Nano anti-sandwich structure coating modified carbon fiber as well as preparation method and application thereof

Abstract

The invention discloses a nanometer anti-sandwich structure coating modified carbon fiber as well as a preparation method and application thereof. The method comprises the following steps: 1, performing desizing treatment on carbon fiber; 2, preparing a graphene oxide or MXene dispersion liquid; 3, preparing a carbon nanotube dispersion liquid; and 4, uniformly paving the carbon fibers obtained in the step 1 on a filter membrane, sequentially carrying out vacuum suction filtration on the carbon nanotube dispersion liquid, the graphene oxide or MXene dispersion liquid and the carbon nanotube dispersion liquid, overturning the carbon fiber tows by 180 degrees, then depositing the dispersion liquid, and drying to obtain the nano anti-sandwich structure coating modified carbon fibers. According to the preparation method, the nanometer anti-sandwich structure coating with the graphene oxide or MXene sheet structure as the core and the carbon nanotube net staggered structure as the panel is constructed on the surface of the carbon fiber, the modification technology is simple and easy to implement, the reaction condition is mild, and environmental protection and high efficiency are achieved. The modified carbon fiber prepared by the method can solve the problem of mutual exclusion of interface toughness of a composite material, the interface bonding strength of the composite material is improved by 43.2-82.6%, and the interface fracture toughness is improved by 90.3-162.3%.

Description

Technical Field

[0001] The present invention relates to the technical field of surface and interface modification applications of materials, and in particular to a nano inverse sandwich structure coating modified carbon fiber and a preparation method and application thereof. Background Art

[0002] Carbon fiber-reinforced resin-based composites have high specific modulus and high specific strength. Their excellent properties, such as corrosion resistance and designability, have led to their widespread application in aerospace, sports, construction, and medical fields. However, the chemical inertness of the carbon fiber surface and its poor wettability with the matrix result in weak interfacial bonding between the composites, limiting their high performance. Therefore, carbon fiber surface modification is crucial for expanding the breadth and depth of carbon fiber composite applications. However, increasing the composite's interfacial strength comes at the expense of interfacial toughness, hindering the long-term, safe, and stable application of the composites. Summary of the Invention

[0003] The present invention aims to provide a nano-inverse sandwich structure-modified carbon fiber, its preparation method, and its application. A nano-inverse sandwich structure coating is constructed on the circumferential surface of the carbon fiber, with a graphene oxide or MXene sheet-like structure as the core and a carbon nanotube network-like interlaced structure as the surface. This coating simultaneously improves the composite material's interfacial bonding strength and fracture toughness, resolving the interfacial strength-toughness trade-off. Furthermore, this method is simple, environmentally friendly, efficient, and low-cost.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A method for preparing a nano inverse sandwich structure coating modified carbon fiber comprises the following steps:

[0006] Step 1: immersing the carbon fiber in an acetone solution, condensing and refluxing, washing with deionized water, and drying to obtain desized carbon fiber;

[0007] Step 2: Prepare graphene oxide or MXene dispersion

[0008] Dispersing graphene oxide or MXene in an organic solvent and uniformly dispersing it by ultrasonication to obtain a graphene oxide or MXene dispersion with a mass fraction of 0.05% to 1%;

[0009] Step 3: Prepare carbon nanotube dispersion

[0010] Dispersing carbon nanotubes in water or an organic solvent, and uniformly dispersing them by magnetic stirring to obtain a carbon nanotube dispersion with a mass fraction of 0.05% to 1%;

[0011] Step 4: Modification of carbon fiber surface nano-anti-sandwich structure coating

[0012] The desized carbon fiber tow obtained in step 1 is evenly laid on the filter membrane, and the carbon nanotube dispersion, graphene oxide or MXene dispersion and carbon nanotube dispersion are vacuum filtered in sequence and deposited on the surface of the desized carbon fiber. After the desized carbon fiber tow is turned 180°, the vacuum filtration and deposition steps are repeated, and a nano inverse sandwich structure coating modified carbon fiber is obtained after drying.

[0013] Furthermore, the condensation reflux temperature in step 1 is 80-100° C., and the time is 12-96 hours.

[0014] Furthermore, in step 2, the ultrasonic dispersion temperature is 0-10° C. and the time is 10-60 min.

[0015] Furthermore, the organic solvent in step 2 and step 3 is tetrahydrofuran, dimethylformamide, ethanol or dichloromethane.

[0016] Furthermore, in step 3, the magnetic stirring speed is 200 to 800 rpm, and the stirring time is 10 to 60 min.

[0017] Furthermore, in step 4, the vacuum filtration is carried out in the ratio of graphene oxide or MXene dispersion volume (ml): filter membrane diameter (cm) = (3-4):1, and the carbon nanotube dispersion volume (ml): filter membrane diameter (cm) = (1-2):1.

[0018] Furthermore, in step 1 and step 4, the drying temperature is 60-80° C. and the drying time is 2-4 hours.

[0019] The present invention also provides a nano-inverse sandwich structure coating modified carbon fiber, wherein the surface of the carbon fiber is evenly covered with a nano-inverse sandwich structure coating with a graphene oxide or MXene sheet structure as a core and a carbon nanotube network staggered structure as a face plate.

[0020] The present invention also provides an application of a nanometer inverse sandwich structure coating modified carbon fiber in solving the problem of strength-toughness mutual exclusion at the interface of a composite material.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention is different from the previous strategy of using only carbon nanotubes, graphene oxide or MXene and simply mixing two nanomaterials to modify the surface of high-performance fibers. A nano-anti-sandwich structure coating with a graphene oxide or MXene sheet structure as the core and a carbon nanotube mesh interlaced structure as the panel is constructed on the carbon fiber surface to simultaneously improve the interfacial bonding strength and fracture toughness of the composite material and solve the problem of interfacial strength-toughness mutual exclusion. The enhancement mechanism of the present invention to improve the interfacial bonding strength of the composite material is as follows: the inner layer carbon nanotube mesh interlaced structure can block the microcracks on the fiber surface from extending, and the outer layer carbon nanotube mesh interlaced structure can enhance the interfacial bonding strength through capillary effect, pinning effect and self-reinforcement effect. The toughening mechanism of the present invention to improve the interfacial fracture toughness of the composite material is as follows: the nano-anti-sandwich structure consumes energy in the process of blocking crack deflection and microcrack generation, and under shearing action, the extraction of carbon nanotubes from the resin can also consume energy.

[0023] The preparation method of the present invention is simple and easy, has mild reaction conditions, is pollution-free, environmentally friendly and highly efficient. The prepared modified carbon fiber can simultaneously improve the interfacial bonding strength and interfacial fracture toughness of the composite material, with the interfacial bonding strength increased by 43.2-82.6% and the interfacial fracture toughness increased by 90.3-162.3%. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a surface morphology of the nano inverse sandwich structure coating modified carbon fiber prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Example 1:

[0027] A method for preparing a nano inverse sandwich structure coating modified carbon fiber comprises the following steps:

[0028] Step 1: immersing the carbon fiber in an acetone solution at 80° C. and refluxing for 48 hours, then washing with deionized water, and drying in a drying oven at 60° C. for 3 hours to obtain desized carbon fiber;

[0029] Step 2: Prepare graphene oxide dispersion

[0030] Graphene oxide was dispersed in dimethylformamide and ultrasonically dispersed at 0°C for 30 minutes to obtain a graphene oxide dispersion with a mass fraction of 0.11%;

[0031] Step 3: Prepare carbon nanotube dispersion

[0032] The carbon nanotubes were dispersed in water and magnetically stirred at 400 rpm for 15 minutes to obtain a carbon nanotube dispersion with a mass fraction of 0.05%.

[0033] Step 4: Modification of carbon fiber surface nano-anti-sandwich structure coating

[0034] The desized carbon fiber tow obtained in step 1 is evenly laid on a filter membrane, and a carbon nanotube dispersion, a graphene oxide dispersion, and a carbon nanotube dispersion are sequentially vacuum filtered and deposited on the surface of the desized carbon fiber, wherein the volume (ml) of the graphene oxide dispersion: the diameter (cm) of the filter membrane is 3.15:1, and the volume (ml) of the carbon nanotube dispersion: the diameter (cm) of the filter membrane is 1.57:1; after the desized carbon fiber tow is turned 180°, the vacuum filtration and deposition steps are repeated, and after drying at 60°C for 3h, a nano inverse sandwich structure coating modified carbon fiber is obtained.

[0035] The surface morphology of a nano-anti-sandwich structure coating modified carbon fiber prepared in this embodiment is as follows Figure 1 As shown, from Figure 1 As can be seen, a dense, entangled carbon nanotube network stands tall on the wrinkled graphene oxide surface, with the inverse sandwich coating uniformly coating the fiber surface. The modified carbon fiber-epoxy composite prepared using this example exhibits an 82.6% increase in interfacial shear strength and a 162.3% increase in interfacial fracture toughness compared to the desized carbon fiber-epoxy composite.

[0036] Example 2:

[0037] A method for preparing a nano inverse sandwich structure coating modified carbon fiber comprises the following steps:

[0038] Step 1: immersing the carbon fiber in a 100° C. acetone solution and condensing and refluxing for 12 hours, then washing with deionized water, and drying in a drying oven at 80° C. for 2 hours to obtain desized carbon fiber;

[0039] Step 2: Prepare graphene oxide dispersion

[0040] Graphene oxide was dispersed in ethanol and ultrasonically dispersed at 10°C for 60 minutes to obtain a graphene oxide dispersion with a mass fraction of 1%;

[0041] Step 3: Prepare carbon nanotube dispersion

[0042] The carbon nanotubes were dispersed in dimethylformamide and magnetically stirred at 800 rpm for 10 min to obtain a carbon nanotube dispersion with a mass fraction of 1%.

[0043] Step 4: Modification of carbon fiber surface nano-anti-sandwich structure coating

[0044] The desized carbon fiber tow obtained in step 1 is evenly laid on the filter membrane, and the carbon nanotube dispersion, graphene oxide dispersion and carbon nanotube dispersion are vacuum filtered in sequence and deposited on the surface of the desized carbon fiber, wherein the volume (ml) of the graphene oxide dispersion: the diameter of the filter membrane (cm) is 3:1, and the volume (ml) of the carbon nanotube dispersion: the diameter of the filter membrane (cm) is 1:1; after the desized carbon fiber tow is turned 180°, the vacuum filtration and deposition steps are repeated, and after drying at 80°C for 2h, a nano inverse sandwich structure coating modified carbon fiber is obtained.

[0045] The modified carbon fiber epoxy composite material prepared in this embodiment has an interface shear strength increased by 43.2% and an interface fracture toughness increased by 90.3% compared to the desized carbon fiber epoxy composite material.

[0046] Example 3:

[0047] A method for preparing a nano inverse sandwich structure coating modified carbon fiber comprises the following steps:

[0048] Step 1: immersing the carbon fiber in a 90° C. acetone solution, condensing and refluxing for 24 hours, washing with deionized water, and drying in a drying oven at 70° C. for 4 hours to obtain desized carbon fiber;

[0049] Step 2: Prepare MXene dispersion

[0050] MXene was dispersed in tetrahydrofuran and ultrasonically dispersed at 5°C for 45 min to obtain a MXene dispersion with a mass fraction of 0.3%;

[0051] Step 3: Prepare carbon nanotube dispersion

[0052] The carbon nanotubes were dispersed in ethanol and magnetically stirred at 200 rpm for 60 min to obtain a carbon nanotube dispersion with a mass fraction of 0.5%.

[0053] Step 4: Modification of carbon fiber surface nano-anti-sandwich structure coating

[0054] The desized carbon fiber tow obtained in step 1 was evenly laid on the filter membrane, and the carbon nanotube dispersion, MXene dispersion, and carbon nanotube dispersion were vacuum filtered and deposited on the surface of the desized carbon fiber in sequence, wherein the volume (ml) of MXene dispersion: the diameter of the filter membrane (cm) was 3.67:1, and the volume (ml) of carbon nanotube dispersion: the diameter of the filter membrane (cm) was 1.77:1; after the desized carbon fiber tow was turned 180°, the vacuum filtration and deposition steps were repeated, and a spider web structure-modified carbon fiber coating was obtained after drying at 60°C for 4h.

[0055] The modified carbon fiber epoxy composite material prepared in this embodiment has an interface shear strength increased by 68.7% and an interface fracture toughness increased by 101.4% compared to the desized carbon fiber epoxy composite material.

[0056] Example 4:

[0057] A method for preparing a nano inverse sandwich structure coating modified carbon fiber comprises the following steps:

[0058] Step 1: immersing the carbon fiber in an acetone solution at 80° C. and refluxing for 96 hours, then washing with deionized water, and drying in a drying oven at 60° C. for 4 hours to obtain desized carbon fiber;

[0059] Step 2: Prepare MXene dispersion

[0060] MXene was dispersed in dichloromethane and ultrasonically dispersed at 5°C for 45 min to obtain a MXene dispersion with a mass fraction of 0.7%;

[0061] Step 3: Prepare carbon nanotube dispersion

[0062] The carbon nanotubes were dispersed in dichloromethane and magnetically stirred at 600 rpm for 20 min to obtain a carbon nanotube dispersion with a mass fraction of 0.8%.

[0063] Step 4: Modification of carbon fiber surface nano-anti-sandwich structure coating

[0064] The desized carbon fiber tow obtained in step 1 was evenly laid on the filter membrane, and the carbon nanotube dispersion, MXene dispersion, and carbon nanotube dispersion were vacuum filtered and deposited on the surface of the desized carbon fiber in sequence, wherein the volume (ml) of MXene dispersion: the diameter of the filter membrane (cm) was 3.1:1, and the volume (ml) of carbon nanotube dispersion: the diameter of the filter membrane (cm) was 1.05:1; after the desized carbon fiber tow was turned 180°, the vacuum filtration and deposition steps were repeated, and a nano inverse sandwich structure coating modified carbon fiber was obtained after drying at 70°C for 3h.

[0065] The modified carbon fiber epoxy composite material prepared in this embodiment has an interface shear strength increased by 71.0% and an interface fracture toughness increased by 135.8% compared to the desized carbon fiber epoxy composite material.

[0066] Example 5:

[0067] A method for preparing a nano inverse sandwich structure coating modified carbon fiber comprises the following steps:

[0068] Step 1: immersing the carbon fiber in an acetone solution at 80° C. and refluxing for 96 hours, then washing with deionized water, and drying in a drying oven at 60° C. for 4 hours to obtain desized carbon fiber;

[0069] Step 2: Prepare MXene dispersion

[0070] MXene was dispersed in dimethylformamide and ultrasonically dispersed at 10°C for 10 min to obtain a MXene dispersion with a mass fraction of 0.05%;

[0071] Step 3: Prepare carbon nanotube dispersion

[0072] The carbon nanotubes were dispersed in tetrahydrofuran and magnetically stirred at 600 rpm for 20 min to obtain a carbon nanotube dispersion with a mass fraction of 0.8%.

[0073] Step 4: Modification of carbon fiber surface nano-anti-sandwich structure coating

[0074] The desized carbon fiber tow obtained in step 1 was evenly laid on the filter membrane, and the carbon nanotube dispersion, MXene dispersion, and carbon nanotube dispersion were vacuum filtered and deposited on the surface of the desized carbon fiber in sequence, wherein the volume (ml) of MXene dispersion: the diameter of the filter membrane (cm) was 4:1, and the volume (ml) of carbon nanotube dispersion: the diameter of the filter membrane (cm) was 2:1; after the desized carbon fiber tow was turned 180°, the above vacuum filtration and deposition steps were repeated, and a nano inverse sandwich structure coating modified carbon fiber was obtained after drying at 70°C for 3h.

Claims

1. A method for preparing nano inverse sandwich structure coating modified carbon fiber, characterized in that: The steps include: Step 1: immersing the carbon fiber in an acetone solution, condensing and refluxing, washing with deionized water, and drying to obtain desized carbon fiber; Step 2: Prepare graphene oxide or MXene dispersion Dispersing graphene oxide or MXene in an organic solvent and uniformly dispersing it by ultrasonication to obtain a graphene oxide or MXene dispersion with a mass fraction of 0.05% to 1%; Step 3: Prepare carbon nanotube dispersion Dispersing carbon nanotubes in water or an organic solvent, and uniformly dispersing them by magnetic stirring to obtain a carbon nanotube dispersion with a mass fraction of 0.05% to 1%; Step 4: Modification of carbon fiber surface nano-anti-sandwich structure coating The desized carbon fiber tow obtained in step 1 is evenly laid on the filter membrane, and the carbon nanotube dispersion, graphene oxide or MXene dispersion and carbon nanotube dispersion are vacuum filtered in sequence and deposited on the surface of the desized carbon fiber. After the desized carbon fiber tow is turned 180°, the vacuum filtration and deposition steps are repeated, and a nano inverse sandwich structure coating modified carbon fiber is obtained after drying.

2. The method for preparing a nano inverse sandwich structure coating modified carbon fiber according to claim 1, characterized in that: The condensation reflux temperature in step 1 is 80-100° C., and the condensation reflux time is 12-96 hours.

3. The method for preparing a nano inverse sandwich structure coating modified carbon fiber according to claim 1, characterized in that: The ultrasonic dispersion temperature in step 2 is 0-10° C. and the time is 10-60 min.

4. The method for preparing a nano inverse sandwich structure coating modified carbon fiber according to claim 1, characterized in that: The organic solvent in step 2 and step 3 is tetrahydrofuran, dimethylformamide, ethanol or dichloromethane.

5. The method for preparing a nano inverse sandwich structure coating modified carbon fiber according to claim 1, characterized in that: In step 3, the magnetic stirring speed is 200 to 800 rpm, and the stirring time is 10 to 60 minutes.

6. The method for preparing a nano inverse sandwich structure coating modified carbon fiber according to claim 1, characterized in that: In the step 4, the vacuum filtration is carried out according to the ratio of graphene oxide or MXene dispersion volume (ml): filter membrane diameter (cm) = (3-4):1, and the carbon nanotube dispersion volume (ml): filter membrane diameter (cm) = (1-2):

1.

7. The method for preparing a nano inverse sandwich structure coating modified carbon fiber according to claim 1, characterized in that: In step 1 and step 4, the drying temperature is 60-80° C. and the drying time is 2-4 hours.

8. A nano inverse sandwich structure coating modified carbon fiber prepared by the preparation method according to any one of claims 1 to 7, characterized in that: The surface of the carbon fiber is evenly covered with a nano inverse sandwich structure coating having a graphene oxide or MXene sheet structure as a core and a carbon nanotube mesh interlaced structure as a panel.

9. Use of the nano inverse sandwich structure coating modified carbon fiber according to claim 8 in solving the problem of strength-toughness mutual exclusion at the interface of composite materials.

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