CN110602812A - Novel degradable film heater and preparation method thereof - Google Patents

Abstract

The invention discloses a degradable film heater and a preparation method thereof, which adopts paper as a substrate, greatly reduces the manufacturing cost, and ensures that the film heater has excellent degradable characteristic and is easy to treat and recycle. The ignition point of the common paper is about 130 ℃ to 180 ℃, the safe temperature range can meet the requirements of most application fields, and the common paper is particularly suitable for disposable use in the medical field. Compared with the traditional process, the degradable film heater prepared by the invention greatly improves the fit degree of the film and the human body, simplifies the processing flow, reduces the cost and is beneficial to the application on the human body.

Description

A novel degradable film heater and its preparation method

technical field

The invention belongs to the field of degradable film heaters, and in particular relates to a degradable film heater based on a silver nanowire conductive network and a preparation method thereof.

Background technique

Due to its good electric heating performance, thin film heaters have great application potential in medical equipment, intelligent defrosting devices, thermal displays, etc.

The thin film heater consists of two parts: a resistive layer and a flexible substrate. From the perspective of the materials used in the resistance layer, the metal nanowires have the good resistance properties and good flexibility properties required by the electrodes. Among them, silver nanowires have become an ideal material for making flexible heaters due to their good stability and relatively cheap price. From the perspective of substrate materials, traditional film heaters use polydimethylsiloxane (PDMS), polyethylene terephthalate (PET), and copolyester (Ecoflex) plastic substrates. Difficult to handle, difficult to degrade, causing environmental pollution.

Contents of the invention

The invention provides a degradable thin film heater and a preparation method thereof, which solves the problem that the traditional thin film heater in the prior art uses a plastic substrate which is not easy to handle, not easy to degrade, and causes environmental pollution.

Technical scheme of the present invention is:

A novel degradable film heater is prepared by the following method:

(1) prepare the silver nanowire solution used in the experiment;

(2) prepare thin film heater;

(a). Paste the paper on the glass slide, and drip-coat the silver nanowire solution;

(b). Put the glass slide on the glue homogenizer, set the speed and time of the glue homogenizer, then take out the slide glass, so that the silver nanowires are evenly dispersed on the paper;

(c). Use copper foil paper to lead out the electrodes at both ends of the paper and fix them;

(d). Drop-coat PVA solution on the silver nanowire conductive paper with electrodes obtained in (c); the PVA solution is purchased from the market or made by yourself.

(e). Put it on the glue homogenizer, set the speed and time of the glue homogenizer, and spread the PVA evenly on the paper to protect the silver nanowire layer on the paper;

(3) By changing the amount of silver nanowires drip-coated on the paper, the resistance of the film heater can be changed, so as to obtain different resistance resistances from 3Ω/sq to 450Ω/sq, and test the heating of different sizes of resistances under different conditions performance.

The preparation method of described step (1) silver nanowire solution is:

(a). Add PVP to ethylene glycol, the mass ratio of PVP to ethylene glycol is 1:500～1:50;

(b). Magnetically stir the solution obtained in (a) at 50-150° C. at 100-5000 rpm for 0.1-10 hours to completely dissolve PVP in ethylene glycol;

(c). Add silver nitrate to the PVP/ethylene glycol solution, dissolve completely, then add FeCl ₃ solution and stir for 1-10 minutes; the mass ratio of silver nitrate to PVP is 1:10-2:1; FeCl ₃ and PVP The mass ratio is 1:1～30:1;

(d). Transfer the mixed solution obtained in (c) to a hydrothermal synthesis reaction kettle, place it in a hot blast circulation drying oven and react at 120-160° C. for 1-10 hours;

(e). After the suspension in (d) is cooled, centrifuge with a centrifuge, and finally purify with absolute ethanol;

(f). Dispersing the purified silver nanowires in absolute ethanol.

The speed of the homogenizer in the step (2)(b) is 300-4000 rpm, and the time is 5-60 seconds.

In the step (2) (e), the homogenizer first rotates at a rotational speed of 300-3000 rpm for 2-60 seconds, and then rotates at a rotational speed of 500-5000 rpm for 5-60 seconds.

A preparation method of a novel degradable film heater, comprising the following steps:

(1) prepare the silver nanowire solution used in the experiment;

(2) prepare thin film heater;

(a) paste the paper on the glass slide, and drip-coat the silver nanowire solution;

(b) Put the glass slide on the glue homogenizer, set the speed and time of the glue homogenizer, then remove the slide glass, so that the silver nanowires are evenly dispersed on the paper;

(c) Use copper foil paper to lead out the electrodes at both ends of the paper and fix them;

(a). (d) The PVA solution is drip-coated on the silver nanowire conductive paper with electrodes obtained in (c); the PVP solution is purchased from the market or made by oneself.

(e) be placed on the homogenizer, set the speed and time of the homogenizer, PVA is more evenly spread on the paper, to protect the silver nanowire layer on the paper;

(3) By changing the amount of silver nanowires drip-coated on the paper, the resistance of the film heater can be changed, thereby obtaining different resistances of 3Ω/sq to 450Ωsq, and testing the heating performance of different sizes of resistances under different conditions.

The preparation method of above-mentioned steps (1) silver nanowire solution is:

(a) Add PVP to ethylene glycol, the mass ratio of PVP to ethylene glycol is 1:500～1:50;

(b) magnetically stir the solution obtained in (a) at 50-150° C. at 100-5000 rpm for 0.1-10 hours, so that the PVP is completely dissolved in ethylene glycol;

(c) Add silver nitrate to the PVP/ethylene glycol solution, dissolve completely, then add FeCl ₃ solution and stir for 1 to 10 minutes; the mass ratio of silver nitrate to PVP is 1:10 to 2:1; the ratio of FeCl ₃ to PVP The mass ratio is 1:1～30:1;

(d) Transfer the mixed solution obtained in (c) to a hydrothermal synthesis reaction kettle, place it in a hot blast circulation drying oven and react at 120-160° C. for 1-10 hours;

(e) After the suspension in (d) is cooled, centrifuge with a centrifuge, and finally purify with absolute ethanol;

(f) Dispersing the purified silver nanowires in absolute ethanol.

The speed of the homogenizer in the above step (2)(b) is 300-4000 rpm, and the time is 5-60 seconds.

In the above step (2) (e), the homogenizer first rotates at a rotational speed of 300-3000 rpm for 2-60 seconds, and then rotates at a rotational speed of 500-5000 rpm for 5-60 seconds.

The beneficial effects of the present invention are:

1. The present invention can change the resistance of the film by changing the amount of silver nanowires dripped, and adjust the heating temperature of the heater by changing the voltage at both ends of the film, so as to better adapt to the needs of different application fields;

2. The material used in the present invention is cheap, harmless to the human body, simplifies the production process, reduces the cost, and can be degraded in the natural environment, and the treatment cost after use is low, without any pollution to the ecological environment, which is beneficial to the environment of sustainable development.

The novel thin film heater of the present invention adopts paper as a substrate, which greatly reduces the manufacturing cost, and makes the thin film heater have excellent characteristics of degradability, and is easy to process and recycle. The ignition point of ordinary paper is about 130°C to 180°C, and the safe temperature range can meet the requirements of most application fields, especially suitable for one-time use in the medical field. Compared with the traditional technology, the degradable film heater prepared by the present invention greatly improves the adhesion between the film and the human body, simplifies the processing flow, reduces the cost, and is beneficial to the application on the human body.

Description of drawings

Fig. 1 adds the voltage that increases gradually in the film two ends in embodiment 1, and initial value is 1V, increases 1V every minute after that, measures the variation situation of the maximum value and average temperature of temperature on the heater;

Fig. 2 is the average temperature change situation recorded under 3V, 4V, 5V continuous voltage in embodiment 1;

Fig. 3 adds the voltage that gradually increases at both ends of the film in embodiment 2, and the initial value of voltage is 1V, increases 1V per minute after that, measures heater temperature maximum value and average temperature change situation;

Fig. 4 is the average temperature change situation recorded under 3V, 4V, 5V continuous voltage in embodiment 2;

Fig. 5 adds the voltage that increases gradually in embodiment 3 in film two ends, initial voltage value is 1V, every minute increases 1V, the variation situation of measuring the maximum value of heater temperature and average temperature;

FIG. 6 shows the measured average temperature variation under continuous voltages of 3V, 4V, and 5V in Example 3.

Detailed ways

The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the protection scope of the present invention.

The paper substrates used in the present invention all adopt ordinary A4 paper, and there is no requirement for the thickness and performance of the paper.

Example 1

1. Prepare the silver nanowire solution used in the experiment;

(a). PVP is added in ethylene glycol, the mass ratio of PVP and ethylene glycol is 1:50;

(b). The solution obtained in (a) was magnetically stirred at 100 rpm at 50° C. for 0.1 h to completely dissolve the PVP in ethylene glycol;

(c). Add silver nitrate to the PVP/ethylene glycol solution, dissolve completely, then add FeCl solution and stir for 10 minutes; the mass ratio of silver nitrate and PVP is 1:10 _; the mass ratio of FeCl and PVP is ₁ : 1;

(d). Transfer the mixed solution obtained in (c) to a hydrothermal synthesis reactor, and place it in a hot air circulation drying oven at 160° C. for 1 hour;

(e). After the suspension in (d) is cooled, centrifuge with a centrifuge, and finally purify with absolute ethanol;

(f). Dispersing the purified silver nanowires in absolute ethanol.

2. Take a film heater with a square resistance of 3Ω/sq as an example:

1. Paste an A4 piece of paper that is as large as the slide glass on the surface of the slide glass and place it on the homogenizer;

2. Drop-coat the silver nanowire solution, use a homogenizer to rotate at a speed of 750rpm for 15s, and disperse the silver nanowires evenly;

3. Repeat the steps in 2 twice;

4. Lead out two electrodes on both sides of the film with copper foil paper;

5. Drop-coat the PVA solution, and then use the homogenizer to rotate at 500rpm for 5s, and then at 2000rpm for 20s to evenly disperse the PVA on the film;

6. After the PVA is dry and solidified, test the heater.

Figure 1-2 is obtained after testing, the results show that the film heater with a square resistance of 3Ω/sq can reach a higher temperature in a short time, and the temperature of the film heater is stable under a stable voltage, which can meet the requirements of most applications. need.

Example 2

1. Prepare the silver nanowire solution used in the experiment;

(a). Add PVP to ethylene glycol, the mass ratio of PVP to ethylene glycol is 1:50

(b). Stir the solution obtained in (a) magnetically at 100 rpm at 150°C for 10 hours to completely dissolve the PVP in ethylene glycol;

(c). Add silver nitrate to the PVP/ethylene glycol solution, dissolve completely, then add FeCl solution and stir for ₁₀ minutes; the mass ratio of silver nitrate and PVP is 2:1; the mass ratio of FeCl and PVP is ₃₀ : 1

(d). Transfer the mixed solution obtained in (c) to a hydrothermal synthesis reactor, and place it in a hot air circulation drying oven at 120° C. for 10 hours;

(e). After the suspension in (d) is cooled, centrifuge with a centrifuge, and finally purify with absolute ethanol;

(f). Dispersing the purified silver nanowires in absolute ethanol.

2. Take a film heater with a square resistance of 15.9Ω/sq as an example:

(a). Paste the paper with the same size as the glass slide on the surface of the glass slide and place it on the glue spreader;

(b). Drop-coat the silver nanowire solution, and use a homogenizer to rotate for 5 seconds at a speed of 500 rpm to evenly disperse the silver nanowire;

(c). Carry out the steps in 2 again;

(d). Use copper foil paper to draw electrodes on both sides of the film;

(e). Drop-coating the PVA solution, using a glue homogenizer to turn at a speed of 500rpm for 5s, and then turn at a speed of 2000rpm for 20s to evenly disperse the PVA on the film;

(f). After the PVA is dried and solidified, test the heater.

Figure 3-4 is obtained after testing, and the results show that the heater with a square resistance of 15.9Ω/sq has a shorter response time, and a stable heating temperature can be obtained under a certain voltage, but the heating temperature is lower than that of a heater with a square resistance of 3Ω under the same voltage heater.

Example 3

.Prepare the silver nanowire solution used in the experiment;

(a). PVP is added to ethylene glycol, and the mass ratio of PVP to ethylene glycol is 1:100;

(b). The solution obtained in (a) was magnetically stirred at 1000 rpm at 140° C. for 1 hour to completely dissolve the PVP in ethylene glycol;

(c). Add silver nitrate to the PVP/ethylene glycol solution, dissolve completely, then add FeCl solution and stir for ₅ minutes; the mass ratio of silver nitrate and PVP is 1:1; the mass ratio of FeCl and PVP is ₁ : 10

(d). Transfer the mixed solution obtained in (c) to a hydrothermal synthesis reaction kettle, place it in a hot air circulation drying oven and react at 140° C. for 5 hours;

(e). After the suspension in (d) is cooled, centrifuge with a centrifuge, and finally purify with absolute ethanol;

(f). Dispersing the purified silver nanowires in absolute ethanol.

Take a film heater with a square resistance of 133Ω/sq as an example:

(a). Paste the paper with the same size as the glass slide on the surface of the glass slide and place it on the glue spreader;

(b). Drop-coating the silver nanowire solution, using a homogenizer to rotate for 60s at a speed of 500rpm, and uniformly disperse the silver nanowire;

(c). Use copper foil paper to draw electrodes on both sides of the film;

(d). Drop-coat the PVA solution, and then use the homogenizer to turn the PVA at a speed of 500rpm for 5s, and then turn it at a speed of 2000rpm for 20s, evenly disperse it on the film, and protect the heater;

(e). After the PVA is dry and solidified, test the heater.

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Figure 5-6 is obtained after testing, the results show that the greater the voltage across the heater with a square resistance of 133Ω/sq, the higher the temperature, but at low voltage, the temperature change of the heater is small and the reached temperature is low.

The above-described embodiment is only a preferred solution of the present invention, and does not limit the present invention in any form. There are other variations and modifications on the premise of not exceeding the technical solution described in the claims.

Claims (8)

1. A novel degradable film heater is characterized by being prepared by the following method:

(1) preparing a silver nanowire solution used for an experiment;

(2) preparing a thin film heater;

(a) pasting the paper on a glass slide, and dripping silver nanowire solution;

(b) putting the glass slide on a spin coater, setting the rotation speed and time of the spin coater, then taking down the glass slide,

uniformly dispersing silver nanowires on paper;

(c) leading out electrodes from two ends of the paper by using copper foil paper and fixing;

(d) dripping PVA solution on the silver nanowire conductive paper with the electrode obtained in the step (c);

(e) the PVA is put on a glue homogenizing machine, the rotating speed and the time of the glue homogenizing machine are set, the PVA is evenly spread on the paper,

to protect the silver nanowire layer on the paper;

(3) the resistance of the film heater can be changed by changing the amount of the silver nanowires dripped on the paper, so that different resistance resistors of 3-450 omega/sq can be obtained, and the heating performance of the resistors with different sizes under different conditions can be tested.

2. The novel degradable film heater of claim 1, wherein the silver nanowire solution prepared in step (1) is prepared by:

(a) adding PVP into ethylene glycol, wherein the mass ratio of the PVP to the ethylene glycol is 1: 500-1: 50;

(b) magnetically stirring the solution obtained in the step (a) at 50-150 ℃ for 100-5000 rpm for 0.1-10 h,

completely dissolving PVP in ethylene glycol;

(c) adding silver nitrate into PVP/ethylene glycol solution, dissolving completely, adding FeCl₃Stirring the solution for 1-10 minutes; the mass ratio of silver nitrate to PVP is 1: 10-2: 1; FeCl₃The mass ratio of the PVP to the PVP is 1:1～30:1；

(d) transferring the mixed solution obtained in the step (c) to a hydro-thermal synthesis reaction kettle, and placing the hydro-thermal synthesis reaction kettle in a hot blast circulating drying oven to react for 1-10 hours at the temperature of 120-160 ℃;

(e) after the suspension in the step (d) is cooled, centrifuging by using a centrifugal machine, and finally purifying by using absolute ethyl alcohol;

(f) dispersing the purified silver nanowires in absolute ethyl alcohol.

3. The novel degradable film heater of claim 1, wherein the spin coater of step (2) (b) is operated at 300-4000 rpm for 5-60 seconds.

4. The novel degradable film heater of claim 1, wherein the spin coater of step (2) (e) is rotated at 300-3000 rpm for 2-60 s and then at 500-5000 rpm for 5-60 s.

5. The preparation method of the novel degradable film heater is characterized by comprising the following steps:

(1) preparing a silver nanowire solution used for an experiment;

(2) preparing a thin film heater;

(a) pasting the paper on a glass slide, and dripping silver nanowire solution;

(b) placing the glass slide on a spin coater, setting the rotation speed and time of the spin coater, and then taking down the glass slide to uniformly disperse the silver nanowires on the paper;

(c) leading out electrodes from two ends of the paper by using copper foil paper and fixing;

(d) dripping PVA solution on the silver nanowire conductive paper with the electrode obtained in the step (c);

(e) placing the PVA film on a spin coater, setting the rotation speed and time of the spin coater, and uniformly spreading the PVA film on the paper to protect the silver nanowire layer on the paper;

(3) the resistance of the film heater can be changed by changing the amount of the silver nanowires dripped on the paper, so that different resistance resistors of 3-450 omega/sq can be obtained, and the heating performance of the resistors with different sizes under different conditions can be tested.

6. The method for preparing the novel degradable film heater according to claim 5, wherein the method for preparing the silver nanowire solution in the step (1) comprises the following steps:

(a) adding PVP into ethylene glycol, wherein the mass ratio of the PVP to the ethylene glycol is 1: 500-1: 50;

(b) magnetically stirring the solution obtained in the step (a) at 50-150 ℃ for 100-5000 rpm for 0.1-10 h to completely dissolve PVP in ethylene glycol;

(c) adding silver nitrate into PVP/ethylene glycol solution, dissolving completely, adding FeCl₃Stirring the solution for 1-10 minutes; the mass ratio of silver nitrate to PVP is 1: 10-2: 1; FeCl₃The mass ratio of the PVP to the PVP is 1: 1-30: 1;

(d) transferring the mixed solution obtained in the step (c) to a hydro-thermal synthesis reaction kettle, and placing the hydro-thermal synthesis reaction kettle in a hot blast circulating drying oven to react for 1-10 hours at the temperature of 120-160 ℃;

(e) after the suspension in the step (d) is cooled, centrifuging by using a centrifugal machine, and finally purifying by using absolute ethyl alcohol;

(f) and dispersing the purified silver nanowires in absolute ethyl alcohol.

7. The preparation method of the novel degradable film heater according to claim 5, wherein the rotation speed of the spin coater in step (2) (b) is 300-4000 rpm for 5-60 seconds.

8. The preparation method of the novel degradable film heater according to claim 5, wherein the step (2) (e) spin coater rotates at 300-3000 rpm for 2-60 s, and then rotates at 500-5000 rpm for 5-60 s.