阅读说明：本技术 一种基于碳纳米管膜的便携式电热元件的制备方法 (Preparation method of portable electric heating element based on carbon nanotube film ) 是由 陈茹 卢永桢 于 2020-06-08 设计创作，主要内容包括：本发明公开了一种基于碳纳米管膜的便携式电热元件的制备方法,包括以下步骤：S1、以50～150mg碳纳米管/100ml去离子水的比例,将碳纳米管和去离子水混合,加入表面活性剂,进行超声分散、真空抽滤和干燥,得到碳纳米管膜；S2、对所得碳纳米管膜进行辐照处理,辐射剂量为50～500kGy；S3、将碳纳米管膜夹于面板层和支撑基底层中间,压缩成型得到夹层结构的电热元件。本发明中采用辐照处理改性后的碳纳米管膜制备电热元件,整体制备工艺简单、清洁环保,提高了所得电热元件的热效率和表面温度,并且所得电热元件仅需较低的外加电压,携带、使用方便。(The invention discloses a preparation method of a portable electric heating element based on a carbon nanotube film, which comprises the following steps: s1, mixing the carbon nano tube with deionized water according to the proportion of 50-150 mg of the carbon nano tube to 100ml of the deionized water, adding a surfactant, and performing ultrasonic dispersion, vacuum filtration and drying to obtain a carbon nano tube membrane; s2, carrying out irradiation treatment on the obtained carbon nanotube film, wherein the irradiation dose is 50-500 kGy; and S3, sandwiching the carbon nanotube film between the panel layer and the support substrate layer, and performing compression molding to obtain the electrothermal element with a sandwich structure. The electric heating element is prepared from the carbon nano tube film subjected to irradiation treatment modification, the whole preparation process is simple, clean and environment-friendly, the heat efficiency and the surface temperature of the obtained electric heating element are improved, the obtained electric heating element only needs lower external voltage, and the electric heating element is convenient to carry and use.)

1. A preparation method of a portable electric heating element based on a carbon nanotube film is characterized by comprising the following steps: the method comprises the following steps:

s1, mixing the carbon nano tube with deionized water according to the proportion of 50-150 mg of the carbon nano tube to 100ml of the deionized water, adding a surfactant, and performing ultrasonic dispersion, vacuum filtration and drying to obtain a carbon nano tube membrane;

s2, carrying out irradiation treatment on the obtained carbon nanotube film, wherein the irradiation dose is 50-500 kGy;

and S3, sandwiching the carbon nanotube film between the panel layer and the support substrate layer, and performing compression molding to obtain the electrothermal element with a sandwich structure.

2. The method of claim 1, wherein the carbon nanotube film based portable electrical heating element comprises: in step S1, the carbon nanotubes are multi-walled carbon nanotubes, the power of ultrasonic dispersion is 50-500W, and the time is 0.5-6 h.

3. The method of claim 1, wherein the carbon nanotube film based portable electrical heating element comprises: in step S2, the obtained carbon nanotube film is subjected to gamma ray irradiation treatment at room temperature.

4. The method of claim 1, wherein the carbon nanotube film based portable electrical heating element comprises: in step S3, the panel layer and the supporting substrate layer are made of PET, PP, PE plastic, non-woven fabric, wood board, ceramic or metal.

5. The method for preparing a carbon nanotube film-based portable electric heating element according to claim 4, wherein: in step S3, when the panel layer and the support substrate layer are made of PET, PP, PE plastic or nonwoven fabric, the electrothermal element with a three-layer structure is manufactured by a hot press molding method.

6. The method for preparing a carbon nanotube film-based portable electric heating element according to claim 4, wherein: in step S3, when the material of the panel layer is wood, ceramic or metal, a heat conducting medium is added between the carbon nanotube film and the panel layer.

7. The method of claim 6, wherein the carbon nanotube film based portable electrical heating element comprises: the heat-conducting medium is MgO.

8. The method of claim 1, wherein the carbon nanotube film based portable electrical heating element comprises: the applied voltage of the obtained electric heating element is 1-10V.

Technical Field

The invention relates to the field of carbon nanotube heating elements, in particular to a preparation method of a portable electric heating element based on a carbon nanotube film.

Background

The carbon material has excellent mechanical, electric and heat radiation performances, so that the carbon material is widely applied to heat protection materials of aerospace and gradually paid attention to the research of civil and industrial electrothermal bodies. At present, heating components of electric heating equipment mainly comprise two types of heating materials, namely carbon and metal wires. Compared with metal electric heating elements, the carbon material has the advantages of good thermal matching, high thermal efficiency and long service life. The existing electric heating products mainly adopt carbon fibers as heating components, and carbon materials become a new generation of energy-saving and environment-friendly heating materials.

As a next-generation high-tech material, the Carbon Nano Tube (CNT) has excellent electrical, magnetic and mechanical properties and wide application prospect. However, the carbon nanotubes have strong van der waals force, are easy to wind and agglomerate, are difficult to disperse in a polymer matrix as a reinforced or functional filler, and are limited in practical application. The carbon tube is prepared into carbon nanotube paper or carbon nanotube film, so that the problem of dispersion of the carbon tube in the polymer matrix is avoided. Along with the improvement of the preparation method of the carbon nano tube, the cost performance advantage of the carbon nano tube is obvious day by day, but the research on the carbon nano tube based electric heating element in the civil field is not common.

The carbon nano tube has high length-diameter ratio, high toughness and extremely strong electric conduction and heat conduction performance, the electric conduction can reach 10000 times of that of copper, the strength is 100 times higher than that of steel, the mass is only 1/6 of steel, the field emission performance is excellent, the carbon nano tube has metallicity and semiconductivity, the electrothermal conversion rate reaches 99.8 percent, and the carbon nano tube is an ideal far infrared wave collecting substance. Carbon nanotube paper or carbon nanotube film is a sheet-like material with a three-dimensional network microporous structure formed by the close aggregation of carbon nanotubes together by van der waals forces. It has the physical and chemical properties of carbon nanotube, such as electricity, heat and magnetism, and is a functional planar electrothermal material with the property of carbon nanotube. The carbon nano tube film is used for the electric heating material and is bound to be colorful by utilizing the outstanding advantages of good electric conductivity, excellent heat transfer performance, outstanding far infrared function, high mechanical strength, good toughness and the like of the carbon nano tube.

Due to weak van der waals force connection or physical entanglement nodes between carbon tubes, effective stress transfer and current flow and heat conduction channels are lacked, resulting in that the mechanical, electrical and heat conductivity properties of the carbon nanotube film are far lower than those of carbon nanotubes. Therefore, people mainly aim to improve the mechanics and conductivity of the carbon nanotube film, and often adopt the method of impregnating resin in the carbon nanotube film to prepare the traditional fiber reinforced composite material with high carbon tube content; the application research of the carbon nanotube film mainly focuses on the aspects of electromagnetic shielding and radar wave absorption stealth. Although there are reports of using carbon tubes for floor heating materials, only the low electric heating performance of carbon nanotubes is currently utilized.

Disclosure of Invention

Aiming at the problems, the invention researches and designs a preparation method of a portable electric heating element based on a carbon nano tube film to overcome the defect of limited application field of the carbon nano tube film. The technical means adopted by the invention are as follows:

a preparation method of a portable electric heating element based on a carbon nanotube film comprises the following steps:

s1, mixing the carbon nano tube with deionized water according to the proportion of 50-150 mg of the carbon nano tube to 100ml of the deionized water, adding a surfactant, and performing ultrasonic dispersion, vacuum filtration and drying to obtain a carbon nano tube membrane;

s2, carrying out irradiation treatment on the obtained carbon nanotube film, wherein the irradiation dose is 50-500 kGy;

and S3, sandwiching the carbon nanotube film between the panel layer and the support substrate layer, and performing compression molding to obtain the electrothermal element with a sandwich structure.

Preferably, in step S1, the carbon nanotubes are multi-walled carbon nanotubes, the power of the ultrasonic dispersion is 50-500W, and the time is 0.5-6 h.

Preferably, in step S2, the obtained carbon nanotube film is subjected to gamma ray irradiation treatment at room temperature.

Preferably, in step S3, the material of the panel layer and the support substrate layer is PET, PP, PE plastic, non-woven fabric, wood board, ceramic or metal.

Preferably, in step S3, when the panel layer and the support substrate layer are made of PET, PP, PE plastic or non-woven fabric, the electrothermal element with a three-layer structure is manufactured by a hot press molding method.

Preferably, in step S3, when the material of the panel layer is wood, ceramic or metal, a heat conducting medium is added between the carbon nanotube film and the panel layer.

Preferably, the heat transfer medium is MgO.

Preferably, the applied voltage of the obtained electric heating element is 1-10V.

Compared with the prior art, the preparation method of the portable electric heating element based on the carbon nanotube film has the following beneficial effects:

1. the electric heating element is prepared by the carbon nano tube film subjected to gamma ray irradiation treatment modification, so that the heat efficiency and the surface temperature of the obtained electric heating element are improved, the overall preparation process is simple, clean and environment-friendly, and the application field of the carbon nano tube film is enlarged.

2. The electric heating element prepared by the invention can be used by using a charger or a computer USB interface and the like only by applying lower external voltage, is convenient to carry and use, and has good heating effect, and the surface temperature of the electric heating element can reach 50-100 ℃.

3. The protective supporting layer and the panel layer can be made of materials such as PET, PP, ceramics, metal and the like, and different materials can be selected according to different use scenes, so that the application field of the obtained electric heating element is wider.

Drawings

FIG. 1 is a graph of resistivity versus applied voltage for samples of different radiation doses in an embodiment of the present invention.

FIG. 2 is a graph of the surface temperature of the carbon paper in example 2 of the present invention over time.

FIG. 3 is a graph showing the surface temperature of the carbon paper according to the comparative example of the present invention as a function of time.

Detailed Description

A preparation method of a portable electric heating element based on a carbon nanotube film comprises the following steps:

s1, adding multi-wall carbon nanotube powder into deionized water according to the proportion of 50-150 mg of carbon nanotubes to 100ml of deionized water, adding a surfactant, performing ultrasonic dispersion at the ultrasonic dispersion power of 50-500W for 0.5-6 h, performing vacuum filtration, and drying to obtain a carbon nanotube film (the diameter is preferably less than 10 cm) with the thickness of 4-15 microns;

s2, performing room-temperature gamma ray irradiation treatment on the obtained carbon nanotube film in the air, wherein the irradiation dose is 50-500 kGy;

and S3, sandwiching the carbon nanotube film between the panel layer and the support substrate layer, and performing compression molding to obtain the electrothermal element with a sandwich structure.

In step S3, the material of the panel layer and the supporting substrate layer is PET, PP, PE plastic or non-woven fabric, wood, ceramic or metal. In order to reduce the heat loss of the heating layer of the carbon nano tube film, when the panel layer and the supporting layer are made of thermoplastic materials such as PET, PP, PE and the like, the electrothermal element with a three-layer structure is directly prepared by a hot press forming method; when the panel layer is made of wood, ceramic, metal and other plates, a heat-conducting medium layer is required to be added between the heating layer and the panel layer, and the heat-conducting medium layer can be made of MgO and other materials with better heat-conducting property. The diameter of the obtained electric heating element is not more than 10cm, and the applicable applied voltage is 1-10V.