CN112850711A

CN112850711A - Preparation method of MXene aerogel with spherical pore structure

Info

Publication number: CN112850711A
Application number: CN202110188360.9A
Authority: CN
Inventors: 马杰; 刘宁宁
Original assignee: Tongji University
Current assignee: Tongji University
Priority date: 2021-02-18
Filing date: 2021-02-18
Publication date: 2021-05-28

Abstract

The invention belongs to the field of synthesis of environmental nano materials, and provides a preparation method of MXene aerogel with a spherical pore structure. The MXene aerogel with a three-dimensional spherical pore structure is constructed by a template induction method and an emulsion method, and the preparation method comprises the steps of preparing Polystyrene (PS) microspheres, preparing Ti3C2Tx MXene dispersion liquid, preparing PS @ MXene, preparing Jauns MXene and preparing the MXene aerogel. The process is simple and convenient to operate, the flow is simple, the prepared MXene aerogel with the spherical pore structure is light in density, rich in micropores, adjustable in pore structure and wide in application value, and can be applied to the fields of electromagnetic shielding, capacitive deionization, electric adsorption and the like.

Description

Preparation method of MXene aerogel with spherical pore structure

Technical Field

The invention belongs to the technical field of synthesis of environmental materials, and particularly relates to a preparation method of MXene aerogel with a spherical pore structure.

Background

Two-dimensional transition metal carbon/nitride (MXene) is a novel two-dimensional nanomaterial with excellent electrical properties and unique chemical properties. Currently, applications of MXene focus on composite membrane materials and powdery nano hybrid materials, and in these applications, MXene sheets often reduce the specific surface area of the materials due to self-stacking, and simultaneously increase the contact resistance and reduce the overall performance. The problem can be solved by constructing a three-dimensional nano porous structure on a microscopic scale, and the overall performance of the material is improved by regulating and controlling the microstructure of the material.

Disclosure of Invention

The invention mainly aims to provide a preparation method of MXene aerogel with a spherical pore structure aiming at the defects in the prior art.

In order to achieve the above purpose, the invention relates to a method for preparing MXene aerogel with spherical pore structure, which comprises the following steps:

(1) and (3) washing styrene by using a separating funnel for three to four times by using a 10% NaOH solution, washing the styrene by using deionized water until effluent is neutral, and storing the pretreated styrene monomer in a refrigerator for later use.

(2) Putting the styrene monomer obtained in the step (1) into a 250mL three-neck flask, respectively weighing azodiisobutyronitrile and methacryloyloxyethyl trimethyl ammonium chloride by using an analytical balance, weighing ionized water and methanol by using a measuring cylinder, and mixing the ionized water and the methanol with styrene.

(3) And (3) putting the three-neck flask in the step (2) into a water bath kettle, magnetically stirring at 350rpm, and introducing argon for 30min to remove oxygen.

(4) Keeping the temperature of the reactant in the step (3) in the water bath at 80 ℃ and continuing the reaction for 6 h.

(5) And (3) centrifugally washing the reaction product in the step (4) with methanol for 3 times, centrifugally washing with deionized water for 2 times, performing solvent replacement to obtain PS microsphere dispersion, and drying at 5mL of 60 ℃ in vacuum to determine the concentration of the dispersion.

(6) Weighing 1-2g LiF, dissolving in 20-40mL of 9M hydrochloric acid solution, placing in a polytetrafluoroethylene reactor, and magnetically stirring at 400rpm for 30min.

(7) 1-2g of MAX-Ti3A1C2 was slowly added to the reactor of (6) and reacted at 35 ℃ for 24 h.

(8) And (3) repeatedly centrifuging and cleaning the product obtained in the step (7) by using deionized water (3500rpm, 5min) until the pH value of effluent is 5, and collecting a lower-layer precipitate.

(9) Dispersing the precipitate collected in (8) in ethanol, performing 750W ultrasonic treatment for 1h under an argon atmosphere, centrifuging (3500rpm, 5min) to collect the lower precipitate, and dispersing the lower precipitate in deionized water.

(10) And (3) carrying out 750W ultrasonic treatment on the dispersion liquid obtained in the step (9) for 20min under the argon atmosphere, centrifuging (3500rpm, 10min), and collecting an upper layer liquid, namely the Ti3C2Tx MXene dispersion liquid with a small flake layer. (5 mL of a small piece of Ti3C2Tx MXene dispersion was dried at 60 ℃ in vacuo and the concentration of the dispersion was calculated from the difference in mass between before and after drying.)

(11) The PS microsphere dispersion prepared in the step (5) and the MXene dispersion prepared in the step (10) are respectively diluted to the same concentration, and the Ti3C2Tx MXene dispersion is quantitatively and dropwise added into the PS emulsion at the speed of 1mL/min under the vigorous stirring for 12 hours.

(12) And (3) carrying out ultrasonic treatment on the reaction liquid in the step (11) for 10min, centrifuging (3500rpm, 5min), washing with deionized water, repeating for three times, and carrying out freeze drying for 48h to obtain PS @ MXene powder.

(13) Soaking the PS @ MXene powder prepared in the step (12) in toluene, and reacting for 12 hours under magnetic stirring.

(14) And (3) centrifugally washing the reaction solution in the step (13) by using toluene for 3 times, centrifugally washing the displacement solvent by using ethanol for 2 times, and drying in vacuum at 60 ℃ to obtain Janus MXene nanosheet powder.

(15) Deionized water and toluene (volume ratio is 1: 8) are respectively taken out by a measuring cylinder, 0.1 wt% (14) of prepared Janus MXene nanosheet powder is added into the deionized water and the toluene, the mixture is stirred for 3min at the rotating speed of 8000rpm by a vortex mixer, then the mixture is centrifuged for 5min at 10000rpm, and high-density creamy liquid generated at the bottom of a tube is taken out.

(16) And (5) freezing the cream-like liquid obtained in the step (15) in liquid nitrogen for 40min, and freeze-drying for 48h to obtain MXene aerogel.

Compared with the prior art, the invention provides the method for constructing the low-density MXene aerogel with the adjustable spherical pore structure by using the template induction method and the emulsion method, solves the self-stacking problem among MXene nanosheets and improves the overall performance of the MXene material. The method has the advantages of simple and convenient process operation and simple flow, and the prepared MXene aerogel with the spherical pore structure has light density, rich micropores, adjustable pore structure and wide application value, and can be applied to the fields of electromagnetic shielding, capacitive deionization, electric adsorption and the like.

Drawings

FIG. 1 is a scanning electron microscope image of PS microspheres prepared in the example.

FIG. 2 is a scanning electron microscope image of PS @ MXene prepared in example.

Fig. 3 is a scanning electron microscope image of MXene aerogel prepared in example.

Detailed Description

The following examples are provided to further illustrate the present invention and are not intended to limit the scope of the present invention.

Example (b):

(1) and (3) cleaning 50mL of styrene by using a separating funnel for three to four times by using a 10% NaOH solution, cleaning by using deionized water until the effluent is neutral, and storing the pretreated styrene monomer in a refrigerator for later use.

(2) Putting the styrene monomer obtained in the step (1) into a 250mL three-neck flask, respectively weighing 0.272g of azodiisobutyronitrile and 0.272g of methacryloyloxyethyl trimethyl ammonium chloride by using an analytical balance, weighing 5mL of deionized water and 145mL of methanol by using a measuring cylinder, and mixing with styrene.

(5) And (3) centrifugally washing the reaction product in the step (4) with methanol for 3 times, centrifugally washing with deionized water for 2 times, performing solvent replacement to obtain PS microsphere dispersion (figure 1), and drying at 5mL of 60 ℃ in vacuum to determine the concentration of the dispersion.

(6) 2g LiF was weighed out and dissolved in 40mL of 9M hydrochloric acid solution, placed in a PTFE reactor and magnetically stirred at 400rpm for 30min.

(7) 2g of MAX-Ti3AlC2 was slowly added to the reactor of (6) and reacted at 35 ℃ for 24 h.

(10) And (3) carrying out 750W ultrasonic treatment on the dispersion liquid obtained in the step (9) for 20min under the argon atmosphere, centrifuging (3500rpm, 10min), and collecting an upper layer liquid, namely the Ti3C2Tx MXene dispersion liquid with a small flake layer. 5mL of the dispersion was dried under vacuum at 60 ℃ to determine the concentration of the dispersion.

(11) The PS microsphere dispersion prepared in (5) and the MXene dispersion prepared in (10) were diluted to 1mg/mL respectively, and 5mL of Ti3C2Tx MXene dispersion was quantitatively added dropwise to 95mL of PS emulsion at a rate of 1mL/min under vigorous stirring for 12 h.

(12) And (3) centrifuging the reaction solution in the step (11) after ultrasonic treatment for 10min (3500rpm, 5min), washing with deionized water, repeating the steps for three times, and freeze-drying for 48h to obtain PS @ MXene powder (figure 2).

(15) 1mL of deionized water and 8mL of toluene are respectively taken by a dosing cylinder, mixed, and added with 7.92mg (14) of prepared Janus MXene nanosheet powder, stirred for 3min at the rotation speed of 8000rpm by a vortex mixer, then centrifuged for 5min at 10000rpm, and the high-density creamy liquid generated at the bottom of the tube is taken.

(16) And (3) freezing the cream-like liquid obtained in the step (15) in liquid nitrogen for 40min, and freeze-drying for 48h to obtain MXene aerogel (figure 3).

FIG. 1 is a scanning electron microscope image of the PS microspheres prepared in step (5) of the example of the present invention, from which it can be seen that the prepared PS microspheres have regular shapes, smooth surfaces and uniform dispersion.

FIG. 2 is a scanning electron microscope image of PS @ MXene prepared in step (12) of the example of the present invention, and it can be seen that MXene flakes have been successfully loaded on the surface of PS microspheres.

Fig. 3 shows the MXene aerogel prepared in step (16) of the embodiment of the present invention, and it can be seen that the prepared MXene aerogel has a spherical pore structure.

The MXene aerogel with the spherical pore structure prepared by the embodiment can be applied to various fields such as electromagnetic shielding, capacitive deionization, electric adsorption and the like.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. It will be readily apparent to those skilled in the art that various modifications to these embodiments and the generic principles defined herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above-described embodiments. Those skilled in the art should appreciate that many modifications and variations are possible in light of the above teaching without departing from the scope of the invention.

Claims

1. A preparation method of MXene aerogel with a spherical pore structure is characterized by comprising the following steps:

(1) placing the pretreated styrene monomer in a refrigerator for storage for later use;

(2) taking azobisisobutyronitrile and methacryloyloxyethyl trimethyl ammonium chloride, taking ionized water and methanol, and mixing with the styrene in the step (1);

(3) putting the mixture into a water bath kettle, stirring and deoxidizing;

(4) keeping the temperature of the reactant in the step (3) in the water bath at 80 ℃ and continuing to react for 6 h;

(5) washing the reaction product in the step (4) with methanol for 3 times, centrifugally washing with deionized water for solvent replacement to obtain PS microsphere dispersion, and drying in vacuum to determine the concentration of the dispersion;

(6) weighing LiF, dissolving in a hydrochloric acid solution, and stirring;

(7) adding MAX-Ti3AlC2 slowly into the reactor in step (6), and reacting for 24h at 35 ℃;

(8) repeatedly centrifuging and cleaning the product obtained in the step (7) by using deionized water until the pH value of effluent is 5, and collecting lower-layer precipitates;

(9) dispersing the precipitate collected in the step (8) in ethanol, centrifugally collecting the lower precipitate in an argon atmosphere, and dispersing the lower precipitate in deionized water;

(10) centrifuging the dispersion liquid obtained in the step (9) in an argon atmosphere to collect upper layer liquid, namely small lamellar layer Ti3C2Tx MXene dispersion liquid;

(11) respectively diluting the PS microsphere dispersion liquid prepared in the step (5) and the MXene dispersion liquid prepared in the step (10) to the same concentration, quantitatively dripping the Ti3C2Tx MXene dispersion liquid into the PS emulsion at the speed of 1mL/min under vigorous stirring, and continuously stirring for 12 hours;

(12) ultrasonically centrifuging the reaction liquid in the step (11), washing with deionized water, repeating for many times, and freeze-drying for 48 hours to obtain PS @ MXene powder;

(13) soaking the PS @ MXene powder prepared in the step (12) in toluene, and reacting for 12 hours under magnetic stirring;

(14) centrifugally washing the reaction solution in the step (13) by using toluene, centrifugally washing the displacement solvent by using ethanol, and drying in vacuum at 60 ℃ to obtain Janus MXene nanosheet powder;

(15) taking deionized water and toluene (the volume ratio is 1: 8), adding 0.1 wt% (14) of prepared Janus MXene nanosheet powder, stirring at the rotating speed of 8000rpm, centrifuging, and taking high-density creamy liquid generated at the bottom of the tube;

(16) and (5) freezing the cream-like liquid obtained in the step (15) in liquid nitrogen, and drying to obtain MXene aerogel.