Preparation method of MXene reinforced resin-based composite material

[0040] The invention provides a preparation method of an MXene sponge reinforced resin-based composite material, which comprises the following steps:

[0041] 1. Etching of titanium aluminum carbide:

[0042] The MXene was prepared by a modified in-situ hydrofluoric acid-etching titanium-aluminum carbide method to avoid the danger of directly using hydrofluoric acid. Take Ti with a mass ratio of 1:1.6~2 3 AlC 2 and lithium fluoride, adding lithium fluoride to 9mol/L hydrochloric acid, of which: 1g Ti 3 AlC 2 Corresponding to 20ml of concentrated hydrochloric acid, lithium fluoride was stirred in hydrochloric acid for at least 20min. After fully stirring the hydrochloric acid and lithium fluoride, slowly add titanium aluminum carbide to the mixed solution and continue magnetic stirring, wherein: the time for adding 1g titanium aluminum carbide should be 10~15min, the speed of magnetic stirring is controlled at 15r/min, and the mixing Changes in temperature and the violent generation of air bubbles are avoided during the process. After adding all the titanium aluminum carbide, the mixed solution was continuously etched by magnetic stirring at 35~50°C for 36 hours, and the magnetic stirring speed was controlled at 10~15r/min.

[0043] 2. Collection of MXene aqueous solution:

[0044]The solution obtained in step 1 was put into a centrifuge tube, and washed with deionized water until the pH value of the solution was greater than 6. The cleaning process is as follows: rotating speed is 3500rpm, 5~10min, pour out the supernatant and continue to add deionized water, repeat the above steps until the pH value of the solution is greater than 6, at this time, the supernatant solution after centrifugation should be blue-black. Shake with a vortex shaker for 30~60min, so that the precipitate after centrifugation is completely dissolved in water, and it is uniform and stable when standing. Then put it into a blue-capped bottle and put it into an ultrasonic machine for 15-20 min under the condition of a power of 400-600w. During the ultrasonic process, nitrogen gas was introduced into the blue-capped bottle as a protective gas. After sonication, MXene was collected, and the MXene aqueous solution was collected by centrifugation at 1400-1600 rpm for 30-35 min. Dilute with deionized water to obtain an aqueous solution of MXene with a concentration of 5-15 mg/ml.

[0045] 3. Preparation of reinforced MXene porous sponge:

[0046] Use vacuum ester (to prevent liquid leakage) evenly coat the lower part and surrounding of the silicone block mold on a copper plate or iron disc; pour the MXene solution obtained in step 2 into the mold, and cover the mold to prevent low temperature airflow The flow along the side of the mold to the upper liquid level causes the destruction of the temperature gradient environment. Put a spacer under the disc and pour liquid nitrogen to make the temperature gradient of the cold source spread evenly from bottom to top, and wait for the liquid-phase MXene solution to freeze completely. Put the solid phase obtained by directional freezing into the refrigerator for 1 hour, take it out and demold it, and put it into the tray of the freeze dryer. The cooling method of the temperature controller is: first freeze at -40°C for 3 to 4 hours , and the drying chamber is evacuated, and the vacuum degree is controlled below 10Pa; after completion, the temperature control partition is heated for 110~130 hours to 25°C to achieve the effect of freeze drying. After drying, the two-dimensional nanosheet MXene (Ti 3 C 2 T, T = -F, -O, -OH) is a three-dimensional network framework built by sheet self-assembly and directional arrangement, that is, the porous sponge of MXene.

[0047] Fourth, the introduction and uniform distribution of MXene porous sponge in the resin system:

[0048] Weigh 50 g of epoxy resin into a beaker, fully immerse 0.15 g of the MXene porous sponge in step 3 in the epoxy resin, and control the immersion time under vacuum pressure to be more than 20 hours. The resin mixture is stirred under the shear flow force of the mechanical mixer, and the shear flow force stirring speed is controlled to be 1800~2000r/min, and the stirring time is not less than 24 hours. No residual particles are observed in the lighting environment. The two-dimensional sheets are sufficiently discretely distributed in the resin. The composite resin is subjected to pressure-maintaining and defoaming treatment in a vacuum drying oven until the upper air bubbles disappear, and the defoaming time in the vacuum drying oven is not less than 20 minutes.

[0049] 5. Curing process and preparation of MXene sponge reinforced resin matrix composites:

[0050] Design an aluminum mold, in which the length and width of the mold groove are 20cm and 3mm respectively, and one end is open (designed for subsequent resin demoulding), and the same aluminum strip is used as the seal, and the aluminum strip is pasted with double-sided tape. At the open end, make sure that the height of the aluminum bar is the same as the depth of the die groove.

[0051] Weigh the curing agent according to the combination of epoxy resin and curing agent and slowly pour it into the beaker containing the above resin, stir slowly with a glass rod, until the surface is free of oil, and the mixing system is uniform and stable, and the stirring time is controlled. for 15 to 20 minutes. Put the mixed resin into a vacuum drying box and pump it until the bubbles disappear, and the time of debubbling in the vacuum drying box is not less than 10min. Brush the mold release agent on the above-mentioned mold, wait for it to dry, and then brush it again, preferably three times. Take out the above resin and slowly pour it into the mold and make it evenly distributed, put it in the oven, adjust the oven temperature to 40~50℃, keep the heat preservation time in the oven for not less than 24 hours, take out the aluminum strip and demould, that is The MXene sponge reinforced resin matrix composites with the same size as the mold were prepared successfully.

[0052] Example 1:

[0053] 1. Etching of titanium aluminum carbide:

[0054] MXene was prepared by etching titanium aluminum carbide with hydrofluoric acid. Take 2g Ti 3 AlC 2 and 3.2g lithium fluoride, add lithium fluoride to 40ml of 9mol/L hydrochloric acid. After the hydrochloric acid and lithium fluoride are fully stirred, titanium aluminum carbide is slowly added to the mixed solution and stirred, and the temperature change and the violent generation of bubbles are avoided during the mixing process. After adding all the titanium aluminum carbide, the mixed solution was etched at 35°C for 36 hours.

[0055] 2. Collection of MXene:

[0056] The solution obtained in step 1 was put into a centrifuge tube and washed with deionized water until the pH value of the solution was about 7. The cleaning process was 3500 rpm, 5 min, and deionized water was continued to be added after the supernatant was poured out. The pellet was layered by vortexing for 60 min. Then put it into a blue-capped bottle and put it into an ultrasonic machine for 15 min under the condition of a power of 500w. During the ultrasonic process, nitrogen gas was introduced into the blue-capped bottle as a protective gas. After sonication, MXene was collected, and the MXene aqueous solution was collected by centrifugation at 1500 rpm for 30 min. Diluted with water to obtain an aqueous solution of MXene with a concentration of 6 mg/ml. MXene aqueous solution such as figure 1 shown.

[0057] 3. Preparation of reinforced MXene porous sponge:

[0058] Use vacuum ester (to prevent liquid leakage) evenly coat the lower part and surrounding of the silicone block mold on the copper plate or iron disc; pour the MXene aqueous solution obtained in step 2 into the mold, and cover the mold to prevent low temperature airflow The flow along the side of the mold to the upper liquid level causes the destruction of the temperature gradient environment. Put a spacer under the disc and pour liquid nitrogen to make the temperature gradient of the cold source spread evenly from bottom to top, and wait for the liquid-phase MXene solution to freeze completely. The solid phase obtained by directional freezing was placed in the refrigerator for 1 hour, taken out and demolded, and then placed in the tray of the freeze dryer. The cooling method of the temperature controller was as follows: first freeze at -40°C for 3 hours, and put The drying chamber is evacuated, and the vacuum degree is 3Pa; after completion, the temperature-controlled partition is heated up to 25°C for 120h to achieve the effect of freeze-drying. After drying, the two-dimensional nanosheet MXene (Ti 3 C 2 T, T=-F, -OH, -O) is a three-dimensional network skeleton built by sheet self-assembly and directional arrangement, namely MXene porous sponge.

[0059] Fourth, the introduction and uniform distribution of MXene sponge in the resin system:

[0060] Weigh 50 g of epoxy resin into a beaker, and fully immerse 0.15 g of the MXene oriented sponge in step 3 in the epoxy resin, and the immersion time under vacuum pressure is 24 hours. The resin mixture was stirred under the shear flow force of a mechanical mixer, the stirring time was 24 h, and the stirring speed was 2000 r/min, so that the two-dimensional flakes were fully dispersed in the resin. The composite resin is subjected to pressure-maintaining and de-foaming treatment in a vacuum drying oven until the upper layer of air bubbles disappears.

[0061] 5. Curing process and preparation of MXene sponge reinforced resin matrix composites:

[0062] Design an aluminum mold, in which the length and width of the mold groove are 20cm and 3mm respectively, and one end is open (designed for subsequent resin demoulding), and the same aluminum strip is used as the seal, and the aluminum strip is pasted with double-sided tape. At the open end, make sure that the height of the aluminum bar is the same as the depth of the die groove.

[0063] According to the proportion of the epoxy resin and curing agent used, weigh 15 g of the modified amine curing agent, slowly pour the curing agent into the beaker containing the above resin, and stir slowly with a glass rod until the surface is free of oil. And the mixing system is uniform and stable, and the stirring time is about 20min. Put the mixed resin into a vacuum drying box and pump it until the bubbles disappear, and the secondary bubble removal time is about 10min. Brush the mold release agent on the above-mentioned mold, wait for it to dry, and then brush it again, preferably three times. Take out the above resin and slowly pour it into the mold and make it evenly distributed, put it in an oven at 40°C for 24 hours, remove the aluminum strip and demould, that is, the MXene sponge reinforced resin matrix composite material with the same size as the mold is successfully prepared. .

[0064] The flexural strength of the composite sponge reinforced resin obtained in this example is 108.75MPa, which is 37.96% higher than that of the pure resin, the flexural modulus is 1793.34MPa, the elongation at break is 9.78%, and the absorbed energy at break is 7.86×10 6 J/m 3 , the tensile strength is 69.66MPa, and the tensile modulus is increased to 675.67MPa.

[0065] Embodiment 2:

[0066] 1. Etching of titanium aluminum carbide:

[0067] MXene was prepared by etching titanium aluminum carbide with hydrofluoric acid. Take 2g Ti 3 AlC 2 and 3.2g lithium fluoride, add lithium fluoride to 40ml of 9mol/L hydrochloric acid. After the hydrochloric acid and lithium fluoride are fully stirred, titanium aluminum carbide is slowly added to the mixed solution and stirred, and the temperature change and the violent generation of bubbles are avoided during the mixing process. After adding all the titanium aluminum carbide, the mixed solution was etched at 50°C for 48 hours.

[0068] 2. Collection of MXene:

[0069] The solution obtained in step 1 was put into a centrifuge tube and washed with deionized water until the pH value of the solution was about 7. The cleaning process was 3500 rpm, 5 min, and deionized water was continued to be added after the supernatant was poured out. Shake well for 60 min by vortex shaker to make the precipitate evenly and stably distributed. Subsequently, the MXene aqueous solution was directly collected by centrifugation at 1500 rpm for 30 min. Diluted with water to obtain an aqueous solution of MXene with a concentration of 6 mg/ml.

[0070] 3. Preparation of reinforced MXene porous sponge:

[0071] Use vacuum ester (to prevent liquid leakage) evenly coat the lower part and surrounding of the silicone block mold on a copper plate or iron disc; pour the MXene solution obtained in step 2 into the mold, and cover the mold to prevent low temperature airflow The flow along the side of the mold to the upper liquid level causes the destruction of the temperature gradient environment. Put a spacer under the disc and pour liquid nitrogen to make the temperature gradient of the cold source spread evenly from bottom to top, and wait for the liquid-phase MXene solution to freeze completely. The solid phase obtained by directional freezing was placed in the refrigerator for 1 hour, taken out and demolded, and then placed in the tray of the freeze dryer. The cooling method of the temperature controller was as follows: first freeze at -40°C for 3 hours, and put The drying chamber is evacuated, and the vacuum degree is 3~10Pa; after completion, the temperature control partition is heated up for 120h to 25℃ to achieve the effect of freeze-drying. After drying, the two-dimensional nanosheet MXene (Ti 3 C 2 T, T=-F, -O, -OH) is a three-dimensional network framework built by sheet self-assembly and directional arrangement, namely MXene porous sponge.

[0072] Fourth, the introduction and uniform distribution of MXene sponge in the resin system:

[0073] Weigh 50 g of epoxy resin in a beaker, and fully immerse 0.15 g of the MXene oriented sponge in step 3 in the epoxy resin, and the immersion time under vacuum pressure is 24 hours. The resin mixture was stirred under the shear flow force of a mechanical mixer, the stirring time was 24 h, and the stirring speed was 2000 r/min, so that the two-dimensional flakes were fully dispersed in the resin. The composite resin is subjected to pressure-maintaining and defoaming treatment in a vacuum drying oven until the upper layer of air bubbles disappears.

[0074] 5. Curing process and preparation of MXene sponge reinforced resin matrix composites:

[0075]Design an aluminum mold, in which the length and width of the mold groove are 20cm and 3mm respectively, and one end is open (designed for subsequent resin demoulding), and the same aluminum strip is used as the seal, and the aluminum strip is pasted with double-sided tape. At the open end, make sure that the height of the aluminum bar is the same as the depth of the die groove.

[0076] According to the composition ratio of the epoxy resin and curing agent used, take 15 g of the modified amine curing agent, slowly pour the curing agent into the beaker containing the above resin, and slowly pour the curing agent into the beaker containing the above resin , Stir slowly with a glass rod until the surface is free of oil, and the mixing system is uniform and stable, and the stirring time is about 20 minutes. Put the mixed resin into a vacuum drying box and pump it until the bubbles disappear, and the secondary bubble removal time is about 10min. Brush the mold release agent on the above-mentioned mold, wait for it to dry, and then brush it again, preferably three times. Take out the above resin and slowly pour it into the mold and make it evenly distributed, put it in an oven at 40°C for 24 hours, remove the aluminum strip and demould, that is, the MXene sponge reinforced resin matrix composite material with the same size as the mold is successfully prepared. .

[0077] The flexural strength of the composite sponge reinforced resin obtained in this example is 104.99MPa, which is 33.18% higher than that of the pure resin, the flexural modulus is 1635.50MPa, the elongation at break is 6.36%, and the absorbed energy at break is 3.94×10 6 J/m 3 , the tensile strength is 60.11MPa, and the tensile modulus is increased to 461.65MPa.