CN114574001A

CN114574001A - Method for preparing hydrophilic carbon black through biomimetic modification of phenolic amine and hydrophilic carbon black

Info

Publication number: CN114574001A
Application number: CN202011370204.6A
Authority: CN
Inventors: 王文才; 李佳伟; 叶欣; 邵晓明; 张博; 张立群
Original assignee: Beijing University of Chemical Technology
Current assignee: Beijing University of Chemical Technology
Priority date: 2020-11-30
Filing date: 2020-11-30
Publication date: 2022-06-03
Anticipated expiration: 2040-11-30
Also published as: CN114574001B

Abstract

The invention discloses a method for preparing hydrophilic carbon black by biomimetic modification of phenolic amine and the hydrophilic carbon black. The method comprises the following steps: (1) dispersing carbon black in water to form a carbon black dispersion; (2) mixing plant polyphenol and polyamine to prepare a phenol amine solution; (3) adding the carbon black dispersion liquid prepared in the step (1) into the phenol amine solution in the step (2), and simultaneously adding a buffer solution to adjust the pH value to 8.0-11; (4) and (4) continuously stirring the mixed solution obtained in the step (3) at 15-80 ℃ for reaction, and drying after cleaning to obtain the hydrophilic carbon black. The method successfully coats the surface of the carbon black with a hydrophilic polymer, so that the content of oxygen and nitrogen on the surface of the carbon black is obviously increased, and the modified carbon black has good dispersibility and stability in water.

Description

Method for preparing hydrophilic carbon black through biomimetic modification of phenolic amine and hydrophilic carbon black

Technical Field

The invention relates to the technical field of carbon black materials, in particular to modified carbon black and a preparation method thereof, and more particularly relates to a method for preparing hydrophilic carbon black by biomimetic modification of phenolic amine and the hydrophilic carbon black.

Background

Carbon black is an agglomerate of nanoparticles formed by the cracking and cyclization of hydrocarbon compounds at high temperatures and has excellent colorability, jetness value, weatherability and chemical stability. Compared with other black organic dyes and inorganic pigments, the carbon black has more excellent comprehensive performance, rich sources and low price. Carbon black is therefore a good ingredient for printing inks, coatings, paints, plastics and inkjet inks. The solvent system for these applications is usually water, and good dispersion of the carbon black is required for environmental and cost reasons. However, carbon black is a nanoparticle, and the primary particle size is small (10-500 nm), the surface energy is high, the surface hydrophilic functional groups are few, and the carbon black is easily aggregated into larger particles and difficult to stably disperse in different systems, and the defects limit the full exertion of the carbon black performance. Therefore, it is important to improve the hydrophilicity of carbon black and to improve the dispersion and stability of carbon black in an aqueous solution.

Factors affecting the dispersion stability of carbon black are mainly affinity of carbon black with a dispersion medium, steric resistance of aggregation between carbon black particles, and electrostatic repulsion. In order to uniformly disperse and stably exist carbon black in an aqueous system, the main preparation methods include dispersant modification, oxidation modification, water-soluble polymer grafting and polymer coating methods.

The dispersant modification is to reduce the surface energy of carbon black particles by using a surfactant to make the surface of the carbon black lose activity, thereby effectively preventing the particles from re-agglomerating or making use of the different polarities of charges of the carbon black and molecular chains to make the carbon black and molecular chains mutually adsorb to make the carbon black particles uniformly dispersed in a solvent. However, the action force between the carbon black modified by the dispersant is physical adsorption, and the dispersant may fall off from the surface of the carbon black under the strong shearing or other actions of the outside, thereby causing the re-agglomeration of the carbon black.

The oxidation modification is classified into gas phase oxidation, liquid phase oxidation, plasma oxidation, and anodic oxidation. The oxidation modification is to increase the number of oxygen-containing functional groups by increasing the oxidation of the surface of the carbon black through some strong oxidizing agents or electrochemical oxidation methods, so as to improve the hydrophilicity of the carbon black. However, the use of strong oxidant puts higher requirements on equipment and the process conditions are more severe.

The water-soluble polymer grafting is to connect the hydrophilic polymer to the surface of the carbon black through chemical bonds. Polar hydrophilic polymer chains are introduced into the carbon black, and the hydrophilic polymer chains are dispersed around the carbon black to generate certain steric hindrance, so that the agglomeration of carbon black particles is prevented, and the carbon black keeps good stability in a polar solution. However, the carbon black has few surface active functional groups, and the grafting efficiency is low due to methods such as free radical polymerization and the like in the reaction process, so that the method is difficult to popularize and use in industry.

The purpose of the polymer coating modification is to deposit a layer of hydrophilic polymer on the surface of the carbon black, so that the carbon black can be stably dispersed in water. Three methods of heterogeneous polymerization coating, microemulsion polymerization coating and phase separation coating modification are common. When the hydrophilic modification is carried out on the carbon black by adopting a polymer coating method, the selection of a modified substance is very important.

The Chinese patent CN106497151A utilizes the fermentation liquor rich in amino acid to modify the surface of the carbon black, and increases the hydrophilic amino groups and carboxyl groups on the surface of the carbon black under the action of microorganisms. However, the natural fermentation process of the method needs 20-30 days, so that the preparation process is long and the production efficiency is low.

The Chinese invention patent CN102337047A is to prepare hydrophilic carbon black by adsorbing the lipophilic end of anionic surfactant onto the surface of carbon black particles to form a uniform coating layer. The strength of the physical adsorption between the carbon black and the anionic surfactant is low, and the coating layer is easy to fall off in the processes of storage, stirring and dispersion, so that the hydrophilicity of the carbon black is reduced.

Therefore, the polymer coating method can be fully performed only by selecting a proper modified substance to carry out surface coating on the carbon black.

Therefore, the search for a suitable raw material for surface coating carbon black to prepare highly hydrophilic carbon black has been one of the focuses of researchers.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a method for preparing hydrophilic carbon black by biomimetic modification of phenolic amine and the hydrophilic carbon black. The invention adopts plant polyphenol and polyamine to successfully coat a hydrophilic coating on the surface of the carbon black, increases the number of hydrophilic functional groups on the surface of carbon black particles, and effectively improves the dispersibility and stability of the carbon black particles in aqueous solution.

The invention aims to provide a method for preparing hydrophilic carbon black by biomimetic modification of phenolic amine.

The method comprises the following steps:

(1) dispersing carbon black in water to form a carbon black dispersion;

(2) mixing plant polyphenol and polyamine to prepare a phenol amine solution;

(3) adding the carbon black dispersion liquid prepared in the step (1) into the phenol amine solution in the step (2), and simultaneously adding a buffer solution to adjust the pH value to 8.0-11;

(4) and (4) continuously stirring the mixed solution obtained in the step (3) for reaction, and cleaning and drying to obtain the hydrophilic carbon black.

In a preferred embodiment of the present invention,

and (1) the concentration of the carbon black dispersion liquid is 1-15 g/L, preferably 4-10 g/L.

In a preferred embodiment of the present invention,

in the step (2),

the plant polyphenol is natural phenols containing catechol or biphenyltriol structures; preferably one or a combination of catechol, tannic acid, gallic acid, catechin, gallocatechin, epicatechin gallate and gallocatechin gallate; more preferably tannic acid;

the polyamine is one combination of diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

In a preferred embodiment of the present invention,

the mass ratio of the plant polyphenol to the polyamine is 1: (1 to 8), preferably 1: (4-6).

In a preferred embodiment of the present invention,

the concentration of the plant polyphenol is 0.5-6 mg/mL, preferably 2-4 mg/mL.

In a preferred embodiment of the present invention,

step (3), the mass ratio of the carbon black to the plant polyphenol is 0.2-6.0; preferably 0.5 to 3.

In a preferred embodiment of the present invention,

a step (3) of,

the buffer solution is one of Tris-HCl buffer solution, glycine-NaOH buffer solution and sodium carbonate-sodium bicarbonate buffer solution.

In a preferred embodiment of the present invention,

step (4) of carrying out a treatment,

the reaction temperature is 15-80 ℃; preferably 20-40 ℃; and/or the presence of a gas in the gas,

the stirring speed is 100-500 r/min.

In a preferred embodiment of the present invention,

step (4) of carrying out a treatment,

the reaction time is 2-20h, preferably 5-10 h under the condition of no catalyst.

Reacting for 10-120 min under the condition of a catalyst; preferably 30-60 min;

the catalyst is one or a combination of hydrogen peroxide, peroxyacetic acid, ammonium persulfate, potassium permanganate and sodium hypochlorite.

The mass ratio of the catalyst to the plant polyphenol is 1: (20-80), preferably 1: (20-60).

Another object of the present invention is to provide a hydrophilic carbon black obtained by the method.

The surface oxygen atoms of the hydrophilic carbon black are 10-35% of the total amount of carbon, oxygen and nitrogen; preferably 20-32%;

the nitrogen atoms on the surface of the hydrophilic carbon black account for 5-15% of the total amount of carbon, oxygen and nitrogen; preferably 6-13%

The content increase of oxygen atom and nitrogen atom after the carbon black is modified by the method can indicate that the carbon black is coated by the polymer, and oxygen and nitrogen elements are both from hydroxyl-OH and amino-NH in the polymer₂Is a watchThe light carbon black has an index of hydrophilicity.

The invention can adopt the following technical scheme:

a method for preparing hydrophilic carbon black by biomimetic modification of phenolic amine comprises the following steps:

(1) preliminarily dispersing carbon black in an aqueous solution by mechanical stirring;

(2) preparing a blending solution of plant polyphenol and polyamine;

the plant polyphenol is natural phenols containing catechol or biphenyltriol structures: preferably one or a combination of catechol, tannic acid, gallic acid, catechin, gallocatechin, epicatechin gallate and gallocatechin gallate, and more preferably tannic acid.

The polyamine is one or a combination of Diethylenetriamine (DETA), triethylenetetramine and tetraethylenepentamine; preferably diethylenetriamine.

(3) Placing the carbon black water slurry prepared in the step (1) into the phenol amine solution in the step (2), and simultaneously adding a buffer solution to adjust the pH value to 8.0-11;

the buffer solution is one of Tris-HCl buffer solution, glycine-NaOH buffer solution and sodium carbonate-sodium bicarbonate buffer solution; preferably Tris-HCl buffer.

(4) And (4) continuously stirring the mixed solution obtained in the step (3) for reaction, and drying after cleaning to obtain the hydrophilic carbon black.

The carbon black comprises all commercial carbon blacks.

The stirring speed is 100-500 r/min; -

The mass ratio of the plant polyphenol to the polyamine is 1: (1-8); preferably 1: (4-6).

The concentration of the plant polyphenol is 0.5-6 mg/mL; preferably 2-4 mg/mL.

The mass ratio of the carbon black to the plant polyphenol is 0.2-6.0; preferably 0.5 to 3.

The reaction time is 2-20h under the condition of no catalyst; preferably 5 to 10 hours.

The reaction is carried out for 10-120 min under the condition of a catalyst; preferably 30-60 min.

The catalyst is one or more of hydrogen peroxide, peroxyacetic acid, ammonium persulfate, potassium permanganate and sodium hypochlorite; ammonium persulfate is preferred.

The reaction temperature is 15-80 ℃; preferably 20 to 40 ℃.

The reaction principle of the invention is as follows: under alkaline conditions, plant polyphenol containing catechol or pyrogallol structure is easily oxidized by oxygen in the air or a catalyst, an oxidation product contains a large amount of structures of o-benzoquinone, active unsaturated carbonyl exists in the o-benzoquinone, the oxidation product can generate Michael addition reaction with a nucleophilic reagent (such as polyamine), and in addition, the o-benzoquinone can also generate Schiff base reaction with polyamine. The two reactions enable the plant polyphenol and the polyamine to form a cross-linked polymer and deposit on the surface of the carbon black, so that abundant hydrophilic functional groups are provided for the carbon black, and the hydrophilicity of the carbon black is enhanced.

Compared with other modification methods, the preparation method of the hydrophilic carbon black provided by the invention has the following beneficial effects:

1) the method is simple to operate, safe and environment-friendly, and the plant polyphenol is rich in natural content, low in price and low in cost;

2) the plant polyphenol and polyamine system adopted by the invention has the advantages of environmental friendliness, low corrosion degree to equipment, mild reaction conditions, high reaction speed and the like;

3) the surface of the carbon black is coated with a layer of compact, uniform and permanent hydrophilic polymer, and hydrophilic functional groups on the surface of the carbon black are increased, so that the carbon black has excellent hydrophilicity.

The experimental result shows that the hydrophilic carbon black preparation method provided by the invention successfully coats a hydrophilic polymer on the surface of the carbon black, so that the content of oxygen atoms on the surface of the carbon black is increased from the initial 1.8 at.% to 30 at.%, and the content of nitrogen atoms is increased from the initial 0.9 at.% to 11 at.%, which shows that the content of functional groups on the surface of the carbon black is greatly increased, so that the modified carbon black has good dispersibility and stability in water.

Drawings

FIG. 1 is an X-ray photoelectron spectroscopy (XPS) broad spectrum of carbon black N134;

FIG. 2 is an X-ray photoelectron spectroscopy (XPS) broad spectrum of the carbon black of example 1.

FIG. 3 is a Scanning Electron Microscope (SEM) image of carbon black N134;

FIG. 4 is a Scanning Electron Microscope (SEM) image of the carbon black of example 1

FIG. 5 experimental results of 0 day settling upon standing;

FIG. 6 experimental results after standing for 90 days;

in FIGS. 5 and 6, the left side shows a sample of carbon black N134, and the right side shows a sample of carbon black of example 1.

Detailed Description

While the present invention will be described in detail and with reference to the specific embodiments thereof, it should be understood that the following detailed description is only for illustrative purposes and is not intended to limit the scope of the present invention, as those skilled in the art will appreciate numerous insubstantial modifications and variations therefrom.

The starting materials used in the examples are all commercial products.

Example 1

(1) Adding 200mg of carbon black N134 into 50mL of deionized water, and stirring at a stirring speed of 200 revolutions per minute for 20min to form uniform carbon black water slurry;

(2) respectively adding 200mg of tannic acid and 600mg of diethylenetriamine into 50mL of deionized water, and uniformly mixing after shaking;

(3) pouring the carbon black water slurry prepared in the step (1) into the phenol amine solution in the step (2), and adding a Tris-HCl buffer solution to adjust the pH value to 10;

(4) and (3) continuously reacting the blending solution obtained in the step (3) at the temperature of 20 ℃ for 5 hours at the stirring speed of 200 r/min, and after the reaction is finished, cleaning and drying to obtain the hydrophilic carbon black.

The atomic percent content of the surface elements of the modified carbon black sample is shown in Table 1.

The XPS broad spectrum and SEM image of the virgin carbon black N134 are shown in FIGS. 1 and 3, respectively. The XPS broad spectrum and SEM images of the modified hydrophilic carbon black are shown in fig. 2 and 4, respectively. The results of the standing sedimentation of the virgin carbon black N134 and the modified carbon black are shown in FIGS. 5 and 6.

As can be seen from the figure, no significant nitrogen peak is present in the XPS broad spectrum of the original carbon black N134 of fig. 1, while the modified carbon black of fig. 2 shows a significant nitrogen peak with a significant enhancement of the oxygen peak, indicating that poly (tannic acid-diethylenetriamine) is deposited on the surface of the carbon black.

In fig. 3, the unmodified carbon black N134 has large aggregate size and is continuously distributed like grape bunch, while the aggregate size of the modified carbon black in fig. 4 is obviously reduced, which indicates that the modified carbon black has stronger hydrophilicity.

After settling on standing for 90 days in fig. 6, the carbon black N134 settled completely to the bottom of the bottle, in contrast to the modified carbon black coated with poly (tannic acid-diethylenetriamine), which still maintained good hydrophilicity and formed an extremely stable carbon black suspension.

Example 2

(1) Adding 400mg of carbon black N134 into 50mL of deionized water, and stirring at a stirring speed of 400 revolutions per minute for 20min to form uniform carbon black water slurry;

(2) respectively adding 200mg of tannic acid and 800mg of diethylenetriamine into 50mL of deionized water, and uniformly mixing after shaking;

(3) pouring the carbon black water slurry prepared in the step (1) into the phenol amine solution in the step (2), and adding a Tris-HCl buffer solution to adjust the pH value to 8.5;

(4) and (3) continuously reacting the blending solution obtained in the step (3) at the temperature of 30 ℃ for 15 hours at the stirring speed of 400 r/min, and after the reaction is finished, cleaning and drying to obtain the hydrophilic carbon black.

Example 3

(1) Adding 400mg of carbon black N134 into 50mL of deionized water, and stirring at a stirring speed of 200 revolutions per minute for 20min to form uniform carbon black water slurry;

(2) respectively adding 300mg of tannic acid and 800mg of diethylenetriamine into 50mL of deionized water, and uniformly mixing after shaking;

(3) pouring the carbon black water slurry prepared in the step (1) into the phenol amine solution in the step (2), and adding Tris-HCl buffer solution to adjust the pH value to 9;

(4) and (4) adding 5mg of ammonium persulfate into the blending solution in the step (3), continuously reacting for 20min at the temperature of 20 ℃ at the stirring speed of 200 r/min, and after the reaction is finished, cleaning and drying to obtain the hydrophilic carbon black.

Example 4

(1) Adding 200mg of carbon black N134 into 50mL of deionized water, and stirring at a stirring speed of 500 revolutions per minute for 20min to form uniform carbon black water slurry;

(2) respectively adding 200mg of gallic acid and 800mg of triethylenetetramine into 50mL of deionized water, and uniformly mixing after shaking;

(3) pouring the carbon black water slurry prepared in the step (1) into the phenol amine solution in the step (2), and simultaneously adding glycine-NaOH buffer solution to adjust the pH value to 11;

(4) and (3) continuously reacting the blending solution obtained in the step (3) at the temperature of 20 ℃ for 8 hours at the stirring speed of 500 r/min, and after the reaction is finished, cleaning and drying to obtain the hydrophilic carbon black.

Example 5

(1) Adding 200mg of carbon black N134 into 50mL of deionized water, and stirring at a stirring speed of 400 revolutions per minute for 20min to form uniform carbon black water slurry;

(2) respectively adding 200mg of catechin and 1200mg of tetraethylenepentamine into 50mL of deionized water, shaking and uniformly mixing;

(3) pouring the carbon black water slurry prepared in the step (1) into the phenol amine solution in the step (2), and simultaneously adding a sodium carbonate-sodium bicarbonate buffer solution to adjust the pH value to 9;

(4) and (3) continuously reacting the blending solution obtained in the step (3) at the temperature of 20 ℃ for 15 hours at the stirring speed of 400 r/min, and after the reaction is finished, cleaning and drying to obtain the hydrophilic carbon black.

Example 6

(2) respectively adding 200mg of catechin and 800mg of tetraethylenepentamine into 50mL of deionized water, shaking and uniformly mixing;

(3) pouring the carbon black water slurry prepared in the step (1) into the phenol amine solution in the step (2), and adding a sodium carbonate-sodium bicarbonate buffer solution to adjust the pH value to 8.5;

(4) and (4) adding 10mg of sodium hypochlorite into the blending solution in the step (3), continuously reacting for 50min at the temperature of 20 ℃ at the stirring speed of 400 r/min, and after the reaction is finished, cleaning and drying to obtain the hydrophilic carbon black.

Example 7

(1) Adding 10g of carbon black N134 into 1L of deionized water, and stirring at a stirring speed of 500 revolutions per minute for 20min to form uniform carbon black slurry;

(2) respectively adding 10g of tannic acid and 40g of diethylenetriamine into 1L of deionized water, and uniformly mixing after shaking;

(4) and (3) continuously reacting the blending solution obtained in the step (3) at the temperature of 40 ℃ for 12 hours at the stirring speed of 500 r/min, and after the reaction is finished, cleaning and drying to obtain the hydrophilic carbon black.

TABLE 1 relative atomic percentages of surface elements of carbon blacks N134 and modified carbon blacks of examples 1-6

As can be seen from the data in Table 1, the carbon black modified by the method of the present invention is successfully coated with a hydrophilic polymer on the surface of the carbon black, and the content of oxygen and nitrogen on the surface of the carbon black is significantly increased, which indicates that the content of the functional group on the surface of the carbon black is greatly increased, such that the modified carbon black has good dispersibility and stability in water.

Claims

1. A method for preparing hydrophilic carbon black by biomimetic modification of phenolic amine is characterized by comprising the following steps:

(1) dispersing carbon black in water to form a carbon black dispersion;

(2) mixing plant polyphenol and polyamine to prepare phenol-amine solution;

2. The method of preparing a hydrophilic carbon black according to claim 1, wherein:

in the step (1), the concentration of the carbon black dispersion liquid is 1-15 g/L, preferably 4-10 g/L.

3. The method of preparing a hydrophilic carbon black according to claim 1, wherein:

in the step (2),

the plant polyphenol is natural phenols containing catechol or biphenyltriol structures; preferably one or a combination of catechol, tannic acid, gallic acid, catechin, gallocatechin, epicatechin gallate and gallocatechin gallate; and/or the presence of a gas in the atmosphere,

the polyamine is one or a combination of diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

4. The method of preparing a hydrophilic carbon black according to claim 3, wherein:

5. The method of preparing a hydrophilic carbon black according to claim 4, wherein:

the concentration of the plant polyphenol is 1-10mg/mL, preferably 4-6 mg/mL.

6. The method of preparing a hydrophilic carbon black according to claim 1, wherein:

step (3), the mass ratio of the carbon black to the plant polyphenol is 0.2-6; preferably 0.5 to 3.

7. The method of preparing a hydrophilic carbon black according to claim 1, wherein:

a step (3) of removing the solvent,

8. The method of preparing a hydrophilic carbon black according to claim 1, wherein:

step (4) of carrying out a treatment,

the reaction temperature is 15-80 ℃; preferably 20-40 ℃; and/or the presence of a gas in the atmosphere,

the stirring speed is 100-500 r/min.

9. The method of preparing a hydrophilic carbon black according to claim 1, wherein:

step (4) of carrying out a treatment,

the reaction time is 2-20h, preferably 5-10 h under the condition of no catalyst;

the catalyst is one or a combination of hydrogen peroxide, peroxyacetic acid, ammonium persulfate, potassium permanganate and sodium hypochlorite;

10. A hydrophilic carbon black obtainable by the process according to any one of claims 1 to 9, wherein:

the nitrogen atoms on the surface of the hydrophilic carbon black account for 5-15% of the total amount of carbon, oxygen and nitrogen; preferably 6-13%.