Preparation method of high-concentration nanoparticle intercalation graphene dispersion liquid

Abstract

The invention discloses a preparation method of a high-concentration nanoparticle intercalation graphene dispersion liquid. The method comprises the following steps: directly mixing a phenyl modified nano silicon dioxide microsphere particle dispersion liquid with sodium sulfate, sodium hydroxide and deionized water to obtain an electrolyte for preparing graphene through electrochemical stripping, and finally, putting graphite paper into the electrolyte solution for multiple times of ionization to obtain the graphene. And settling and separating to obtain the phenyl silicon dioxide microsphere nanoparticle intercalated graphene dispersion liquid with the mass concentration of more than 5%. According to the technology, phenyl modified nano silicon dioxide microspheres are added in the electrochemical stripping process, a six-membered carbon ring large pi bond on the phenyl of the microspheres and a six-membered honeycomb-shaped carbon ring large pi bond on a stripped graphene structure form a pi-pi stacking effect, and the phenyl modified nano silicon dioxide microspheres are intercalated between graphene; the secondary agglomeration caused by overhigh concentration of the graphene dispersion liquid prepared by electrochemical stripping is greatly avoided, and the long-term dispersion stability of the high-concentration graphene dispersion liquid is improved.

Description

Technical Field

[0001] The invention relates to the technical field of graphene dispersion and stabilization, and in particular to a method for preparing a high-concentration nanoparticle intercalated graphene dispersion. Background Art

[0002] Graphene is a type of two-dimensional nanocarbon material with a thickness of only a single atomic layer. It has unique properties such as excellent mechanical properties, good barrier properties, and high specific surface area. It is widely used in sensing, catalysis, environmental governance, biomedicine, and energy. The main method for producing graphene is the "top-down" method, that is, using graphite as the "upper" raw material, the stacked graphene is peeled off from the graphite structure by means of oxidation intercalation, electrochemical intercalation, ultrasound or mechanical shearing, thereby obtaining "lower" graphene products with different numbers of layers. Due to the large specific surface area of ​​graphene and the interaction between layers caused by van der Waals forces, graphene cannot be evenly and stably dispersed in the matrix, and is prone to agglomeration, resulting in flocculation, and the effect is poor. Summary of the invention

[0003] In view of this, the present invention aims to provide a method for preparing a high-concentration nanoparticle intercalated graphene dispersion, which prepares graphene by using an electrochemical exfoliation method, initially dispersing phenyl-modified nano-silica microspheres in an electrolyte, and intercalating between graphenes through the large π bonds of the six-membered carbon ring on the phenyl group of the microspheres and the large π bonds of the six-membered honeycomb carbon ring on the exfoliated graphene structure to form a π-π stacking effect, thereby avoiding secondary agglomeration of the graphene dispersion prepared by electrochemical exfoliation due to excessively high concentration, and improving the long-term dispersion stability of the high-concentration graphene dispersion.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A method for preparing a high-concentration nanoparticle intercalated graphene dispersion comprises the following steps:

[0006] 1) Preparation of phenyl-modified nano-silica microspheres: adding ammonia water to the nano-silica microspheres, and dripping phenyltriethoxysilane ethanol dispersion to obtain phenyl-modified nano-silica microsphere particle dispersion after reaction;

[0007] 2) Preparation of electrolyte: Sodium sulfate, sodium hydroxide, nano-phenyl silica microsphere dispersion and deionized water are mixed to obtain an electrolyte for preparing graphene by electrochemical exfoliation;

[0008] 3) Preparation of nanoparticle intercalated graphene dispersion: using graphite paper as raw material as the positive electrode and platinum electrode as the negative electrode, placing them in the above-prepared electrolyte, and using electrochemical stripping method to prepare nano-phenyl silica microsphere particle intercalated graphene dispersion;

[0009] 4) Preparation of high-concentration nanoparticle intercalated graphene dispersion: The above electrolyte solution is repeatedly subjected to graphite paper ionization operation, and sedimentation separation is performed to obtain a phenyl silica microsphere nanoparticle intercalated graphene dispersion with a mass concentration greater than 5%.

[0010] Optionally, the nano-silica microspheres described in step 1) are one or a mixture of any two of hydrophilic gas-phase nano-silica, nano-silica microspheres prepared by a sol-gel method, or a modified silica fume dispersion, and are further preferably nano-silica microspheres prepared by a sol-gel method.

[0011] Optionally, in step 2), the mass ratio of the sodium sulfate, sodium hydroxide, phenyl-modified nano-silica microspheres and deionized water is 35.5-142:2-10:1-5:200-600, and may be further preferably 71:2:1:500.

[0012] Optionally, in the electrolyte solution of step 2), the concentration of sodium sulfate is 0.5-2 mol / L, and the concentration of sodium hydroxide is 0.1-0.5 mol / L, and it is further preferred that the concentration of sodium sulfate is 1 mol / L, and the concentration of sodium hydroxide is 0.1 mol / L.

[0013] Optionally, the electrolysis voltage (DC) of the electrochemical stripping method in step 3) is 5-15V, the electrolysis time is 10-60min, and the electrolysis temperature is 10-50°C, which can be further optimized to a voltage of 10V, a time of 30min, and a temperature of 25°C.

[0014] Compared with the prior art, the method for preparing a high-concentration nanoparticle intercalated graphene dispersion of the present invention has the following advantages:

[0015] 1. The present invention discloses a method for preparing a high-concentration nanoparticle intercalated graphene dispersion, which directly adds phenyl-modified nano-silica microspheres to an electrolyte solution for preparing graphene by electrochemical exfoliation, and electrochemically exfoliates graphite paper in one step to obtain a high-concentration graphene dispersion of nanoparticle intercalation, thereby avoiding secondary aggregation of graphene caused by operations such as transfer, and the operation is simple and efficient.

[0016] 2. The electrochemical stripping method used in the present invention is advanced in technology, green and environmentally friendly, has mild conditions, simple preparation process and safe operation process.

[0017] 3. The electrolyte solution used in the electrochemical stripping of the present invention is directly used as the dispersion liquid of graphene, does not contain strong oxidants and reducing agents, and will not have a significant impact on the physical and chemical properties of the graphene itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0019] Figure 1 Schematic diagram of preparing high-concentration graphene dispersion by continuous electrochemical exfoliation in Examples 1-3 of the present invention.

[0020] Explanation of the reference numerals: 1 - graphite paper, 2 - platinum electrode, 3 - electrolyte solution in which phenyl-modified nano-silica particles are dispersed.

[0021] Figure 2 The present invention is a schematic diagram of graphene, wherein (a) is a schematic diagram of original graphene; (b) is a schematic diagram of graphene intercalated with phenyl-modified nano-silica particles to achieve a dispersed and stable effect. Explanation of the accompanying drawings: 1-graphene sheet, 2-phenyl-modified nano-silica particles.

[0022] Figure 3 Schematic diagram of a high-concentration nanoparticle intercalated graphene dispersion prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0024] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0025] Embodiment 1:

[0026] A method for preparing a high-concentration nanoparticle intercalated graphene dispersion comprises the following steps:

[0027] 1) Preparation of phenyl-modified nano-silica microspheres: 10 ml of ammonia water was added to 1 g of nano-silica microspheres, and 20 ml of ethanol dispersion containing 5 wt % phenyltriethoxysilane was added dropwise to obtain a phenyl-modified nano-silica microsphere particle dispersion after reaction;

[0028] 2) Preparation of electrolyte: 71 g of sodium sulfate, 2 g of sodium hydroxide, the nano-phenyl silica microsphere dispersion prepared in step 1) and 500 g of deionized water are mixed to obtain an electrolyte for preparing graphene by electrochemical exfoliation;

[0029] 3) Preparation of nanoparticle intercalated graphene dispersion: using graphite paper as raw material as the positive electrode and platinum electrode as the negative electrode, placing them in the electrolyte prepared in step 2), and performing electrochemical exfoliation under the conditions of electrolysis voltage (DC) of 10V and electrolysis temperature of 25°C to prepare nano-phenyl silica microsphere particle intercalated graphene dispersion, and the electrolysis time is 30min;

[0030] 4) Preparation of high-concentration nanoparticle intercalated graphene dispersion: The electrolyte solution in step 3) is repeatedly subjected to graphite paper ionization operation, and sedimentation separation is performed to obtain a phenyl silica microsphere nanoparticle intercalated graphene dispersion with a mass concentration greater than 5%.

[0031] Embodiment 2:

[0032] A method for preparing a high-concentration nanoparticle intercalated graphene dispersion comprises the following steps:

[0033] 1) Preparation of phenyl-modified nano-silica microspheres: 5 ml of ammonia water was added to 0.5 g of nano-silica microspheres, and 10 ml of ethanol dispersion containing 5 wt % phenyltriethoxysilane was added dropwise to obtain a phenyl-modified nano-silica microsphere particle dispersion after reaction;

[0034] 2) Preparation of electrolyte: 40 g of sodium sulfate, 2 g of sodium hydroxide, the nano-phenyl silica microsphere dispersion prepared in step 1) and 400 g of deionized water are mixed to obtain an electrolyte for preparing graphene by electrochemical exfoliation;

[0035] 3) Preparation of nanoparticle intercalated graphene dispersion: using graphite paper as raw material as the positive electrode and platinum electrode as the negative electrode, placing them in the electrolyte prepared in step 2), and performing electrochemical stripping under the conditions of electrolysis voltage (DC) of 8V and electrolysis temperature of 30°C to prepare nano-phenyl silica microsphere particle intercalated graphene dispersion, and the electrolysis time is 25min;

[0036] 4) Preparation of high-concentration nanoparticle intercalated graphene dispersion: The electrolyte solution in step 3) is repeatedly subjected to graphite paper ionization operation, and sedimentation separation is performed to obtain a phenyl silica microsphere nanoparticle intercalated graphene dispersion with a mass concentration greater than 5%.

[0037] Embodiment 3:

[0038] A method for preparing a high-concentration nanoparticle intercalated graphene dispersion comprises the following steps:

[0039] 1) Preparation of phenyl-modified nano-silica microspheres: 15 ml of ammonia water was added to 2 g of nano-silica microspheres, and 30 ml of ethanol dispersion containing 5 wt % phenyltriethoxysilane was added dropwise to obtain a phenyl-modified nano-silica microsphere particle dispersion after reaction;

[0040] 2) Preparation of electrolyte: 100 g of sodium sulfate, 5 g of sodium hydroxide, the nano-phenyl silica microsphere dispersion prepared in step 1) and 600 g of deionized water are mixed to obtain an electrolyte for preparing graphene by electrochemical exfoliation;

[0041] 3) Preparation of nanoparticle intercalated graphene dispersion: using graphite paper as raw material as the positive electrode and platinum electrode as the negative electrode, placing them in the electrolyte prepared in step 2), and performing electrochemical stripping under the conditions of electrolysis voltage (DC) of 12V and electrolysis temperature of 20°C to prepare nano-phenyl silica microsphere particle intercalated graphene dispersion, and the electrolysis time is 60min;

[0042] 4) Preparation of high-concentration nanoparticle intercalated graphene dispersion: The electrolyte solution in step 3) is repeatedly subjected to graphite paper ionization operation, and sedimentation separation is performed to obtain a phenyl silica microsphere nanoparticle intercalated graphene dispersion with a mass concentration greater than 5%.

[0043] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a high-concentration nanoparticle intercalated graphene dispersion, characterized in that: The following steps are involved: 1) Preparation of phenyl-modified nano-silica microspheres: adding ammonia water to the nano-silica microspheres, and dripping phenyltriethoxysilane ethanol dispersion to obtain phenyl-modified nano-silica microsphere particle dispersion after reaction; 2) Preparation of electrolyte: Sodium sulfate, sodium hydroxide, nano-phenyl silica microsphere dispersion and deionized water are mixed to obtain an electrolyte for preparing graphene by electrochemical exfoliation; 3) Preparation of nanoparticle intercalated graphene dispersion: using graphite paper as raw material as the positive electrode and platinum electrode as the negative electrode, placing them in the above-prepared electrolyte, and using electrochemical stripping method to prepare nano-phenyl silica microsphere particle intercalated graphene dispersion; 4) Preparation of high-concentration nanoparticle intercalated graphene dispersion: The above electrolyte solution is repeatedly subjected to graphite paper ionization operation, and sedimentation separation is performed to obtain a phenyl silica microsphere nanoparticle intercalated graphene dispersion with a mass concentration greater than 5%.

2. The method for preparing a high-concentration nanoparticle intercalated graphene dispersion according to claim 1, characterized in that: The nano-silica microspheres described in step 1) are one of hydrophilic gas-phase nano-silica, nano-silica microspheres prepared by a sol-gel method, or a modified silica fume dispersion, or a mixture of any two thereof.

3. The method for preparing a high-concentration nanoparticle intercalated graphene dispersion according to claim 1, characterized in that: Step 2) Phenyl silica microspheres are initially dispersed in an electrolyte, and can be intercalated between graphenes through the large π bonds of the six-membered carbon ring on the phenyl group of the microspheres and the six-membered honeycomb carbon ring on the exfoliated graphene structure to form a π-π stacking effect, thereby avoiding secondary agglomeration of the graphene dispersion prepared by electrochemical exfoliation due to excessively high concentrations, thereby improving the long-term dispersion stability of the high-concentration graphene dispersion.

4. The method for preparing a high-concentration nanoparticle intercalated graphene dispersion according to claim 1, characterized in that: Step 2) The mass ratio of the sodium sulfate, sodium hydroxide, phenyl-modified nano-silica microspheres and deionized water is 35.5-142:2-10:1-5:200-600.

5. The method for preparing a high-concentration nanoparticle intercalated graphene dispersion according to claim 1, characterized in that: Step 2) In the electrolyte solution, the concentration of sodium sulfate is 0.5-2 mol / L, and the concentration of sodium hydroxide is 0.1-0.5 mol / L.

6. The method for preparing a high-concentration nanoparticle intercalated graphene dispersion according to claim 1, characterized in that: Step 3) The electrolysis voltage (DC) of the electrochemical stripping method is 5-15V, the electrolysis time is 10-60min, and the electrolysis temperature is 10-50°C.

7. The method for preparing a high-concentration nanoparticle intercalated graphene dispersion according to claim 1, characterized in that: Step 4) Continuous electrolytic exfoliation is achieved by designing a specific electrolytic device and selecting a suitable graphite paper size to prepare graphene, and graphite fragments settled in the lower layer are collected to prepare new graphite paper, thereby greatly improving the utilization rate.

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