Preparation method of super-amphiphobic wave-absorbing fabric based on MoS2 / RGO composite material

Abstract

The application relates to a preparation method of a MoS2 / RGO composite-based super-biphobic wave-absorbing fabric, in which dopamine-modified fabric is immersed in a fluorinated MoS2 / RGO dispersion solution, and then is subjected to padding, pre-drying and baking to obtain the MoS2 / RGO composite-based super-biphobic wave-absorbing fabric; the fluorinated MoS2 / RGO dispersion solution is obtained by stirring at room temperature after adding tetraethyl orthosilicate, fluorosilane and ammonia water into an ethanol dispersion solution of the MoS2 / RGO composite; the water contact angle of the product is not less than 162.8 DEG, the oil contact angle is not less than 150.4 DEG, the minimum reflection loss (RL min ) is not higher than-50.68 dB, and the effective absorption bandwidth is 3.54-3.99 GHz. The product prepared by the method has excellent wave-absorbing performance, and the super-biphobic performance can effectively avoid adhesion or corrosion damage of a large amount of pollutants, and realizes long service life of electromagnetic shielding.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wave-absorbing fabrics, and relates to a preparation method of super-amphiphobic wave-absorbing fabric based on MoS2 / RGO composite materials. BACKGROUND

[0002] With the rapid development of electronic technology, microwave absorbing materials play an important role in solving the problem of electromagnetic pollution. Giving fabrics wave-absorbing properties is widely used in wearable displays, biomedical sensors, radiation-proof clothing, etc. An ideal wave-absorbing fabric should be soft, breathable and waterproof to ensure comfort and durability, and ensure long-term use. However, most of the wave-absorbing fabric surfaces are hydrophilic, and when they are used in actual application environments such as rain, ice, humidity, dust, etc., these contaminants will affect normal use, and their wave-absorbing properties are easily damaged or lost during use, greatly reducing their service life; and most sensors are sensitive to water and easily eroded by water, and also have a lot of human sweat, which causes serious signal distortion, thereby limiting their application. Although these problems can be solved by giving the wave-absorbing fabric a super-hydrophobic surface. However, super-hydrophobic surfaces are easily contaminated by organic liquids with lower surface tension (such as wax esters, triglycerides, etc.) in the real environment, which seriously hinders their application. Unlike super-hydrophobic surfaces, super-amphiphobic surfaces are repulsive to both low-surface-tension water and organic liquids, so super-amphiphobic wave-absorbing textiles have a wider application prospect.

[0003] The document (Metal-Organic Framework Derived Multidimensional Carbon / Multifluorination Epoxy Nanocomposite with Electromagnetic Wave Absorption, Environmentally Adaptive, and Blue Energy Harvesting [J]. Small Structures, 2023, 4(11): 2300210.) prepared CoCNT and FeNirGO multidimensional nanofillers by in-situ growth and high-temperature pyrolysis, then added the multidimensional nanofillers to a long-chain perfluorinated epoxy resin matrix through C-F…π interaction, and finally obtained a CoC@FeNiG-F nanocomposite with super-amphiphobicity and wave-absorbing properties by a microwave irradiation method. In the document, CoCNT and FeNirGO are mainly used as wave-absorbing agents, which have excellent wave-absorbing effect, but the preparation process of MOF-derived multidimensional carbon is complex, the yield is low, and it does not involve fabric surfaces, which has certain limitations in the field of industrialized super-amphiphobic wave-absorbing fabrics.

[0004] Chinese patent CN110144135A discloses a super-bi-scratching coating material and its preparation method, and a super-bi-scratching coating. The prepared super-bi-scratching coating has the effect of super-hydrophobicity and super-oleophobicity, but the invention processes the micron powder and the nanometer powder step by step for hydrophobic and oleophobic treatment, the process steps are complex, and at the same time, it does not involve the wave absorption performance, the functionalization is single, and it does not meet the current social demand for multifunctional fabrics.

[0005] Chinese patent CN103709882A discloses a super-bi-scratching surface with universality and its preparation method. The method is suitable for glass sheet, cotton cloth, filter paper, film material, metal sheet and other substrate materials. However, the method uses fluorine-containing epoxy resin as a binder to bond microspheres and the substrate together, which greatly affects the air permeability of the fabric, and also cannot meet the requirement of wave absorption performance.

[0006] Therefore, it is of great significance to study a preparation method of super-bi-scratching wave-absorbing fabric based on MoS2 / RGO composite material to solve the problems in the prior art. SUMMARY

[0007] The purpose of the present application is to solve the problems in the prior art and provide a preparation method of super-bi-scratching wave-absorbing fabric based on MoS2 / RGO composite material.

[0008] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0009] A preparation method of super-bi-scratching wave-absorbing fabric based on MoS2 / RGO composite material, wherein the dopamine-modified fabric is immersed in a fluorinated MoS2 / RGO dispersion liquid, and then is subjected to padding, pre-drying and baking in sequence to obtain the super-bi-scratching wave-absorbing fabric based on MoS2 / RGO composite material;

[0010] The fluorinated MoS2 / RGO dispersion liquid is obtained by adding tetraethyl orthosilicate (TEOS), fluorosilane and ammonia (NH3·H2O) to the ethanol dispersion liquid of MoS2 / RGO composite material and then stirring at room temperature;

[0011] The water contact angle of the super-bi-scratching wave-absorbing fabric based on MoS2 / RGO composite material is not less than 162.8°, the oil contact angle is not less than 150.4°, the minimum reflection loss (RL min ) is not higher than -50.68 dB, and the effective absorption bandwidth is 3.54-3.99 GHz. The super-bi-scratching wave-absorbing fabric based on MoS2 / RGO composite material has excellent wave absorption performance, and the super-bi-scratching performance can effectively avoid the adhesion or corrosion damage of a large amount of pollutants, realizing long service life of electromagnetic shielding.

[0012] As a preferred technical scheme:

[0013] The preparation method of the super-amphiphobic wave-absorbing fabric based on the MoS2 / RGO composite material as described above, the volume ratio of tetraethyl orthosilicate to fluorosilane is 1:1-2, and the volume ratio of tetraethyl orthosilicate, ammonia water and the ethanol dispersion solution of the MoS2 / RGO composite material is 1:10:50.

[0014] The fluorosilane is perfluorooctyltrichlorosilane, perfluorooctyltrimethoxysilane, perfluorooctyltriethoxysilane, perfluorodecyltrichlorosilane, perfluorodecyltrimethoxysilane or perfluorodecyltriethoxysilane.

[0015] The preparation method of the super-amphiphobic wave-absorbing fabric based on the MoS2 / RGO composite material as described above, the mass fraction of the ethanol dispersion solution of the MoS2 / RGO composite material is 0.5-2.5wt%.

[0016] The preparation method of the super-amphiphobic wave-absorbing fabric based on the MoS2 / RGO composite material as described above, the preparation process of the dopamine-modified fabric is that dopamine is dissolved in a Tris-HCl buffer solution to obtain a mixed solution, the fabric is immersed in the mixed solution, taken out after oscillation at room temperature, and cleaned and dried to obtain the dopamine-modified fabric.

[0017] The preparation method of the super-amphiphobic wave-absorbing fabric based on the MoS2 / RGO composite material as described above, the content of dopamine in the mixed solution is 0.1-0.5wt%.

[0018] The preparation method of the super-amphiphobic wave-absorbing fabric based on the MoS2 / RGO composite material as described above, the fabric is a polyester fabric, a cotton fabric, a soybean fiber fabric, a milk fabric, a wool fabric, a polysulfone fabric, a polyester-cotton blended fabric or a cotton-ramie blended fabric.

[0019] The preparation method of the super-amphiphobic wave-absorbing fabric based on the MoS2 / RGO composite material as described above, the preparation process of the MoS2 / RGO composite material is that ammonium molybdate tetrahydrate, thiourea and graphene oxide (RGO) are dissolved and dispersed in deionized water, the mixture is uniformly mixed and then ultrasonically treated, the ultrasonically treated mixture is transferred into a reaction kettle for hydrothermal reaction, and the product of the hydrothermal reaction is centrifugally cleaned with anhydrous ethanol and deionized water, respectively, and then vacuum dried to obtain the MoS2 / RGO composite material.

[0020] The preparation method of the super-amphiphobic wave-absorbing fabric based on the MoS2 / RGO composite material as described above, the molar ratio of ammonium molybdate tetrahydrate to thiourea is 1:3, the mass ratio of thiourea to graphene oxide is 228:105-210, and the mass ratio of thiourea to deionized water is 3-6:100.

[0021] The preparation method of the super-dual-absorbing wave fabric based on the MoS2 / RGO composite material as described above, the temperature of the hydrothermal reaction is 180-260 DEG C, and the time is 8-16h.

[0022] The preparation method of the super-dual-absorbing wave fabric based on the MoS2 / RGO composite material as described above, the impregnation time is 30-90min, the liquid rate during impregnation is 70-85%, the baking temperature is 100-200 DEG C, and the baking time is 10-60min.

[0023] Invention principle:

[0024] The application prepares fluorosilane MoS2 / RGO dispersion liquid by hydrolysis and dehydration condensation reaction of TEOS and fluorosilane under alkaline conditions and hydroxyl on the surface of the MoS2 / RGO composite material, then deposits fluorinated MoS2 / RGO composite material on the surface of the dopamine modified fabric, and obtains durable super-dual-absorbing wave fabric with excellent absorbing wave performance.

[0025] The excellent absorbing wave performance of the MoS2 / RGO composite material is determined by excellent impedance matching performance, high attenuation constant and excellent dielectric loss characteristics, which are derived from the modulation of interface polarization center, the defects in the carbon skeleton and the three-dimensional interconnected conductive network between MoS2 and RGO. First, the addition of RGO improves the impedance matching of the interface, so that the three-dimensional porous MoS2 / RGO composite material can absorb more electromagnetic waves, instead of reflection between the boundary of air and the absorber. At the same time, due to the continuous structure, the incident electromagnetic wave is further absorbed in the MoS2 / RGO composite material and is not easy to transmit. Second, the existence of multiple polarization is the main reason for dielectric loss, including the dipole polarization produced by the functional defects of RGO and the bound charges of MoS2 nanosheet. In addition, there is also interface polarization in the rich interface of MoS2 and the interface between MoS2 nanosheet and RGO microsheet. Fluorinated modification is carried out on the MoS2 / RGO composite material by hydrolysis of fluorosilane under alkaline conditions. The dehydration condensation of fluorosilane and TEOS generates SiO2 nanoparticles on the surface of the MoS2 / RGO composite material. The SiO2 nanoparticles form a heterojunction interface with the surface of the composite material, further improving the interface polarization performance of the absorbing wave material. At the same time, the addition of SiO2 nanoparticles increases the reflection times of electromagnetic waves and the transmission path, gradually attenuates the energy of the incident wave, and improves the microwave energy loss capacity of the fluorinated MoS2 / RGO composite material.

[0026] In addition, inspired by the hydrophobic phenomenon in nature, low surface energy materials and micro-nano rough structure are the premise to realize super double-surface. MoS2 / RGO composite material has high porosity and three-dimensional porous micro-multiple concave rough structure characteristics, hydrolyzing TEOS and fluorosilane under alkaline conditions to generate fluorosiloxane with active chemical properties of silanol, and dehydrating and condensing with the surface hydroxyl group of MoS2 / RGO composite material, -CF3 group covers the surface of MoS2 / RGO composite material to form a thin film with low surface tension, which reduces the surface energy of MoS2 / RGO composite material; Dehydrating and condensing fluorosilane and TEOS generates SiO2 nanoparticles, which can further increase the roughness of the surface of MoS2 / RGO composite material.

[0027] MoS2 / RGO composite material is applied to the surface of the substrate through coating, but the durability of the coating is still a major problem. Dopamine is an organic compound containing rich catechol and amino functional groups, which can deposit a polymer film on the surface of the fabric after oxidation and polymerization, so that the durability and corrosion resistance of the coating are significantly improved.

[0028] Beneficial effects:

[0029] (1) The preparation method of the super double-surface wave-absorbing fabric based on MoS2 / RGO composite material has excellent dielectric loss performance. MoS2 with nano-flower structure and layered RGO with low density, large specific surface area and high conductivity synergistically optimize the impedance matching of the fabric, so that more electromagnetic waves can enter the interior of the fabric, and a small amount of reflected electromagnetic waves are reflected multiple times between the fabrics. The dense coating formed on the surface of the fabric effectively builds a continuous conductive network, and the electromagnetic waves are dissipated by conductive loss in the conductive network. At the same time, there are a large number of heterojunctions and dipoles on the surface of the super double-surface wave-absorbing fabric based on MoS2 / RGO composite material, which can produce a large number of interface polarization and dipole polarization phenomena after the electromagnetic waves enter, and the polarization relaxation enhances the dissipation ability of the material to electromagnetic waves, so the material has excellent wave-absorbing performance.

[0030] (2) The preparation method of the super double-surface wave-absorbing fabric based on MoS2 / RGO composite material gives the wave-absorbing fabric super double-surface performance, effectively avoids the adhesion or corrosion damage of a large amount of pollutants, realizes long service life of electromagnetic shielding, and does not affect the air permeability of the fabric.

[0031] (3) The preparation method of the super double-surface wave-absorbing fabric based on MoS2 / RGO composite material has simple process, and the prepared super double-surface wave-absorbing fabric has wide application range. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 SEM diagram of fluorinated MoS2 / RGO composite material of Example 2;

[0033] Figure 2 SEM image of the super-amphiphobic wave-absorbing fabric of Example 3;

[0034] Figure 3 Reflection loss image of the super-amphiphobic wave-absorbing fabric of Example 3;

[0035] Figure 4 Contact angle image of Example 4; the left image is the water contact angle, and the right image is the oil contact angle. DETAILED DESCRIPTION

[0036] The application will be further described below in connection with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not used to limit the scope of the application. Furthermore, it should be understood that after reading the content of the application, those skilled in the art can make various modifications or changes to the application, and these equivalent forms also fall within the scope of the appended claims.

[0037] The test methods involved in the performance indicators in the examples and comparative examples of the application are as follows:

[0038] Contact angle (CA): The contact angle of the sample is tested at a temperature of 25°C using a video contact angle measuring instrument of type DSA30S, with water / oil as the test liquid, and a droplet of 5uL in volume is used for testing. For each sample, 5 measurements at different positions are made, and the average value is taken as the average result.

[0039] Reflection loss (RL): The electromagnetic parameters of the super-amphiphobic wave-absorbing fabric are measured using a vector network analyzer (VNA). The results are imported into an RL calculation program to simulate the RL values of the super-amphiphobic wave-absorbing fabric of different thicknesses.

[0040] Effective absorption bandwidth (EAB): The frequency range in which the super-amphiphobic wave-absorbing fabric has an electromagnetic wave absorption loss of -10dB.

[0041] Example 1

[0042] A preparation method of a super-amphiphobic wave-absorbing fabric based on a MoS2 / RGO composite material, the specific steps are as follows:

[0043] (1) First, ammonium molybdate tetrahydrate, thiourea and graphene oxide are dispersed in deionized water, mixed uniformly, and then subjected to ultrasonic treatment. Then, the mixed solution after ultrasonic treatment is transferred into a reaction kettle for hydrothermal reaction at a temperature of 180°C for 8h. Finally, the product of the hydrothermal reaction is centrifugally cleaned with anhydrous ethanol and deionized water, respectively, and vacuum dried after centrifugal cleaning to obtain a MoS2 / RGO composite material;

[0044] The molar ratio of ammonium molybdate tetrahydrate to thiourea is 1:3, the mass ratio of thiourea to graphene oxide is 228:105, and the mass ratio of thiourea to deionized water is 3:100.

[0045] (2) After adding tetraethyl orthosilicate, perfluorooctyltrimethoxysilane and ammonia water into the ethanol dispersion of MoS2 / RGO composite material, stirring at room temperature to obtain a fluorinated MoS2 / RGO dispersion;

[0046] The mass fraction of the ethanol dispersion of MoS2 / RGO composite material is 0.5wt%; the volume ratio of tetraethyl orthosilicate to perfluorooctyltrimethoxysilane is 1:1, and the volume ratio of tetraethyl orthosilicate, ammonia water to the ethanol dispersion of MoS2 / RGO composite material is 1:10:50;

[0047] (3) First, dissolve dopamine in Tris-HCl buffer solution with pH=8.5 to obtain a mixed solution with a dopamine content of 0.1wt%, then immerse the polyester fabric in the mixed solution, take it out after oscillation at room temperature, and clean and dry it to obtain a dopamine modified fabric;

[0048] (4) Soak the dopamine modified fabric of step (3) in the fluorinated MoS2 / RGO dispersion of step (2) for 30 minutes, and then perform padding, pre-drying and baking at 120℃ for 50 minutes to obtain a MoS2 / RGO composite material-based super-amphiphobic wave-absorbing fabric;

[0049] The liquid retention rate during padding is 70%.

[0050] The water contact angle of the finally prepared MoS2 / RGO composite material-based super-amphiphobic wave-absorbing fabric is 162.9°, the oil contact angle is 152.6°, the minimum reflection loss is-51.29dB, and the effective absorption bandwidth is 3.62GHz.

[0051] Example 2

[0052] A method for preparing a MoS2 / RGO composite material-based super-amphiphobic wave-absorbing fabric, the specific steps are as follows:

[0053] (1) First, disperse ammonium molybdate tetrahydrate, thiourea and graphene oxide in deionized water, mix uniformly, then perform ultrasonic treatment, then transfer the mixed solution after ultrasonic treatment into a reaction kettle, and perform hydrothermal reaction at a temperature of 180℃ for 8h, finally centrifugally clean the product of hydrothermal reaction with anhydrous ethanol and deionized water, and vacuum dry after centrifugal cleaning to obtain MoS2 / RGO composite material;

[0054] The molar ratio of ammonium molybdate tetrahydrate to thiourea is 1:3, the mass ratio of thiourea to graphene oxide is 228:210, and the mass ratio of thiourea to deionized water is 6:100.

[0055] (2) Tetraethyl orthosilicate, perfluorodecyltriethoxysilane and ammonia were added to the ethanol dispersion of MoS2 / RGO composite material and stirred at room temperature to obtain fluorinated MoS2 / RGO dispersion.

[0056] The mass fraction of the ethanol dispersion of the MoS2 / RGO composite material is 0.5 wt%; the volume ratio of tetraethyl orthosilicate to perfluorodecyltriethoxysilane is 1:1; and the volume ratio of tetraethyl orthosilicate, ammonia and the ethanol dispersion of the MoS2 / RGO composite material is 1:10:50.

[0057] Fluorinated MoS2 / RGO dispersions can be vacuum dried at 60°C to obtain fluorinated MoS2 / RGO composites. SEM images of the fluorinated MoS2 / RGO composites are shown below. Figure 1 As shown, RGO is reduced to form plate-like RGO, while MoS2 forms in situ on the RGO surface, resulting in a MoS2 / RGO composite material with a three-dimensional porous flower-like structure. Fluorination modification of the MoS2 / RGO composite material using perfluorodecyltriethoxysilane and TEOS produced SiO2 nanospheres, further improving the surface roughness of the material.

[0058] (3) First, dopamine is dissolved in Tris-HCl buffer solution with pH=8.5 to obtain a mixture with a dopamine content of 0.1wt%. Then, cotton fabric is immersed in the mixture, shaken at room temperature, taken out, washed and dried to obtain dopamine modified fabric.

[0059] (4) The dopamine-modified fabric from step (3) was immersed in the fluorinated MoS2 / RGO dispersion from step (2) for 45 min, and then subjected to padding, pre-drying, and baking at 100°C for 60 min to obtain a super-dual-absorbent wave fabric based on MoS2 / RGO composite material.

[0060] The liquid retention rate during immersion was 70%.

[0061] The final fabric based on MoS2 / RGO composite material has a water contact angle of 162.8°, an oil contact angle of 150.4°, a minimum reflection loss of -50.68dB, and an effective absorption bandwidth of 3.54GHz.

[0062] Example 3

[0063] A method for preparing a superabsorbent wave fabric based on MoS2 / RGO composite material, the specific steps of which are as follows:

[0064] (1) First, ammonium molybdate tetrahydrate, thiourea and graphene oxide are dispersed in deionized water, mixed uniformly, and then ultrasonic treatment is performed, then the mixed solution after ultrasonic treatment is transferred into a reaction kettle for hydrothermal reaction at a temperature of 220℃ for 12h, finally the product of hydrothermal reaction is centrifugally cleaned with anhydrous ethanol and deionized water respectively, and vacuum drying is performed after centrifugal cleaning to obtain MoS2 / RGO composite material;

[0065] The molar ratio of ammonium molybdate tetrahydrate to thiourea is 1:3, the mass ratio of thiourea to graphene oxide is 228:105, and the mass ratio of thiourea to deionized water is 3:100;

[0066] (2) After adding tetraethyl orthosilicate, perfluorodecyl triethoxysilane and ammonia water to the ethanol dispersion of MoS2 / RGO composite material, stirring at room temperature to obtain fluorinated MoS2 / RGO dispersion;

[0067] The mass fraction of the ethanol dispersion of MoS2 / RGO composite material is 1.5wt%; the volume ratio of tetraethyl orthosilicate to perfluorodecyl triethoxysilane is 1:2, and the volume ratio of tetraethyl orthosilicate, ammonia water to the ethanol dispersion of MoS2 / RGO composite material is 1:10:50;

[0068] (3) First, dopamine is dissolved in Tris-HCl buffer solution with pH=8.5 to obtain a mixed solution with dopamine content of 0.3wt%, then the cotton fabric is immersed in the mixed solution, taken out after room temperature oscillation, and cleaned and dried to obtain dopamine modified fabric;

[0069] (4) The dopamine modified fabric of step (3) is immersed in the fluorinated MoS2 / RGO dispersion of step (2) for 60min, and then is subjected to padding, pre-drying and 150℃ baking for 30min in sequence to prepare MoS2 / RGO composite material-based super-amphiphobic wave-absorbing fabric;

[0070] The liquid retention rate during padding is 75%.

[0071] The water contact angle of the finally prepared MoS2 / RGO composite material-based super-amphiphobic wave-absorbing fabric is 163.6°, the oil contact angle is 152.4°, the minimum reflection loss is-52.29dB, and the effective absorption bandwidth is 3.99GHz.

[0072] As shown in Figure 2 After the dopamine modified fabric is treated with fluorinated MoS2 / RGO composite material, the fabric surface is covered with a large amount of fluorinated MoS2 / RGO composite material, and has a significant micro-nano multi-scale rough structure.

[0073] As shown in Figure 3 The super-amphiphobic wave-absorbing fabric has a minimum reflection loss of-52.29dB at a corresponding frequency of 11.9GHz. minThe value is -52.29 dB, and the EAB can reach a range of 3.99 GHz (8.5-12.49 GHz), covering more than 92% of the X-band, and the performance is excellent in terms of absorption intensity and effective absorption bandwidth.

[0074] Comparative Example 1

[0075] A preparation method of a finishing fabric based on MoS2 / RGO composite material is basically the same as that of Example 3, except that the operation of step (2) is omitted, i.e., the MoS2 / RGO composite material is not subjected to fluorination modification treatment, and step (4) is impregnated with an ethanol dispersion solution of the MoS2 / RGO composite material.

[0076] The water contact angle of the finally prepared finishing fabric based on MoS2 / RGO composite material is 0°, the oil contact angle is 0°, the minimum reflection loss is -36.61 dB, and the effective absorption bandwidth is 1.68 GHz.

[0077] Comparing Comparative Example 1 and Example 3, it can be found that the finishing fabric of Comparative Example 1 does not have hydrophobic and oleophobic properties, and the wave absorption performance is also poor. This is because micro-nano rough surface and low surface tension are two necessary conditions for obtaining super-amphiphobic properties, and one cannot be dispensed with. Only using MoS2 / RGO composite material to finish the fabric gives the fabric surface a micro-nano rough structure, but the fabric does not have low surface tension, so the water and oil contact angles are both 0°; compared with fluorinated MoS2 / RGO composite material, MoS2 / RGO composite material does not have multiple reflection loss and heterojunction interface caused by SiO2 nanoparticles, so the wave absorption performance of the finished fabric is decreased.

[0078] Comparative Example 2

[0079] A preparation method of a finishing fabric based on MoS2 / RGO composite material is basically the same as that of Example 3, except that the operation of step (3) is omitted, i.e., the fabric is not subjected to dopamine modification treatment.

[0080] The water contact angle of the finally prepared finishing fabric based on MoS2 / RGO composite material is 163.2°, the oil contact angle is 147.9°, the minimum reflection loss is -49.34 dB, and the effective absorption bandwidth is 2.31 GHz.

[0081] Comparative Example 2 and Example 3 can be compared, it can be found that Comparative Example 2 does not achieve super-amphiphobic performance, and the wave absorption performance also decreases, because dopamine modification can enhance the activity of the fabric surface, promote further reaction, and be conducive to the adsorption of fluorinated MoS2 / RGO composite. However, because the fabric is not treated by dopamine modification, the amount of fluorinated MoS2 / RGO composite adsorbed on the fabric surface is small, so the finished fabric does not achieve super-amphiphobic performance. At the same time, because the wave absorption performance of the finished fabric is mainly provided by the fluorinated MoS2 / RGO composite, the amount of composite adsorbed is reduced, so the wave absorption performance decreases.

[0082] Comparative Example 3

[0083] A method for preparing a MoS2 / RGO composite-based finished fabric, which is basically the same as Example 3, except that steps (2) and (3) are omitted, and step (4) is to immerse the fabric in an ethanol dispersion of MoS2 / RGO composite.

[0084] The water contact angle of the MoS2 / RGO composite-based finished fabric finally prepared is 0°, the oil contact angle is 0°, the minimum reflection loss is -33.05 dB, and the effective absorption bandwidth is 1.39 GHz.

[0085] Comparative Example 3 and Example 3 can be compared, it can be found that the surface of the finished fabric of Comparative Example 3 does not have hydrophobic and oleophobic properties, and the wave absorption performance is also poor, because micro-nano rough surface and low surface tension are two necessary conditions for achieving super-amphiphobic performance, and one is indispensable. Only MoS2 / RGO composite is used to finish the fabric to give the fabric surface a micro-nano rough structure, but the fabric does not have low surface tension, so the water and oil contact angles are both 0°; the finished fabric is not modified by PDA, so the amount of MoS2 / RGO composite adsorbed is reduced, so the wave absorption performance is worse than that of Comparative Example 1.

[0086] Example 4

[0087] A method for preparing a MoS2 / RGO composite-based super-amphiphobic wave-absorbing fabric, the specific steps are as follows:

[0088] (1) First, ammonium molybdate tetrahydrate, thiourea and graphene oxide are dispersed in deionized water, mixed uniformly, then subjected to ultrasonic treatment, then the mixed solution after ultrasonic treatment is transferred into a reaction kettle for hydrothermal reaction at a temperature of 220°C for 12h, and finally the product of hydrothermal reaction is centrifuged and washed with anhydrous ethanol and deionized water, and vacuum dried after centrifugal washing to obtain MoS2 / RGO composite;

[0089] The molar ratio of ammonium molybdate tetrahydrate to thiourea is 1:3, the mass ratio of thiourea to graphene oxide is 228:210, and the mass ratio of thiourea to deionized water is 6:100.

[0090] (2) After adding tetraethyl orthosilicate, perfluorodecyltrichlorosilane and ammonia water to the ethanol dispersion of the MoS2 / RGO composite material, stirring at room temperature to obtain a fluorinated MoS2 / RGO dispersion;

[0091] The mass fraction of the ethanol dispersion of the MoS2 / RGO composite material is 2.5wt%; the volume ratio of tetraethyl orthosilicate to perfluorodecyltrichlorosilane is 1:2, and the volume ratio of tetraethyl orthosilicate, ammonia water and the ethanol dispersion of the MoS2 / RGO composite material is 1:10:50;

[0092] (3) Dissolve dopamine in Tris-HCl buffer solution with pH=8.5 to obtain a mixed solution with a dopamine content of 0.5wt%, then immerse the cotton fabric in the mixed solution, take it out after oscillation at room temperature, and clean and dry to obtain a dopamine modified fabric;

[0093] (4) Immerse the dopamine modified fabric of step (3) in the fluorinated MoS2 / RGO dispersion of step (2) for 75min, and then perform padding, pre-drying and 180℃ baking for 20min to obtain a MoS2 / RGO composite material based super-amphiphobic wave-absorbing fabric;

[0094] The pick-up rate during padding is 80%.

[0095] As shown in Figure 4 The water contact angle of the MoS2 / RGO composite material based super-amphiphobic wave-absorbing fabric finally prepared is 163.9°, the oil contact angle is 153.6°, the minimum reflection loss is-53.83dB, and the effective absorption bandwidth is 3.87GHz.

[0096] Example 5

[0097] A method for preparing a MoS2 / RGO composite material based super-amphiphobic wave-absorbing fabric, the specific steps are as follows:

[0098] (1) First, disperse ammonium molybdate tetrahydrate, thiourea and graphene oxide in deionized water, mix uniformly, then perform ultrasonic treatment, then transfer the mixed solution after ultrasonic treatment into a reaction kettle, and perform hydrothermal reaction at a temperature of 260℃ for 16h, finally centrifugally clean the product of the hydrothermal reaction with anhydrous ethanol and deionized water, and vacuum dry after centrifugal cleaning to obtain a MoS2 / RGO composite material;

[0099] The molar ratio of ammonium molybdate tetrahydrate to thiourea is 1:3, the mass ratio of thiourea to graphene oxide is 228:210, and the mass ratio of thiourea to deionized water is 6:100.

[0100] (2) After adding tetraethyl orthosilicate, perfluorodecyltrimethoxysilane and ammonia water to the ethanol dispersion of MoS2 / RGO composite material, stirring at room temperature to obtain a fluorinated MoS2 / RGO dispersion;

[0101] The mass fraction of the ethanol dispersion of MoS2 / RGO composite material is 2.5wt%; the volume ratio of tetraethyl orthosilicate to perfluorodecyltrimethoxysilane is 1:2, and the volume ratio of tetraethyl orthosilicate, ammonia water to the ethanol dispersion of MoS2 / RGO composite material is 1:10:50;

[0102] (3) Dissolve dopamine in Tris-HCl buffer solution with pH=8.5 to obtain a mixed solution with a dopamine content of 0.5wt%, then immerse the polyester-cotton blended woven fabric with a blending ratio of 65 / 35 in the mixed solution, take it out after oscillation at room temperature, and clean and dry to obtain a dopamine modified fabric;

[0103] (4) Immerse the dopamine modified fabric of step (3) in the fluorinated MoS2 / RGO dispersion of step (2) for 90min, and then successively pad, pre-dry, and bake at 200℃ for 10min to obtain a MoS2 / RGO composite material-based super-amphiphobic wave-absorbing fabric;

[0104] The liquid retention rate during padding is 85%.

[0105] The water contact angle of the finally prepared MoS2 / RGO composite material-based super-amphiphobic wave-absorbing fabric is 163.1°, the oil contact angle is 152.9°, the minimum reflection loss is-52.67dB, and the effective absorption bandwidth is 3.74GHz.

Claims

1. A method for preparing a MoS2 / RGO composite-based super-biphobic wave-absorbing fabric, characterized in that: The dopamine modified fabric is immersed in a fluorinated MoS2 / RGO dispersion liquid, and then is subjected to padding, pre-drying and baking in sequence to obtain a super-amphiphobic wave-absorbing fabric based on MoS2 / RGO composite material. The fluorinated MoS2 / RGO dispersion liquid is obtained by stirring at room temperature after adding tetraethyl orthosilicate, fluorosilane and ammonia to an ethanol dispersion liquid of MoS2 / RGO composite material. The volume ratio of tetraethyl orthosilicate to fluorosilane is 1:1-2, and the volume ratio of tetraethyl orthosilicate, ammonia and the ethanol dispersion liquid of MoS2 / RGO composite material is 1:10:

50. The dehydration condensation of fluorosilane and tetraethyl orthosilicate generates SiO2 nanoparticles on the surface of MoS2 / RGO composite material, and the SiO2 nanoparticles form a heterojunction interface with the surface of fluorinated MoS2 / RGO composite material, further improving the interface polarization performance; meanwhile, the addition of SiO2 nanoparticles increases the reflection times of electromagnetic waves and the transmission path, gradually attenuates the energy of incident waves, and improves the ability of fluorinated MoS2 / RGO composite material to lose microwave energy. The water contact angle of the super-amphiphobic wave-absorbing fabric based on MoS2 / RGO composite material is not less than 162.8°, the oil contact angle is not less than 150.4°, the minimum reflection loss is not higher than -50.68 dB, and the effective absorption bandwidth is 3.54-3.99 GHz.

2. The method for preparing a MoS2 / RGO composite-based super-biphobic wave-absorbing fabric according to claim 1, characterized in that, The fluorosilane is perfluorooctyltrichlorosilane, perfluorooctyltrimethoxysilane, perfluorooctyltriethoxysilane, perfluorodecyltrichlorosilane, perfluorodecyltrimethoxysilane or perfluorodecyltriethoxysilane.

3. The method for preparing a superabsorbent wave fabric based on MoS2 / RGO composite material according to claim 1, characterized in that, The mass fraction of the ethanol dispersion liquid of MoS2 / RGO composite material is 0.5-2.5wt%.

4. The method for preparing a superabsorbent wave fabric based on MoS2 / RGO composite material according to claim 1, characterized in that, The preparation process of dopamine modified fabric is as follows: first, dopamine is dissolved in Tris-HCl buffer solution to obtain a mixed liquid, then the fabric is immersed in the mixed liquid, shaken at room temperature, taken out, washed and dried to obtain the dopamine modified fabric.

5. The method for preparing a MoS2 / RGO composite-based super-biphobic wave-absorbing fabric according to claim 4, characterized in that, The content of dopamine in the mixed liquid is 0.1-0.5wt%.

6. The method for preparing a MoS2 / RGO composite-based super-biphobic wave-absorbing fabric according to claim 4, characterized in that, The fabric is polyester fabric, cotton fabric, soybean fiber fabric, milk fabric, wool fabric, arnosulfone fabric, polyester-cotton blended fabric or cotton-ramie blended fabric.

7. The method for preparing a superabsorbent wave fabric based on MoS2 / RGO composite material according to claim 1, characterized in that, The preparation process of MoS2 / RGO composite material is as follows: first, ammonium molybdate tetrahydrate, thiourea and graphene oxide are dispersed in deionized water, mixed uniformly, then subjected to ultrasonic treatment, then the mixed liquid after ultrasonic treatment is transferred into a reaction kettle for hydrothermal reaction, finally, the product of hydrothermal reaction is centrifuged and washed with anhydrous ethanol and deionized water respectively, and then vacuum dried to obtain MoS2 / RGO composite material.

8. The method for preparing a MoS2 / RGO composite-based super-biphobic wave-absorbing fabric according to claim 7, characterized in that, The molar ratio of ammonium molybdate tetrahydrate to thiourea is 1:3, the mass ratio of thiourea to graphene oxide is 228:105-210, and the mass ratio of thiourea to deionized water is 3-6:

100.

9. The method for preparing a superabsorbent wave fabric based on MoS2 / RGO composite material according to claim 7, characterized in that, The temperature of hydrothermal reaction is 180-260℃, and the time is 8-16h.

10. The method for preparing a MoS2 / RGO composite-based super-biphobic wave-absorbing fabric according to claim 1, characterized in that, The immersion time is 30-90min, the liquid retention rate during padding is 70-85%, the baking temperature is 100-200℃, and the baking time is 10-60min.

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