CN111333053A

CN111333053A - Preparation method of water-soluble carbon nano tube

Info

Publication number: CN111333053A
Application number: CN202010166584.5A
Authority: CN
Inventors: 孙华杰
Original assignee: Jiangsu Huamo New Material Technology Co ltd
Current assignee: Sun Huajie
Priority date: 2020-03-11
Filing date: 2020-03-11
Publication date: 2020-06-26
Anticipated expiration: 2040-03-11
Also published as: CN111333053B

Abstract

The invention discloses a preparation method of a water-soluble carbon nano tube, which adopts a solid carbon source catalytic cracking method to prepare the carbon nano tube, urea and nickel nitrate are used as reactants, the carbon nano tube with less impurities and the length of about 500nm is prepared by catalytic cracking at the temperature of 380 plus 420 ℃, and the carbon nano tube with better water solubility is prepared by histidine modification.

Description

Preparation method of water-soluble carbon nano tube

Technical Field

The invention relates to the technical field of new materials, in particular to a preparation method of a water-soluble carbon nano tube.

Background

In 1991, when the electron microscopy expert rice island (Iijima) of basic research laboratory of NEC corporation of Japan examined spherical carbon molecules generated in a graphite arc device under a high-resolution transmission electron microscope, carbon molecules consisting of tubular, coaxial nanotubes, i.e., carbon nanotubes, including both single-walled and multi-walled, were unexpectedly found.

At present, the preparation method of the carbon nanotube is many, including the following methods:

1. the arc method is characterized in that inert gas or hydrogen is introduced into a vacuum reaction chamber, a cathode adopts a thick graphite rod, an anode adopts a thin graphite rod, the anode graphite rod is continuously consumed in the arc discharge process, and meanwhile, a product containing carbon nano tubes is precipitated on a graphite cathode. The carbon nano tube prepared by the pure graphite electrode has impurities such as graphite carbon nano particles, amorphous carbon and the like, and has low yield and difficult separation. The method has high quality, low yield and high cost, and is not suitable for mass production.

2. The laser evaporation method adopts laser beams to irradiate a graphite target containing transition metals to evaporate the graphite target, excites carbon atoms and catalyst particles, is then moved from a high-temperature zone to a low-temperature zone by airflow, and then mutually collides under the action of a catalyst to generate carbon nanotubes.

3. The Chemical Vapor Deposition (CVD), also called catalytic cracking, is a method of directly cracking and synthesizing carbon nanotubes by supplying a carbon source with a hydrocarbon gas or a carbon-containing gas such as Co under the action of a metal catalyst such as a transition metal of Mo, Fe, Co, Ni, etc. and an oxide thereof, and the temperature is generally controlled to be 500 to 1000 ℃ during the preparation of the carbon nanotubes, so that the defects of the generated carbon nanotubes are few. Meanwhile, the CVD method has the characteristics of simple equipment, easily controlled conditions, high yield and the like, and shows good industrial application prospect.

At present, the preparation of the water-soluble carbon nano tube is mainly to acidify the carbon nano tube so that the surface of the carbon nano tube is provided with water-soluble functional groups to increase the water solubility.

The carbon nano tube is prepared by catalytic cracking by taking solid as a carbon source, so that the cracking temperature is greatly reduced, and the histidine is used for surface modification to increase the water solubility. The preparation temperature, raw materials and the prepared regular and uniform water-soluble short carbon nano-tube have not been reported in the literature and patents. The carbon nano tube prepared by the method is expected to be further popularized, produced and applied.

Disclosure of Invention

In view of this, the invention provides a method for preparing water-soluble carbon nanotubes, which is simple and convenient to prepare, low in cost and less in impurities.

In order to achieve the purpose, the invention adopts the following technical scheme:

the method adopts a solid carbon source catalytic cracking method to prepare the carbon nano tube, urea and nickel nitrate are used as reactants, the carbon nano tube with less impurities and the length of about 500nm is prepared by catalytic cracking at the temperature of 380-420 ℃, and the carbon nano tube with better water solubility is prepared by modifying histidine.

Further, the preparation method comprises the following steps:

(1) uniformly mixing nickel nitrate and urea, and adding the mixture into a polytetrafluoroethylene reaction kettle;

(2) putting the reaction kettle into an oven, heating for 14-18h at the temperature of 130-;

(3) wetting the blue-green product with alcohol, and then putting the product into a reaction furnace to heat to 380-420 ℃ for 1.5-2.5h to obtain the carbon nano tube;

(4) dispersing the obtained carbon nano tube into 1L histidine aqueous solution with the concentration of 0.12-0.25mol/L at the temperature of 20-30 ℃, adjusting the PH, stirring uniformly and drying to obtain the water-soluble carbon nano tube.

N on the imidazole group of histidine carries extra electrons and has electrostatic attraction effect on substances with positive charges, and by utilizing the principle, the histidine can adsorb the carbon nano-tube with nickel nano-particles to increase the water solubility of the carbon nano-tube.

Preferably, the molar ratio of nickel nitrate to urea in step (1) is: and (3) nickel nitrate and urea are 1, (42-323).

Preferably, the heating rate in the step (3) is 4-6 ℃/min.

Preferably, the PH value is adjusted to 9-11 in the step (4)

According to the technical scheme, compared with the prior art, the invention discloses the preparation method of the water-soluble carbon nano tube, which is simple, low in requirement on production equipment, energy-saving, green and environment-friendly.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a diagram illustrating an XRD pattern of carbon nanotubes prepared in example 1 of the present invention;

FIG. 2 is a Raman spectrum of a carbon nanotube prepared in example 1 of the present invention;

FIG. 3 is a transmission electron micrograph of a carbon nanotube prepared in example 1 of the present invention;

fig. 4 is a high resolution transmission electron micrograph of the carbon nanotubes prepared in example 1 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

1) Firstly, uniformly mixing reactants of nickel nitrate and urea in a molar ratio of 0.1883g to 20g (the molar ratio is 1:323), adding the mixture into a liner of a 100ml polytetrafluoroethylene reaction kettle, sleeving a stainless steel outer sleeve on the liner, transferring the stainless steel outer sleeve into an oven, and heating for 16 hours at the set temperature of 150 ℃. And then waiting for natural cooling.

2) And after natural cooling, taking out the blue-green product, adding a certain amount of ethanol, preferably wetting the blue-green product, heating at 400 ℃ for 2h, and keeping the temperature rise speed at 5 ℃/min.

3) Dispersing the prepared carbon nanotube powder in 1L histidine aqueous solution with the concentration of 0.12mol/L at the temperature of 25 ℃, adding NaOH solution to adjust the pH value to 10, stirring uniformly, and drying to obtain the water-soluble carbon nanotube.

Example 2

1) Firstly, uniformly mixing reactants of nickel nitrate and urea in a molar ratio of 0.1883g to 20g (the molar ratio is 1:323), adding the mixture into a liner of a 100ml polytetrafluoroethylene reaction kettle, sleeving a stainless steel outer sleeve on the liner, transferring the stainless steel outer sleeve into an oven, and heating for 14 hours at the temperature of 170 ℃. And then waiting for natural cooling.

2) And after natural cooling, taking out the blue-green product, adding a certain amount of ethanol, preferably wetting the blue-green product, heating for 1.5h at the temperature of 420 ℃, and keeping the temperature rising speed at 6 ℃/min.

3) Dispersing the prepared carbon nano-tube powder in 1L histidine aqueous solution with the concentration of 0.25mol/L at the temperature of 20 ℃, adding NaOH solution to adjust the pH value to 11, stirring uniformly, and drying to obtain the water-soluble carbon nano-tube.

Example 3

1) Firstly, uniformly mixing reactants of nickel nitrate and urea in a molar ratio of 0.1883g to 2.6216g (the molar ratio is 1:42), adding the mixture into a 100ml polytetrafluoroethylene reaction kettle inner container, sleeving a stainless steel outer sleeve on the inner container, transferring the inner container into an oven, and heating the inner container for 18 hours at a set temperature of 130 ℃. And then waiting for natural cooling.

2) And after natural cooling, taking out the blue-green product, adding a certain amount of ethanol, preferably wetting the blue-green product, heating at 380 ℃ for 2.5h, and keeping the temperature rise speed at 4 ℃/min.

3) Dispersing the prepared carbon nano-tube powder in 1L histidine aqueous solution with the concentration of 0.20mol/L at the temperature of 30 ℃, adding NaOH solution to adjust the pH value to 9, stirring uniformly, and drying to obtain the water-soluble carbon nano-tube.

Performance testing

The water-soluble carbon nanotubes prepared in example 1 were subjected to performance tests, and the test results are shown in fig. 1 to 4.

Fig. 1, two distinct peaks in the XRD pattern correspond to two species: a 2 θ of 44.52 ° corresponds to (011) of nickel (JCPDS No. 45-1027); another 2 theta of 26 deg. corresponds to the (002) crystal plane of graphite (JCPDS No.02-0456), indicating the formation of nickel particles and graphite-like structures during the cracking stage.

FIG. 2 Raman spectra at 1349 and 1591cm^-1The peaks are shown and correspond to the D band and the G band respectively, which indicates that the carbon nanotubes in the sample have certain surface defects.

Fig. 3, a transmission electron micrograph, fig. 3b shows that the prepared carbon nanotube is a hollow tubular structure, and the inner diameter is about 20nm, and fig. 3a shows that the length of the carbon nanotube is about 500 nm.

Fig. 4 shows the high resolution tem image showing that fig. 4a is a tubular hollow structure, the lattice diffraction fringe spacing on the tube wall is 0.335nm, corresponding to the (002) crystal face of graphite, which belongs to the crystalline multi-walled carbon nanotube, and the lattice diffraction fringe spacing in fig. 4b is 0.203nm, corresponding to the (011) crystal face of nickel.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The preparation method of the water-soluble carbon nanotube is characterized in that the water-soluble carbon nanotube is obtained by performing catalytic pyrolysis on a solid carbon source to obtain the carbon nanotube and then modifying the carbon nanotube with histidine.

2. The method for preparing water-soluble carbon nanotubes according to claim 1, comprising the steps of:

3. The method for preparing water-soluble carbon nanotubes according to claim 2, wherein the molar ratio of the nickel nitrate to the urea in the step (1) is as follows: and (3) nickel nitrate and urea are 1, (42-323).

4. The method of claim 2, wherein the temperature increase rate in step (3) is 4-6 ℃/min.

5. The method of claim 2, wherein the pH of the water-soluble carbon nanotube in the step (4) is adjusted to 9-11.