CN112591736B

CN112591736B - Method for dispersing carbon nano tube with assistance of cellulose

Info

Publication number: CN112591736B
Application number: CN202011484328.7A
Authority: CN
Inventors: 杜开峰; 乔亮智
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2020-12-16
Filing date: 2020-12-16
Publication date: 2022-12-20
Anticipated expiration: 2040-12-16
Also published as: CN112591736A

Abstract

The invention relates to a novel method for dispersing carbon nanotubes with the aid of cellulose, and belongs to the technical field of materials. The invention adopts natural polysaccharide cellulose as a carbon nano tube dispersing agent, and realizes uniform and stable dispersion of the carbon nano tube in NaOH/urea solution in a short time through mild stirring in ice bath. The preparation method is simple to operate, does not need any pretreatment of raw materials, and is easy for large-scale production; the cellulose is used as a raw material, so that the cost is low, and the environment is not polluted; the preparation process of the invention does not damage the electronic structure of the carbon nano tube, and effectively protects the inherent property of the carbon nano tube.

Description

Method for dispersing carbon nano tube with assistance of cellulose

Technical Field

The invention belongs to the technical field of materials, and relates to a novel method for dispersing carbon nanotubes with the assistance of cellulose.

Background

Since the discovery of carbon nanotubes, carbon nanotubes have exhibited great application potential in the fields of catalysis, energy storage and conversion, flexible electronics, and the like due to their superior properties such as excellent electrical conductivity, ultra-high mechanical strength, and high thermal stability, and are considered as one of the core materials of next-generation ultra-light structural materials. However, since it has a large specific surface area and aspect ratio, the carbon nanotubes are aggregated and entangled due to strong van der waals force. The formation of such aggregates can seriously affect the subsequent processability and useful life of the carbon nanotubes. Therefore, effective dispersion of the aggregated carbon nanotubes becomes a key technology for promoting the development of carbon nanotube-based materials.

At present, the dispersion method of carbon nanotubes mainly includes four methods: physical dispersion, chemical modification, surfactant dispersion, and polymer exfoliation. However, they have drawbacks. Physical methods require strong energy processes such as ultrasound to disperse carbon nanotubes, but the dispersion effect is poor and the carbon nanotubes tend to aggregate quickly despite the simple process; chemical modification can destroy the electronic structure of the carbon nano tube and influence the conductivity and mechanical property of the carbon nano tube; the surfactant method may cause weak interfacial adhesion between the carbon nanotubes and the substrate material. The polymer stripping method is considered as one of the most potential carbon nanotube dispersing methods, and DNA, protein, chitosan, etc. can be used as a dispersing agent.

Nanocellulose has proven to be a highly efficient carbon nanotube dispersant because it has similar spatial dimensions as carbon nanotubes and is an amphiphilic molecule. However, the process of dispersing carbon nanotubes by cellulose reported at present is very complicated, and the cellulose and the carbon nanotubes need to be modified respectively first, and then the carbon nanotubes are dispersed by a strong physical process, so that the production period is long, the cost is high, and the large-scale application is not facilitated. Based on the problems, the invention provides a novel method for dispersing carbon nanotubes with the assistance of cellulose. The key points of the preparation method are as follows: dissolving cellulose and carbon nano tubes into NaOH/urea solution together, and stirring at ice bath temperature to obtain uniform and stable carbon nano tube dispersion liquid.

Disclosure of Invention

The invention utilizes cellulose, a rich natural biomass resource, as a carbon nano tube dispersing agent, and realizes the high-efficiency dispersion of the carbon nano tube in the NaOH/urea solution through a simple and mild stirring process in an ice bath.

The purpose of the invention is realized by the following technical scheme.

A novel method for dispersing carbon nano tubes with the assistance of cellulose is characterized by comprising the following steps:

(1) Adding cellulose and carbon nano tubes into 11 wt% NaOH/4 wt% urea solution according to a fixed proportion;

(2) Placing the mixed solution in an ice bath, and stirring at the rotating speed of 1000 rpm/min for 5min;

(3) And centrifuging the obtained solution to remove insoluble substances, thereby obtaining a uniform and stable carbon nano tube dispersion liquid.

Preferably, the ratio of cellulose to carbon nanotubes in step (1) is greater than 3.

Preferably, the cellulose in the step (1) can be microcrystalline cellulose, nano cellulose fiber, bamboo fiber, hemp fiber, cellulose derivatives and the like, and the concentration of the cellulose is 1% -8%.

Preferably, the carbon nanotube species in step (1) may be single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes.

Preferably, the mixture in step (1) is stirred in an ice bath.

Compared with the prior art, the invention has the following advantages:

(1) The method is simple to operate, does not need any pretreatment of raw materials, and is easy for large-scale production;

(2) The invention takes cellulose as raw material, has low cost and no pollution to the environment;

(3) The preparation process of the invention does not damage the electronic structure of the carbon nano tube, and effectively protects the inherent property of the carbon nano tube.

Drawings

FIG. 1 is a pictorial representation of a product of example 1 of an embodiment of the present invention.

FIG. 2 is a UV-Vis spectral diagram of the product of inventive example 1.

Detailed Description

For a better understanding of the invention, it will be explained further below with reference to the embodiment examples and the accompanying drawings. It should be noted that the embodiments are only used for further explaining the invention, and the scope of the invention to be claimed is not limited to the scope shown in the embodiments.

Examples 1

Adding 3 g of cellulose and 0.2 g of carbon nano tube into 45 g of 11 wt% NaOH/4 wt% urea solution; then, the mixed solution is placed in an ice bath and stirred for 5min at the rotating speed of 1000 rpm/min; and centrifuging the obtained solution at the rotating speed of 3000 rpm/min for 3 min, and removing insoluble substances to obtain uniform and stable carbon nanotube dispersion liquid. Fig. 1 shows a physical diagram of the obtained carbon nanotube dispersion, and the solution did not precipitate even when left at room temperature for 1 day. Meanwhile, we performed an absorbance test on the solution to examine the dispersibility of the carbon nanotubes. As shown in fig. 2, at 290 nm, the carbon nanotube dispersion showed a broad peak, demonstrating monodispersity of the carbon nanotubes in solution.

Claims

1. A method for dispersing carbon nano tubes with the assistance of cellulose is characterized by comprising the following steps:

(2) Placing the mixed solution in an ice bath, stirring at the rotating speed of 1000 rpm for 5min to promote cellulose dissolution and carbon nanotube dispersion;

(3) The solution obtained above was centrifuged to remove insoluble substances, and a uniform and stable carbon nanotube dispersion was obtained.

2. The method for cellulose-assisted dispersion of carbon nanotubes as claimed in claim 1, wherein the mass ratio of cellulose to carbon nanotubes in step (1) is greater than 3.

3. The method for dispersing carbon nanotubes with the assistance of cellulose according to claim 1, wherein the cellulose in step (1) can be microcrystalline cellulose or nanocellulose fiber, and the concentration of cellulose is 1% to 8%.

4. The method of claim 1, wherein the carbon nanotubes used in step (1) are single-walled carbon nanotubes, multi-walled carbon nanotubes, or multi-walled carbon nanotubes.

5. The method of claim 1, wherein the mixture in step (2) is stirred in an ice bath.