阅读说明：本技术 一种碳纳米管纳米复合材料的制备方法与应用 (Preparation method and application of carbon nanotube nano composite material ) 是由 徐晖 赵春燕 于 2020-06-12 设计创作，主要内容包括：本发明公开了一种聚合物制备碳纳米管无机纳米复合材料的方法。其特征在于在碳纳米管表面进行共价修饰后,通过表面原子转移自由基聚合反应在碳纳米管表面引入带有络合性基团的聚合物,前驱体在接枝位点上原位生长,合成负载率高,分散性能优良的碳纳米管纳米复合材料。本发明具有合成方法简单,反应条件温和,可以对复合材料形貌进行简单有效调控等优点。(The invention discloses a method for preparing a carbon nano tube inorganic nano composite material by using a polymer. The method is characterized in that after covalent modification is carried out on the surface of the carbon nano tube, a polymer with a complexing group is introduced on the surface of the carbon nano tube through surface atom transfer radical polymerization reaction, a precursor grows in situ on a grafting site, and the carbon nano tube nano composite material with high load rate and excellent dispersion performance is synthesized. The method has the advantages of simple synthesis method, mild reaction conditions, simple and effective regulation and control of the morphology of the composite material and the like.)

1. A preparation method of a carbon nano tube nano particle composite material comprises the following steps:

firstly, a reaction site for initiating an atom transfer radical reaction on the surface modification of a carbon nano tube through a chemical reaction is used as a carbon nano tube macroinitiator;

then, the carbon nano tube macromolecular initiator is used for preparing a polymer-based carbon nano tube as a carrier through active atom transfer free radical reaction;

and finally, mixing the carrier with an inorganic precursor, and reacting by a chemical synthesis method to prepare the carbon nano tube nano particle composite material.

2. The method as claimed in claim 1, wherein the carbon nanotubes comprise one or more carbon nanotubes, and the carbon nanotubes may be one or more of single-walled carbon nanotubes or multi-walled carbon nanotubes.

3. The method of claim 1, wherein the carbon nanotube/photoinitiator has a structure represented by the following general formula,

wherein X is selected from O, NH, L is a divalent linking group.

4. The method of claim 1, wherein the polymer is a polymer containing a complexing group, and the complexing group comprises one or more of a carboxyl group, an amino group, a thiol group, a phosphonic acid group, and a sulfonic acid group.

5. The method of claim 1, wherein the carrier is a polymer-based carbon nanotube, and the polymer-coated carbon nanotube is prepared by atom transfer radical reaction induced on the surface of the carbon nanotube and is connected to the carbon nanotube by covalent bond.

6. The method according to claim 1, wherein the inorganic precursor comprises a metal ion precursor and a non-metal precursor; wherein the metal ion precursor comprises one or more of inorganic salts of gold, silver, platinum, copper, ruthenium, rhodium, palladium, lead, tin, iron, cobalt, manganese, cesium, zirconium and nickel; the nonmetal precursor comprises one or more of oxygen, sulfur, selenium, tellurium, silicon, bromine and iodine simple substances or compounds.

7. The method of claim 1, wherein the chemical synthesis method comprises one or more of a colloid method, a solution reduction method, an impregnation method, an electrochemical deposition method, and a supercritical fluid method.

8. The method as claimed in claim 1, wherein the nanoparticles comprise one or more of metal nanoparticles, metal oxide nanoparticles, inorganic semiconductor nanoparticles, and perovskite nanoparticles.

9. The method of claim 4, wherein the polymer containing complexing groups comprises one or more of polyacrylic acid, poly-2-vinylpyridine, poly-4-vinylpyridine, polyvinylpyrrolidone, polyacrylonitrile, polyvinylbenzenesulfonic acid, polyisopropenephosphonic acid, and derivatives thereof.

10. The method as claimed in claim 8, wherein the metal nanoparticles comprise one or more of gold nanoparticles, silver nanoparticles, copper nanoparticles, platinum nanoparticles, palladium nanoparticles, ruthenium nanoparticles, and rhodium nanoparticles.

11. The method of claim 8, wherein the metal oxide nanoparticles comprise one or more of zinc oxide nanoparticles, nickel oxide nanoparticles, manganese dioxide nanoparticles, titanium dioxide nanoparticles, tin dioxide nanoparticles, ferric oxide nanoparticles, ferroferric oxide nanoparticles, and cobaltosic oxide nanoparticles.

12. The method of claim 8, wherein the inorganic semiconductor nanoparticles comprise one or more of cadmium selenide, cadmium sulfide, zinc sulfide, cadmium telluride, lead telluride, and bismuth telluride.

13. The method of claim 8, wherein the perovskite nanoparticles comprise barium titanate nanoparticles, lead zirconate nanoparticles, cesium lead bromide (CsPbBr)₃) Nanoparticles, cesium lead iodide (CsPbI)₃) Nanoparticles, cesium lead iodobromide (CsPbI)_xBr_3-x) One or more of the nanoparticles.

Technical Field

The invention belongs to the field of nano composite materials, and particularly relates to a preparation method of a carbon nano tube nano particle composite material.

Background

Carbon nanotubes are a particular crystalline structure in the form of a hollow and closed tube, consisting of one or more rolled graphene. Since their discovery in 1991, carbon nanotubes have attracted extensive interest in the scientific community of physics, chemistry and materials all over the world. The carbon nanotube has the advantages of large specific surface area, high conductivity, excellent chemical and electrochemical stability, adjustable nanotube cavity structure, large length-diameter ratio, etc. and is widely applied to the aspects of hydrogen storage materials, field emission materials, battery materials, reinforced composite materials, sensor materials, catalyst carrier materials, etc. The nano particles have extremely large specific surface area and size effect, and the compound formed by loading the nano particles on the carbon nano tube has extremely excellent performance. Different loading of nanoparticles on carbon nanotubes can be applied in different directions. For example, the carbon nanotube surface loaded with noble metal nanoparticles can be applied to the fields of electrochemical cells, fuel cells, catalytic reactions, biomedicine and the like, and the composite formed by loading inorganic semiconductor nanoparticles on the carbon nanotube can be applied to the fields of thermoelectric materials, photoelectric materials, solar cells and the like. However, in general, carbon nanotubes have strong hydrophobicity and cannot be infiltrated by a liquid with a surface tension of more than 100 to 200mN/m, most of nanoparticles cannot be carried on the surface of the carbon nanotubes, and the nanoparticles are easy to fall off and agglomerate to grow during ultrasonic oscillation, stirring or heating, so that the surface of the carbon nanotubes is usually subjected to proper oxidation treatment, and functional groups such as hydroxyl, carboxyl, aldehyde and the like are introduced, and the functional groups can adsorb the nanoparticles and become active sites for the deposition of the nanoparticles. However, the number of such surface functional groups is limited and the distribution is not uniform. In addition, although the performance of the composite material can be improved by increasing the loading amount of the nanoparticles on the surface of the carbon nanotubes, the nanoparticles are easily agglomerated on the surface of the carbon nanotubes with the increase of the content of the nanoparticles, so that the dispersibility of the nanoparticles is reduced, thereby affecting the overall performance of the composite material. At present, the dispersibility and the load capacity of the carbon nano tube nano particle compound prepared by the prior art are difficult to meet the requirements at the same time, thereby influencing the performance and the application range of the carbon nano tube composite material. Therefore, the method for improving the loading of the nano particles on the surface of the carbon nano tube and uniformly dispersing the nano particles on the surface of the carbon nano tube becomes a research hotspot for preparing the carbon nano tube nano particle composite material.

Disclosure of Invention

Aiming at the defects of poor dispersity and low load of carbon nano tube loaded nano particles, the invention provides a preparation method of a carbon nano tube nano particle composite material. Compared with the prior art, the method is characterized in that the polymer with the complexing group is connected to the surface of the carbon nano tube through a covalent bond through free radical polymerization reaction to be used as an active site for nano particle deposition. The strong complexation effect exists between the complexation group on the polymer and the nano particle precursor, so that the nano particle precursor can be effectively adsorbed on the surface of the carbon nano tube, and can be dispersed and uniformly grown on the surface of the carbon nano tube in the subsequent nano crystal growth process. The method can effectively improve the loading capacity and the dispersity of the nano particles on the carbon nano tubes.

A preparation method of a carbon nano tube nano particle composite material is characterized by comprising the following steps:

in the first step, a reaction site which can initiate an atom transfer radical reaction on the surface modification of the carbon nano tube through a chemical reaction is used as a carbon nano tube macroinitiator.

Step 1, dispersing carbon nanotubes in a concentrated nitric acid solution by ultrasonic, heating to 100-120 ℃, carrying out reflux reaction for 6-12 h under magnetic stirring, cooling to room temperature, diluting with distilled water, carrying out vacuum filtration by using a filter funnel with an aperture G5, diluting a filtrate with distilled water, carrying out vacuum filtration, washing with deionized water to be neutral, and drying in a vacuum drying oven. After the reaction, the carbon tube surface has many reaction sites of carboxyl and hydroxyl for subsequent functionalization.

In an embodiment of the present invention, the carbon nanotube may be one or more of a single-walled carbon nanotube, a double-walled carbon nanotube, or a multi-walled carbon nanotube. The carbon nano tube can be prepared by methods such as an arc discharge method, a chemical vapor deposition method or a laser evaporation method, and the multi-walled carbon nano tube is prepared by the chemical vapor deposition method in the embodiment of the invention. The inner diameter of the multi-wall carbon nano tube is 10nm to 50nm, the outer diameter is 30nm to 80nm, and the length is 50 mu m to 100 mu m.

And 2, dispersing the acidified carbon nano tube in a thionyl chloride solution by ultrasonic, heating to 60 ℃, and reacting for 24 hours under magnetic stirring. After the reaction, the carboxyl group on the surface of the carbon nano tube is substituted by acyl, so that the acylated carbon nano tube (MWCNT-COCl) can be obtained. After removing the reaction liquid by centrifugation, the acylated carbon nano tube is washed by anhydrous THF for a plurality of times and is dried in a vacuum drying oven at 50 ℃ for 2h to obtain the acylated carbon nano tube.

And 3, dispersing the acylated carbon nano tube in a dihydric alcohol compound or a dihydric amine compound by ultrasonic, heating to 100-120 ℃, and reacting for 24 hours under magnetic stirring. And centrifuging the hydroxylated carbon nanotube to remove reaction liquid, washing with absolute ethyl alcohol for several times, and drying in a vacuum drying oven at 50 ℃ for 24 hours. In this step, the acyl group on the surface of the carbon nanotube is substituted with a hydroxyl group or an amino group to obtain a hydroxylated or aminated carbon nanotube (MWCNT-OH/MWCNT-NH)₂)。

In the embodiment of the present invention, as specific examples thereof, the dihydric alcohol may be exemplified by, but not limited to, ethylene glycol, propylene glycol, 1, 4-butanediol, diethylene glycol, tetraethylene glycol, neopentyl glycol, 1, 6-hexanediol, octanediol, nonanediol, decanediol, diethylene glycol, and the like.

In the embodiment of the present invention, specific examples of the diamine include, but are not limited to, methylenediamine, 1, 2-ethylenediamine, propylenediamine, 1, 2-diaminopropane, 1, 3-diaminopentane, hexamethylenediamine, diaminoheptane, diaminododecane, diethylaminopropylamine, and the like.

And 4, preparing the carbon nano tube macromolecular initiator. Ultrasonically dispersing the hydroxylated carbon nano tube in N-methyl pyrrolidone (NMP), adding 2-bromine isobutyryl bromide under the magnetic stirring of ice-water bath, and reacting for 24 hours at normal temperature. And centrifuging to remove reaction liquid, washing with dichloromethane and ethanol respectively, and drying in a vacuum drying oven at 50 ℃ for 24h to obtain the carbon nanotube macroinitiator (MWCNT-Br).

The carbon nano tube macromolecular initiator contains a structure shown in the following general formula,

wherein X is selected from O, NH, L is a divalent linking group;

l, the number of carbon atoms is not particularly limited, but is preferably 1 to 20, more preferably 1 to 10.

L including but not limited to single bonds, linear structures, branched structures containing pendant groups L is selected from the group consisting of C_1-20Alkylene, divalent C_1-20Heterohydrocarbyl, substituted C_1-20Alkylene, substituted divalent C_1-20Any divalent linking group or combination of divalent linking groups in the heterohydrocarbon group. The substituent atom or the substituent is not particularly limited, and is selected from a halogen atom, a hydrocarbon substituent, and a heteroatom-containing substituent.

Secondly, preparing a polymer-based carbon nanotube structure as a carrier by the carbon nanotube initiator through active atom transfer radical reaction;

and 5, adding a carbon nano tube macroinitiator, a polymer monomer, a catalyst for active polymerization and a solvent into a reaction bottle, uniformly mixing, introducing nitrogen for bubbling, reacting for 8-48 h at 25-120 ℃ in an oil bath, stopping, centrifuging the product, washing for several times by using dichloromethane, and drying for 24h at 30-50 ℃ in a vacuum oven.

In the embodiment of the present invention, specific examples of the polymer having a complexing group include, but are not limited to, polyacrylic acid, poly-2-vinylpyridine, poly-4-vinylpyridine, polyvinylpyrrolidone, polyacrylonitrile, polyvinylbenzenesulfonic acid, polyisopropenephosphonic acid, and the like.

The polymer containing a complexing group may be obtained by first polymerizing a precursor and then subjecting the precursor to a hydrolysis reaction, if necessary. For example, when preparing polyacrylic acid based carbon nanotube (MWCNT-PAA), tert-butyl acrylate (tBA) is used as a polymer monomer to react according to the steps to obtain polyacrylic acid tert-butyl ester based carbon nanotube (MWCNT-PtBA), and then hydrolysis is carried out to obtain polyacrylic acid based carbon nanotube. The specific hydrolysis step is that the carbon nanotube-based poly (tert-butyl acrylate) is dispersed in dichloromethane, excessive trifluoroacetic acid is added, and the reaction is carried out for 24 hours under magnetic stirring. And (3) centrifuging the product after the reaction is finished, washing the product for a plurality of times by using absolute ethyl alcohol, and drying the product in a vacuum oven at 50 ℃ for 24 hours to obtain the polyacrylic acid-based carbon nanotube.

In an embodiment of the invention, the living polymerization reaction is synergistically catalyzed by a monovalent copper compound in combination with an amine ligand. As specific examples thereof, the monovalent copper compound may be selected from Cu (I) salts such as CuCl, CuBr, CuI, CuCN, CuOAc, etc.; may also be selected from Cu (I) complexes, e.g. [ Cu (CH)₃CN)₄]PF₆、[Cu(CH₃CN)₄]OTf、CuBr(PPh₃)₃Etc.; among them, the Cu (I) salt is preferably CuBr and CuI, and the Cu (I) complex is preferably CuBr (PPh)₃)₃. The amine ligand can be selected from Pentamethyldiethylenetriamine (PMDETA), and tris [ (1-benzyl-1H-1, 2, 3-triazol-4-yl) methyl]Amine (TBTA), tris [ (1-tert-butyl-1H-1, 2, 3-triazol-4-yl) methyl]Amines (TTTA), tris (2-benzimidazolemethyl) amine (TBIA), and the like; among them, the amine ligand is preferably PMDETA and TBTA. The amount of the catalyst used is not particularly limited, but is usually 0.1 to 2% by weight.

In the embodiment of the present invention, the temperature and time of the living polymerization reaction are related to the kind of the polymer monomer, the temperature of the polymerization reaction may be 25 to 120 ℃, and the reaction time is preferably 8 to 48 hours.

And thirdly, reacting the carrier with an inorganic precursor through a chemical synthesis method to prepare the carbon nano tube nano particle composite material.

The chemical synthesis method comprises one or more of a colloid method, a solution reduction method, an impregnation method, an electrochemical deposition method and a supercritical fluid method. In the embodiment of the present invention, the solution reduction method is preferable.

The specific steps of the solution reduction method are that the carrier and the inorganic precursor are mixed and dispersed in a proper solvent, the polymer grafted on the carbon tube contains complexing groups such as carboxylic acid, amino, sulfydryl, sulfonic group and the like, the complexing group has good complexing effect on the inorganic precursor, and a reducing agent is added into the solution or the temperature is raised for reaction, so that the inorganic nano particles are uniformly deposited on the surface of the carbon nano tube.

The inorganic precursor comprises a metal ion precursor and a nonmetal precursor; wherein the metal ion precursor comprises acid or inorganic salt of gold, silver, platinum, copper, ruthenium, rhodium, palladium, lead, tin, iron, barium, cobalt, manganese, cesium, zirconium, and nickel, such as chloroauric acid (HAuCl)₄) Gold chloride (AuCl)₃) Silver nitrate (AgNO)₃) Lead nitrate (PbNO)₃) Chloroplatinic acid (H)₂PtCl₆) Ruthenium chloride (RuCl)₃) Chlororhodic acid (H)₃RhCl₆) Palladium chloride (PdCl)₂) Chloro osmic acid (H)₂OsCl₆) Chloro-iridic acid (H)₂IrCl₆) Copper sulfate (CuSO)₄) Barium chloride (BaCl)₂) Iron chloride (FeCl)₃) And ferrous chloride (FeCl)₂) Potassium permanganate (KMnO)₄) Zirconium chloride (ZrCl)₄) One or more of (a). The nonmetallic precursor comprises oxygen, sulfur, selenium, tellurium, silicon simple substance or compound, such as oxygen, ammonia water, sodium sulfide (NaS), sodium hydrogen selenide (NaHSe), sodium hydrogen telluride (NaHTe), and Tetraethoxysilane (TEOS).

In an embodiment of the present invention, the solvent used for mixing the carrier and the inorganic precursor includes water, ethanol, ethylene glycol, DMF, NMP, dichloromethane, chloroform, acetone, tetrahydrofuran, and the like.

In an embodiment of the present invention, the carrier is mixed with the inorganic precursor and the mixture is ultrasonically dispersed for 0.5 to 24 hours.

In an embodiment of the present invention, the reducing agent used for the reaction of the support with the inorganic precursor includes ethylene glycol, sodium borohydride, ethanol, ascorbic acid, sodium citrate, borane-tert-butylamine, tri-n-octylphosphine, tributylphosphine, and the like.

In an embodiment of the present invention, the temperature used for the reaction of the support and the inorganic precursor may be 25 ℃ to 180 ℃

The metal nanoparticles comprise one or more of gold nanoparticles, silver nanoparticles, copper nanoparticles, platinum nanoparticles, palladium nanoparticles, ruthenium nanoparticles and rhodium nanoparticles.

The metal oxide nanoparticles comprise one or more of zinc oxide nanoparticles, nickel oxide nanoparticles, manganese dioxide nanoparticles, titanium dioxide nanoparticles, tin dioxide nanoparticles, ferric oxide nanoparticles, ferroferric oxide nanoparticles and cobaltosic oxide nanoparticles.

The inorganic semiconductor nanoparticles comprise one or more of cadmium selenide, cadmium sulfide, zinc sulfide, cadmium telluride, lead telluride, bismuth telluride and selenium sulfide nanoparticles

The perovskite nano particles comprise barium titanate nano particles, lead zirconate nano particles and lead cesium bromide (CsPbBr)₃) Nanoparticles, cesium lead iodide (CsPbI)₃) Nanoparticles, cesium lead iodobromide (CsPbI)_xBr_3-x) One or more of the nanoparticles.

In other aspects, the metal precursor or inorganic precursor can comprise other metal salts or solutions not specifically described herein, and the present invention is not intended to be limited to any particular inorganic precursor.

The carbon nano tube nano composite material comprises a carbon nano tube, a polymer coated on the surface of the carbon nano tube and nano particles adsorbed on the surface of the polymer. The nano particles are uniformly distributed on the surface of the polymer, the particle size of the nano particles is 1 nm-10 nm, and the particle size of the nano particles can be controllably adjusted through the reaction time and the type of the reducing agent. The mass ratio of the nano particles in the carbon nano tube nano particle compound is 20-60%.

Drawings

The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a Transmission Electron Microscope (TEM) image of the carbon nanotube-supported lead telluride nanoparticle composite material of the present invention.

Fig. 2 is a TEM of carbon nanotube-supported lead telluride nanoparticles without graft polymer.

It is shown that the carbon nanotube composite material prepared according to an embodiment of the present invention can greatly improve the nanoparticle dispersibility and loading amount.

FIG. 3 is a TEM image of the carbon nanotube supported ferroferric oxide nanoparticle composite material of the present invention.

Fig. 4 is a TEM image of the carbon nanotube-supported cadmium selenide nanoparticle composite material of the present invention.

Fig. 5 is a TEM image of the carbon nanotube-supported cesium lead bromide nanoparticle composite material of the present invention.

FIG. 6 is a TEM image of the carbon nanotube-supported titania nanoparticle composite of the present invention.

Fig. 7 is a TEM image of the carbon nanotube-supported palladium nanoparticle composite material of the present invention.

Fig. 8 is a TEM image of the carbon nanotube-supported barium titanate nanoparticle composite material of the present invention.

Fig. 9 is a TEM image of the carbon nanotube supported cobalt oxide nanoparticle composite material of the present invention.

Fig. 10 is a TEM image of the carbon nanotube silver-loaded nanoparticle composite material of the present invention.

Detailed Description

The present invention provides a method for preparing a carbon nanotube nanoparticle composite material, and for better understanding of the present invention, the present invention will be further described in detail with reference to the accompanying drawings and examples, but the scope of the present invention is not limited to the scope shown in the examples.