Preparation method of fiber-based graphene / polyaniline electrothermal material

Abstract

The application discloses a preparation method of graphene / polyaniline electrothermal material, which comprises the following steps: treating terylene fabric after alkali reduction by a coupling agent, and then loading graphene and polyaniline (PANI) on the surface of the fiber by in-situ deposition to prepare graphene / polyaniline electrothermal material. The application adopts large-size graphene oxide to reduce the heat conductivity reduction caused by atomic defects, and to improve the electric conductivity and heat conductivity of graphene to a certain extent. The application adopts the coupling agent to couple the fabric and graphene by Si-O-C bond, which can effectively improve the loading of graphene and polyaniline on the fabric and improve the electric conductivity. The prepared composite material has excellent electrothermal performance and can be rapidly heated in a short time. The process of the application is simple and convenient to operate, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of high-performance textile fabrics, and particularly relates to a preparation method of a fiber-based graphene / polyaniline electrothermal material. BACKGROUND

[0002] Carbon-based materials are widely used in flexible electronic components due to their good flexibility, excellent electrical conductivity and thermal conductivity. Graphene, as a new ultra-thin two-dimensional material, is tightly packed by sp 2 The hybrid-connected carbon atoms form a single-layer two-dimensional honeycomb lattice structure, which has excellent electrical conductivity, thermal conductivity and high specific surface area, and has become one of the most popular candidate materials in the field of electronic components in conductive and thermal conductive textiles. In addition, polyaniline is a low-cost conductive and thermal conductive polymer, which is often used as an active material for sensors and supercapacitors. Its synthesis process is simple, and the obtained composite material has high latent heat and heat storage capacity. Graphene with high thermal conductivity is added as a filler to the polyaniline matrix to fill the intermolecular gaps of polyaniline, forming an effective heat conduction channel. The synergistic effect of graphene and polyaniline can greatly enhance the thermal conductivity of the fabric. However, graphene and polyaniline have poor water solubility, especially graphene often agglomerates during the dispersion process, which affects the uniformity and fastness of the fabric.

[0003] Currently, graphene electrothermal fabric is mainly prepared by coating, padding, printing and other methods to load graphene material on the fabric to give it high thermal conductivity by reacting graphene with various thermal conductive materials such as metal particles, carbon-based materials, and high polymers. The preparation of graphene thermal conductive dispersion is particularly important.

[0004] CN111436168A discloses a graphene electrothermal paste, a graphene electrothermal film and a preparation method and application thereof. The graphene powder, polyamide resin and additives are used to prepare a polar organic solvent, which is then prepared into a film by screen printing. However, the electrothermal film has uneven heating. CN110283456A discloses a preparation method of graphene and secondary doped polyaniline nanocomposite, which improves the electrical conductivity and corrosion resistance of graphene to some extent, but the water solubility and dispersion performance of the obtained composite material are weak. CN106012086A discloses a preparation method of graphene / polyaniline composite fiber. The polyaniline is generated by in-situ polymerization, and the graphene oxide / polyaniline composite fiber is prepared by wet spinning. Nitrogen is used to protect the polymerization of polyaniline, and hydriodic acid is used to reduce graphene oxide. The reduction temperature and time are 80-200℃ and 8-24h, respectively. The preparation process is time-consuming and complex.

[0005] Therefore, it is necessary to provide a preparation method of an electric heating material with simple operation process, stable material dispersion and excellent heat conduction performance. SUMMARY

[0006] The purpose of the present application is to provide a preparation method of a fiber-based graphene electric heating material, which uses in-situ deposition to load graphene and polyaniline on the fiber, and the prepared composite material has excellent electric heating performance.

[0007] Technical scheme: A preparation method of a graphene / polyaniline electric heating material, which uses a coupling agent to treat polyester fabric after alkali reduction, and then in-situ deposition is used to load graphene and polyaniline (PANI) on the surface of the fiber to prepare the graphene / polyaniline electric heating material. The specific steps are as follows:

[0008] Step (1), graphite foil is used as the positive electrode, platinum wire is used as the negative electrode, concentrated sulfuric acid solution is used as the electrolyte, an electrochemical workstation is connected, a direct current power supply is input, and after power-on for 30 min, the electrochemically modified graphite is collected by filtration, and then a modified Hummers method is used to prepare graphene oxide and large-size graphene;

[0009] Step (2), after the polyester fabric is treated by alkali reduction, it is immersed in a silane coupling agent solution with a certain concentration, and the coupling agent is attached to the fiber by the method of immersion-drying;

[0010] Step (3), the fabric obtained in step (2) is immersed in the dispersion liquid prepared from the graphene oxide obtained in step (1), so that the graphene oxide is deposited on the fiber, and then the graphene oxide is reduced by a reducing agent to prepare a graphene fabric;

[0011] Step (4), a proper amount of aniline is dissolved in a protic acid solution, the fabric in step (3) is immersed, and the prepared catalyst is added dropwise under ice bath conditions to prepare a graphene / polyaniline composite material.

[0012] As a preferred scheme of the present application, the average size of the graphene oxide prepared in step (1) is >50 mu m.

[0013] As a preferred scheme of the present application, the alkali reduction formula in step (2) is: NaOH 50 g / L, bath ratio = 50:1, 100 DEG C reaction for 1 h.

[0014] As a preferred scheme of the present application, the method of immersion-drying in step (2) is: the silane coupling agent uses one of KH550 and KH560, the concentration is 5-20 g / L, and the reaction is carried out at 70 DEG C for 1 h.

[0015] As a preferred embodiment of the present invention, in step (3), the concentration of graphene oxide is 5 g / L, the number of depositions is 7, and the deposition time is 30 min.

[0016] As a preferred embodiment of the present invention, in step (3), the reducing agent is hydrazine hydrate, and the reducing formula is: hydrazine hydrate (30mL / L) reduced at 90℃ for 2h.

[0017] As a preferred embodiment of the present invention, in step (4), the concentration of aniline is 0.25-1.25 mol / L, the protic acid is hydrochloric acid, and the catalyst is ammonium persulfate, wherein n(aniline):n(ammonium persulfate) = 1:1.

[0018] Beneficial effects: The specific advantages of this invention are as follows:

[0019] (1) This invention uses large-size graphene oxide to reduce the decrease in thermal conductivity caused by atomic defects, thereby improving the electrical and thermal conductivity of graphene to a certain extent.

[0020] (2) The present invention uses a coupling agent to couple the fabric and graphene with Si-OC bonds, which can effectively increase the load of graphene and polyaniline on the fabric and thus improve the conductivity. The prepared composite material has excellent electrothermal properties and can be heated rapidly in a short time.

[0021] (3) The process of this invention is simple and easy to operate, and has a good application prospect. Attached Figure Description

[0022] Appendix Figure 1 A digital photograph of the graphene / polyaniline composite material of Example 1 of the present invention;

[0023] Appendix Figure 2 This is a SEM image of the graphene / polyaniline composite material of Example 1 of the present invention;

[0024] Appendix Figure 3 This is a schematic diagram of infrared imaging according to Embodiment 1 of the present invention. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below, so that those skilled in the art can better understand the advantages and features of the present invention, thereby making a clearer definition of the scope of protection of the present invention. The embodiments described in this invention are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] (1) Graphite foil as the positive electrode, platinum wire as the negative electrode, concentrated sulfuric acid solution as the electrolyte, connecting the electrochemical workstation, inputting 5v direct current power, after electrifying for 30min, collecting the electrochemically modified graphite through filtration, and then preparing graphene oxide by using the improved hummers method;

[0028] (2) After the polyester fabric was subjected to alkali reduction (NaOH 50g / L, bath ratio = 50:1, 100℃ for 1h), the fabric was immersed into the prepared 10g / L KH560 solution, and was subjected to water bath reaction at 70℃ for 1h, and was dried at 60℃;

[0029] (3) The fabric prepared in (2) was immersed into 5g / L graphene oxide dispersion solution for 30min after ultrasonic treatment for 10min, and was dried at 60℃ for 10min, and the above operation was repeated for 6 times, and hydrazine hydrate (30mL / L) was used for reduction at 90℃ for 2h;

[0030] (4) 0.02mol aniline was dissolved in 1mol / L HCl to prepare aniline solution with a concentration of 0.5mol / L as A solution, and 0.02mol APS was dissolved in deionized water to prepare B solution. Under ice bath condition, the fabric prepared in the above step (3) was immersed into the A solution, and B solution was added dropwise, and after the dropwise addition was completed, the fabric was placed in a constant temperature water bath for reaction for 24h, and after the reaction was completed, the fabric was taken out and dried, and graphene / polyaniline composite electrothermal material was prepared.

[0031] Example 2

[0032] (1) Graphite foil as the positive electrode, platinum wire as the negative electrode, concentrated sulfuric acid solution as the electrolyte, connecting the electrochemical workstation, inputting 5v direct current power, after electrifying for 30min, collecting the electrochemically modified graphite through filtration, and then preparing graphene oxide by using the improved hummers method;

[0033] (2) After the polyester fabric was subjected to alkali reduction (NaOH 50g / L, bath ratio = 50:1, 100℃ for 1h), the fabric was immersed into the prepared 20g / L KH560 solution, and was subjected to water bath reaction at 70℃ for 1h, and was dried at 60℃;

[0034] (3) The fabric prepared in (2) was immersed into 5g / L graphene oxide dispersion solution for 30min after ultrasonic treatment for 10min, and was dried at 60℃ for 10min, and the above operation was repeated for 6 times, and hydrazine hydrate (30mL / L) was used for reduction at 90℃ for 2h;

[0035] (4) Take 0.02 mol aniline dissolved in 1 mol / L HCl to prepare A solution with aniline concentration of 0.5 mol / L, and take 0.02 mol APS dissolved in deionized water to prepare B solution. Under ice bath condition, the fabric prepared in step (3) above is immersed in A solution, and B solution is added dropwise thereto. After dropwise addition is completed, it is placed in constant temperature water bath for 24 h. After reaction is completed, the fabric is taken out and dried to prepare graphene / polyaniline composite electrothermal material.

[0036] Example 3

[0037] (1) Graphite foil is used as positive electrode, platinum wire is used as negative electrode, concentrated sulfuric acid solution is used as electrolyte, electrochemical workstation is connected, 5v direct current power supply is input, and electricity is passed for 30 min. After that, electrochemically modified graphite is collected by filtration, and then improved hummers method is used to prepare graphene oxide;

[0038] (2) After terylene fabric is subjected to alkali reduction (NaOH 50 g / L, bath ratio = 50:1, 100℃ reaction for 1 h), it is immersed in prepared 10 g / L KH560 solution, and is subjected to water bath at 70℃ for 1 h and then is dried at 60℃;

[0039] (3) The fabric prepared in (2) is ultrasonically treated for 10 min, then is immersed in 5 g / L graphene oxide dispersion liquid for 30 min, is dried at 60℃ for 10 min, and the above operation is repeated for 6 times. Hydrazine hydrate (30 mL / L) is used for reduction at 90℃ for 2 h;

[0040] (4) Take 0.01 mol aniline dissolved in 1 mol / L HCl to prepare A solution with aniline concentration of 0.25 mol / L, and take 0.01 mol APS dissolved in deionized water to prepare B solution. Under ice bath condition, the fabric prepared in step (3) above is immersed in A solution, and B solution is added dropwise thereto. After dropwise addition is completed, it is placed in constant temperature water bath for 24 h. After reaction is completed, the fabric is taken out and dried to prepare graphene / polyaniline composite electrothermal material.

[0041] Example 4

[0042] (1) Graphite foil is used as positive electrode, platinum wire is used as negative electrode, concentrated sulfuric acid solution is used as electrolyte, electrochemical workstation is connected, 5v direct current power supply is input, and electricity is passed for 30 min. After that, electrochemically modified graphite is collected by filtration, and then improved hummers method is used to prepare graphene oxide;

[0043] (2) After terylene fabric is subjected to alkali reduction (NaOH 50 g / L, bath ratio = 50:1, 100℃ reaction for 1 h), it is immersed in prepared 10 g / L KH560 solution, and is subjected to water bath at 70℃ for 1 h and then is dried at 60℃;

[0044] (3) The fabric prepared in (2) is immersed in 5 g / L graphene oxide dispersion solution for 30 min after ultrasonic treatment for 10 min, dried at 60°C for 10 min, and the above operation is repeated for 6 times, and hydrazine hydrate (30 mL / L) is used for reduction at 90°C for 2 h;

[0045] (4) A solution of 0.05 mol of aniline dissolved in 1 mol / L HCl is prepared to have aniline concentration of 1.25 mol / L, and a B solution is prepared by dissolving 0.05 mol of APS in deionized water. The fabric prepared in the above step (3) is immersed in the A solution under ice bath condition, and the B solution is added dropwise thereto, and after the dropwise addition is completed, the fabric is placed in a constant temperature water bath for reaction for 24 h, and after the reaction is completed, the fabric is taken out and dried to prepare a graphene / polyaniline composite electrothermal material.

[0046] Comparative Example 1

[0047] (1) Graphite foil is used as an anode, platinum wire is used as a cathode, concentrated sulfuric acid solution is used as an electrolyte, an electrochemical workstation is connected, a 5V direct current power supply is input, and after power-on for 30 min, the electrochemically modified graphite is collected by filtration, and then the improved hummers method is used to prepare graphene oxide;

[0048] (2) The polyester fabric is subjected to alkali reduction treatment after (NaOH 50 g / L, bath ratio = 50:1, 100°C reaction for 1 h);

[0049] (3) The fabric prepared in (2) is immersed in 5 g / L graphene oxide dispersion solution for 30 min after ultrasonic treatment for 10 min, dried at 60°C for 10 min, and the above operation is repeated for 6 times, and hydrazine hydrate (30 mL / L) is used for reduction at 90°C for 2 h;

[0050] (4) A solution of 0.05 mol of aniline dissolved in 1 mol / L HCl is prepared to have aniline concentration of 1.25 mol / L, and a B solution is prepared by dissolving 0.05 mol of APS in deionized water. The fabric prepared in the above step (3) is immersed in the A solution under ice bath condition, and the B solution is added dropwise thereto, and after the dropwise addition is completed, the fabric is placed in a constant temperature water bath for reaction for 24 h, and after the reaction is completed, the fabric is taken out and dried to prepare a graphene / polyaniline composite electrothermal material.

[0051] Comparative Example 2

[0052] (1) Graphite foil is used as an anode, platinum wire is used as a cathode, concentrated sulfuric acid solution is used as an electrolyte, an electrochemical workstation is connected, a 5V direct current power supply is input, and after power-on for 30 min, the electrochemically modified graphite is collected by filtration, and then the improved hummers method is used to prepare graphene oxide;

[0053] (2) The polyester fabric is subjected to alkali reduction treatment after (NaOH 50 g / L, bath ratio = 50:1, 100°C reaction for 1 h);

[0054] (3) The fabric prepared in (2) is immersed in 5 g / L graphene oxide dispersion for 30 min after ultrasonic treatment for 10 min, and is baked at 60°C for 10 min. The above operation is repeated 6 times, and hydrazine hydrate (30 mL / L) is used for reduction at 90°C for 2 h.

[0055] The obtained fiber-based graphene electrothermal material is tested according to the present application, as follows:

[0056] 1. Conductive performance test

[0057] The four-probe resistance tester is used to measure the surface resistance of the fabric at any five positions, and the average value is the surface resistance of the fabric.

[0058] 2. Electrothermal performance characterization

[0059] The stabilized power supply line is connected to both ends of the fabric, the distance between the power supply connection is controlled to be 3 cm, and the apparent heating temperature and infrared imaging of the fabric under different voltage conditions and different power-on time are tested by using the infrared imaging instrument.

[0060] Figure 1 Figure 1 Figure 1 is a digital photo of the graphene / polyaniline composite material of Example 1. Figure 2 Figure 2 is a SEM image of the graphene / polyaniline composite material of Example 1, and the magnification is 10000 times, as shown in Figure 2, a large number of nanorod structures are stacked on the surface of the fiber, indicating that aniline is successfully polymerized into polyaniline and loaded on the surface of graphene. Figure 2 Figure 3 Figure 3 is an infrared imaging schematic diagram of Example 1, as shown in the figure, the heating temperature of the prepared fabric reaches 77.3°C when powered on for 2 min under 14V voltage, and the heating is uniform.

[0061] Table 1

[0062]

[0063] Table 1 above is the surface resistance of Examples 1-4 and Comparative Examples 1-2, as shown in Table 1, according to Examples 1-2 and Comparative Example 1, when the concentration of aniline is the same, with the increase of the concentration of KH560, the resistance first decreases and then increases, and the resistance is the smallest when the concentration is 10 g / L, because the treatment of KH560 promotes the deposition of GO on the fabric, but when the concentration is too high, it is cross-linked and polymerized itself, thereby hindering the deposition of graphene.

[0064] ​As can be seen from Examples 1 and 3-4, when the concentration of KH560 is 10 g / L, the surface resistance also presents a trend of first decreasing and then increasing with the increase of the concentration of aniline, and the resistance is the lowest when the concentration of aniline is 0.5 mol / L. This is because aniline is doped and polymerized in the protonic acid solution, and the surface is positively charged, which can crosslink with the negatively charged graphene loaded on the fiber surface. When the content of aniline is too high, it cannot deposit the fiber and thus aggregates in the solution, at this time, the deposited graphene will partially fall off, thereby causing the resistance to increase;

[0065] As can be seen from Examples 1 and Comparative Examples 1-2, the surface resistance is 4.912 KΩ / Sq (Comparative Example 2) when no KH560 and polyaniline are added, and the resistance is reduced to 1.808 KΩ / Sq (Comparative Example 1) after adding 0.5 mol / L aniline (the resistance is reduced by 63%). On this basis, the surface resistance is reduced to 0.329 KΩ / Sq (Example 1) after the fabric is treated with KH560 (the resistance is reduced by 93%), which proves that the fabric treated with KH560 has a good synergistic effect on the deposition of graphene and polyaniline.

Claims

1. A method for preparing a fiber-based graphene / polyaniline electrocaloric material, characterized in that: The specific steps are as follows: Step (1), graphite foil is used as the positive electrode, platinum wire is used as the negative electrode, concentrated sulfuric acid solution is used as the electrolyte, an electrochemical workstation is connected, a direct current power supply is input, and electricity is passed for 30 min, then the electrochemically modified graphite is collected after filtration, and then the improved Hummers method is used to prepare graphene oxide, and large-size graphene with an average size of > 50 microns is prepared; Step (2), after the polyester fabric is treated by alkali reduction, it is immersed in a silane coupling agent solution with a certain concentration, and the coupling agent is attached to the fiber by the method of immersion-drying; wherein the alkali reduction formula is: NaOH 50g / L, bath ratio = 50:1, 100℃ reaction for 1h; the immersion-drying method is: the silane coupling agent uses one of KH550 and KH560, and the concentration is 5-20g / L, 70℃ reaction for 1h; Step (3), the fabric obtained in step (2) is immersed in the dispersion liquid prepared from the graphene oxide obtained in step (1), so that the graphene oxide is deposited on the fiber, and then the graphene oxide is reduced by a reducing agent to prepare a graphene fabric; wherein the concentration of graphene oxide is 5g / L, the deposition times is 7 times, and the deposition time is 30min; the reducing agent is hydrazine hydrate, and the reduction formula is: 30mL / L hydrazine hydrate is reduced at 90℃ for 2h; Step (4), a proper amount of aniline is dissolved in a proton acid solution, the fabric in step (3) is immersed, and the prepared catalyst is added dropwise under ice bath conditions to prepare a graphene / polyaniline composite material; wherein the concentration of aniline is 0.25-1.25mol / L, the proton acid is hydrochloric acid, and the catalyst is ammonium persulfate, wherein n(aniline):n(ammonium persulfate) = 1:1.

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