阅读说明：本技术 一种MXene/天然橡胶柔性复合薄膜及其制备方法 (MXene/natural rubber flexible composite film and preparation method thereof ) 是由 杨伟 李�浩 汪林强 鲁红典 于 2019-09-25 设计创作，主要内容包括：一种MXene/天然橡胶柔性复合薄膜及其制备方法,属于纳米复合材料制备技术领域。MXene/天然橡胶柔性复合薄膜由MXene二维纳米材料和天然橡胶复合而成。首先利用氟化锂和盐酸的混合溶液刻蚀M<Sub>n+1</Sub>AX<Sub>n</Sub>中的A原子层制备得到MXene沉淀；然后将MXene沉淀重新分散在水中,超声、离心,除去沉淀物,取上层清液,得到MXene纳米片悬浮液；最后将天然橡胶水乳液和MXene纳米片悬浮液混合,经超声、抽滤、干燥,即得。本发明的制备方法简单,且不含有机溶剂,具有良好的环境友好性。制备的MXene/天然橡胶柔性复合薄膜具有优异的柔韧性、力学强度和电磁波屏蔽性能,并且可灵活改变其形状,应用前景广阔。(An MXene/natural rubber flexible composite film and a preparation method thereof belong to the technical field of nano composite material preparation. The MXene/natural rubber flexible composite film is formed by compounding an MXene two-dimensional nano material and natural rubber. Firstly, etching M by using a mixed solution of lithium fluoride and hydrochloric acid n+1 AX n Preparing MXene precipitate from the A atomic layer; then dispersing the MXene precipitate in water again, performing ultrasonic treatment and centrifugation, removing the precipitate, and taking supernatant to obtain MXene nanosheet suspension; and finally, mixing the natural rubber aqueous emulsion and the MXene nanosheet suspension, and performing ultrasonic treatment, suction filtration and drying to obtain the modified MXene nanosheet. The preparation method is simple, does not contain organic solvent, and has good environmental friendliness. The prepared MXene/natural rubber flexible composite film has excellent flexibility, mechanical strength and electromagnetic wave shielding performance, can flexibly change the shape of the film, and has wide application prospect.)

1. An MXene/natural rubber flexible composite film is characterized in that: the composite film is formed by compounding MXene two-dimensional nano material and natural rubber, wherein the MXene is a metal conductive layered M_n+1AX_nPrepared by phase-selectively etching out the A layer, M_n+1AX_nWherein M is a transition metal, A is an element IIIA or IVA, X is a C and/or N element, and N is equal to 1, 2 or 3.

2. The MXene/natural rubber flexible composite film according to claim 1, wherein: the MXene is Ti₃C₂、Nb₂C、Ti₃CN or Mo₂C。

3. A method for preparing the MXene/natural rubber flexible composite film according to claim 1 or 2, wherein: the method comprises the following steps:

1) etching M by using mixed solution of lithium fluoride and hydrochloric acid_n+1AX_nPreparation of A atomic layer to obtain MXene, precipitating;

2) re-dispersing the MXene precipitate obtained in the step 1) in water, performing ultrasonic treatment and centrifugation, removing the precipitate, and taking supernatant to obtain MXene nanosheet suspension;

3) and adding the aqueous emulsion of the natural rubber into the MXene nanosheet suspension, and performing ultrasonic treatment, suction filtration and drying to obtain the MXene/natural rubber flexible composite film.

4. The method of claim 3, wherein: step 1) was to take 0.5g M_n+1AX_nAnd 0.5g of lithium fluoride are placed in a plastic beaker, 10-15mL of hydrochloric acid with the concentration of 7-10mol/L is added, the mixture is stirred and reacted for 36-60h at the temperature of 30-50 ℃, the stirring speed is 400-600rpm, after the reaction is finished, the mixture is repeatedly centrifuged and washed until the pH value is 6-7, and MXene precipitate is obtained after drying.

5. The method of claim 4, wherein: step 2) dispersing 0.2g of MXene precipitate obtained in step 1) in 40-60mL of deionized water, performing ultrasonic treatment at 0-5 ℃ for 30-60min and the ultrasonic power of 100-300W, centrifuging at 4000-5000rpm for 5-15min, removing the precipitate, and taking the supernatant to obtain the MXene nanosheet suspension.

6. The method of claim 5, wherein: step 3) preparing MXene obtained in step 2) into 2mg/mL suspension, preparing natural rubber into 2mg/mL emulsion, and mixing the MXene nano-sheet suspension and the natural rubber emulsion according to the volume ratio of 1-9: 9-1, preparing a mixed solution, carrying out ultrasonic treatment at 0-5 ℃ for 10-30min with the ultrasonic power of 100-200W, carrying out suction filtration on 20-40mL of the mixed solution by using a microporous filter membrane, and then drying at 50-70 ℃ for 1-6h to obtain the MXene/natural rubber flexible composite film.

Technical Field

The invention belongs to the technical field of nano composite material preparation, and particularly relates to an MXene/natural rubber flexible composite film and a preparation method thereof.

Background

MXene is a new generation of two-dimensional nanomaterial, consisting of a transition metal carbide, nitride or carbonitride of several atomic layer thicknesses (e.g. Ti₃C₂、Ti₂C、Nb₂C、V₂C、Ti₃CN and Mo₂C, etc.) having a specific structure and excellent conductive properties. MXene is generally a conductive layer M from a metal_n+1AX_nPhase-selectively etching a layer A, wherein M is a transition metal, A is an element IIIA or IVA, X is a C and/or N element, and N is equal to 1, 2 or 3. During the etching process, M_n+1X_nThe a atoms between the layers are substituted with various functional groups to produce MXene nanoplatelets having hydroxyl, oxygen, or fluorine groups on the surface.

MXene has excellent conductivity and large specific surface area, so that the MXene has wide application prospects in the fields of energy storage, electromagnetic shielding, composite materials and the like. Chinese patent CN 107128922A reports a titanium carbide (Ti)₃C₂) The flexible paper and the preparation method thereof have the advantages of good flexibility, simple process and the like, but the flexible paper has poor mechanical property and cannot be folded. Chinese patent CN 108584939A reports a preparation method of a titanium carbide/graphene oxide composite film, the heat resistance of the film is good, the dielectric property is excellent, but the patent does not mention the mechanical property of the invented film. The chinese patent CN 107099054a adopts a composite of a polymer material (such as polyvinyl alcohol, polymethyl methacrylate, polystyrene, etc.) and titanium carbide to prepare a film material, and the mechanical properties of the film are significantly improved, but the preparation method adopted in the patent has complicated steps and contains an organic solvent, and the polymer material used in the patent has poor reproducibility, cannot be biodegraded, and has a certain problem of environmental pollution.

The Natural Rubber (NR) is a natural high molecular compound taking cis-1, 4-polyisoprene as a main component, has high elasticity and excellent mechanical strength at normal temperature, has strong reproducibility, and is an ideal material for improving the flexibility and the mechanical strength of the MXene film. At present, no relevant literature report is found about MXene/natural rubber flexible composite films.

Disclosure of Invention

The invention provides an MXene/natural rubber flexible composite film and a preparation method thereof, aiming at overcoming the defects of poor mechanical property, complex process, poor environmental friendliness and the like in the existing MXene film preparation technology.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: an MXene/natural rubber flexible composite film is prepared by compounding MXene two-dimensional nano material and natural rubber, wherein MXene is a metal conductive layered M_n+1AX_nPrepared by phase-selectively etching out the A layer, M_n+1AX_nWherein M is a transition metal, A is an element IIIA or IVA, X is a C and/or N element, and N is equal to 1, 2 or 3.

Preferably, in the MXene/natural rubber flexible composite film of the invention, the MXene is preferably Ti₃C₂、Nb₂C、Ti₃CN or Mo₂C。

A preparation method of an MXene/natural rubber flexible composite film comprises the following steps:

1) etching M by using mixed solution of lithium fluoride and hydrochloric acid_n+1AX_nPreparing MXene precipitate from the A atomic layer;

2) re-dispersing the MXene precipitate obtained in the step 1) in water, performing ultrasonic treatment and centrifugation, removing the precipitate, and taking supernatant to obtain MXene nanosheet suspension;

3) and adding the aqueous emulsion of the natural rubber into the MXene nanosheet suspension, and performing ultrasonic treatment, suction filtration and drying to obtain the MXene/natural rubber flexible composite film.

Preferably, in the preparation method of the MXene/natural rubber flexible composite film, the steps of:

step 1) was to take 0.5g M_n+1AX_nAnd 0.5g of lithium fluoride are placed in a plastic beaker, 10 to 15mL of hydrochloric acid with the concentration of 7 to 10mol/L is added, the mixture is stirred and reacted for 36 to 60 hours at the temperature of between 30 and 50 ℃, the stirring speed is 400rpm and 600rpm, after the reaction is finished, the mixture is repeatedly centrifuged and washed until the pH value is between 6 and 7, and the mixture is driedMXene precipitate is obtained after drying.

Step 2) dispersing 0.2g of MXene precipitate obtained in step 1) in 40-60mL of deionized water, performing ultrasonic treatment at 0-5 ℃ for 30-60min and the ultrasonic power of 100-300W, centrifuging at 4000-5000rpm for 5-15min, removing the precipitate, and taking the supernatant to obtain the MXene nanosheet suspension.

Step 3) preparing MXene obtained in step 2) into 2mg/mL suspension, preparing natural rubber into 2mg/mL emulsion, and mixing the MXene nano-sheet suspension and the natural rubber emulsion according to the volume ratio of 1-9: 9-1, preparing a mixed solution, carrying out ultrasonic treatment at 0-5 ℃ for 10-30min with the ultrasonic power of 100-200W, carrying out suction filtration on 20-40mL of the mixed solution by using a microporous filter membrane, and then drying at 50-70 ℃ for 1-6h to obtain the MXene/natural rubber flexible composite film.

Compared with the prior art, the MXene/natural rubber flexible composite film and the preparation method thereof have the following advantages:

1) the preparation method of the MXene/natural rubber flexible composite film is simple, does not contain organic solvent, and has good environmental friendliness.

2) The MXene/natural rubber flexible composite film prepared by the method has excellent flexibility, mechanical strength and electromagnetic wave shielding performance, can flexibly change the shape of the MXene/natural rubber flexible composite film, and has wide application prospect.

3) The MXene/natural rubber flexible composite film prepared by the method has the advantages of low cost, strong reproducibility and good market application prospect.

Drawings

FIG. 1 shows etched Ti prepared in example 1₃C₂Scanning Electron Microscopy (SEM) of the precipitate.

FIG. 2 shows Ti after exfoliation prepared in example 1₃C₂Transmission Electron Microscopy (TEM) and electron diffraction patterns (inset) of the nanoplates.

FIG. 3 shows Ti prepared in example 1₃C₂Scanning Electron Microscopy (SEM) of natural rubber flexible composite film.

FIG. 4 shows Ti prepared in example 2₃C₂Scanning Electron Microscopy (SEM) of natural rubber flexible composite film.

FIG. 5 shows Ti prepared in example 2₃C₂Digital pictures of the natural rubber flexible composite film.

FIG. 6 shows Ti prepared in example 3₃C₂Scanning Electron Microscopy (SEM) of natural rubber flexible composite film.

FIG. 7 shows Ti prepared in examples 1 to 4₃C₂Natural rubber flexible composite film and pure Ti₃C₂X-ray diffraction pattern (XRD) of the nanoplatelets.

FIG. 8 shows Ti prepared in examples 1 to 4₃C₂Electromagnetic wave shielding curve diagram of the natural rubber flexible composite film.

Detailed Description

The MXene/natural rubber flexible composite film and the preparation method thereof according to the present invention will be further described in detail by the accompanying drawings and specific examples.