Fabric composite processing technology and electromagnetic shielding composite fabric

Abstract

The invention discloses a fabric composite processing technology and an electromagnetic shielding composite fabric, and relates to the technical field of composite fabrics, and the fabric composite processing technology comprises the following steps: 1, acidizing 2-3.5 g of graphene sheets, pouring the acidized graphene sheets into a solvent, carrying out ultrasonic treatment for 40-60 min, adding 1.35-1.52 g of ferric chloride hexahydrate and 4.32-4.65 g of sodium acetate, carrying out mechanical stirring for 10-20 min, and carrying out ultrasonic treatment for 20-30 min; and carrying out ultrasonic treatment for 50-70 min, heating to 160-200 DEG C, carrying out heat preservation for 10-12 h, cooling to room temperature, and sequentially carrying out suction filtration, washing and drying on the product until the weight is constant. According to the preparation method disclosed by the invention, the graphene sheet is acidized, and oxygen-containing functional groups such as hydroxyl and carboxyl are introduced to the surface of the graphene sheet, so that the hydrophilicity of the graphene is improved, the graphene can be better and uniformly mixed with a subsequent solution system, the binding force between the graphene and other substances is improved, and the formation of a stable composite material is facilitated; therefore, the electromagnetic shielding effect can be effectively exerted.

Description

Technical Field

[0001] The present invention relates to the technical field of composite fabrics, and specifically to a fabric composite processing technology and an electromagnetic shielding composite fabric. Background Art

[0002] Electromagnetic shielding fabrics are usually used to make various products such as clothing with electromagnetic protection functions, flexible masks, flexible isolation layers, composite material reinforcements, and stealth materials, and have wide applications and huge demands in the fields of national defense and military, aerospace, electric power and electrical, special industries, electronic information, medical and civilian, etc., and the application prospects are very broad.

[0003] However, in the prior art, silver plating is usually carried out on the surface of the composite fabric to make the fabric have electromagnetic shielding function. However, in some specific environments, such as high humidity, corrosive gas environments containing sulfur, etc., silver is prone to oxidation reaction to generate substances such as silver oxide, which reduces the conductivity and electromagnetic shielding performance of the silver plating layer; for this reason, the present invention proposes a fabric composite processing technology and an electromagnetic shielding composite fabric to solve the above-mentioned problems. Summary of the Invention

[0004] (1) Technical Problems to be Solved

[0005] Aiming at the deficiencies of the prior art, the present invention provides a fabric composite processing technology and an electromagnetic shielding composite fabric, which solve the problems mentioned in the above background art.

[0006] (2) Technical Solutions

[0007] To achieve the above purposes, the present invention is realized through the following technical solutions: A fabric composite processing technology includes the following processing steps:

[0008] Step 1: Acidify 2 - 3.5 g of graphene sheets, then pour them into a solvent, after ultrasonic treatment for 40 - 60 min, add 1.35 - 1.52 g of ferric chloride hexahydrate and 4.32 - 4.65 g of sodium acetate, first mechanically stir for 10 - 20 min, then continue ultrasonic treatment for 50 - 70 min, then heat to 160 - 200 °C and keep warm for 10 - 12 h, and then cool to room temperature. Filter the product by suction, wash it, and dry it to constant weight in sequence;

[0009] Step 2: Disperse the product dried in Step 1 in deionized water to prepare a dispersion with a concentration of 2.5 - 5 mg / mL, then add polyallylamine hydrochloride with a mass ratio of 1:5 - 10 to the product, and stir at room temperature for 2 - 4 h to obtain a mixed dispersion;

[0010] Step 3: Place the fabric successively in the mixed solution, 200 g / L sodium hydroxide solution, and the mixed solution of ethyl acetate and 3-propyltriethoxysilane, then take it out and wash it 4 - 6 times with absolute ethanol, and finally put it in a drying oven at 80 - 90 °C and dry it for 15 - 20 min;

[0011] Step 4: Place the fabric treated in Step 3 in a silver ammonia solution at 35 - 45 °C, stir for 50 - 70 min, then take it out and dry it by blowing air at a temperature of 50 - 60 °C;

[0012] Step 5: First, soak the fabric dried in Step 4 in a sodium polystyrene sulfonate solution with a concentration of 2 - 4 mg / mL for 20 - 35 min and then wash it, then soak it in the mixed dispersion liquid in Step 2 for 20 - 30 min and then wash it. Repeat this operation 4 - 8 times, and finally put it in a drying oven at 60 - 80 °C and dry it for 1 - 2 h.

[0013] Preferably, in Step 1, 2 - 3.5 g of graphene flakes are placed in a mixed acid solution of 90 - 95 mL of concentrated sulfuric acid with a mass fraction of 98% and 30 - 36 mL of concentrated nitric acid with a mass fraction of 68%. After stirring for 10 - 20 min, the temperature is raised to 130 - 140 °C by oil bath, and then continue to stir for 45 - 60 min and then cool naturally. Then, add 1000 mL of deionized water for dilution, let it stand for 10 - 12 h, and then filter under reduced pressure. Finally, filter and place the product in a vacuum drying oven at 55 - 65 °C and dry it for 10 - 12 h.

[0014] Preferably, in Step 1, the solvent is a mixed solution of 80 - 90 mL of ethylene glycol and 2 - 3.2 g of PEG - 200.

[0015] Preferably, in Step 2, the deionized water contains 0.1 - 0.5 mmol of sodium chloride.

[0016] Preferably, in Step 3, the mixed solution is made by mixing 12 - 15 g / L of sodium hydroxide solution and 4.6 - 7 g of fatty alcohol polyoxyethylene ether. The treatment temperature of the fabric in the mixed solution is 60 - 70 °C, and the treatment time is 20 - 30 min.

[0017] Preferably, in Step 3, the treatment temperature of the fabric in 200 g / L sodium hydroxide solution is 55 - 65 °C, and the treatment time is 30 - 40 min.

[0018] Preferably, in Step 3, the treatment temperature of the fabric in the mixed solution of ethyl acetate and 3-propyltriethoxysilane is at room temperature, and the treatment time is 25 - 40 min.

[0019] Preferably, in the fifth step, after the fabric is soaked, it is washed 3-5 times with deionized water.

[0020] (III) Beneficial effects

[0021] The present invention provides a fabric composite processing technology and an electromagnetic shielding composite fabric. Compared with the prior art, it has the following beneficial effects:

[0022] (1) In the present invention, graphene itself has excellent electrical properties and has a certain ability to absorb and scatter electromagnetic waves. By acidifying graphene flakes, oxygen-containing functional groups such as hydroxyl groups and carboxyl groups are introduced on its surface, increasing the hydrophilicity of graphene, enabling it to better mix evenly with the subsequent solution system, and improving the binding force between graphene and other substances, which is beneficial to the formation of a stable composite material, thereby more effectively exerting its electromagnetic shielding effect; at the same time, by reacting with substances such as ferric chloride hexahydrate, iron ions, etc. are evenly loaded on the graphene flakes, thus combining the electrical properties of graphene and the characteristics of iron compounds, making the fabric have more excellent antibacterial properties and electromagnetic loss ability, enhancing the absorption of electromagnetic waves; by adding the polymer electrolyte polyallylamine hydrochloride, it interacts with the surface of the composite through electrostatic action or chemical bonding, further improving the dispersibility and stability of the composite in the solution, and at the same time, its own polymer structure can produce a certain scattering and absorption effect on electromagnetic waves, thereby enhancing the electromagnetic shielding performance of the entire system.

[0023] (2) In the present invention, by treating the fabric, impurities and oils on the fabric surface are removed, making the fabric surface clean and having a certain hydrophilicity. The fabric surface is etched with a 200 g / L sodium hydroxide solution to increase the surface roughness and specific surface area, which is beneficial to the adhesion of subsequent substances. The fabric is treated with a mixed solution of ethyl acetate and 3-propyltriethoxysilane to form an organosilicon film on the fabric surface. On the one hand, it can improve the adhesion and chemical stability of the fabric surface, and on the other hand, it can more firmly bind the substances introduced in the subsequent treatment to the fabric surface through chemical bonding to form a stable shielding layer.

[0024] (3) In the present invention, by immersing the fabric in a silver ammonia solution, silver particles are evenly deposited on the fabric surface, which can not only play an antibacterial and disinfection role, but also may form chemical bonds or physical adsorption with the substances introduced in other treatment steps, enhancing the binding force between layers. At the same time, since silver itself is a good conductor and has excellent electromagnetic reflection performance, it can effectively reflect electromagnetic waves, thereby improving the electromagnetic shielding effect of the fabric.

[0025] (4) In the present invention, by alternately soaking the fabric in the sodium polystyrene sulfonate solution and the mixed dispersion liquid, a uniform and stable polymer film is formed on the fabric surface by sodium polystyrene sulfonate, which improves the stability and durability of the fabric, and increases the charge density and polarity of the fabric surface, facilitating the tight binding with the complex in the mixed dispersion liquid through electrostatic interaction and hydrogen bond and other interactions. At the same time, through repeated operations for multiple times, a multi-layer structure is formed on the fabric surface, which can reflect, scatter and absorb electromagnetic waves multiple times, thereby significantly improving the electromagnetic shielding performance of the fabric. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is the SEM diagram of the product in Step 1 provided by the present invention. SPECIFIC EMBODIMENTS

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] In this application, the fabric can be selected from natural fiber fabrics (such as cotton fabrics, linen fabrics) and synthetic fiber fabrics (such as polyester fiber fabrics, nylon fiber fabrics).

[0029] Preparation method of silver ammonia solution: Slowly add 1-2 mL of distilled water dropwise to 0.1-0.5 g of silver nitrate solid, and gently stir to completely dissolve the silver nitrate to form a colorless and transparent dilute silver nitrate solution; then gradually add 2%-5% dilute ammonia water, and white silver hydroxide precipitate will be formed. Continue to add dropwise, and the precipitate will gradually dissolve. Keep adding dilute ammonia water until the initially formed white precipitate is just completely dissolved. At this time, the obtained clear solution is the silver ammonia solution.

[0030] Example 1

[0031] A fabric composite processing technology includes the following processing technologies:

[0032] Step 1: Acidify 2 g of graphene sheets, then pour them into a mixed solution of 80 mL of ethylene glycol and 2 g of PEG-200. After ultrasonic treatment for 40 min, add 1.35 g of ferric chloride hexahydrate and 4.32 g of sodium acetate. First, mechanically stir for 10 min, then continue ultrasonic treatment for 50 min, then heat to 160 °C and keep warm for 10 h, and then cool to room temperature. Filter the product by suction, wash it, and dry it to constant weight in sequence;

[0033] Among them, the acidification treatment method of the graphene sheets is as follows: Place 2 g of graphene sheets in a mixed acid solution containing 90 mL of concentrated sulfuric acid with a mass fraction of 98% and 30 mL of concentrated nitric acid with a mass fraction of 68%. After stirring for 10 min, heat the oil bath to 130 °C, continue stirring for 45 min, and then cool naturally. Then add 1000 mL of deionized water for dilution, let it stand for 10 h, carry out vacuum filtration under reduced pressure, and finally filter and place the product in a vacuum drying oven at 55 °C for drying for 10 h;

[0034] Step 2: Disperse the dried product in Step 1 in deionized water containing 0.1 mmol of sodium chloride to prepare a dispersion with a concentration of 2.5 mg / mL. Then add polyallylamine hydrochloride with a mass ratio of 1:5 to the product and stir at room temperature for 2 h to obtain a mixed dispersion;

[0035] Step 3: First place the fabric in a mixed solution of 12 g / L sodium hydroxide solution and 4.6 g of fatty alcohol polyoxyethylene ether, heat to 60 °C and treat for 20 min. Then place it in a 200 g / L sodium hydroxide solution, cool to 55 °C and treat for 30 min. Finally, place it in a mixed solution of ethyl acetate and 3-propyltriethoxysilane, treat at room temperature for 25 min, then take it out and wash it 4 times with absolute ethanol, and finally put it in a drying oven at 80 °C for drying for 15 min;

[0036] Step 4: Place the fabric treated in Step 3 in a silver ammonia solution at 35 °C, stir and treat for 50 min, then take it out and dry it by blowing air at a temperature of 50 °C;

[0037] Step 5: First soak the fabric dried in Step 4 in a sodium polystyrene sulfonate solution with a concentration of 2 mg / mL for 20 min, then wash it 3 times with deionized water. Then soak it in the mixed dispersion in Step 2 for 20 min, and then wash it 3 times with deionized water. Repeat this operation 4 times, and finally put it in a drying oven at 60 °C for drying for 1 h.

[0038] Example 2

[0039] A fabric composite processing technology, including the following processing technologies:

[0040] Step 1: Acidify 3 g of graphene sheets, then pour them into a mixed solution of 85 mL of ethylene glycol and 2.6 g of PEG-200. After ultrasonic treatment for 50 min, add 1.45 g of ferric chloride hexahydrate and 4.5 g of sodium acetate. First, mechanically stir for 15 min, then continue ultrasonic treatment for 60 min, then heat to 180 °C and keep it warm for 11 h, and then cool to room temperature. Carry out suction filtration, washing, and drying of the product to constant weight in sequence;

[0041] Among them, the acidification treatment method of the graphene sheets is as follows: Place 3 g of graphene sheets in a mixed acid solution of 92 mL of concentrated sulfuric acid with a mass fraction of 98% and 33 mL of concentrated nitric acid with a mass fraction of 68%. After stirring for 15 min, heat the oil bath to 135 °C, continue to stir for 50 min, then cool naturally. Then add 1000 mL of deionized water for dilution, let it stand for 11 h, carry out vacuum filtration under reduced pressure, and finally filter and place the product in a vacuum drying oven at 60 °C for drying for 11 h;

[0042] Step 2: Disperse the dried product in Step 1 in deionized water containing 0.35 mmol of sodium chloride to prepare a dispersion with a concentration of 4 mg / mL. Then add polyallylamine hydrochloride with a mass ratio of 1:8 to the product and stir at room temperature for 3 h to obtain a mixed dispersion;

[0043] Step 3: First place the fabric in a mixed solution of 13 g / L sodium hydroxide solution and 5.5 g of fatty alcohol polyoxyethylene ether, heat to 65 °C and treat for 25 min. Then place it in a 200 g / L sodium hydroxide solution, cool to 60 °C and treat for 35 min. Finally, place it in a mixed solution of ethyl acetate and 3-propyltriethoxysilane, treat at room temperature for 30 min, then take it out and wash it 5 times with absolute ethanol, and finally put it in a drying oven at 85 °C for drying for 18 min;

[0044] Step 4: Place the fabric treated in Step 3 in a silver ammonia solution at 40 °C, stir and treat for 60 min, then take it out and dry it by blowing air at a temperature of 55 °C;

[0045] Step 5: First soak the fabric dried in Step 4 in a sodium polystyrene sulfonate solution with a concentration of 3 mg / mL for 30 min, then wash it 4 times with deionized water. Then soak it in the mixed dispersion in Step 2 for 25 min, and then wash it 4 times with deionized water. Repeat this operation 6 times, and finally put it in a drying oven at 70 °C for drying for 1.5 h.

[0046] Example 3

[0047] A fabric composite processing technology, including the following processing technologies:

[0048] Step 1: Acidify 3.5 g of graphene sheets, then pour them into a mixed solution of 90 mL of ethylene glycol and 3.2 g of PEG-200. After ultrasonic treatment for 60 min, add 1.52 g of ferric chloride hexahydrate and 4.65 g of sodium acetate. First, mechanically stir for 20 min, then continue ultrasonic treatment for 70 min. Then heat to 200 °C and keep warm for 12 h, and then cool to room temperature. Carry out suction filtration, washing, and drying of the product to constant weight in sequence;

[0049] Among them, the acidification treatment method of graphene sheets is as follows: Place 3.5 g of graphene sheets in a mixed acid solution of 95 mL of concentrated sulfuric acid with a mass fraction of 98% and 36 mL of concentrated nitric acid with a mass fraction of 68%. After stirring for 20 min, heat the oil bath to 140 °C, continue stirring for 60 min, then cool naturally. Then add 1000 mL of deionized water for dilution, let it stand for 12 h, carry out vacuum filtration under reduced pressure, and finally filter and place the product in a vacuum drying oven at 65 °C for drying for 12 h;

[0050] Step 2: Disperse the dried product in Step 1 in deionized water containing 0.5 mmol of sodium chloride to prepare a dispersion with a concentration of 5 mg / mL. Then add polyallylamine hydrochloride with a mass ratio of 1:10 to the product and stir at room temperature for 4 h to obtain a mixed dispersion;

[0051] Step 3: First place the fabric in a mixed solution of 15 g / L sodium hydroxide solution and 7 g of fatty alcohol polyoxyethylene ether, heat to 70 °C and treat for 30 min. Then place it in a 200 g / L sodium hydroxide solution, cool to 65 °C and treat for 40 min. Finally, place it in a mixed solution of ethyl acetate and 3-propyltriethoxysilane and treat at room temperature for 40 min. Then take it out and wash it 6 times with absolute ethanol. Finally, put it in a drying oven at 90 °C for drying for 20 min;

[0052] Step 4: Place the fabric treated in Step 3 in a silver ammonia solution at 45 °C, stir and treat for 70 min, then take it out and dry it by blowing air at a temperature of 60 °C;

[0053] Step 5: First soak the fabric dried in Step 4 in a sodium polystyrene sulfonate solution with a concentration of 4 mg / mL for 35 min, then wash it 5 times with deionized water. Then soak it in the mixed dispersion in Step 2 for 30 min, and then wash it 5 times with deionized water. Repeat this operation 8 times. Finally, put it in a drying oven at 80 °C for drying for 2 h.

[0054] Comparative Example 1

[0055] Step 1: First place the fabric in a mixed solution of 12 g / L sodium hydroxide solution and 4.6 g of fatty alcohol polyoxyethylene ether, heat to 60 °C and treat for 20 min. Then place it in a 200 g / L sodium hydroxide solution, cool to 55 °C and treat for 30 min. Finally, place it in a mixed solution of ethyl acetate and 3-propyltriethoxysilane and treat at room temperature for 25 min. Then take it out and wash it 4 times with absolute ethanol. Finally, put it in a drying oven at 80 °C for drying for 15 min;

[0056] Step 2: Place the fabric treated in Step 1 in a silver ammonia solution at 35 °C, stir and treat for 50 min, then take it out and dry it by blowing air at a temperature of 50 °C.

[0057] Comparative Example 2

[0058] The fabric was placed in a silver ammonia solution at 35°C, stirred for 50 min, then taken out and dried by blowing air at a temperature of 50°C.

[0059] Electromagnetic shielding effectiveness test: The test was carried out with reference to GJB 8820-2015; the results are shown in Table 1.

[0060] Bacteriostatic rate test: The test was carried out with reference to GB / T 20944.2-2007; the results are shown in Table 1.

[0061] Table 1

[0062]

[0063] As shown in Table 1, the bacteriostatic rates and electromagnetic shielding performances of the samples in Examples 1-3 were significantly improved compared with those in Comparative Examples 1-2.

[0064] As Figure 1 shown, the graphene sheets reacted with substances such as ferric chloride hexahydrate, enabling iron ions and the like to be uniformly loaded on the graphene sheets.

[0065] Meanwhile, the content not described in detail in this specification belongs to the prior art well known to those skilled in the art.

[0066] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A fabric composite processing technology, characterized in that, It includes the following processing techniques: Step 1: Acidify 2 - 3.5 g of graphene sheets, then pour them into a solvent. After ultrasonic treatment for 40 - 60 min, add 1.35 - 1.52 g of ferric chloride hexahydrate and 4.32 - 4.65 g of sodium acetate. First, mechanically stir for 10 - 20 min, then continue ultrasonic treatment for 50 - 70 min, then heat to 160 - 200 °C and keep warm for 10 - 12 h, and then cool to room temperature. Filter, wash, and dry the product to constant weight in sequence; Step 2: Disperse the dried product in Step 1 in deionized water to prepare a dispersion with a concentration of 2.5 - 5 mg / mL, and then add polyallylamine hydrochloride with a mass ratio of 1:5 - 10 to the product. Stir at room temperature for 2 - 4 h to obtain a mixed dispersion; Step 3: Place the fabric in the mixed solution, 200 g / L sodium hydroxide solution, and a mixed solution of ethyl acetate and 3 - propyltriethoxysilane in sequence, then take it out and wash it 4 - 6 times with absolute ethanol, and finally put it in a drying oven at 80 - 90 °C and dry for 15 - 20 min; Step 4: Place the fabric treated in Step 3 in a silver ammonia solution at 35 - 45 °C, stir for 50 - 70 min, then take it out and dry it by air blowing at a temperature of 50 - 60 °C; Step 5: First, soak the fabric dried in Step 4 in a sodium polystyrene sulfonate solution with a concentration of 2 - 4 mg / mL for 20 - 35 min and then wash it, then soak it in the mixed dispersion in Step 2 for 20 - 30 min and then wash it. Repeat this operation 4 - 8 times, and finally put it in a drying oven at 60 - 80 °C and dry for 1 - 2 h.

2. A fabric composite processing technology according to claim 1, characterized in that: In Step 1, place 2 - 3.5 g of graphene sheets in a mixed acid solution of 90 - 95 mL of concentrated sulfuric acid with a mass fraction of 98% and 30 - 36 mL of concentrated nitric acid with a mass fraction of 68%. After stirring for 10 - 20 min, raise the temperature of the oil bath to 130 - 140 °C, then continue stirring for 45 - 60 min and then cool naturally. Then add 1000 mL of deionized water for dilution, let it stand for 10 - 12 h and then carry out vacuum filtration under reduced pressure. Finally, filter and place the product in a vacuum drying oven at 55 - 65 °C and dry for 10 - 12 h.

3. A fabric composite processing technology according to claim 1, characterized in that: In Step 1, the solvent is a mixed solution of 80 - 90 mL of ethylene glycol and 2 - 3.2 g of PEG - 200.

4. A fabric composite processing technology according to claim 1, characterized in that: In Step 2, the deionized water contains 0.1 - 0.5 mmol of sodium chloride.

5. A fabric composite processing technology according to claim 1, characterized in that: In Step 3, the mixed solution is made by mixing 12 - 15 g / L of sodium hydroxide solution and 4.6 - 7 g of fatty alcohol polyoxyethylene ether. The treatment temperature of the fabric in the mixed solution is 60 - 70 °C, and the treatment time is 20 - 30 min.

6. A fabric composite processing technology according to claim 1, characterized in that: In Step 3, the treatment temperature of the fabric in 200 g / L sodium hydroxide solution is 55 - 65 °C, and the treatment time is 30 - 40 min.

7. A fabric composite processing technology according to claim 1, characterized in that: In Step 3, the treatment temperature of the fabric in the mixed solution of ethyl acetate and 3 - propyltriethoxysilane is room temperature, and the treatment time is 25 - 40 min.

8. A fabric composite processing technology according to claim 1, characterized in that: In Step 5, after the fabric is soaked, wash it 3 - 5 times with deionized water.

9. An electromagnetic shielding composite fabric prepared by the fabric composite processing technology according to any one of claims 1-8.

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