阅读说明：本技术 一种纳米纤维素基电热膜及其制备方法 (Nano cellulose-based electrothermal film and preparation method thereof ) 是由 罗屹东 魏巍 李玉柱 王国忠 刘耀春 于 2020-08-14 设计创作，主要内容包括：本发明提供了一种纳米纤维素基电热膜及其制备方法,通过纳米纤维素粉末分散均匀的悬浊液后,再添加天然石墨粉末进行分散,有助于天然石墨粉末在纳米纤维素粉末悬浊液中充分分散均匀,最后添加纳米铜粉末或电气石粉末协同作用,有效增加电热膜在低压中的发热温度,且纤维素粉末、天然石墨粉末、纳米铜粉末以及电气石粉末的原料来源广,价格低廉,在无需添加连接料的以及较低的生产成本前提下,能制备具有低压、高热特点的电热膜。总体上能有效解决电热膜制备中需要使用环保性能差的连接料以及成本高的问题。(The invention provides a nano cellulose-based electrothermal film and a preparation method thereof, wherein natural graphite powder is added for dispersion after nano cellulose powder is uniformly dispersed to be beneficial to full and uniform dispersion of the natural graphite powder in a nano cellulose powder suspension, and finally nano copper powder or tourmaline powder is added for synergistic action to effectively increase the heating temperature of the electrothermal film in low pressure. Can effectively solve the problems of the need of using a connecting material with poor environmental protection performance and high cost in the preparation of the electrothermal film on the whole.)

1. A nanocellulose-based electrothermal film, comprising: the composite film layer is prepared from nano-cellulose, natural graphite, a solvent and tourmaline or nano-copper;

wherein tourmaline can be replaced by nano copper.

2. The nanocellulose-based electrothermal film of claim 1, wherein the solvent is water.

3. A method of preparing a nanocellulose-based electrothermal film according to claim 1 or 2, comprising the steps of:

s1, starting a high-speed dispersion machine, adding nano cellulose powder under the stirring condition, and continuing stirring at a high speed for dispersing for 10-30min after the nano cellulose powder is completely added to obtain a nano cellulose suspension;

s2, under the stirring condition, continuously adding natural graphite powder and tourmaline powder into the nano-cellulose turbid liquid, and uniformly stirring and dispersing at a high speed to obtain mixed slurry A; wherein the tourmaline powder can be replaced by nano copper powder;

s3, treating the mixed slurry A by using an ultrasonic cell crusher to obtain mixed slurry B;

s4, carrying out ultrasonic treatment on the mixed slurry B by using an ultrasonic cell cleaning machine to obtain mixed slurry C;

s5, concentrating the mixed slurry C to a solid content of 5-15 wt%, coating the mixed slurry C on the surface of the substrate layer, and drying to obtain the nanocellulose-based electrothermal film.

4. The preparation method of the nanocellulose-based electrothermal film according to claim 3, wherein the raw materials are added in the following amounts by mass: 1-10% of nano cellulose powder, 1-10% of natural graphite powder, 1-5% of tourmaline powder and the balance of water; wherein, 1 to 5 percent of tourmaline powder can be replaced by 0.1 to 1 percent of nano copper powder.

5. The method of preparing a nanocellulose-based electrothermal film as claimed in claim 4, wherein the particle size of the natural graphite powder in step S2 is 3-50 μm.

6. The method of preparing a nanocellulose-based electrothermal film as claimed in claim 4, wherein the particle size of the tourmaline powder in step S2 is less than 1 μm.

7. The method for preparing a nanocellulose-based electrothermal film as claimed in claim 4, wherein the particle size of the copper nanopowder in step S2 is 100-500 nm.

8. The method for preparing a nanocellulose-based electrothermal film as claimed in claim 4, wherein the stirring condition in step S1 is 2000-4000 r/min.

9. The method for preparing a nanocellulose-based electrothermal film as claimed in claim 4, wherein the conditions of the ultrasonic cell disruptor in step S3 are: the power is 800 and 1500W, and the total processing time is 5-15 min.

10. The method for preparing a nanocellulose-based electrothermal film as claimed in claim 4, wherein the ultrasonic treatment conditions of the ultrasonic cell washer in step S4 are as follows: the power is 600-1600W, and the time is 5-30 min.

Technical Field

The invention relates to the field of preparation of electrothermal films, in particular to a nanocellulose-based electrothermal film and a preparation method thereof.

Background

The nano-cellulose has good flexibility and mechanical property, and the fibers are connected in a staggered manner, so that a porous structure convenient for ion and electron transmission is easily formed; the fiber surface is also attached with hydrophilic functional groups such as hydroxyl, carboxyl and the like, and has good moisturizing capability. The excellent performance of the nano-cellulose enables the nano-cellulose to have great development potential in a plurality of fields, including the fields of biomedical treatment, biosensors, food packaging, composite materials, super capacitors, battery diaphragms and negative electrode materials, electronic ink-jet, 3D printing and the like.

The conventional electrothermal film is formed by adding carbon nanotubes, graphene and the like into conductive slurry to improve the conductivity and reduce the resistance, so that the heating efficiency is improved, but the carbon nanotubes and the graphene are added to the conductive slurry through an additional chemical treatment process, so that the preparation cost is relatively high, and more environmental pollution is caused. In addition, the connecting materials commonly used by the electrothermal film in the prior art are non-degradable acrylic resin, polyurethane resin and the like, but the environment-friendly performance of the electrothermal film is poor, and the requirement of the electrothermal film on the market on the environment-friendly electrothermal film can not be met.

In summary, the above problems still remain to be solved in the field of electric heating film preparation and its practical application.

Disclosure of Invention

The invention provides a nano cellulose-based electrothermal film and a preparation method thereof, and aims to solve the problems that a connecting material with poor environmental protection performance needs to be used in the preparation of the electrothermal film and the cost is high.

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

a nanocellulose-based electrothermal film comprising: the composite film layer is prepared from nano-cellulose, natural graphite, a solvent and tourmaline; the tourmaline can be replaced by nano copper

Optionally, the solvent is water.

Optionally, the nanocellulose, the natural graphite, the tourmaline and the nano copper are nano cellulose powder, natural graphite powder, tourmaline powder and nano copper powder, respectively.

In addition, the invention also provides a preparation method of the nano cellulose-based electrothermal film, which comprises the following steps:

s1, starting a high-speed dispersion machine, adding nano cellulose powder and a solvent under the stirring condition, and continuing stirring at a high speed for dispersing for 10-30min after the nano cellulose powder and the solvent are completely added to obtain a nano cellulose suspension;

s2, under the stirring condition, continuously adding natural graphite powder and tourmaline powder into the nano-cellulose turbid liquid, and uniformly stirring and dispersing at a high speed to obtain mixed slurry A; wherein the tourmaline powder can be replaced by nano copper powder;

s3, treating the mixed slurry A by using an ultrasonic cell crusher to obtain mixed slurry B;

s4, carrying out ultrasonic treatment on the mixed slurry B by using an ultrasonic cell cleaning machine to obtain mixed slurry C;

s5, concentrating the mixed slurry C to a solid content of 5-15 wt%, coating the mixed slurry C on the surface of the substrate layer, and drying to obtain the nanocellulose-based electrothermal film.

Optionally, the solvent in step S1 is water.

Optionally, the raw materials are added in the following amounts by mass: 1-10% of nano cellulose powder, 1-10% of natural graphite powder, 1-5% of tourmaline powder and the balance of water; wherein, 1 to 5 percent of tourmaline powder can be replaced by 0.1 to 1 percent of nano copper powder.

Optionally, the mass ratio of the nanocellulose powder and the natural graphite is 2: 3.

Optionally, the particle size of the natural graphite powder in step S2 is 3 to 50 μm.

Optionally, the particle size of the tourmaline powder in step S2 is less than 1 μm.

Optionally, the particle size of the nano copper powder in step S2 is 100-500 nm.

Alternatively, the stirring condition in step S1 is 2000-4000 r/min.

Alternatively, the conditions for the ultrasonic cell disruptor to perform the processing in step S3 are: the power is 50-600w, the total treatment time is 5-15min, and the ultrasonic cell crusher adopts an intermittent treatment mode, wherein the intermittent frequency is 4s of starting and 4s of pausing.

Alternatively, the conditions of the ultrasonic cell washing machine ultrasonic treatment in step S4 are: the power is 25-120w, and the time is 5-30 min.

Compared with the prior art, the invention has the beneficial technical effects that:

1. according to the electric heating film, the nano cellulose powder forms a uniformly dispersed turbid liquid, then the natural graphite powder is added for dispersion, the process steps are favorable for fully and uniformly dispersing the natural graphite powder in the nano cellulose powder turbid liquid, and finally the nano copper powder or tourmaline powder is added for synergistic effect, so that the heating of the electric heating film is effectively increased, and the electric heating film has a remarkable heating temperature at low pressure.

2. The raw materials of the nano-cellulose powder, the natural graphite powder, the nano-copper powder and the tourmaline powder of the electric heating film are wide in source, easy to obtain and low in price, and the electric heating film with uniform integral heating can be prepared on the premise of not adding a connecting material and low production cost.

3. The preparation process of the electrothermal film is simple, the controllable degree is high, the electrothermal film with the characteristics of low pressure and high heat can be prepared under the action of components and the process, the preparation process is environment-friendly, the product is environment-friendly, and the requirements of the market on the environment-friendly electrothermal film can be met.

Drawings

The invention will be further understood from the following description in conjunction with the accompanying drawings.

FIG. 1 is a schematic diagram of a film layer of a nanocellulose-based electrothermal film according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the heating measured at 5V voltage of the nanocellulose-based electrothermal film of example 5 of the present invention;

FIG. 3 is a schematic diagram of the heating measured at 10V of the nanocellulose-based electrothermal film of example 5 of the present invention;

FIG. 4 is a schematic diagram of the heating of the nanocellulose-based electrothermal film of example 5 of the present invention measured at a voltage of 15V;

FIG. 5 is a schematic diagram of the heating measured at 20V of the nanocellulose-based electrothermal film of example 5 of the present invention;

fig. 6 is a schematic view of the nanocellulose-based electrothermal film with electrodes according to one embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Referring to fig. 1, a nanocellulose-based electrothermal film of an embodiment includes: the composite film layer is prepared by mixing nano-cellulose, natural graphite, a solvent and tourmaline. In one embodiment, tourmaline may be substituted with nano copper.

In one embodiment, the nanocellulose, the natural graphite, the tourmaline and the nanocopper are nanocellulose powder, natural graphite powder, tourmaline powder and nanocopper powder, respectively.

In one embodiment, the solvent is water.

In one embodiment, the substrate layer is one or more of a copper foil, an aluminum foil, a polytetrafluoroethylene plate, a release film and a glass plate. The prepared mixed slurry is coated on the surface of a base material layer to form a directionally arranged structure, which is beneficial to obtaining an electrothermal film with excellent electric and thermal conductivity.

In addition, a method of preparing a nanocellulose-based electrothermal film in one embodiment includes the steps of:

s1, starting a high-speed dispersion machine, adding nano cellulose powder and a solvent under the stirring condition, and continuing stirring at a high speed for dispersing for 10-30min after the nano cellulose powder and the solvent are completely added to obtain a nano cellulose suspension;

s2, under the stirring condition, continuously adding natural graphite powder and tourmaline powder into the nano-cellulose turbid liquid, and uniformly stirring and dispersing at a high speed to obtain mixed slurry A;

s3, treating the mixed slurry A by using an ultrasonic cell crusher to obtain mixed slurry B; the nano-cellulose powder in an agglomerated state is dispersed into a nano-scale distribution state by processing with an ultrasonic cell crusher.

S4, carrying out ultrasonic treatment on the mixed slurry B by using an ultrasonic cell cleaning machine to obtain mixed slurry C; the ultrasonic treatment by the ultrasonic cell cleaning machine aims to eliminate bubbles in the mixed slurry B, so that a uniform, stable and high-quality composite film layer can be obtained in the subsequent coating step.

S5, concentrating the mixed slurry C to a solid content of 5-15 wt%, coating the mixed slurry C on the surface of the substrate layer, and drying to obtain the nanocellulose-based electrothermal film.

In one embodiment, the tourmaline powder of step S2 may be replaced with nano copper powder.

Form the turbid liquid with nanometer cellulose and water, after the intensive dispersion in high-speed dispersion machine, add natural graphite again and carry out the intensive dispersion, for prior art, through adding natural graphite composition, need not to carry out extra chemical treatment with the raw materials, reduce the pollution degree of production, and nanometer cellulose and natural graphite composite dispersion are even, help forming the even mixed slurry that wholly generates heat. In addition, tourmaline powder or nanometer copper powder can reduce resistance with natural graphite synergism for the electric heat membrane has certain anion release effect when electric heating, helps increasing the generating heat of electric heat membrane.

In one embodiment, the raw materials are added in the method according to the mass percentage as follows: 1-10% of nano cellulose powder, 1-10% of natural graphite powder, 1-5% of tourmaline powder and the balance of water. In one embodiment, 1-5% of tourmaline powder added as raw material can be replaced by 0.1-1% of nano copper powder. Under the synergistic effect of the optimized components and the component content, the production cost can be further reduced and the production benefit can be increased while the electric and heat conduction performance of the electric heating film is ensured.

In one embodiment, the natural graphite powder in the step S2 has a particle size of 3 to 50 μm. In one embodiment, the particle size of the tourmaline powder in step S2 is less than 1 μm. In one embodiment, the particle size of the copper nanoparticles in step S2 is 100-500 nm. The particle size of the prepared raw materials is limited, so that the dispersibility of the raw materials in a system is improved, and the quality of the prepared electrothermal film is improved to a great extent.

In one embodiment, the stirring condition in step S1 is 2000-4000 r/min. Under the stirring condition, the full dispersion of the components can be ensured.

In one embodiment, the conditions for the ultrasonic cell disruptor to perform the processing in step S3 are as follows: the power is 50-600w, and the time is 5-15 min.

In one embodiment, the conditions of the ultrasonic cell washing machine ultrasonic treatment in step S4 are as follows: the power is 25-120w, and the time is 5-30 min.

In one embodiment, the concentration temperature in step S6 is 80-110 ℃.

In one embodiment, the thickness of the coating in step S6 is 0.5-2 mm.

The nano-cellulose contains hydrophilic functional groups and hydrophobic groups, the hydrophobic center interacts with the hydrophobic plane of the natural graphite, and the hydrophilic hydroxyl groups and the defect edges form hydrogen bonds, so that the nano-cellulose can prevent the natural graphite from being stacked again, and the prepared electrothermal film has an excellent electrothermal effect by adopting the optimized preparation method.

The following are specific examples: