阅读说明：本技术 摩擦纳米发电机的负性摩擦材料的制备方法 (Preparation method of negative friction material of friction nano generator ) 是由 阙妙玲 孙云飞 陈丽香 孙佳惟 吴靖 刘传洋 于 2021-08-09 设计创作，主要内容包括：本发明提供摩擦纳米发电机的负性摩擦材料的制备方法,用于制备如用于摩擦纳米发电机的负性摩擦材料；方法包括：改性硅胶作为聚合物基底填充改性钛酸钡纳米线,将制备的混合物涂于导电布上,真空、固化制得复合纳米薄膜作为摩擦材料；其中,改性硅胶、改性钛酸钡纳米线的重量份为：改性硅胶100重量份；改性钛酸钡纳米线5-30重量份。本发明在改性硅胶中填充改性钛酸钡纳米线,可使得负性摩擦材料的介电性能及拉伸性能同时得到提高；同时对钛酸钡纳米线进行改性处理,避免因钛酸钡的高介电常数性能导致的复合材料的电场分布不均匀。(The invention provides a preparation method of a negative friction material of a friction nano generator, which is used for preparing the negative friction material used for the friction nano generator; the method comprises the following steps: filling modified barium titanate nanowires by using modified silica gel as a polymer substrate, coating the prepared mixture on conductive cloth, and performing vacuum curing to obtain a composite nano film serving as a friction material; the modified silica gel and the modified barium titanate nanowire are prepared from the following components in parts by weight: 100 parts of modified silica gel; 5-30 parts of modified barium titanate nanowire. According to the invention, the modified barium titanate nanowires are filled in the modified silica gel, so that the dielectric property and tensile property of the negative friction material can be improved simultaneously; meanwhile, the barium titanate nanowire is subjected to modification treatment, so that the phenomenon that the electric field distribution of the composite material is uneven due to the high dielectric constant performance of barium titanate is avoided.)

1. The preparation method of the negative friction material of the friction nano generator is characterized by being used for preparing the negative friction material used for the friction nano generator; the method comprises the following steps:

filling modified barium titanate nanowires by using modified silica gel as a polymer substrate, coating the prepared mixture on conductive cloth, and performing vacuum curing to obtain a composite nano film serving as a friction material;

the modified silica gel and the modified barium titanate nanowire are prepared from the following components in parts by weight:

100 parts of modified silica gel;

5-30 parts of modified barium titanate nanowire.

2. The method for preparing a negative friction material of a triboelectric nanogenerator according to claim 1, wherein the method for preparing the modified silica gel comprises: adding foaming microsphere particles into silica gel to form a foaming microsphere-silica gel mixture;

wherein the silica gel and the foaming particles are prepared from the following components in parts by mass:

100 parts of silica gel;

3-20 parts of foaming microsphere particles.

3. The method for preparing a negative friction material of a triboelectric nanogenerator according to claim 1, wherein the method for preparing the modified silica gel comprises:

adding the foaming microsphere particles Y-180D into silica gel to form a foaming microsphere-silica gel mixture, and adding a curing agent after stirring;

wherein, the silica gel, the foaming particles and the curing agent; the mass parts of the three components are as follows:

100 parts of silica gel;

3-20 parts by weight of foaming particles;

1-3 parts of curing agent.

4. The method for preparing a negative friction material of a triboelectric nanogenerator according to claim 2 or 3, wherein the method for preparing the modified silica gel further comprises: negative ions are injected into the foaming microsphere-silica gel mixture, and the negative ions comprise at least one of CO3-, NO3-, O3-and O2-.

5. The method for preparing a negative friction material of a triboelectric nanogenerator according to claim 1, wherein the method for preparing the modified barium titanate nanowire comprises:

preparing barium titanate nanowires;

performing surface modification on the barium titanate nanowire;

grafting isothiocyanate on the surface of the barium titanate nanowire, adding 4,4 '-diaminodiphenylmethane, carrying out in-situ polymerization reaction on the 4, 4' -diaminodiphenylmethane and unreacted isothiocyanate to generate polythiourea, coating the polythiourea on the outer surface of the modified barium titanate nanowire, and drying.

6. The method for preparing a negative friction material of a triboelectric nanogenerator according to claim 5, wherein the modified barium titanate nanowire comprises:

10 parts of barium titanate nanowire;

20-100 parts by weight of isothiocyanate;

800-2000 parts by weight of 4, 4' -diaminodiphenylmethane.

7. The method for preparing a negative friction material of a triboelectric nanogenerator according to claim 5, wherein the surface modification of the barium titanate nanowires comprises surface modification with a dopamine solution.

8. The method for preparing a negative friction material of a triboelectric nanogenerator according to claim 5, wherein the surface modification of the barium titanate nanowire comprises: dissolving 3g of barium titanate nanowires in each 10g/ml of dopamine solution; stirring at 50 ℃ for 20 h.

9. The method for preparing a negative friction material of a triboelectric nanogenerator according to claim 5, wherein the method for preparing the barium titanate nanowire comprises:

will deionize H₂Mixing O and ethanol in a ratio of 3:1, and dissolving potassium hydroxide in the solution to form a mixed solution A;

dissolving polyethylene glycol in 14ml ethanol, and adding 10ml of prepared titanate ethanol solution with the molar concentration of 1M to prepare solution B;

mixing solutions A and B, adding 1mmol Ba (OH)₂·8H₂And O, putting the total solution into a 50ml hydrothermal kettle, heating the hydrothermal kettle to 150-200 ℃, reacting for 12 hours, cooling to normal temperature, washing by deionized water, and drying.

Technical Field

The invention relates to the field of material preparation, in particular to a preparation method of a negative friction material of a friction nano generator.

Background

The friction separation type friction nano generator generally adopts two different dielectric materials as a friction contact surface, an electrode is prepared on the back, and when the two dielectric materials are mutually contacted due to external force, surface charges with opposite signs are formed on the friction contact surface.

Therefore, the dielectric performance of the friction nano-generator, which is one of the generators, is an important index considering the performance of the generator.

The friction nanometer generator in the prior art has poor stretching and twisting effects, so that the friction nanometer generator is difficult to be directly matched with a wearable device. And poor dielectric properties, which are difficult to be used as a continuous power source for electronic devices. The main reason for this is the difference in properties due to the composition of the material and the manufacturing process.

If the surface of the friction layer is simply subjected to structural treatment, the friction layer is easily abraded during work, so that a new preparation method for preparing a negative friction material serving as a friction material source of a friction nano-generator is urgently needed.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a preparation method of a negative friction material for a friction nano generator.

The technical scheme of the invention is summarized as follows:

the invention provides a preparation method of a negative friction material of a friction nano generator, which is used for preparing the negative friction material used for the friction nano generator; the method comprises the following steps:

filling modified barium titanate nanowires by using modified silica gel as a polymer substrate, coating the prepared mixture on conductive cloth, and performing vacuum curing to obtain a composite nano film serving as a friction material;

the modified silica gel and the modified barium titanate nanowire are prepared from the following components in parts by weight:

100 parts of modified silica gel;

5-30 parts of modified barium titanate nanowire.

Further, the preparation method of the modified silica gel comprises the following steps: adding foaming microsphere particles into silica gel to form a foaming microsphere-silica gel mixture;

wherein the silica gel and the foaming particles are prepared from the following components in parts by mass:

100 parts of silica gel;

3-20 parts of foaming microsphere particles.

Further, the preparation method of the modified silica gel comprises the following steps:

adding the foaming microsphere particles Y-180D into silica gel to form a foaming microsphere-silica gel mixture, and adding a curing agent after stirring;

wherein, the silica gel, the foaming particles and the curing agent; the mass parts of the three components are as follows:

100 parts of silica gel;

3-20 parts by weight of foaming particles;

1-3 parts of curing agent.

Further, the preparation method of the modified silica gel further comprises the following steps: negative ions are injected into the foaming microsphere-silica gel mixture, and the negative ions comprise at least one of CO3-, NO3-, O3-and O2-.

Further, the preparation method of the modified barium titanate nanowire comprises the following steps:

preparing barium titanate nanowires;

performing surface modification on the barium titanate nanowire;

grafting isothiocyanate on the surface of the barium titanate nanowire, adding 4,4 '-diaminodiphenylmethane, carrying out in-situ polymerization reaction on the 4, 4' -diaminodiphenylmethane and unreacted isothiocyanate to generate polythiourea, coating the polythiourea on the outer surface of the modified barium titanate nanowire, and drying.

Further, the modified barium titanate nanowire includes:

10 parts of barium titanate nanowire;

20-100 parts by weight of isothiocyanate;

800-2000 parts by weight of 4, 4' -diaminodiphenylmethane.

Further, the surface modification of the barium titanate nanowire comprises surface modification with dopamine.

Further, the surface modification of the barium titanate nanowire comprises: dissolving 3g of barium titanate nanowires in each 10g/ml of dopamine solution; stirring at 50 ℃ for 20 h.

Further, the preparation method of the barium titanate nanowire comprises the following steps:

will deionize H₂Mixing O and ethanol in a ratio of 3:1, and dissolving potassium hydroxide in the solution to form a mixed solution A;

dissolving polyethylene glycol in 14ml ethanol, and adding 10ml of prepared titanate ethanol solution with the molar concentration of 1M to prepare solution B;

mixing solutions A and B, adding 1mmol Ba (OH)₂·8H₂And O, putting the total solution into a 50ml hydrothermal kettle, heating the hydrothermal kettle to 150-200 ℃, reacting for 12 hours, cooling to normal temperature, washing by deionized water, and drying.

Compared with the prior art, the invention has the beneficial effects that: according to the method for preparing the negative friction material, the modified barium titanate nanowires are filled in the modified silica gel, so that the dielectric property and the tensile property of the negative friction material can be improved at the same time; meanwhile, the barium titanate nanowire is subjected to modification treatment, so that the phenomenon that the electric field distribution of the composite material is uneven due to the high dielectric constant performance of barium titanate is avoided.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings. The detailed description of the present invention is given in detail by the following examples and the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

FIG. 1 is a schematic diagram showing the relationship between the prepared modified barium titanate nanowires of different qualities and the breakdown strength of the electric field in the present invention;

FIG. 2 is a schematic diagram showing the relationship between the prepared modified barium titanate nanowires with different mass and the dielectric constant.

Detailed Description

The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, which will enable those skilled in the art to practice the present invention with reference to the accompanying specification. In the drawings, the shape and size may be exaggerated for clarity, and the same reference numerals will be used throughout the drawings to designate the same or similar components. In the following description, terms such as center, thickness, height, length, front, back, rear, left, right, top, bottom, upper, lower, and the like are used based on the orientation or positional relationship shown in the drawings. In particular, "height" corresponds to the dimension from top to bottom, "width" corresponds to the dimension from left to right, and "depth" corresponds to the dimension from front to back. These relative terms are for convenience of description and are not generally intended to require a particular orientation. Terms concerning attachments, coupling and the like (e.g., "connected" and "attached") refer to a relationship wherein structures are secured or attached, either directly or indirectly, to one another through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise.

The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that any combination of the embodiments or technical features described below can be used to form a new embodiment without conflict. It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.

The invention relates to a preparation method of a negative friction material of a friction nano generator, which is characterized by being used for preparing the negative friction material for the friction nano generator; the method comprises the following steps:

filling modified barium titanate nanowires by using modified silica gel as a polymer substrate, coating the prepared mixture on conductive cloth, and performing vacuum curing to obtain a composite nano film serving as a friction material;

the modified silica gel and the modified barium titanate nanowire are prepared from the following components in parts by weight:

100 parts of modified silica gel;

5-30 parts of modified barium titanate nanowire.

The stretching rate of the modified barium titanate nanowire formed by the mass parts can reach 100-180%, the silica gel is low in cost, is not affected by humidity and is high in chemical stability, and the modified silica gel keeps the performance of the original silica gel. After the test, the clothes are more easily worn by human body.

The modified barium titanate nanowires are pretreated by a silica gel coupling agent, silica gel is used as a polymer substrate to be filled with the modified barium titanate nanowires with high dielectric constant, the prepared mixture is coated on an electrode on conductive cloth, and the composite nano silica gel film is prepared after vacuum and solidification and is used as a friction negative material.

In the test process, the mass fraction of the barium titanate nanowire is increased to improve the dielectric property, but the excessive mass fraction can reduce the contact area of the composite nano polymer film and the conductive cloth, and reduce the output property. Multiple tests show that the output performance is best when the weight ratio of the modified silica gel to the modified barium titanate nanowire is 10: 1.

Refer to table 1 for comparative data of mass fraction and output current of modified silica gel and modified barium titanate nanowires under different examples. In table 1, barium titanate nanowires with different mass fractions were uniformly added to the same silica gel, and output currents with different mass fractions were measured at different frequencies.

TABLE 1 Mass fraction vs. output Current for different examples

The preparation method of the modified silica gel comprises the following steps: adding foaming microsphere particles into silica gel to form a foaming microsphere-silica gel mixture;

wherein the silica gel and the foaming particles are prepared from the following components in parts by mass:

100 parts of silica gel;

3-20 parts of foaming microsphere particles.

Or the preparation method of the modified silica gel comprises the following steps:

adding the foaming microsphere particles Y-180D into silica gel to form a foaming microsphere-silica gel mixture, and adding a curing agent after stirring;

wherein, the silica gel, the foaming particles and the curing agent; the mass parts of the three components are as follows:

100 parts of silica gel;

3-20 parts by weight of foaming particles;

1-3 parts of curing agent.

The preparation method of the modified silica gel also comprises the following steps: negative ions are injected into the foaming microsphere-silica gel mixture, and the negative ions comprise at least one of CO3-, NO3-, O3-and O2-. Specifically, an air ion gun is used to inject negative ions into the surface of the negative electrode material.

It has been found through experimentation that the void structure reduces the effective thickness of the dielectric material. Adding the foaming microsphere particles Y-180D into the silica gel to form a foaming microsphere-silica gel mixture, and adding the curing agent after stirring. Wherein the mass ratio of the silica gel to the curing agent is 100: 2; the dielectric substance prepared after film forming has the best performance.

Referring to the relationship between the parts by weight of the foamed microspheres and the output current in table 2, after the same amount of barium titanate nanowires in the silica gel were unified, different parts by weight of the foamed microsphere particles were added, and the comparative data of the output current was measured.

See table 2, and a number of tests have shown that silica gel: when the ratio of the foaming microsphere particles is 100:9, the output current reaches the maximum.

TABLE 2 relationship between parts by weight and output current for different examples

Although a large number of experiments prove that the barium sulfate nanowire can improve the dielectric property. However, the present invention also found that barium titanate has a relatively high dielectric constant. If barium titanate with high dielectric constant is directly added into silica gel, the electric field distribution of the whole composite material is not uniform due to large electrical mismatch, and the breakdown strength of the composite film is greatly reduced.

Therefore, the invention improves the interface compatibility by an in-situ polymerization method to obtain the modified barium titanate nanowire.

The barium titanate nanowire in the composite silica gel film is a modified barium titanate nanowire. The modified barium titanate nanowire comprises a barium titanate nanowire, isothiocyanate and 4, 4' -diaminodiphenylmethane.

Specifically, the method for modifying the barium titanate nanowire comprises the following steps:

s1, preparing barium titanate nanowires;

the traditional preparation of barium titanate is prepared by mixing titanium dioxide and barium titanate, filter pressing and drying. But the traditional method has insufficient purity and irregular appearance.

The preparation of the barium titanate nanowire in the invention comprises the following steps: will deionize H₂O and ethanol were mixed at a ratio of 3:1, and potassium hydroxide (KOH) was dissolved in the solution to form a mixed solution A. Dissolving polyethylene glycol in 14ml ethanol, adding 10ml prepared titanate (TBOT) -ethanol solution with the molar concentration of 1M to prepare solution B. Mixing solutions A and B, adding 1mmol Ba (OH)₂·8H₂And O (barium hydroxide octahydrate), putting the total solution into a 50ml hydrothermal kettle, heating the hydrothermal kettle to 150-200 ℃, reacting for 12 hours, cooling to normal temperature, washing by deionized water, and drying.

S2, performing surface modification on the barium titanate nanowire; specifically, a dopamine solution is adopted for surface modification; preferably, 3g of barium titanate nanowires are dissolved in 10g/ml of dopamine solution; stirring at 50 ℃ for 20 h.

S3, grafting isothiocyanate on the surface of the barium titanate nanowire, adding 4,4 '-diaminodiphenylmethane, carrying out in-situ polymerization reaction on the 4, 4' -diaminodiphenylmethane and unreacted isothiocyanate to generate polythiourea, and coating the polythiourea on the outer surface of the modified barium titanate nanowire. And forming a film from the mixed solution, and drying to obtain the in-situ polymerization high-dielectric film based on the modified barium titanate nanowire.

Specifically, the modified barium titanate nanowire includes:

10 parts of barium titanate nanowire;

20-100 parts by weight of isothiocyanate;

800-2000 parts by weight of 4, 4' -diaminodiphenylmethane.

The mass of the isothiocyanate is 2-10 times of that of the barium titanate nanowire; the mass of the 4, 4' -diaminodiphenylmethane is 80-200 times of that of the barium titanate nanowire.

Preferably, in the above process, the isothiocyanate is grafted on the surface of the barium titanate nanowire, and then 4,4 ' -diaminodiphenylmethane is added at least 25 times, so that the subsequently added 4,4 ' -diaminodiphenylmethane is introduced into the reaction product of the two, and the added 4,4 ' -diaminodiphenylmethane and unreacted-N ═ C ═ S undergo an in-situ polymerization reaction to generate polythiourea, so that the polythiourea is coated on the outer surface of the modified barium titanate nanowire. And forming a film from the mixed solution, and drying to obtain the in-situ polymerization high-dielectric film based on the modified barium titanate nanowire.

Referring to fig. 1 and 2, the relationship between the prepared modified barium titanate nanowires under different qualities and the electric field breakdown strength and the dielectric constant is characterized.

In the first embodiment, the mass of the isothiocyanate is 2 times that of the barium titanate nanowire; the mass of the 4,4 '-diaminodiphenylmethane is 80 times that of the barium titanate nanowire, specifically, the barium titanate nanowire is 0.1g, and the isothiocyanate is 0.2g, and the 4' -diaminodiphenylmethane is 8 g.

In the second embodiment, the mass of the isothiocyanate is 4 times that of the barium titanate nanowire; the mass of the 4,4 '-diaminodiphenylmethane is 110 times that of the barium titanate nanowire, specifically, the barium titanate nanowire is 0.1g, the isothiocyanate is 0.4g, and the 4, 4' -diaminodiphenylmethane is 11 g.

In the third embodiment, the mass of the isothiocyanate is 6 times that of the barium titanate nanowire; the mass of the 4 '-diaminodiphenylmethane is 140 times that of the barium titanate nanowire, specifically, the barium titanate nanowire is 0.1g, the isothiocyanate is 0.6g, and the 4, 4' -diaminodiphenylmethane is 14 g.

In the fourth embodiment, the mass of the isothiocyanate is 8 times that of the barium titanate nanowire; the mass of the 4 '-diaminodiphenylmethane is 170 times that of the barium titanate nanowire, specifically, the barium titanate nanowire is 0.1g, the isothiocyanate is 0.8g, and the 4, 4' -diaminodiphenylmethane is 17 g.

In the fifth embodiment, the mass of the isothiocyanate is 10 times that of the barium titanate nanowire; the mass of the 4 '-diaminodiphenylmethane is 200 times of that of the barium titanate nanowire, specifically, the barium titanate nanowire is 0.1g, and the isothiocyanate is 1g, and the 4, 4' -diaminodiphenylmethane is 20 g.

Comparative example, 0.1g of barium titanate nanowire. In particular, the breakdown strength and dielectric constant under different embodiments refer to fig. 1 and 2. As can be seen from the figure, the dielectric constant of the modified barium titanate nanowire is improved, and the breakdown strength is integrally improved. However, it is not necessarily said that the greater the mass of isothiocyanate, the better, the higher the dielectric constant, the lower the breakdown strength. But the breakdown strength is improved compared with that of the barium titanate nanowire before the modification.

According to the method for preparing the negative friction material, the modified barium titanate nanowires are filled in the modified silica gel, so that the dielectric property and the tensile property of the negative friction material can be improved at the same time; meanwhile, the barium titanate nanowire is subjected to modification treatment, so that the phenomenon that the electric field distribution of the composite material is uneven due to the high dielectric constant performance of barium titanate is avoided.

It should be noted that: the precedence order of the above embodiments of the present invention is only for description, and does not represent the merits of the embodiments. And specific embodiments thereof have been described above. Other embodiments are within the scope of the following claims.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments.

The foregoing description has disclosed fully preferred embodiments of the present invention. It should be noted that those skilled in the art can make modifications to the embodiments of the present invention without departing from the scope of the appended claims. Accordingly, the scope of the appended claims is not to be limited to the specific embodiments described above.