CN111447694A

CN111447694A - Palladium quantum dot doped graphene-based electric heating plate and electric heating device

Info

Publication number: CN111447694A
Application number: CN202010296752.2A
Authority: CN
Inventors: 吴立刚; 叶德林; 胡柱东; 彭令; 曾垂彬; 孔金波; 刘秋明; 马宇飞
Original assignee: Guangdong Kangxi Technology Co Ltd
Current assignee: Guangdong Kangxi Technology Co Ltd
Priority date: 2020-04-15
Filing date: 2020-04-15
Publication date: 2020-07-24
Anticipated expiration: 2040-04-15
Also published as: CN111447694B

Abstract

The invention provides a palladium quantum dot doped graphene-based electric heating plate which comprises an insulating layer and a graphene conducting film arranged on the insulating layer; the preparation method of the graphene conductive film comprises the following steps of: preparing a graphite oxide allyl ketone dispersion liquid, preparing a palladium quantum dot doped graphene-carbon black color paste, preparing a resin paste, preparing a palladium quantum dot doped graphene base mixed liquid, preparing a palladium quantum dot doped graphene base conductive ink and preparing a palladium quantum dot doped graphene base electric heating plate. The invention also provides an electric heating device. The palladium quantum dot doped graphene-based electric heating plate has the advantages of quick manufacturing process, convenience in thickness control and quick manufacturing process, and the prepared palladium quantum dot doped graphene-based conductive film has the functions of flexibility, tear resistance or fracture resistance.

Description

Palladium quantum dot doped graphene-based electric heating plate and electric heating device

Technical Field

The invention relates to the technical field of nano materials, in particular to a palladium quantum dot doped graphene-based electric heating plate and an electric heating device using the same.

Background

Graphene is a two-dimensional nanomaterial with a hexagonal honeycomb lattice structure formed by carbon atoms through sp2 hybrid orbitals and only one layer of carbon atoms thick. The unique structure of graphene gives it a number of excellent properties, such as a high theoretical specific surface area (2630 m)²G) and ultrahigh electron mobility (200000 cm)²/v.s), high thermal conductivity (5000W/m.K), high Young's modulus (1.0TPa), and high light transmittance (97.7%), among others. By virtue of the advantages of the structure and the performance of the graphene, the graphene has a huge application prospect in the fields of energy storage and conversion devices, nano-electronic devices, multifunctional sensors, flexible wearable electronics, electromagnetic shielding, corrosion prevention and the like. In view of the flexibility and the conductive characteristic of graphene, the graphene slurry is added into the printing ink to prepare the conductive printing ink, and the graphene heating layer is further prepared by spraying and drying the printing ink to prepare the graphene heating body.

Along with the trend of people to good and healthy life, the traditional heating system is improved, more economic and clean alternative energy is searched, and the development of a novel green low-carbon heating system is reluctant. An electric heating technology based on graphene infrared emission performance, namely graphene-based infrared heating ink and an infrared heating body technology thereof, provides an effective solution for solving the problems. Compared with the traditional heating methods such as coal burning, steam, hot air and resistance, the graphene heating method has the advantages of high heating speed, high electricity-heat conversion rate, automatic temperature control, zone control, stable heating, no noise in the heating process, low operation cost, relatively uniform heating, small occupied area, low investment and production cost, long service life, high working efficiency and the like, and is more beneficial to popularization and application. The energy-saving heating device replaces the traditional heating, has particularly remarkable electricity-saving effect, can generally save electricity by about 30 percent, and even can achieve 60 to 70 percent in individual occasions.

The most central part of devices such as graphene infrared heating murals, wallpaper, floors and the like is the graphene heating plate/functional layer. In the prior art, graphene is generally prepared into graphene slurry, ink or paint, and then prepared into a graphene heating coating layer by a printing method. However, the graphene heating plate/functional layer prepared by the methods has the problems of poor thickness controllability, unstable structure of the graphene heating layer, too large sheet resistance, difficulty in practical application, easiness in brittle fracture after long-term use, single selectable printing base material, uneven heat generation and the like, so that the conventional graphene-based conductive ink heating layer is short in service life and not suitable for long-term use.

Disclosure of Invention

In view of the above, the invention provides a palladium quantum dot doped graphene-based electric heating plate, which is used for solving the common problems in the prior art that the electric heating plate is poor in stability, the thickness of a graphene heating layer is difficult to control, the electric conductivity is poor, a conductive film formed after printing is easy to crack and age, and the heating is uneven after long-time use.

In a first aspect, the invention provides a palladium quantum dot doped graphene-based electric heating plate, which comprises an insulating layer and a graphene conducting film arranged on the insulating layer;

the preparation method of the graphene conductive film comprises the following steps of:

preparing a graphite oxide allyl ketone dispersion liquid: providing graphite powder, preparing graphene oxide by adopting a modified Hummers method, centrifuging, and carrying out acetone heavy suspension to prepare a graphite oxide allyl ketone dispersion liquid;

preparing a palladium quantum dot doped graphene dispersion liquid: adding heteropoly acid into the graphite oxide allyl ketone dispersion liquid, stirring and mixing uniformly, centrifuging, collecting a first precipitate, drying, re-suspending the first precipitate with acetone, adding palladium acetylacetonate, stirring and mixing uniformly again, centrifuging, collecting a second precipitate, drying, reducing the second precipitate in a hydrogen environment to prepare palladium quantum dot doped graphene, and re-suspending with ethanol to prepare palladium quantum dot doped graphene dispersion liquid;

preparing palladium quantum dot doped graphene-carbon black color paste: taking and stirring 50-250 parts of first dispersing agent, and slowly adding 15-40 parts of palladium quantum dot doped graphene dispersion liquid and 5-25 parts of conductive carbon black into the first dispersing agent to obtain palladium quantum dot doped graphene-carbon black color paste;

preparing resin slurry: taking 50-250 parts of first dispersing agent and stirring, and slowly adding 5-20 parts of stripping resin into the first dispersing agent to prepare resin slurry;

preparing a mixed solution of palladium quantum dots and graphene doped: respectively and slowly dripping the resin slurry and 50-200 parts of second dispersing agent into the stirred palladium quantum dot doped graphene-carbon black color paste, transferring the mixed solution into a high-pressure reaction kettle at 70-100 ℃ after finishing dripping, naturally cooling after reacting for 0.5-2 h, and continuously stirring in the reaction process to prepare the palladium quantum dot doped graphene-based mixed solution;

preparing palladium quantum dot doped graphene-based conductive ink: adding 0.5-2.5 parts of structure stabilizer, 0.5-2.5 parts of polyacrylonitrile-maleic anhydride copolymer and 5-10 parts of flatting agent into the palladium quantum dot doped graphene base mixed solution while stirring the palladium quantum dot doped graphene base mixed solution, and stirring at 1000-5000 rpm for 0.5-6 hours after the addition is finished to prepare the palladium quantum dot doped graphene base conductive ink;

preparing a palladium quantum dot doped graphene-based electric heating plate: providing an insulating base layer, arranging palladium quantum dot doped graphene-based conductive ink on the insulating layer through blade coating, spin coating, direct writing, screen printing, silk printing or ink-jet printing, and curing to obtain the palladium quantum dot doped graphene-based electric heating plate;

the heteropoly acid comprises one or a combination of more of phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid and silicotungstic acid, and the polymerization degree of the polyacrylonitrile-maleic anhydride copolymer is 50-500.

In one embodiment, in the step of preparing the graphene oxide allyl ketone dispersion liquid, the prepared graphene oxide is transferred to a high-temperature carbonization furnace to be carbonized for 30-90 seconds, inert gas is filled in the high-temperature carbonization furnace, the temperature of the high-temperature carbonization furnace is 500-1200 ℃, and the graphene oxide expanded at high temperature is prepared into the graphene oxide allyl ketone dispersion liquid with the concentration of 5-150 mg/m L.

More preferably, the inert gas is nitrogen or argon.

Preferably, in the step of preparing the palladium quantum dot doped graphene dispersion liquid, adding heteropoly acid into the graphite oxide allyl ketone dispersion liquid, wherein the mass-volume ratio of the heteropoly acid to the graphite oxide allyl ketone dispersion liquid is 1-5: 1000;

and (3) adding heteropoly acid, carrying out water bath ultrasonic treatment on the graphite oxide allyl ketone dispersion liquid for 20-90 min, wherein the water bath temperature is 20-25 ℃, stirring the ultrasonic graphite oxide allyl ketone dispersion liquid for 2-12 h at 600-1400 rpm, centrifuging at 8000-15000 rpm, collecting a first precipitate, and drying the first precipitate for 30-120 min at 60-80 ℃.

Preferably, in the step of preparing the palladium quantum dot doped graphene dispersion liquid, resuspending a first precipitate with acetone and adding palladium acetylacetonate, wherein the mass ratio of the first precipitate to the palladium acetylacetonate is 1000: 0.5-5;

and stirring the mixed solution at 600-1400 rpm for 2-12 h, centrifuging at 8000-15000 rpm to collect a second precipitate, and drying the second precipitate at 60-80 ℃ for 30-120 min.

Preferably, in the step of preparing the palladium quantum dot doped graphene dispersion liquid, transferring the second precipitate to a quartz tube of a tube furnace, and introducing a reducing gas for reduction, wherein the reducing gas is a hydrogen/nitrogen mixed gas or a hydrogen/argon mixed gas;

wherein the volume percentage of the hydrogen is 5-20%, the flow rate of the mixed gas is 30-150m L/min, the temperature of the reduction reaction is 160-200 ℃, and the reaction time is 1-4 h.

Preferably, in the step of preparing the palladium quantum dot doped graphene dispersion liquid, ethanol is used for resuspending to prepare 5-150 mg/m L palladium quantum dot doped graphene dispersion liquid;

in the step of preparing the palladium quantum dot doped graphene-carbon black color paste, 100-200 parts of a first dispersing agent is taken and stirred, 20-30 parts of palladium quantum dot doped graphene dispersion liquid and 10-20 parts of conductive carbon black are slowly added into the first dispersing agent, and stirring is carried out at 500-1000 rpm for 1-4 hours to prepare the palladium quantum dot doped graphene-carbon black color paste;

the first dispersing agent comprises 1-10 mol/L of strong acid solution, ethanol and cellulose derivatives, wherein the weight ratio of the strong acid solution to the ethanol to the cellulose derivatives is 10: 50-300: 5-20;

the strong acid solution is hydrochloric acid solution or sulfuric acid solution, and the cellulose derivative is one or more of methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, cellulose acetate and cellulose nitrate. Preferably, in the step of preparing the resin slurry, the release resin is one or more of epoxy resin, polydimethylsiloxane resin, polycarbonate resin, polyurethane resin, acrylic resin, water-based alkyd resin, phenolic resin and silicone-acrylate resin;

in the step of preparing the mixed liquid of the palladium quantum dots and the graphene, the second dispersing agent comprises one or more of propylene glycol, cyclohexanol, terpineol, ethanol, ethylene glycol, isopropanol and ethyl acetate.

Preferably, in the step of preparing the palladium quantum dot doped graphene-based mixed solution, the resin slurry and 50-200 parts of a second dispersing agent are respectively and slowly dripped into the stirred palladium quantum dot doped graphene-carbon black color paste, after dripping is completed, the mixed solution is firstly transferred into a microwave digestion instrument for microwave digestion for 5-15 min, the microwave digestion temperature is 65-70 ℃, and the power is 280-330W.

Preferably, in the step of preparing the palladium quantum dot doped graphene-based conductive ink, the leveling agent comprises polypyrrole and also comprises polyvinyl alcohol or polyethylene glycol, wherein the mass ratio of the polypyrrole to the polyvinyl alcohol or the polyethylene glycol is 8: 1-5;

the structural stabilizer comprises ethylenediamine and p-methylphenol, the mass ratio of the ethylenediamine to the p-methylphenol is 10: 1-15, and the polymerization degree of the polyacrylonitrile-maleic anhydride copolymer is 100-200.

The preparation method of the palladium quantum dot doped graphene-based electric heating plate comprises the steps of preparing a graphite oxide allyl ketone dispersion liquid, preparing a palladium quantum dot doped graphene-carbon black color paste, preparing a resin slurry, preparing a palladium quantum dot doped graphene-based mixed liquid, preparing a palladium quantum dot doped graphene-based conductive ink, preparing a palladium quantum dot doped graphene-based electric heating plate and the like, and the conductive ink, the conductive film and the corresponding electric heating plate which are stable in structure and complete in function can be prepared through the steps. The palladium quantum dot doped graphene-based electric heating plate comprises an insulating layer and a graphene conducting film arranged on the insulating layer, wherein the insulating layer plays roles of insulation and a carrier, the graphene conducting film is conveniently attached to the insulating layer, the graphene conducting film plays a role of an electric heating sheet, and heat is generated to heat other equipment or air after the graphene conducting film is electrified. The reason why the palladium quantum dots are selected and doped is as follows: the palladium quantum dots have good physical stability, can be well dispersed in the ink and keep the excellent conductivity of the conductive ink, and moreover, the palladium quantum dots have stable chemical properties, are not easy to react with other chemical substances in the environment, keep the quantum dot effect of the palladium quantum dots for a long time and avoid annihilation of the quantum effect caused by environmental change; for the applicant, the preparation process of the palladium quantum dot doped graphene-based conductive ink is relatively mature, and the product quality is easy to control. Most importantly, the palladium quantum dot doped graphene-based conductive ink achieves unexpected technical effects: the palladium quantum dots are uniformly doped into the graphene sheet layer, so that the dispersion of the graphene sheet layer is effectively promoted, meanwhile, by means of factors such as quantum filling effect and surface steric hindrance effect of the palladium quantum dots, the structural stability and chemical stability of the graphene are improved, and the structure, sheet resistance stability and the like of the conductive ink and a heating device using the conductive ink are improved.

Firstly, preparing a palladium quantum dot doped graphene dispersion liquid by adopting a space separation scheme, namely modifying the surface of graphene oxide by using heteropoly acid molecules by using a wet chemical method, then introducing a metal precursor with strong interaction with the heteropoly acid molecules, namely palladium acetylacetonate, and then preparing the palladium quantum dot loaded on the heteropoly acid modified graphene oxide by hydrogen reduction. The palladium quantum dot doped graphene prepared by the method has the advantages of uniform doping of the palladium quantum dots, uniform nano-size of the quantum dots, small average particle size, stable structure of the graphene oxide and the like. The step of preparing the palladium quantum dot doped graphene-carbon black color paste can ensure that all components are fully mixed and dissolved, and then the palladium quantum dot doped graphene-carbon black color paste is mixed and stirred with the resin paste, so that on one hand, all the components can be ensured to be further and completely mixed, on the other hand, the further dispersion of the graphene and the carbon black can be promoted, and preparation conditions are provided for the reaction in a high-pressure reaction kettle in the next step. And finally, the structural stabilizer, the polyacrylonitrile-maleic anhydride copolymer and the leveling agent are added to mainly blend the uniformity of the ink and reduce the viscosity of the ink, and meanwhile, the long-term stability of the ink structure can be maintained, and the effective storage period is prolonged.

The core of this palladium quantum dot doping graphite alkene base electric heating plate lies in palladium quantum dot doping graphite alkene base conductive ink, palladium quantum dot doping graphite alkene base conductive ink passes through the blade coating, spin coating, direct writing, the screen printing, mode such as silk screen printing or inkjet printing prints is printed on the insulating layer, it is quick to have the manufacturing process, be convenient for control thickness (square resistance), the preparation process is swift, the palladium quantum dot doping graphite alkene base conductive film who prepares possesses that the square resistance is little, high temperature resistance, advantages such as long service life, all have stronger adhesive force to various substrates, the convenience is used with other substrates cooperations, it just tears or anti breaking function to have flexibility.

In a second aspect, the invention provides an electric heating device, which is used for solving the problems that the existing electric heating device is poor in thickness controllability of a heating plate/functional layer, unstable in structure of a heating layer, too large in sheet resistance, difficult to practically apply to high-power heat-generating equipment, easy to crack after long-term use, easy to wear a conductive film, uneven in heat generation, low in heat-generating power, complicated in assembly process and the like, so that the existing electric heating device is short in service life of the heating layer and difficult to effectively popularize.

An electric heating device comprises a groove base, an upper cover and any one of the palladium quantum dot doped graphene-based electric heating plates, wherein the upper cover covers the groove base and is used for enclosing an accommodating cavity, and the palladium quantum dot doped graphene-based electric heating plate is accommodated in the accommodating cavity;

at least one pair of electrode rods is arranged in the groove of the groove base, and electrode holes corresponding to the electrode rods are formed in the palladium quantum dot doped graphene-based electric heating plate;

when the palladium quantum dot doped graphene-based electric heating plate is installed, the electrode rod penetrates through the electrode hole to fix the palladium quantum dot doped graphene-based electric heating plate, and the electrode rod is electrically connected with the palladium quantum dot doped graphene-based electric heating plate.

Preferably, a metal ring buckle is arranged at the electrode hole, the outer edge of the metal ring buckle is electrically connected with the graphene conductive film, and the inner edge of the metal ring buckle is used for sleeving an electrode rod.

Preferably, four electrode rods are arranged in the groove of the groove base, and four electrode holes are formed in the palladium quantum dot doped graphene-based electric heating plate;

the palladium quantum dot doped graphene-based electric heating plate is rectangular, and the four electrode holes are formed in four corners of the palladium quantum dot doped graphene-based electric heating plate.

Preferably, the inner wall of the groove base is provided with a heat reflection layer, the upper cover comprises an insulation heat conduction layer and an anti-slip layer arranged on the insulation heat conduction layer, and when the upper cover covers the groove base, the insulation heat conduction layer faces the groove base;

the groove of the groove base is also internally provided with a heat storage slow release layer, and the heat storage slow release layer is arranged between the insulating heat conduction layer and the palladium quantum dot doped graphene-based electric heating plate.

Preferably, the heat reflection layer is a silver mirror layer, and the anti-slip layer is made of flexible heat-conducting resin.

Preferably, a plurality of layers of palladium quantum dot doped graphene-based electric heating plates are arranged in the grooves of the groove base, the graphene conductive films of the plurality of layers of palladium quantum dot doped graphene-based electric heating plates face the upper cover, and the plurality of layers of palladium quantum dot doped graphene-based electric heating plates are sequentially crenellated and fixed on the electrode rods.

The electric heating device comprises a groove base, an upper cover and a palladium quantum dot doped graphene-based electric heating plate, wherein the palladium quantum dot doped graphene-based conductive ink is applied to preparation of a graphene conductive film, the obtained graphene conductive film has considerable flexibility, toughness, hardness and adhesion, can be printed on various base materials to prepare heating plates or other heating equipment, and has certain bending, abrasion and stretching resistant functions. The conductive film and the electric heating device prepared by the palladium quantum dot doped graphene-based conductive ink have the characteristics of high heating speed, accurate temperature control, uniform heating, low energy consumption, low production cost, high temperature resistance, long service life and the like, and are high in practicability and outstanding in economic value.

Advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of the invention.

Drawings

In order to more clearly illustrate the contents of the present invention, a detailed description thereof will be given below with reference to the accompanying drawings and specific embodiments.

FIG. 1 is an exploded view of an electrical heating apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the internal structure of the groove base shown in FIG. 1 (hiding the four walls of the groove base);

FIG. 3 is a schematic structural view of the upper cover shown in FIG. 1;

FIG. 4 is a schematic diagram of an arrangement structure between the heating plate and the upper cover in another embodiment;

fig. 5 is a schematic structural view of a PI board on which a temperature sensor is disposed.

Detailed Description

While the following is a description of the preferred embodiments of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

As shown in fig. 1, the present invention discloses an electric heating apparatus. This electric heater unit recess base 1, upper cover 2 and hot plate 3, wherein hot plate 3 is palladium quantum dot doping graphite alkene base electric heating board. The upper cover 2 covers the groove base 1 to form an accommodating cavity, and when the electric heating device is assembled, the heating plate 3 is accommodated in the groove of the groove base 1, and then the upper cover 2 covers the groove base 1 to seal the groove, so that the electric heating device is assembled. In this embodiment, as shown in fig. 2 (the four walls of the groove base are omitted), four electrode rods 11, which may be metal electrode rods made of aluminum, for example, are further disposed in the grooves of the groove base 1, and the heating plate 3 is provided with electrode holes 31 corresponding to the electrode rods 11. When the heating plate 3 is assembled, the four electrode rods 11 are aligned to the four electrode holes 31 and penetrate into the four electrode holes, so that the heating plate 3 is firmly fixed in the groove of the groove base 1, and meanwhile, the electrode rods 11 are electrically connected with the heating plate 3, so that the heating plate 3 is conveniently powered through the electrode rods 11.

As a preferred embodiment of this embodiment, a plug or a socket may be provided on the outer wall of the groove base 1, and the plug or the socket is electrically connected to one pair of the four electrode rods 11, so as to conveniently supply power and generate heat for the heating plate 3 through the plug or the socket on the outer wall of the groove base 1 and the electrode rods 11. In other preferred embodiments, a power adjusting knob may be further disposed on the outer wall of the groove base 1 for adjusting the heat generating power of the heating plate 3. In other preferred embodiments, six plugs or sockets are provided on the outer wall of the groove base 1, and the six plugs or sockets are electrically connected with two of the four electrode rods 11. Therefore, when any one electrode rod 11 or electrode hole 31 breaks down, different electrode rods 11 or electrode holes 31 can be selected to realize electric conduction, and the complicated process of replacing the heating plate 3 or the groove base 1 is avoided.

In this embodiment, the number of the electrode rods 11 and the number of the electrode holes 31 are four, so that the heating plate 3 can be fixed well and the loosening of the heating plate 3 can be prevented. In other embodiments, the number of the electrode rods 11 and the electrode holes 31 can be 2, 3, 5, 6, 7, 8, etc., so as to ensure that the heating plate 3 is fixed and electrically conducted.

In the present embodiment, the cross section of the groove seat 1 is rectangular, and correspondingly, the heating plate 3 is also rectangular, and in other embodiments, the cross section of the groove seat 1 and the heating plate 3 may also be polygonal, circular, oval or irregular.

In the present embodiment, the electrode hole 31 is further provided with a metal ring 32, for example, a metal nickel ring, an outer edge of the metal ring 32 is electrically connected to the graphene conductive film, and an inner edge of the metal ring 32 is used for sleeving the electrode rod 11. The metal ring buckle 32 can protect the graphene conductive film, so that the graphene conductive film is ensured to be well electrically connected with the electrode rod 11, and the heating plate 3 can be ensured to be fixed.

In a preferred embodiment, a heat reflective layer 12 is further disposed on the inner wall of the groove base 1. From this, can prevent through setting up heat reflection layer 12 that the heat that hot plate 3 produced from leading to the fact the waste of heat through the outer wall of recess base 1 and base diffusion, the heat reflection layer 12 that sets up ensures that the heat that hot plate 3 produced only diffuses to the outside through upper cover 2, ensures the effective use of heat energy. In the present embodiment, the heat reflective layer 12 is a silver mirror layer. In this embodiment, the groove base 1 is made of a heat-resistant material, or the groove base 1 may be configured to have an inner layer, an outer layer and a middle vacuum heat-insulating layer, and also has a function of ensuring effective utilization of heat energy.

As a preferred embodiment, as shown in fig. 3, the upper cover 2 includes an insulating heat conducting layer 21 and an anti-slip layer 22 disposed on the insulating heat conducting layer 21, wherein the insulating heat conducting layer 21 is preferably made of ceramic material, which can not only quickly dissipate the heat generated by the heat generating plate 3, but also play a good role in supporting. The preferred flexible heat conduction resin that is of skid resistant course 22, when upper cover 2 approximately fits groove base 1, insulating heat-conducting layer 21 is down, skid resistant course 22 is up, and skid resistant course 22 can heat conduction fast, still has certain flexibility, has the effect of antiskid and gentle pressure.

As a preferred embodiment, as shown in fig. 4, a temperature sensor 211 is further disposed on the insulating and heat conducting layer 21, and the temperature sensor 211 is used for detecting the temperature of the insulating and heat conducting layer 21. Can also set up temperature display screen 221 on skid resistant course 22 for the temperature that shows temperature sensor 211 and detect, convenience of customers knows heating device's heat production condition in real time.

In a preferred embodiment, as shown in fig. 4, a heat storage slow release layer 4 is further arranged in the groove of the groove base 1, and the heat storage slow release layer 4 is arranged between the insulating and heat conducting layer 21 and the heating plate 3. The heat accumulation slow release layer 4 has the function of accumulating heat energy and slowly releasing the heat energy.

In a preferred embodiment, a plurality of layers of heating plates 3 may be further disposed in the grooves of the groove base 1, the graphene conductive films of the plurality of layers of heating plates 3 face the upper cover 2, and the plurality of layers of heating plates 3 are sequentially crenellated and fixed to the electrode rod 11. The compound hot plate is constituteed to the hot plate 3 that the multilayer set up, has the effect that promotes heat production power, when certain hot plate 3 breaks down, because multilayer hot plate 3 connects in parallel each other, can not disturb each other.

The following describes in detail the preparation method of the palladium quantum dot doped graphene-based electric heating plate according to the present invention and the palladium quantum dot doped graphene-based electric heating plate prepared in each example.

Example 1

Preparing a graphite oxide allyl ketone dispersion liquid: 500mg of graphite powder is provided, and Graphene Oxide (GO) is prepared by adopting a modified Hummers method. In order to further obtain few-layer graphene oxide, the graphene oxide is placed in an ice water bath, ultrasonic treatment is carried out for 10 minutes under the power of 250W by using an ultrasonic dispersion instrument, the ultrasonic treatment is repeated once, and the supernatant is taken for centrifugation and acetone resuspension to prepare graphene oxide allyl ketone dispersion liquid with the thickness ranging from 12 to 20 layers and the transverse dimension ranging from 700 nm to 1000 nm. The concentration was centrifuged as required to adjust the concentration of the graphite oxide allyl ketone dispersion to 150 mg/ml.

Preparing a palladium quantum dot doped graphene dispersion liquid: 50ml of the graphite allyl ketone oxide dispersion prepared above was taken, 0.05g of phosphomolybdic acid was added thereto, and after stirring at 600rpm for 10 hours, the mixture was centrifuged at 15000rpm for 30 minutes, and the first precipitate at the bottom of the centrifuge tube was collected and transferred to a 60 ℃ drying oven to be dried for 120 minutes, to obtain a dried first precipitate. And (3) resuspending the first precipitate by 50ml of acetone, adding 0.025g of palladium acetylacetonate, stirring at 600rpm for 10h again, uniformly mixing, centrifuging at 15000rpm for 30min, collecting a second precipitate at the bottom of a centrifuge tube, transferring to a 60 ℃ drying oven, and drying for 120min to obtain a dried second precipitate. And (4) putting the second precipitate into a quartz tube of a tube furnace, and introducing diluted hydrogen for reduction. The reduction conditions are as follows: the reducing gas is hydrogen/nitrogen mixed gas, wherein the volume percentage of the hydrogen is 5 percent, the flow rate of the mixed gas is 120 ml/min, the reduction reaction temperature is 160 ℃, and the reaction time is 4 hours. And (3) resuspending the palladium quantum dot doped graphene by 400ml of ethanol to prepare a palladium quantum dot doped graphene dispersion solution.

Preparing palladium quantum dot doped graphene-carbon black color paste, namely taking 200m L of 2 mol/L sulfuric acid solution and 0.4Kg of methyl cellulose, respectively adding the sulfuric acid solution and the methyl cellulose into ethanol, adding ethanol to 5000m L while stirring to obtain first dispersing agent, taking 2500m L first dispersing agent and stirring the first dispersing agent, slowly adding 400m L of the prepared palladium quantum dot doped graphene dispersing liquid and 50g of conductive carbon black into the first dispersing agent, and continuously stirring at 1500rpm for 30min to obtain the palladium quantum dot doped graphene-carbon black color paste.

And (3) preparing resin slurry, namely taking the residual 2500m L first dispersing agent and stirring the first dispersing agent, slowly adding 200g of acrylic resin into the first dispersing agent, and continuously stirring at 5000rpm for 30min to obtain the resin slurry.

And (2) preparing a palladium quantum dot doped graphene-based mixed solution, namely respectively slowly dropwise adding the prepared resin slurry and 2000m L terpineol into the palladium quantum dot doped graphene-carbon black color paste while stirring, wherein the stirring speed is 500rpm, after dropwise addition is finished, transferring the stirred mixed solution into a stainless steel high-pressure reaction kettle at 100 ℃, reacting for 0.5h, naturally cooling after reaction is finished, and continuously stirring at high speed of 500rpm in the reaction process to obtain the palladium quantum dot doped graphene-based mixed solution.

Preparing a palladium quantum dot doped graphene-based electric heating plate: while stirring the palladium quantum dot doped graphene-based mixed solution at a high speed of 500rpm, 25g of the structural stabilizer, 25g of the polyacrylonitrile-maleic anhydride copolymer and 100g of the leveling agent are added to the palladium quantum dot doped graphene-based mixed solution. Wherein, 25g of the structure stabilizer comprises 10g of ethylenediamine and 15g of p-methylphenol, the polymerization degree of the polyacrylonitrile-maleic anhydride copolymer is 50, and 100g of the flatting agent comprises 83.5g of polypyrrole and 16.3g of polyvinyl alcohol. And after the addition is finished, stirring at 1500rpm for 6 hours to prepare the palladium quantum dot doped graphene-based conductive ink, and printing to prepare the palladium quantum dot doped graphene-based electric heating plate.

Example 2

Preparing graphite Oxide allyl ketone dispersion liquid, namely providing 500mg of graphite powder, preparing Graphene Oxide (GO) by adopting a modified Hummers method, further transferring the prepared Graphene Oxide to a high-temperature carbonization furnace for high-temperature carbonization for 30s, filling nitrogen into the high-temperature carbonization furnace, wherein the temperature of the high-temperature carbonization furnace is 1200 ℃, placing the Graphene Oxide expanded at high temperature into an ice water bath, carrying out ultrasonic treatment for 20 minutes under the power of 250W by using an ultrasonic dispersion instrument, repeating the ultrasonic treatment once, taking supernatant, centrifuging, and carrying out acetone re-suspension to prepare the graphite Oxide allyl ketone dispersion liquid with the thickness ranging from 8 to 15 layers and the transverse dimension ranging from 700 to 1000nm, and carrying out centrifugal concentration according to requirements to adjust the concentration of the graphite Oxide allyl ketone dispersion liquid to 120mg/m L.

Preparing a palladium quantum dot doped graphene dispersion liquid: 50ml of the graphite allyl ketone oxide dispersion prepared above was taken, 0.1g of silicomolybdic acid was added thereto, and after stirring at 800rpm for 12 hours, centrifugation was carried out at 13500rpm for 45 minutes, and the first precipitate at the bottom of the centrifuge tube was collected and transferred to a 65 ℃ drying oven to be dried for 100 minutes, to obtain a dried first precipitate. And (3) resuspending the first precipitate by 50ml of acetone, adding 0.05g of palladium acetylacetonate, stirring again at 800rpm for 12h, uniformly mixing, centrifuging at 13500rpm for 45min, collecting a second precipitate at the bottom of a centrifuge tube, transferring the second precipitate to a 65 ℃ drying oven, and drying for 100min to obtain a dried second precipitate. And (4) putting the second precipitate into a quartz tube of a tube furnace, and introducing diluted hydrogen for reduction. The reduction conditions are as follows: the reducing gas is hydrogen/argon gas mixture, wherein the volume percentage of the hydrogen is 8 percent, the flow rate of the gas mixture is 150 ml/min, the reduction reaction temperature is 168 ℃, and the reaction time is 3.5 h. And resuspending the palladium quantum dot doped graphene by 200ml of ethanol to prepare a palladium quantum dot doped graphene dispersion solution.

Preparing palladium quantum dot doped graphene-carbon black color paste, namely taking 100m L and 0.05Kg of methyl cellulose in 10 mol/L hydrochloric acid solution and 0.15Kg of cellulose nitrate, respectively adding the hydrochloric acid solution, the methyl cellulose and the cellulose nitrate into ethanol, stirring and complementing the ethanol to 4000m L to obtain first dispersing agent, taking 2000m L of the first dispersing agent and stirring the first dispersing agent, slowly adding 200m L of the prepared palladium quantum dot doped graphene dispersing liquid and 100g of conductive carbon black into the first dispersing agent, and continuously stirring at 500rpm for 120min to obtain the palladium quantum dot doped graphene-carbon black color paste.

And (3) preparing resin slurry, namely taking the residual 2000m L first dispersing agent and stirring the first dispersing agent, slowly adding 180g of epoxy resin into the first dispersing agent, and continuously stirring at 4000rpm for 60min to obtain the resin slurry.

And (2) preparing a mixed solution of the palladium quantum dot doped graphene base, namely respectively slowly dropwise adding the prepared resin slurry and 800m L propylene glycol into the palladium quantum dot doped graphene-carbon black color paste while stirring, wherein the stirring speed is 400rpm, after dropwise addition is finished, transferring the stirred mixed solution into a stainless steel high-pressure reaction kettle at the temperature of 95 ℃, reacting for 0.5h, naturally cooling after reaction is finished, and stirring at the high speed of 4000rpm in the reaction process to obtain the mixed solution of the palladium quantum dot doped graphene base.

Preparing a palladium quantum dot doped graphene-based electric heating plate: 20g of structure stabilizer, 20g of polyacrylonitrile-maleic anhydride copolymer and 85g of flatting agent are added into the palladium quantum dot doped graphene-based mixed solution while stirring the palladium quantum dot doped graphene-based mixed solution at a high speed of 500rpm, wherein 20g of structure stabilizer comprises 10g of ethylenediamine and 10g of p-methylphenol, the polymerization degree of the polyacrylonitrile-maleic anhydride copolymer is 400, and 85g of flatting agent comprises 60g of polypyrrole and 25g of polyvinyl alcohol. And after the addition is finished, stirring at 2500rpm for 6 hours to prepare the palladium quantum dot doped graphene-based conductive ink, and printing to prepare the palladium quantum dot doped graphene-based electric heating plate.

Example 3

Preparing graphite Oxide allyl ketone dispersion liquid, namely providing 500mg of graphite powder, preparing Graphene Oxide (GO) by adopting a modified Hummers method, further transferring the prepared Graphene Oxide to a high-temperature carbonization furnace for high-temperature carbonization for 60s, filling argon into the high-temperature carbonization furnace, wherein the temperature of the high-temperature carbonization furnace is 1000 ℃, placing the Graphene Oxide after high-temperature expansion in an ice water bath, carrying out ultrasonic treatment for 30 minutes under 250W power by using an ultrasonic dispersion instrument, repeating the ultrasonic treatment once, taking supernatant, centrifuging, and carrying out acetone re-suspension to prepare the graphite Oxide allyl ketone dispersion liquid with the thickness range of 1-8 layers and the transverse dimension of 700-1000 nm, and carrying out centrifugal concentration according to requirements to adjust the concentration of the graphite Oxide allyl ketone dispersion liquid to 100mg/m L.

Preparing a palladium quantum dot doped graphene dispersion liquid: 50ml of the graphite oxide allyl ketone dispersion prepared above was taken, 0.12g of phosphotungstic acid was added thereto, and after stirring at 900rpm for 8 hours, centrifugation was carried out at 12000rpm for 1 hour, and the first precipitate at the bottom of the centrifuge tube was collected and transferred to a 68 ℃ drying oven to be dried for 90 minutes, to obtain a dried first precipitate. And (3) resuspending the first precipitate by using 50ml of acetone, adding 0.1g of palladium acetylacetonate, stirring at 900rpm for 8h again, uniformly mixing, centrifuging at 12000rpm for 1h, collecting a second precipitate at the bottom of a centrifuge tube, transferring to a 68 ℃ drying oven, and drying for 90min to obtain a dried second precipitate. And (4) putting the second precipitate into a quartz tube of a tube furnace, and introducing diluted hydrogen for reduction. The reduction conditions are as follows: the reducing gas is hydrogen/nitrogen mixed gas, wherein the volume percentage of the hydrogen is 10 percent, the flow rate of the mixed gas is 110 ml/min, the reduction reaction temperature is 175 ℃, and the reaction time is 3 h. And (3) resuspending the palladium quantum dot doped graphene by 320ml of ethanol to prepare a palladium quantum dot doped graphene dispersion solution.

Preparing palladium quantum dot doped graphene-carbon black color paste, namely taking 150m L, 0.1Kg of ethyl cellulose, 0.1Kg of hydroxymethyl cellulose and 0.1Kg of cellulose acetate of 8 mol/L sulfuric acid solution, respectively adding the sulfuric acid solution, the ethyl cellulose, the hydroxymethyl cellulose and the cellulose acetate into ethanol, stirring and complementing the ethanol to 3500m L to prepare first dispersing agent, taking 1750m L first dispersing agent and stirring the first dispersing agent, slowly adding 320m L of the prepared palladium quantum dot doped graphene dispersing liquid and 120g of conductive carbon black into the first dispersing agent, and continuously stirring at 100rpm for 60min to obtain the palladium quantum dot doped graphene-carbon black color paste.

And (3) preparing resin slurry, namely taking the remaining 1750m L of first dispersing agent, stirring the first dispersing agent, slowly adding 50g of polydimethylsiloxane resin and 100g of acrylic resin into the first dispersing agent, and continuously stirring at 3500rpm for 100min to obtain the resin slurry.

And (2) preparing a palladium quantum dot doped graphene-based mixed solution, namely respectively slowly dropwise adding the prepared resin slurry, 400m L cyclohexanol and 600m L ethyl acetate into the palladium quantum dot doped graphene-carbon black color paste while stirring, wherein the stirring speed is 300rpm, after dropwise adding is finished, transferring the stirred mixed solution into a stainless steel high-pressure reaction kettle at the temperature of 90 ℃, reacting for 1h, naturally cooling after the reaction is finished, and continuously stirring at the high speed of 3000rpm in the reaction process to obtain the palladium quantum dot doped graphene-based mixed solution.

Preparing a palladium quantum dot doped graphene-based electric heating plate: while stirring the palladium quantum dot doped graphene-based mixed solution at a high speed of 300rpm, 8g of a structural stabilizer, 16g of a polyacrylonitrile-maleic anhydride copolymer and 65g of a leveling agent were added to the palladium quantum dot doped graphene-based mixed solution. Wherein 8g of the structure stabilizer comprises 4g of ethylenediamine and 4g of p-methylphenol, the polymerization degree of the polyacrylonitrile-maleic anhydride copolymer is 100, and 65g of the flatting agent comprises 40g of polypyrrole and 25g of polyethylene glycol. And after the addition is finished, stirring at 3000rpm for 5 hours to prepare the palladium quantum dot doped graphene-based conductive ink, and printing to prepare the palladium quantum dot doped graphene-based electric heating plate.

Example 4

Preparing a Graphene Oxide and allyl ketone dispersion liquid, namely providing 500mg of graphite powder, preparing Graphene Oxide (GO) by adopting a modified Hummers method, further transferring the prepared Graphene Oxide to a high-temperature carbonization furnace for high-temperature carbonization for 60s, filling nitrogen into the high-temperature carbonization furnace, wherein the temperature of the high-temperature carbonization furnace is 900 ℃, in order to further obtain few-layer Graphene Oxide, placing the Graphene Oxide subjected to high-temperature expansion in an ice water bath, carrying out ultrasonic treatment for 20 minutes at 350W power by using an ultrasonic dispersion instrument, collecting the Graphene Oxide, transferring the primarily dispersed Graphene Oxide into a microfluidic reactor, wherein the pressure of a feeding pump of the microfluidic reactor is 100MPa, the strong-pressure shearing time is 15s, collecting the Graphene Oxide, carrying out ultrasonic treatment for 30 minutes at 250W power by using the ultrasonic dispersion instrument again, taking supernatant, centrifuging, and carrying out acetone to prepare the allyl Oxide and allyl ketone dispersion liquid with the thickness range of 1-5 layers and the transverse dimension of 700-1000 nm, and carrying out centrifugal concentration of the allyl ketone dispersion liquid according to requirements so as to adjust the concentration of the Graphene Oxide and the allyl ketone dispersion liquid to L mg/L m.

Preparing a palladium quantum dot doped graphene dispersion liquid: taking 50ml of the graphite oxide allyl ketone dispersion prepared above, adding 0.15g of silicotungstic acid into the dispersion, stirring the mixture at 1000rpm for 6h, centrifuging the mixture at 10000rpm for 2h, collecting a first precipitate at the bottom of a centrifuge tube, transferring the first precipitate to a drying oven at 70 ℃, and drying the first precipitate for 80min to obtain a dried first precipitate. And (3) resuspending the first precipitate by using 50ml of acetone, adding 0.15g of palladium acetylacetonate, stirring at 1000rpm for 6h again, uniformly mixing, centrifuging at 10000rpm for 2h, collecting a second precipitate at the bottom of a centrifuge tube, transferring to a 70 ℃ drying oven, and drying for 80min to obtain a dried second precipitate. And (4) putting the second precipitate into a quartz tube of a tube furnace, and introducing diluted hydrogen for reduction. The reduction conditions are as follows: the reducing gas is hydrogen/argon gas mixture, wherein the volume percentage of the hydrogen is 12 percent, the flow rate of the gas mixture is 100 ml/min, the reduction reaction temperature is 180 ℃, and the reaction time is 2.5 h. And resuspending the palladium quantum dot doped graphene by 300ml of ethanol to prepare a palladium quantum dot doped graphene dispersion solution.

Preparing palladium quantum dot doped graphene-carbon black color paste, namely taking 100m L mol/L hydrochloric acid solution, 0.1Kg of hydroxymethyl cellulose and 0.1Kg of cellulose nitrate, respectively adding the hydrochloric acid solution, the hydroxymethyl cellulose and the cellulose nitrate into ethanol, stirring while complementing the ethanol to 3000m L to obtain first dispersing agent, taking 1500m L first dispersing agent and stirring the first dispersing agent, slowly adding 300m L of the prepared palladium quantum dot doped graphene dispersing liquid and 120g of conductive carbon black into the first dispersing agent, and continuously stirring at 3000rpm for 30min to obtain the palladium quantum dot doped graphene-carbon black color paste.

And (3) preparing resin slurry, namely taking the rest 1500m L first dispersing agent and stirring the first dispersing agent, slowly adding 60g of polycarbonate resin, 30g of polyurethane resin and 30g of epoxy resin into the first dispersing agent, and continuously stirring at 3000rpm for 120min to obtain the resin slurry.

And (2) preparing a palladium quantum dot doped graphene-based mixed solution, namely respectively slowly dropwise adding the prepared resin slurry, 800m L ethanol and 400m L terpineol into the palladium quantum dot doped graphene-carbon black color paste while stirring, wherein the stirring speed is 250rpm, after dropwise adding is finished, the mixed solution is transferred into a microwave digestion instrument to be subjected to microwave digestion for 15min, the microwave digestion temperature is 65 ℃, the power is 280W, the mixed solution subjected to microwave digestion is transferred into a stainless steel high-pressure reaction kettle at 85 ℃, the reaction is carried out for 1h, the mixed solution is naturally cooled after the reaction is finished, and the high-speed stirring at 250rpm is continued in the reaction process, so that the palladium quantum dot doped graphene-based mixed solution is prepared.

Preparing a palladium quantum dot doped graphene-based electric heating plate: while stirring the palladium quantum dot doped graphene-based mixed solution at a high speed of 300rpm, 12g of a structural stabilizer, 13g of a polyacrylonitrile-maleic anhydride copolymer and 75g of a leveling agent were added to the palladium quantum dot doped graphene-based mixed solution. Wherein, 12g of the structure stabilizer comprises 5g of ethylenediamine and 7g of p-methylphenol, the polymerization degree of the polyacrylonitrile-maleic anhydride copolymer is 150, and 75g of the flatting agent comprises 60g of polypyrrole and 15g of polyvinyl alcohol. And after the addition is finished, stirring at 3500rpm for 4 hours to prepare the palladium quantum dot doped graphene-based conductive ink, and printing to prepare the palladium quantum dot doped graphene-based electric heating plate.

Example 5

Preparing a Graphene Oxide and allyl ketone dispersion liquid, namely providing 500mg of graphite powder, preparing Graphene Oxide (GO) by adopting a modified Hummers method, further transferring the prepared Graphene Oxide to a high-temperature carbonization furnace for high-temperature carbonization for 90s, filling nitrogen into the high-temperature carbonization furnace, wherein the temperature of the high-temperature carbonization furnace is 700 ℃, in order to further obtain few-layer Graphene Oxide, placing the Graphene Oxide subjected to high-temperature expansion in an ice water bath, carrying out ultrasonic treatment for 20 minutes at 350W power by using an ultrasonic dispersion instrument, collecting the Graphene Oxide, transferring the primarily dispersed Graphene Oxide into a microfluidic reactor, wherein the pressure of a feeding pump of the microfluidic reactor is 100MPa, the strong-pressure shearing time is 15s, collecting the Graphene Oxide, carrying out ultrasonic treatment for 20 minutes at 250W power by using the ultrasonic dispersion instrument, taking supernate, centrifuging, and acetone to prepare the allyl ketone Oxide dispersion liquid with the thickness range of 1-5 layers and the transverse dimension of 700-1000 nm, and concentrating according to centrifugal requirements to adjust the concentration of the Graphene Oxide and the allyl ketone dispersion liquid to be 50 mg/L heavy suspension.

Preparing a palladium quantum dot doped graphene dispersion liquid: 50ml of the graphite allyl ketone oxide dispersion prepared above was taken, 0.18g of phosphomolybdic acid was added thereto, and after stirring at 1200rpm for 5 hours, centrifugation was carried out at 9000rpm for 2.5 hours, and the first precipitate at the bottom of the centrifuge tube was collected and transferred to a 72 ℃ drying oven to be dried for 60 minutes, to obtain a dried first precipitate. And (3) resuspending the first precipitate by using 50ml of acetone, adding 0.2g of palladium acetylacetonate, stirring at 1200rpm for 5h again, uniformly mixing, centrifuging at 9000rpm for 2.5h, collecting a second precipitate at the bottom of a centrifuge tube, transferring to a 72 ℃ drying oven, and drying for 60min to obtain a dried second precipitate. And (4) putting the second precipitate into a quartz tube of a tube furnace, and introducing diluted hydrogen for reduction. The reduction conditions are as follows: the reducing gas is hydrogen/nitrogen mixed gas, wherein the volume percentage of the hydrogen is 15 percent, the flow rate of the mixed gas is 80 ml/min, the reduction reaction temperature is 188 ℃, and the reaction time is 2 h. 250ml of ethanol is used for resuspending the palladium quantum dot doped graphene to prepare the palladium quantum dot doped graphene dispersion liquid.

Preparing palladium quantum dot doped graphene-carbon black color paste, namely taking 300m L of 4 mol/L sulfuric acid solution and 0.5Kg of ethyl cellulose, respectively adding the sulfuric acid solution and the ethyl cellulose into ethanol, adding the ethanol to 2500m L while stirring to obtain first dispersing agent, taking 1250m L first dispersing agent and stirring the first dispersing agent, slowly adding 250m L of the prepared palladium quantum dot doped graphene dispersing liquid and 150g of conductive carbon black into the first dispersing agent, and continuously stirring at 2000rpm for 45min to obtain the palladium quantum dot doped graphene-carbon black color paste.

And (3) preparing resin slurry, namely taking the rest 1250m L first dispersing agent and stirring the first dispersing agent, slowly adding 60g of acrylic resin and 20g of waterborne alkyd resin into the first dispersing agent, and continuously stirring at 2500rpm for 200min to obtain the palladium quantum dot slurry.

And (2) preparing a palladium quantum dot doped graphene-based mixed solution, namely, respectively slowly dropwise adding the prepared resin slurry, 600m L ethylene glycol and 900m L isopropanol into the palladium quantum dot doped graphene-carbon black color paste while stirring, wherein the stirring speed is 200rpm, after dropwise adding is finished, the mixed solution is transferred into a microwave digestion instrument to be subjected to microwave digestion for 5min, the microwave digestion temperature is 70 ℃, the power is 330W, the mixed solution subjected to microwave digestion is transferred into a stainless steel high-pressure reaction kettle at 80 ℃, the reaction is carried out for 1h, the mixed solution is naturally cooled after the reaction is finished, and the high-speed stirring is carried out at 200rpm in the reaction process, so that the palladium quantum dot doped graphene-based mixed solution is prepared.

Preparing a palladium quantum dot doped graphene-based electric heating plate: while stirring the palladium quantum dot doped graphene-based mixed solution at a high speed of 300rpm, adding 15g of a structural stabilizer, 10g of a polyacrylonitrile-maleic anhydride copolymer and 90g of a leveling agent into the palladium quantum dot doped graphene-based mixed solution, wherein the 15g of the structural stabilizer comprises 6g of ethylenediamine and 9g of p-methylphenol, the polymerization degree of the polyacrylonitrile-maleic anhydride copolymer is 200, and the 90g of the leveling agent comprises 80g of polypyrrole and 10g of polyethylene glycol. And after the addition is finished, stirring at 4000rpm for 3 hours to prepare the palladium quantum dot doped graphene-based conductive ink, and printing to prepare the palladium quantum dot doped graphene-based electric heating plate.

Example 6

Preparing a Graphene Oxide and allyl ketone dispersion liquid, namely providing 500mg of graphite powder, preparing Graphene Oxide (GO) by adopting a modified Hummers method, further transferring the prepared Graphene Oxide to a high-temperature carbonization furnace for high-temperature carbonization for 90s, filling nitrogen into the high-temperature carbonization furnace, wherein the temperature of the high-temperature carbonization furnace is 500 ℃, in order to further obtain few-layer Graphene Oxide, placing the Graphene Oxide subjected to high-temperature expansion in an ice water bath, carrying out ultrasonic treatment for 20 minutes at 350W power by using an ultrasonic dispersion instrument, collecting the Graphene Oxide, transferring the primarily dispersed Graphene Oxide into a microfluidic reactor, wherein the pressure of a feeding pump of the microfluidic reactor is 100MPa, the strong-pressure shearing time is 15s, collecting the Graphene Oxide, carrying out ultrasonic treatment for 20 minutes at 250W power by using the ultrasonic dispersion instrument, taking supernate, centrifuging, and acetone to prepare the allyl ketone Oxide dispersion liquid with the thickness range of 1-5 layers and the transverse dimension of 700-1000 nm, and concentrating according to the centrifugal requirement to adjust the concentration of the allyl ketone Oxide dispersion liquid to be L mg/m.

Preparing a palladium quantum dot doped graphene dispersion liquid: 50ml of the graphite allyl ketone oxide dispersion prepared above was taken, 0.2g of phosphomolybdic acid was added thereto, and after stirring at 1300rpm for 4 hours, centrifugation was carried out at 8500rpm for 3 hours, and the first precipitate at the bottom of the centrifuge tube was collected and transferred to a 78 ℃ drying oven to be dried for 45 minutes, to obtain a dried first precipitate. And (3) resuspending the first precipitate by using 50ml of acetone, adding 0.225g of palladium acetylacetonate, stirring at 1300rpm for 4h again, uniformly mixing, centrifuging at 8500rpm for 3h, collecting a second precipitate at the bottom of a centrifuge tube, transferring to a 78 ℃ drying oven, and drying for 45min to obtain a dried second precipitate. And (4) putting the second precipitate into a quartz tube of a tube furnace, and introducing diluted hydrogen for reduction. The reduction conditions are as follows: the reducing gas is a hydrogen/argon gas mixture, wherein the volume percentage of the hydrogen is 17 percent, the flow rate of the gas mixture is 50 ml/min, the reduction reaction temperature is 195 ℃, and the reaction time is 1.5 h. And re-suspending the palladium quantum dot doped graphene by 360ml of ethanol to prepare a palladium quantum dot doped graphene dispersion solution.

Preparing palladium quantum dot doped graphene-carbon black color paste, namely taking 5 mol/L hydrochloric acid solution 200m L, 0.1Kg of methyl cellulose and 0.05Kg of ethyl cellulose, respectively adding the hydrochloric acid solution, the methyl cellulose and the ethyl cellulose into ethanol, and complementing the ethanol to 2000m L while stirring to prepare first dispersing agent, taking 1000m L first dispersing agent and stirring the first dispersing agent, slowly adding 360m L of the prepared palladium quantum dot doped graphene dispersing liquid and 200g of conductive carbon black into the first dispersing agent, and continuously stirring at 4000rpm for 15min to obtain the palladium quantum dot doped graphene-carbon black color paste.

And (3) preparing resin slurry, namely taking the residual 1000m L first dispersing agent and stirring the first dispersing agent, adding 25g of phenolic resin and 40g of silicone-acrylate resin into the first dispersing agent slowly in half, and stirring at 2000rpm for 250min to obtain the resin slurry.

And (2) preparing a mixed solution of the palladium quantum dot doped graphene base, namely respectively slowly dropwise adding the prepared resin slurry and 1800m L isopropanol into the palladium quantum dot doped graphene-carbon black color paste while stirring, wherein the stirring speed is 150rpm, after dropwise adding is finished, transferring the stirred mixed solution into a 75-DEG C stainless steel high-pressure reaction kettle, reacting for 1.5h, naturally cooling after the reaction is finished, and continuously stirring at a high speed of 150rpm in the reaction process to obtain the mixed solution of the palladium quantum dot doped graphene base.

Preparing a palladium quantum dot doped graphene-based electric heating plate: 10g of structure stabilizer, 15g of polyacrylonitrile-maleic anhydride copolymer and 80g of flatting agent are added into the palladium quantum dot doped graphene-based mixed solution while the palladium quantum dot doped graphene-based mixed solution is stirred at a high speed of 200 rpm. Wherein, 10g of the structure stabilizer comprises 5g of ethylenediamine and 5g of p-methylphenol, the polymerization degree of the polyacrylonitrile-maleic anhydride copolymer is 300, and 80g of the flatting agent comprises 60g of polypyrrole and 20g of polyvinyl alcohol. And after the addition is finished, stirring at 4500rpm for 2 hours to prepare the palladium quantum dot doped graphene-based conductive ink, and printing to prepare the palladium quantum dot doped graphene-based electric heating plate.

Example 7

Preparing graphite Oxide allyl ketone dispersion liquid, namely providing 500mg of graphite powder, and preparing Graphene Oxide (GO) by adopting a modified Hummers method, in order to further obtain few-layer Graphene Oxide, placing the Graphene Oxide in an ice water bath, performing ultrasonic treatment for 10 minutes at 350W power by using an ultrasonic dispersion instrument, repeating the operation once, taking supernate, centrifuging and re-suspending acetone to prepare the graphite Oxide allyl ketone dispersion liquid with the thickness of 2-20 layers and the transverse dimension of 700-1000 nm, and performing centrifugal concentration according to requirements to adjust the concentration of the graphite Oxide allyl ketone dispersion liquid to 5mg/m L.

Preparing a palladium quantum dot doped graphene dispersion liquid: 50ml of the graphite allyl ketone oxide dispersion prepared above was taken, 0.25g of phosphomolybdic acid was added thereto, and after stirring at 1400rpm for 2 hours, the mixture was centrifuged at 8000rpm for 4 hours, and the first precipitate at the bottom of the centrifuge tube was collected and transferred to a 80 ℃ drying oven to be dried for 30 minutes, to obtain a dried first precipitate. And (3) resuspending the first precipitate by using 50ml of acetone, adding 0.25g of palladium acetylacetonate, stirring again at 1400rpm for 2h, uniformly mixing, centrifuging at 8000rpm for 4h, collecting a second precipitate at the bottom of a centrifuge tube, transferring to a drying oven at 80 ℃ and drying for 30min to obtain a dried second precipitate. And (4) putting the second precipitate into a quartz tube of a tube furnace, and introducing diluted hydrogen for reduction. The reduction conditions are as follows: the reducing gas is a hydrogen/nitrogen mixed gas, wherein the volume percentage of the hydrogen is 20 percent, the flow rate of the mixed gas is 30 ml/min, the reduction reaction temperature is 200 ℃, and the reaction time is 1 h. And 150ml of ethanol is used for resuspending the palladium quantum dot doped graphene to prepare the palladium quantum dot doped graphene dispersion liquid.

Preparing palladium quantum dot doped graphene-carbon black color paste, namely taking 1 mol/L sulfuric acid solution 180m L and 0.2Kg of cellulose acetate, respectively adding the sulfuric acid solution and the cellulose acetate into ethanol, stirring and complementing the ethanol to 1000m L to obtain a first dispersing agent, taking 500m L of the first dispersing agent and stirring the first dispersing agent, slowly adding 150m L of the prepared palladium quantum dot doped graphene dispersing solution and 250g of conductive carbon black into the first dispersing agent, and continuously stirring at 5000rpm for 10min to obtain the palladium quantum dot doped graphene-carbon black color paste.

And (3) preparing resin slurry, namely taking the residual 500m L first dispersing agent and stirring the first dispersing agent, slowly adding 30g of epoxy resin and 20g of waterborne alkyd resin into the first dispersing agent, and continuously stirring at 500rpm for 300min to obtain the resin slurry.

And (2) preparing a mixed solution of the palladium quantum dot doped graphene base, namely respectively slowly dropwise adding the prepared resin slurry and 500m L ethyl acetate into the palladium quantum dot doped graphene-carbon black color paste while stirring, wherein the stirring speed is 100rpm, after dropwise adding is finished, transferring the stirred mixed solution into a stainless steel high-pressure reaction kettle at the temperature of 70 ℃, reacting for 2 hours, naturally cooling after the reaction is finished, and continuously stirring at the high speed of 100rpm in the reaction process to prepare the mixed solution of the palladium quantum dot doped graphene base.

Preparing a palladium quantum dot doped graphene-based electric heating plate: while stirring the palladium quantum dot doped graphene-based mixed solution at a high speed of 200rpm, 5g of a structural stabilizer, 5g of a polyacrylonitrile-maleic anhydride copolymer and 50g of a leveling agent were added to the palladium quantum dot doped graphene-based mixed solution. Wherein, 5g of the structure stabilizer comprises 2g of ethylenediamine and 3g of p-methylphenol, the polymerization degree of the polyacrylonitrile-maleic anhydride copolymer is 500, and 50g of the flatting agent comprises 29g of polypyrrole and 21g of polyvinyl alcohol. And after the addition is finished, stirring at 5000rpm for 1h to prepare the palladium quantum dot doped graphene-based conductive ink, and printing to prepare the palladium quantum dot doped graphene-based electric heating plate.

Comparative example 1

Preparation of graphite oxide allyl ketone Dispersion A graphite oxide allyl ketone dispersion was prepared at a concentration of 80mg/m L with reference to example 4.

Preparing a palladium quantum dot doped graphene dispersion liquid: a palladium quantum dot-doped graphene dispersion was prepared with reference to example 4.

Preparing palladium quantum dot doped graphene-carbon black color paste: and preparing palladium quantum dot doped graphene-carbon black color paste according to example 4.

Preparing resin slurry: resin syrup was prepared with reference to example 4.

And (2) preparing a palladium quantum dot doped graphene-based mixed solution, namely respectively slowly dropwise adding the prepared resin slurry, 800m L ethanol and 400m L terpineol into the palladium quantum dot doped graphene-carbon black color paste while stirring, wherein the stirring speed is 250rpm, after dropwise adding is finished, the mixed solution is transferred into a microwave digestion instrument to be subjected to microwave digestion for 15min, the microwave digestion temperature is 65 ℃, and the power is 280 W.250rpm and continuously stirred for 1h to prepare the palladium quantum dot doped graphene-based mixed solution.

Comparative example 2

Preparing palladium quantum dot doped graphene-carbon black color paste, namely taking 0.1Kg of hydroxymethyl cellulose and 0.1Kg of cellulose nitrate, respectively adding the hydroxymethyl cellulose and the cellulose nitrate into ethanol, stirring and complementing the ethanol to 3000m L to obtain a first dispersing agent, taking 1500m L of the first dispersing agent, stirring the first dispersing agent, slowly adding 300m L of the prepared palladium quantum dot doped graphene dispersion liquid and 120g of conductive carbon black into the first dispersing agent, and continuously stirring at 3000rpm for 30min to obtain the palladium quantum dot doped graphene-carbon black color paste.

And (2) preparing a palladium quantum dot doped graphene base mixed solution, namely respectively slowly dropwise adding the prepared palladium quantum dot slurry, 800m L ethanol and 400m L terpineol into the palladium quantum dot doped graphene-carbon black color paste while stirring, wherein the stirring speed is 250rpm, after dropwise adding is finished, the mixed solution is transferred into a microwave digestion instrument for microwave digestion for 15min, the microwave digestion temperature is 65 ℃, the power is 280W, the mixed solution subjected to microwave digestion is transferred into a stainless steel high-pressure reaction kettle at 85 ℃, the reaction is carried out for 1h, the mixed solution is naturally cooled after the reaction is finished, and the high-speed stirring is carried out at the speed of 250rpm in the reaction process, so that the palladium quantum dot doped graphene base mixed solution is prepared.

Comparative example 3

Preparing resin slurry: resin syrup was prepared with reference to example 4.

Preparing a mixed solution of palladium quantum dots and graphene doped: a mixed solution of palladium quantum dots doped with graphene was prepared with reference to example 4.

Preparing a palladium quantum dot doped graphene-based electric heating plate: 13g of polyacrylonitrile-maleic anhydride copolymer and 75g of leveling agent are added into the palladium quantum dot doped graphene-based mixed solution while stirring the palladium quantum dot doped graphene-based mixed solution at a high speed of 300 rpm. Wherein the polymerization degree of the polyacrylonitrile-maleic anhydride copolymer is 150, and 75g of the flatting agent comprises 60g of polypyrrole and 15g of polyvinyl alcohol. And after the addition is finished, stirring at 3500rpm for 4 hours to prepare the palladium quantum dot doped graphene-based conductive ink, and printing to prepare the palladium quantum dot doped graphene-based electric heating plate.

Effect embodiment:

(1) adhesion Performance test

Respectively blade-coating the palladium quantum dot doped graphene-based conductive inks prepared in examples 1 to 7 and comparative examples 1 to 3 on an aluminum foil, a PE plate and a ceramic plate, wherein the aluminum foil plate is transferred to an air-blast drying oven at 80 ℃ to be dried for 1h to obtain a graphene conductive film; transferring the PE plate to a 70 ℃ forced air drying oven to be dried for 1h to obtain a graphene conductive film; and (5) transferring the ceramic plate to a 70 ℃ forced air drying oven for drying for 1h to obtain the graphene conductive film. Hardness was tested according to the national standard GB/T6739-1996 using a Chinese pencil, and the results are shown in Table 1. According to the national standard GB/T13217.4-2008, the adhesive force is tested by using the 3M special adhesive tape, and the test result is shown in Table 1.

TABLE 1

As can be seen from the results in table 1, the graphene conductive ink films formed by respectively blade-coating the palladium quantum dot doped graphene-based conductive inks prepared in examples 1 to 7 have good adhesion to aluminum foils, PE plates, and ceramic plates, which indicates that the palladium quantum dot doped graphene-based conductive ink prepared according to the present invention can be applied to the preparation of external heating wall paintings, wallpaper, or floors, and is disposed on a heating substrate by blade coating, spin coating, direct writing, screen printing, silk printing, inkjet printing, or electrostatic spinning, and the graphene conductive ink film (graphene conductive film) can be obtained after curing, and the heating substrate can include a common metal substrate, and can also be directly printed on a polymer substrate or a ceramic material, and has a wide application range. The palladium quantum dot doped graphene-based conductive inks prepared in comparative examples 1 to 3 had poor adhesion to aluminum foils, PE plates, and ceramic plates, compared to the palladium quantum dot doped graphene-based conductive inks prepared in examples 1 to 7. Compared with the palladium quantum dot doped graphene-based conductive ink corresponding to the comparative example 1, the prepared graphene oxide is not sufficiently doped with the palladium quantum dot, and meanwhile, an active group of the graphene oxide exposed on the surface is not reacted with resin, so that the prepared ink film has poor adhesion effect with a metal substrate, a PE substrate and ceramic. In comparative example 2, a strong acid solution having a catalytic effect is not added, and active groups of graphene oxide exposed on the surface do not sufficiently react with the resin, so that the prepared ink film has a poor adhesion effect with a metal substrate, a PE substrate, and ceramics. In comparative example 3, no structural stabilizer was added, and graphene oxide in the prepared palladium quantum dot doped graphene-based conductive ink was not reduced and was in an unstable state, which also affected the adhesion effect of the ink film to the metal substrate, the PE substrate, and the ceramic.

The graphene conductive ink films formed by the palladium quantum dot doped graphene-based conductive inks prepared in examples 1 to 7 and comparative example 3 have strong hardness, while the graphene conductive ink films formed by the palladium quantum dot doped graphene-based conductive inks in comparative example 1 and comparative example 2 have low hardness, which may be related to that the active groups exposed on the surface of graphene oxide do not react with the resin or do not react sufficiently.

(2) High temperature resistance test and service life test

The palladium quantum dot doped graphene-based conductive ink prepared in examples 1 to 7 and comparative examples 1 to 3 was printed on a PI plate by a relief printing technique, and the printed PI plate was transferred to a forced air drying oven at 80 ℃ to be dried and cured for 4 hours, thereby finally obtaining a graphene conductive ink film with a thickness of 10 μm.

The graphene conductive ink film with the length and the width of 10cm is cut by a blade to carry out an initial sheet resistance test, and the test result is shown in table 2. And cutting the graphene conductive ink film printed on the PI plate into graphene conductive ink films with the length and the width of 10cm by adopting a blade, cutting three films corresponding to each embodiment, and dividing the films into A, B, C groups for carrying out a high temperature resistance test. The experimental method is as follows: placing the graphene conductive ink film of the group A in an oven at 100 ℃, and measuring the square resistance value every other day; placing the graphene conductive ink film of the group B in an oven at 200 ℃, and measuring the square resistance value every other day; the graphene conductive ink film of group C was placed in an oven at 300 ℃, and the square resistance was measured every other day, the measurement results are shown in table 2.

TABLE 2

From the results in table 2, it can be seen that the graphene conductive ink films corresponding to examples 1 to 7 are generally relatively high temperature resistant, and the sheet resistance of the graphene conductive ink films after long-time high-temperature treatment is not greatly changed, wherein the sheet resistance of the graphene conductive ink films corresponding to examples 1 to 7 is less than 300, and the graphene conductive ink films can be used as a heating layer of a high-power electrothermal device. In contrast, the sheet resistance of the graphene conductive ink film prepared in the comparative examples 1 to 3 is obviously changed, and the reason for the change is probably related to the instability of the palladium quantum dot doped graphene conductive ink prepared in the comparative examples 1 to 3, especially the instability of the graphene oxide structure, and as a result, the graphene conductive ink film is rapidly aged under a high temperature condition, and the service life is greatly shortened.

The graphene conductive ink film with the length and width of 1m is cut by a blade to perform an initial sheet resistance test, and the test results are shown in table 3. Inserting metal electrodes into opposite corners of two ends of the cut graphene conductive ink film respectively and connecting the metal electrodes into commercial power to test the service life, wherein the test method comprises the following steps: and continuously electrifying the graphene conductive ink film to generate heat, and testing the square resistance value of the graphene conductive ink film every other week (W).

TABLE 3

From the results in table 3, it is clear that the graphene conductive ink films according to examples 1 to 7 do not change much in the overall sheet resistance value after being continuously electrified for 5W to generate heat, and thus can be used for the heat generating layer of the electric heating device which is heated for a long time. The larger the change in sheet resistance of the graphene conductive ink films corresponding to comparative examples 1-3 may be related to the instability of the graphene oxide structure and the overall ink mixing system therein.

(3) Test of anti-aging Performance

The graphene conductive ink film with the length and the width of 1m is cut by a blade to carry out an anti-aging performance test, and the test results are shown in table 4. And inserting metal electrodes into opposite corners of two ends of the cut graphene conductive ink film respectively and connecting the metal electrodes to mains supply to perform continuous heat production. Firstly, testing the initial heat generation power of the graphene conductive ink film by using instruments such as an ammeter and the like, continuously working for 300 hours, testing the heat generation power of the graphene conductive ink film by using instruments such as an ammeter and the like, and calculating the heat generation power attenuation rate of the graphene conductive ink film, wherein the results are shown in table 4.

After the continuous operation for 300h, as shown in fig. 5, 9 temperature sensors are sequentially arranged on the PI plate to measure the temperature of each position of the graphene conductive ink film, and the difference between the maximum value and the minimum value of the 9 temperature sensors is selected to be recorded as the temperature nonuniformity of the graphene conductive ink film.

TABLE 4

From the results in table 4, it can be seen that the power attenuation rate and the temperature non-uniformity of the graphene conductive ink thin films corresponding to examples 1 to 7 are not large, which indicates that the graphene conductive ink thin film prepared by the present invention can be used for long-term heat generation, and the variation of the heat generation power and the heat generation non-uniformity in the production period is not large. In contrast, the graphene conductive ink thin films corresponding to comparative examples 1 to 3 have large power attenuation rates and temperature non-uniformity, and are not suitable for long-term heat generation of the heat-generating conductive film, which may be related to the unstable structure of graphene oxide.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A palladium quantum dot doped graphene-based electric heating plate is characterized by comprising an insulating layer and a graphene conducting film arranged on the insulating layer;

2. The palladium quantum dot-doped graphene-based electrical heating plate according to claim 1, wherein in the step of preparing the graphene oxide allyl ketone dispersion liquid, the prepared graphene oxide is transferred to a high temperature carbonization furnace to be carbonized at a high temperature for 30 to 90 seconds, the high temperature carbonization furnace is filled with an inert gas, the temperature of the high temperature carbonization furnace is 500 to 1200 ℃, and the graphene oxide expanded at a high temperature is prepared into the graphene oxide allyl ketone dispersion liquid with a concentration of 5 to 150mg/m L.

3. The palladium quantum dot doped graphene-based electrical heating plate of claim 1, wherein in the step of preparing the palladium quantum dot doped graphene dispersion, a heteropoly acid is added to the graphite oxide allyl ketone dispersion, and the mass-to-volume ratio of the heteropoly acid to the graphite oxide allyl ketone dispersion is 1-5: 1000;

4. The palladium quantum dot doped graphene-based electric heating plate according to claim 1, wherein in the step of preparing the palladium quantum dot doped graphene dispersion solution, the first precipitate is resuspended with acetone and palladium acetylacetonate is added, and the mass ratio of the first precipitate to the palladium acetylacetonate is 1000: 0.5-5;

5. The palladium quantum dot doped graphene-based electric heating plate according to claim 1, wherein in the step of preparing the palladium quantum dot doped graphene dispersion liquid, the second precipitate is transferred to a quartz tube of a tube furnace, and a reducing gas is introduced for reduction, wherein the reducing gas is a hydrogen/nitrogen mixed gas or a hydrogen/argon mixed gas;

6. The palladium quantum dot doped graphene-based electric heating plate according to claim 1, wherein in the step of preparing the palladium quantum dot doped graphene dispersion liquid, ethanol is resuspended to prepare 5-150 mg/m L of the palladium quantum dot doped graphene dispersion liquid;

the strong acid solution is hydrochloric acid solution or sulfuric acid solution, and the cellulose derivative is one or more of methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, cellulose acetate and cellulose nitrate.

7. The palladium quantum dot doped graphene-based electric heating plate according to claim 1, wherein in the step of preparing a resin slurry, the release resin is one or a combination of more of epoxy resin, polydimethylsiloxane resin, polycarbonate resin, polyurethane resin, acrylic resin, waterborne alkyd resin, phenolic resin, and silicone-acrylic resin;

8. The palladium quantum dot doped graphene-based electric heating plate according to claim 1, wherein in the step of preparing the palladium quantum dot doped graphene-based conductive ink, the leveling agent comprises polypyrrole, and the leveling agent further comprises polyvinyl alcohol or polyethylene glycol, wherein the mass ratio of the polypyrrole to the polyvinyl alcohol or polyethylene glycol is 8: 1-5;

9. An electric heating device, which is characterized by comprising a groove base, an upper cover and the palladium quantum dot doped graphene-based electric heating plate as recited in any one of claims 1 to 8, wherein the upper cover covers the groove base and is used for enclosing an accommodating cavity, and the palladium quantum dot doped graphene-based electric heating plate is accommodated in the accommodating cavity;

10. The electric heating device as claimed in claim 9, wherein the inner wall of the groove base is provided with a heat reflecting layer, the upper cover comprises an insulating heat-conducting layer and an anti-slip layer arranged on the insulating heat-conducting layer, and when the upper cover is covered on the groove base, the insulating heat-conducting layer faces the groove base;