP2 for use.

(3) As shown in fig. 3, the powder Z and the powder PEEK were mixed in a solid-phase mixing manner according to the mixing scheme as follows:

Pouring the mixed solution after mechanical grinding into a beaker, and placing the beaker in a vacuum oven for 24 hours, wherein the temperature of the oven is 90-95 ℃, thus obtaining powder ZP 3.

And taking out the dried mixed powder ZP3, sieving by a sieve of 200-800 meshes for 1-3 times, and sealing and storing the powder ZP3 for later use.

Step two, as shown in fig. 4, the sintering preparation method of the piezoresistor is as follows:

weighing 1g-2g of powder ZP1, ZP2 or ZP3 prepared by the three preparation processes, putting the powder in an agate mortar or a common mortar with the diameter phi of 100 mm-phi 200mm, manually grinding for 2-3 minutes to refine the powder ZP, measuring 0.06g-0.4g of acetic acid aqueous solution by using a dropper, continuously and manually stirring in the process of dripping the acetic acid aqueous solution into the mortar until the dripping of the acetic acid aqueous solution is finished, and continuously and manually grinding for 10 minutes.

The acetic acid aqueous solution is prepared according to the concentration of 1mol/L-2 mol/L.

And pouring the grinded powder ZP into a metal mold with the mold cavity diameter phi of 10 mm-phi of 12 mm.

Placing the metal mould filled with the powder ZP in the central area of a loading plate of a hot press, and setting the cold sintering process parameters as shown in Table 1:

TABLE 1 Cold sintering Process parameters

And (4) taking down the metal mould from the hot press, carrying out demoulding operation, and taking out the ZnO-polyether-ether-ketone composite material piezoresistor sample.

And step three, performing surface polishing treatment on the sample. The polishing treatment process comprises the following steps:

firstly, coarse grinding is carried out by using 600-mesh quartz sand paper for 5-10 minutes, when no obvious stain exists on the surface of the product, fine grinding is carried out for 10-20 minutes by using 1200-mesh sand paper, when the number of scratches on the surface of the product is reduced, fine grinding is carried out for 10-20 minutes by using 2000-mesh sand paper until the surface of the product has certain plastic luster.

And step four, packaging the ZnO/polyether-ether-ketone high-breakdown voltage-dependent resistor product, and placing the packaged ZnO/polyether-ether-ketone high-breakdown voltage-dependent resistor product in a dry place for later use.

And step five, if the ZnO/polyether-ether-ketone high-breakdown voltage dependent resistor needs to be subjected to electrical property detection, preparing an electrode by adopting a metal spraying process or brushing conductive silver paste on the surface, and reserving the electrode for subsequent electrical test.

The first embodiment is as follows:

the mass fraction ratio is 60 wt%: mixing 40 wt% of powder Z and powder PEEK, wherein the powder Z comprises 90 mol% of ZnO and 1 mol% of metal oxide dopant;

the purity of ZnO powder is higher than 99%, and the average particle diameter is 1 ч m. The purity of the powder PEEK (polyether-ether-ketone) is higher than 99 percent, the average particle diameter is 1200 meshes, and the melting temperature of the powder PEEK is 330-360 ℃.

The powder ZP is prepared by mixing powder Z and powder PEEK in the following preparation method:

powder ZP1 was prepared from powder Z and powder PEEK in a liquid phase assisted blending of powder Z and powder PEEK as follows:

and (3) mixing the tetrahydrofuran solution and the pure toluene solution to obtain a solution A, pre-stirring for 60min by using a magnetic stirring device, gradually heating to 55 ℃ at the heating speed of 5 ℃/s, and continuously stirring for 40min at the stirring speed of 200 r/min. 0.1g of powder P is weighed and dissolved in the solution A, and the mixture is continuously stirred for 120min at the stirring speed of 200 r/min.

In the solution A, the purity of a tetrahydrofuran solution is higher than 99%, the purity of a toluene solution is higher than 99%, and the volume ratio of the two solutions is as follows: 0.8.

and (3) dissolving the powder Z and the powder PEEK in the solution A according to the mass fraction ratio of the powder Z to the powder PEEK, preserving heat at 55 ℃, and simultaneously uniformly stirring and mixing for 40min at the stirring speed of 200 r/min.

And pouring the mixed solution into a Teflon tank, and mechanically grinding by adopting a planetary ball mill mixer, wherein the stirring speed of the mechanical grinding is 400r/min, and the continuous stirring time is 300 min.

Pouring the mixed solution after mechanical grinding into a beaker, placing the beaker in a vacuum oven for 24 hours at the temperature of 80 ℃, and drying to obtain the varistor powder raw material powder ZP 1.

And taking out the dried mixed powder ZP1, sieving by using a 800-mesh sieve for 1 time continuously, and sealing and storing the powder ZP1 for later use.

Step two, the sintering preparation mode of the piezoresistor is as follows:

weighing 1g of powder ZP1 prepared by the three preparation processes, placing the powder in an agate mortar or a common mortar with the diameter phi of 100mm, manually grinding for 2 minutes to refine the powder ZP1, measuring 0.06g of acetic acid aqueous solution by using a dropper, continuously and manually stirring in the process of dripping the acetic acid aqueous solution into the mortar until the dripping of the acetic acid aqueous solution is finished, and continuously and manually grinding for 10 minutes.

The aqueous acetic acid solution was prepared at a concentration of 1 mol/L.

And pouring the grinded powder ZP1 into a metal mold with the mold cavity diameter phi of 10 mm.

Placing the metal mold filled with the powder ZP1 in the central area of a loading plate of a hot press, and setting the cold sintering process parameters as shown in Table 2:

TABLE 2 Cold sintering Process parameters

firstly, coarse grinding is carried out by using 600-mesh quartz sand paper for 5 minutes, when no obvious stain exists on the surface of a product, fine grinding is carried out by using 1200-mesh sand paper for 10 minutes, when the number of scratches on the surface of the product is reduced, fine grinding is carried out by using 2000-mesh sand paper for 10 minutes until the surface of the product has certain plastic luster.

Example two:

the mixing method of the first embodiment is changed to a second mixing method.

Powder ZP2 is prepared by mixing powder Z and powder PEEK according to a mode of melting and coating powder Z with powder PEEK as follows:

and according to the mass fraction ratio of the powder Z to the powder PEEK, dissolving the powder Z and the powder PEEK in an alcohol solution with the concentration of 99%, and uniformly stirring and mixing for 40min at the stirring speed of 200 r/min.

And pouring the mixed solution into a Teflon tank, and mechanically grinding by adopting a planetary ball mill mixer, wherein the stirring speed of the mechanical grinding is 400r/min, and the continuous stirring time is 240 min.

Pouring the mixed solution after mechanical grinding into a beaker, and placing the beaker in a vacuum oven for 24 hours, wherein the temperature of the oven is 90 ℃.

And taking out the dried mixed powder, and continuously sieving for 1 time by adopting a 200-mesh sieve for sieving operation.

And placing the powder in a crucible, and placing the crucible in a muffle furnace for heat treatment. Keeping the temperature at 360 ℃ for 18h, heating up at the rate of 5 ℃/min, and cooling along with the furnace.

Taking out the mixed powder ZP2, grinding, sieving with 200 mesh sieve for 1 time, and sealing and storing powder ZP2 for use.

Example three:

the mixing method of the first embodiment is changed to a third mixing method.

Powder ZP3 was prepared according to the mixing protocol powder Z and powder PEEK mixed in solid phase as follows:

Pouring the mixed solution after mechanical grinding into a beaker, and placing the beaker in a vacuum oven for 24 hours, wherein the temperature of the oven is 90 ℃, thus obtaining powder ZP 3.

And taking out the dried mixed powder ZP3, sieving by a 200-mesh sieve for 1 time continuously, and sealing and storing the powder ZP3 for later use.

Example four:

step one, mixing the mass fraction of 99.95 wt%: 0.05 wt% of powder Z and powder PEEK are mixed, the powder Z comprising 99 mol% of ZnO and 1 mol% of metal oxide dopant by molar mass fraction;

the purity of ZnO powder is higher than 99%, and the average particle diameter is 50 nm. The purity of the powder PEEK (polyether-ether-ketone) is higher than 99 percent, the average particle diameter is 600 meshes, and the melting temperature of the powder PEEK is 330-360 ℃.

Powder ZP4 is prepared by mixing powder Z and powder PEEK in the following steps:

powder ZP4 is prepared by the powder Z and the powder PEEK according to a mixing mode of liquid phase assisted mixing of the powder Z and the powder PEEK as follows:

and (3) mixing the tetrahydrofuran solution and the pure toluene solution to obtain a solution A, pre-stirring for 120min by adopting a magnetic stirring device, gradually heating to 90 ℃ at a heating speed of 10 ℃/s, and continuously stirring for 40min at a stirring speed of 1200 r/min. Weighing 10g of powder P, dissolving in the solution A, and continuously stirring for 120min at the stirring speed of 1200 r/min.

In the solution A, the purity of a tetrahydrofuran solution is higher than 99%, the purity of a toluene solution is higher than 99%, and the volume ratio of the two solutions is as follows: 1.5.

and (3) dissolving the powder Z and the powder PEEK in the solution A according to the mass fraction ratio of the powder Z to the powder PEEK, preserving heat at 90 ℃, and simultaneously uniformly stirring and mixing for 40min at the stirring speed of 1200 r/min.

And pouring the mixed solution into a Teflon tank, and mechanically grinding by adopting a planetary ball mill mixer, wherein the stirring speed of the mechanical grinding is 600r/min, and the continuous stirring time is 450 min.

Pouring the mixed solution after mechanical grinding into a beaker, placing the beaker in a vacuum oven for 24 hours at the temperature of 95 ℃, and drying to obtain the varistor powder raw material powder ZP 4.

And taking out the dried mixed powder ZP4, sieving by using a 800-mesh sieve for 3 times, and sealing and storing the powder ZP4 for later use.

Step two, the sintering preparation mode of the piezoresistor is as follows:

weighing 2g of powder ZP4 prepared by the three preparation processes, placing the powder in an agate mortar or a common mortar with the diameter phi of 200mm, manually grinding for 3 minutes to refine the powder ZP4, measuring 0.4g of acetic acid aqueous solution by using a dropper, continuously and manually stirring in the process of dripping the acetic acid aqueous solution into the mortar until the dripping of the acetic acid aqueous solution is finished, and continuously and manually grinding for 10 minutes.

The aqueous acetic acid solution was prepared at a concentration of 2 mol/L.

And pouring the grinded powder ZP4 into a metal mold with the mold cavity diameter phi of 12 mm.

Placing the metal mold filled with the powder ZP4 in the central area of a loading plate of a hot press, and setting the cold sintering process parameters as shown in Table 3:

TABLE 3 Cold sintering Process parameters

firstly, coarse grinding is carried out for 10 minutes by using 600-mesh quartz sand paper, when no obvious stain exists on the surface of a product, fine grinding is carried out for 20 minutes by using 1200-mesh sand paper, when the number of scratches on the surface of the product is reduced, fine grinding is carried out for 20 minutes by using 2000-mesh sand paper, until the surface of the product has certain plastic luster.

Example five:

the mixing method of the fourth embodiment is changed to the second mixing method.

Powder ZP5 is prepared by mixing powder Z and powder PEEK according to a mode of melting and coating powder Z with powder PEEK as follows:

and according to the mass fraction ratio of the powder Z to the powder PEEK, dissolving the powder Z and the powder PEEK in an alcohol solution with the concentration of 99%, and uniformly stirring and mixing for 40min at the stirring speed of 1200 r/min.

And pouring the mixed solution into a Teflon tank, and mechanically grinding by adopting a planetary ball mill mixer, wherein the stirring speed of the mechanical grinding is 600r/min, and the continuous stirring time is 360 min.

Pouring the mixed solution after mechanical grinding into a beaker, and placing the beaker in a vacuum oven for 24 hours, wherein the temperature of the oven is 95 ℃.

And taking out the dried mixed powder, and continuously sieving for 3 times by adopting a 800-mesh sieve for sieving operation.

And placing the powder in a crucible, and placing the crucible in a muffle furnace for heat treatment. Keeping the temperature at 360 ℃ for 24h, heating up at a rate of 10 ℃/min, and cooling along with the furnace.

Taking out the mixed powder ZP5, grinding, sieving with 800 mesh sieve for 3 times, and sealing and storing powder ZP5 for use.

Example six:

the mixing method of the fourth embodiment is changed to the third mixing method.

The powder Z and the powder PEEK are mixed according to a mixing scheme, and the powder ZP6 is prepared in a mixing mode of solid-phase mixing of the powder Z and the powder PEEK as follows:

Pouring the mixed solution after mechanical grinding into a beaker, and placing the beaker in a vacuum oven for 24 hours, wherein the temperature of the oven is 95 ℃, thus obtaining powder ZP 6.

And taking out the dried mixed powder ZP6, sieving by using a 800-mesh sieve for 3 times, and sealing and storing the powder ZP6 for later use.

Example seven:

step one, mixing the mass fraction of 97 wt%: mixing 3 wt% of powder Z and powder PEEK, wherein the powder Z comprises 98.2 mol% of ZnO and 0.8 mol% of metal oxide dopant;

the purity of ZnO powder is higher than 99%, and the average particle diameter is 400 nm. The purity of the powder PEEK (polyether-ether-ketone) is higher than 99 percent, the average particle diameter is 1000 meshes, and the melting temperature of the powder PEEK is 330-360 ℃.

Powder ZP7 is prepared by mixing powder Z and powder PEEK in the following steps:

powder ZP7 is prepared by the powder Z and the powder PEEK according to a mixing mode of liquid phase assisted mixing of the powder Z and the powder PEEK as follows:

and (3) mixing the tetrahydrofuran solution and the pure toluene solution to obtain a solution A, pre-stirring for 80min by using a magnetic stirring device, gradually heating to 80 ℃ at the heating speed of 8 ℃/s, and continuously stirring for 40min at the stirring speed of 700 r/min. 5g of powder P is weighed and dissolved in the solution A, and the mixture is continuously stirred for 120min at the stirring speed of 700 r/min.

In the solution A, the purity of a tetrahydrofuran solution is higher than 99%, the purity of a toluene solution is higher than 99%, and the volume ratio of the two solutions is as follows: 1.1.

and (3) dissolving the powder Z and the powder PEEK in the solution A according to the mass fraction ratio of the powder Z to the powder PEEK, preserving heat at 82 ℃, and simultaneously uniformly stirring and mixing for 40min at the stirring speed of 700 r/min.

And pouring the mixed solution into a Teflon tank, and mechanically grinding by adopting a planetary ball mill mixer, wherein the stirring speed of the mechanical grinding is 500r/min, and the continuous stirring time is 360 min.

Pouring the mixed solution after mechanical grinding into a beaker, placing the beaker in a vacuum oven for 24 hours at the temperature of 87 ℃, and drying to obtain the varistor powder raw material powder ZP 7.

And taking out the dried mixed powder ZP7, sieving by using a 600-mesh sieve for 2 times, and sealing and storing the powder ZP7 for later use.

Step two, the sintering preparation mode of the piezoresistor is as follows:

weighing 1g-2g of powder ZP7 prepared by the three preparation processes, placing the powder in an agate mortar or a common mortar with the diameter phi of 150mm, manually grinding for 2.5 minutes to refine the powder ZP7, measuring 0.1g of acetic acid aqueous solution by using a dropper, dropwise adding the acetic acid aqueous solution into the mortar, continuously and manually stirring until the dropwise adding of the acetic acid aqueous solution is finished, and continuously and manually grinding for 10 minutes.

The aqueous acetic acid solution was prepared at a concentration of 1.5 mol/L.

Pouring the grinded powder ZP7 into a metal mould with the mould cavity diameter phi 11 mm.

Placing the metal mold filled with the powder ZP7 in the central area of a loading plate of a hot press, and setting the cold sintering process parameters as shown in Table 4:

TABLE 4 Cold sintering Process parameters

firstly, coarse grinding is carried out for 8 minutes by using 600-mesh quartz sand paper, when no obvious stain exists on the surface of a product, fine grinding is carried out for 18 minutes by using 1200-mesh sand paper, when the number of scratches on the surface of the product is reduced, fine grinding is carried out for 18 minutes by using 2000-mesh sand paper, until the surface of the product has certain plastic luster.

Example eight:

the mixing pattern of the eighth embodiment is changed to the second mixing pattern.

Powder ZP8 is prepared by mixing powder Z and powder PEEK according to a mode of melting and coating powder Z with powder PEEK as follows:

and according to the mass fraction ratio of the powder Z to the powder PEEK, dissolving the powder Z and the powder PEEK in an alcohol solution with the concentration of 99%, and uniformly stirring and mixing for 40min at the stirring speed of 800 r/min.

And pouring the mixed solution into a Teflon tank, and mechanically grinding by adopting a planetary ball mill mixer, wherein the stirring speed of the mechanical grinding is 500r/min, and the continuous stirring time is 270 min.

Pouring the mixed solution after mechanical grinding into a beaker, and placing the beaker in a vacuum oven for 24 hours, wherein the temperature of the oven is 87 ℃.

And taking out the dried mixed powder, and continuously sieving for 2 times by adopting a 600-mesh sieve.

And placing the powder in a crucible, and placing the crucible in a muffle furnace for heat treatment. Keeping the temperature at 360 ℃ for 20h, heating up at the rate of 8 ℃/min, and cooling along with the furnace.

Taking out the mixed powder ZP8, grinding, sieving with 600 mesh sieve for 2 times, and sealing and storing powder ZP8 for use.

Example nine:

the mixing pattern of example eight was changed to a third mixing pattern.

Powder ZP9 was prepared according to the mixing protocol powder Z and powder PEEK mixed in solid phase as follows:

and according to the mass fraction ratio of the powder Z to the powder PEEK, dissolving the powder Z and the powder PEEK in 99% alcohol solution, and uniformly stirring and mixing for 40min at the stirring speed of 700 r/min.

And pouring the mixed solution into a Teflon tank, and mechanically grinding by adopting a planetary ball mill mixer, wherein the stirring speed of the mechanical grinding is 500r/min, and the continuous stirring time is 300 min.

Pouring the mixed solution after mechanical grinding into a beaker, and placing the beaker in a vacuum oven for 24 hours, wherein the temperature of the oven is 92 ℃, thus obtaining powder ZP 9.

And taking out the dried mixed powder ZP9, sieving by using a 800-mesh sieve for 2 times, and sealing and storing the powder ZP9 for later use.

The properties of the final piezoresistors of examples one to nine are shown in table 5;

TABLE 5 Main electrical properties of an example

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.

Claims

1. The zinc oxide polyether-ether-ketone piezoresistor is characterized by comprising the following components in percentage by weight of 60-99.95%: 40-0.05 wt% of component Z and PEEK, wherein the component Z comprises 90-99 mol% of ZnO and 1-10 mol% of metal oxide dopant.

2. A preparation method of a zinc oxide polyether-ether-ketone piezoresistor is characterized by comprising the following steps;

and step two, performing cold sintering on the mixed powder to obtain the piezoresistor with the required shape.

3. The method for preparing the zinc oxide polyetheretherketone varistor as claimed in claim 2, wherein in the second step, the sintering is cold sintering, wherein the load during the cold sintering is 200-480MPa, and the temperature is 250-340 ℃.

4. The preparation method of the zinc oxide polyetheretherketone varistor according to claim 2, characterized in that in the first step, a tetrahydrofuran solution with a purity of 99% and a toluene pure solution with a purity of 99% are mixed according to a volume ratio of 0.8-1.5 to obtain a solution A, the solution A is pre-stirred for 60-120 min, the temperature is gradually increased, the temperature is increased to 55-90 ℃ at a rate of 5-10 ℃/s, and the mixture is uniformly stirred; weighing 0.1g-10g of PEEK powder, dissolving in the solution A, and uniformly stirring;

5. The preparation method of the zinc oxide polyetheretherketone varistor according to claim 2, characterized in that in the first step, the powder Z and the powder PEEK in the mass fraction ratio of the first step are dissolved in an alcohol solution with a concentration of 99%, and are stirred uniformly; mechanically grinding and stirring the mixed solution for 240-450 min, drying the stirred mixed solution at 90-95 ℃, and sieving the dried powder by a sieve of 200-800 meshes for 1-3 times; then carrying out heat treatment on the sieved powder, keeping the temperature at 360 ℃ for 18-24h, increasing the temperature rate at 5-10 ℃/min, and cooling along with the furnace; then sieving with 200-800 mesh sieve for 1-3 times.

6. The preparation method of the zinc oxide polyetheretherketone varistor according to claim 2, characterized in that in the first step, the powder Z and the powder PEEK in the mass fraction ratio of the first step are dissolved in an alcohol solution with a concentration of 99%, and are stirred uniformly; mechanically grinding and stirring the mixed solution for 240-450 min, drying the stirred mixed solution at 90-95 ℃, and sieving the dried powder by a sieve of 200-800 meshes for 1-3 times continuously.

7. The preparation method of the zinc oxide polyetheretherketone varistor according to claim 2, wherein in step two, 1g to 2g of the sieved powder is selected and placed in a mortar with a diameter of Φ 100mm to Φ 200mm, and ground for 2 to 3 minutes, 0.06g to 0.4g of the acetic acid aqueous solution with a concentration of 1mol/L to 2mol/L is taken, and the acetic acid aqueous solution is added dropwise into the mortar while being stirred until the acetic acid aqueous solution is added dropwise and ground for 10 minutes.

8. The method for preparing a zinc oxide polyetheretherketone varistor as claimed in claim 2, wherein after step two, the quartz sand paper of 600 mesh is used for rough grinding for 5-10 minutes, the sand paper of 1200 mesh is used for fine grinding for 10-20 minutes, and the sand paper of 2000 mesh is used for fine grinding for 10-20 minutes.

9. The preparation method of the zinc oxide polyetheretherketone varistor as claimed in claim 2, wherein after the second step, the varistor is prepared into an electrode by a metal spraying process or by brushing conductive silver paste on the surface.