CN112158822B - Preparation method of porous carbon microsphere - Google Patents

Abstract

The invention discloses a preparation method of porous carbon microspheres, which comprises the following steps: 1) Mixing resin and curing agent to form a uniform phase; 2) Adding deionized water into the resin homogeneous phase, and stirring at high speed to form emulsion; 3) Dripping the emulsion into silicone oil, and stirring at high speed to form a complex phase emulsion; 4) Heating to solidify the resin, preparing the water-in-resin microcapsule; 5) And (3) placing the filtered, washed and dried resin water-in-resin microcapsule under the protection of inert gas, and performing high-temperature pyrolysis to obtain the porous carbon microsphere. The preparation method provided by the invention has the advantages of simple process, low cost, high coating rate, environmental friendliness and easiness in industrialization.

Description

A kind of preparation method of porous carbon microsphere

technical field

The invention belongs to the field of porous carbon materials, and in particular relates to a preparation method of porous carbon microspheres.

Background technique

In recent years, porous carbon materials have become a new type of rapidly developed new material system, and their applications in various fields have received extensive attention, especially in energy-related fields. Porous materials have some corresponding excellent properties due to their high porosity in structure. Among many porous materials, porous carbon materials are characterized by low cost, light weight, non-toxicity, surface chemical inertness, high temperature resistance, acid and alkali resistance, high mechanical stability, good electrical conductivity, adsorption, and large specific surface area and pore volume. And other characteristics, in the fields of _CO2 adsorption, hydrogen storage, catalysis, and fuel cells and electrochemical double-layer capacitors, it has shown huge application potential and has attracted attention from all walks of life.

Contents of the invention

The present invention aims to provide a method for preparing porous carbon microspheres, which has wide sources of raw materials, low price, simple process, low energy consumption, environmental friendliness, high yield of carbon microspheres, and good industrialization prospects.

In the present invention, the resin is immiscible with water, and when the volume of the resin is greater than that of water, a water-in-resin emulsion can be formed under high-speed stirring. Therefore, when the emulsion is added to the continuous phase, many emulsion droplets can be formed by stirring. After the resin in the emulsion droplets solidifies and covers them with water, the water-in-resin microcapsules can be formed.

The invention provides a preparation method of novel porous carbon microspheres. The method is to mix resin and curing agent into one, then add deionized water, stir at high speed to form an emulsion, then add the emulsion dropwise into silicone oil, and stir at high speed Water-in-resin droplets are formed, and the resin is cured by heating to form water-in-resin microcapsules, which are then subjected to high-temperature pyrolysis and carbonization to finally produce porous carbon microspheres.

The preparation method of the above-mentioned porous carbon microspheres specifically comprises the following steps:

(1) Mix the resin and curing agent to form a homogeneous phase;

(2) Add deionized water into the resin homogeneous phase and stir at high speed to form an emulsion;

(3) Add the emulsion dropwise to the silicone oil, and stir at high speed to form a complex emulsion;

(4) Heating the multiphase emulsion to solidify the resin to prepare water-in-resin microcapsules;

(5) Put the filtered, washed and dried water-in-resin microcapsules under the protection of an inert gas, and perform high-temperature pyrolysis and carbonization to finally obtain porous carbon microspheres.

Further, the resin is one of epoxy resin and phenolic resin.

Further, the curing agent is one of ethylenediamine, diethylenetriamine, triethylenetetramine, and p-toluenesulfonic acid.

Further, in the step (1), the mass ratio of the resin to the curing agent is 100:7-100:13.

Further, in the step (2), the mass ratio of resin to deionized water is 100:50-100:70.

Further, the silicone oil is methyl silicone oil, the viscosity is 100ps-2000ps, and the mass ratio of resin to silicone oil is 1:3-1:6.

Further, the stirring speed is 10000-30000r/min.

Further, in the step (4), the heating temperature is 60-150°C, the heating rate is 1-5°C/min, and the holding time is 1-24h.

Further, in the step (5), the drying temperature is 40-80° C., and the drying time is 1-8 hours.

Further, in the step (5), the inert gas is argon.

Further, in the step (5), the process conditions of high-temperature pyrolysis and carbonization are: at 80-90°C, keep warm for 20-40min, then raise the temperature to 350-450°C, keep warm for 50-90min, and then raise the temperature to 600-1000°C ℃, keep warm for 60-180min, and the heating rate is 1-5℃/min.

Beneficial effects of the present invention:

The preparation method of the novel porous carbon microspheres provided by the present invention has simple process steps, low cost of raw materials, no pollution, high yield of carbon microspheres, low energy consumption, low requirements on the environmental conditions for preparation and equipment used, and can be simple and fast The efficient preparation of porous carbon microspheres provides a new way for the preparation of porous carbon materials.

Description of drawings

FIG. 1 is an SEM image of carbon microspheres prepared in Example 1 of the present invention.

Fig. 2 is a pore size distribution diagram of carbon microspheres prepared in Example 1 of the present invention.

Fig. 3 is a pore size distribution diagram of carbon microspheres prepared in Example 2 of the present invention.

Fig. 4 is a pore size distribution diagram of carbon microspheres prepared in Example 3 of the present invention.

Fig. 5 is a pore size distribution diagram of carbon microspheres prepared in Example 4 of the present invention.

Fig. 6 is a pore size distribution diagram of carbon microspheres prepared in Example 5 of the present invention.

Detailed ways

The present invention is further illustrated by the following examples, but not limited to the following examples.

Example 1

A preparation method of novel porous carbon microspheres, which mainly comprises the following steps:

(1) Mix the epoxy resin and the curing agent ethylenediamine to form a homogeneous phase; the mass ratio of the epoxy resin to the curing agent is 100:7.

(2) Add deionized water into the homogeneous phase of epoxy resin, and stir at high speed to form an emulsion; the mass ratio of the epoxy resin to deionized water is 100:50.

(3) Add the emulsion dropwise to the silicone oil, and stir at high speed to form a multi-phase emulsion; the mass ratio of the epoxy resin to the silicone oil is 1:3; the stirring speed is 10000r/min.

(4) Heating to solidify the resin, the heating temperature is 60°C, the heating rate is 5°C/min, and the holding time is 24h; prepare water-coated epoxy resin microcapsules;

(5) Put the water-in-epoxy microcapsules after filtration, washing and drying (drying temperature at 40°C for 8 hours) under the protection of argon for high-temperature pyrolysis and carbonization, heat preservation at 80°C for 30 minutes, and heat preservation at 400°C 60min, 800°C for 120min, heating rate 5°C/min.

Figure 1 is a SEM image of the carbon microspheres prepared in this example.

It can be seen from Figure 1a that the carbon microspheres are spherical, and their particle size distribution is between 1-100 μm. In Fig. 1b, it can be seen that carbon microspheres are easy to agglomerate under natural conditions, indicating that they have high surface energy and are easy to adsorb together; Fig. 1c is a partial enlarged view of Fig. 1b, which can be It is seen that a large number of microvoids are present.

Figure 2 is a pore size distribution diagram of the carbon microspheres prepared in this example. It can be seen from Figure 2 that the pore distribution is micropores of 2nm, mesopores of 10-50nm and macropores of 50-100nm, and its specific surface area is 80.83m ² /g.

Example 2

A preparation method of novel porous carbon microspheres, which mainly comprises the following steps:

(1) Mix the phenolic resin and the curing agent p-toluenesulfonic acid to form a homogeneous phase; the mass ratio of the phenolic resin to the curing agent is 100:10.

(2) Add deionized water into the homogeneous phase of phenolic resin, and stir at high speed to form an emulsion; the mass ratio of the phenolic resin to deionized water is 100:60.

(3) Add the emulsion dropwise to the silicone oil, and stir at high speed to form a multi-phase emulsion; the mass ratio of the phenolic resin to the silicone oil is 1:4; the stirring speed is 10000r/min.

(4) Heating to solidify the resin, the heating temperature is 120°C, the heating rate is 3°C/min, and the holding time is 1h, to prepare water-coated phenolic resin microcapsules;

(5) Put the water-coated phenolic resin microcapsules after filtration, washing, and drying (drying temperature at 50°C for 6 hours) under the protection of argon for high-temperature pyrolysis and carbonization, heat preservation at 90°C for 40 minutes, and heat preservation at 450°C for 50 minutes , keep at 900°C for 90min, and the heating rate is 5°C/min.

Figure 3 is a pore size distribution diagram of the carbon microspheres prepared in this example. It can be seen from Figure 3 that the pore distribution is mainly micropores of 1 nm, and there are a small amount of mesopores of 20-50 nm and macropores of 50-100 nm, and its specific surface area is 277.3 m ² /g.

Example 3

A preparation method of novel porous carbon microspheres, which mainly comprises the following steps:

(1) Mix the phenolic resin and the curing agent p-toluenesulfonic acid to form a homogeneous phase; the mass ratio of the phenolic resin to the curing agent is 100:11.

(2) Add deionized water into the homogeneous phase of phenolic resin, and stir at high speed to form an emulsion; the mass ratio of the phenolic resin to deionized water is 100:55.

(3) Add the emulsion dropwise to the silicone oil, and stir at high speed to form a multi-phase emulsion; the mass ratio of the phenolic resin to the silicone oil is 1:5; the stirring speed is 15000r/min.

(4) Heating to solidify the resin, the heating temperature is 150°C, the heating rate is 4°C/min, and the holding time is 1h; prepare water-coated phenolic resin microcapsules;

(5) Put the water-coated phenolic resin microcapsules after filtration, washing and drying (drying temperature at 70°C for 4 hours) under the protection of argon for high-temperature pyrolysis and carbonization, heat preservation at 85°C for 30 minutes, and heat preservation at 300°C for 80 minutes , 750°C for 120min, heating rate 5°C/min.

Figure 4 is a pore size distribution diagram of the carbon microspheres prepared in this example. It can be seen from Figure 4 that the pore distribution is micropores of 1-2nm, mainly micropores of 1nm, mesopores of 5-50nm and macropores of 50-100nm, and the specific surface area is 124.97m ² /g.

Example 4

A preparation method of novel porous carbon microspheres, which mainly comprises the following steps:

(1) Mix the phenolic resin and the curing agent p-toluenesulfonic acid to form a homogeneous phase; the mass ratio of the phenolic resin to the curing agent is 100:9.

(2) Add deionized water into the homogeneous phase of phenolic resin, and stir at high speed to form an emulsion; the mass ratio of the phenolic resin to deionized water is 100:65.

(3) Add the emulsion dropwise to the silicone oil, and stir at a high speed to form a multi-phase emulsion; the mass ratio of the phenolic resin to the silicone oil is 1:4.5; the stirring speed is 20000r/min.

(4) Heating to solidify the resin, the heating temperature is 140°C, the heating rate is 3°C/min, and the holding time is 2.5h; prepare water-coated phenolic resin microcapsules;

(5) Put the water-coated phenolic resin microcapsules after filtration, washing, and drying (drying temperature at 60°C for 8 hours) under the protection of argon for high-temperature pyrolysis and carbonization, heat preservation at 80°C for 20 minutes, and heat preservation at 450°C for 70 minutes , keep at 800°C for 100min, and the heating rate is 3°C/min.

Fig. 5 is a diagram of the pore size distribution of the carbon microspheres prepared in this example. It can be seen from Figure 5 that the pore distribution is micropores of 1-2nm, mainly micropores of 1.5nm, a small amount of mesopores of 15-50nm and macropores of 50-100nm, and its specific surface area is 244.08m ² / g.

Example 5

A preparation method of novel porous carbon microspheres, which mainly comprises the following steps:

(1) Mix the epoxy resin and the curing agent diethylenetriamine to form a homogeneous phase; the mass ratio of the epoxy resin to the curing agent is 100:8.

(2) Add deionized water into the homogeneous phase of epoxy resin, and stir at high speed to form an emulsion; the mass ratio of the epoxy resin to deionized water is 100:55.

(3) Add the emulsion dropwise to the silicone oil, and stir at high speed to form a multi-phase emulsion; the mass ratio of the epoxy resin to the silicone oil is 1:5; the stirring speed is 30000r/min.

(4) Heating to solidify the resin, the heating temperature is 60°C, the heating rate is 3°C/min, and the holding time is 18h; prepare water-coated epoxy resin microcapsules;

(5) Put the water-in-epoxy microcapsules after filtration, washing, and drying (drying temperature at 50°C for 6 hours) under the protection of argon for high-temperature pyrolysis and carbonization, heat preservation at 80°C for 30 minutes, and heat preservation at 350°C 80min, 800°C for 120min, heating rate 1°C/min.

Fig. 6 is a pore size distribution diagram of the carbon microspheres prepared in this example. It can be seen from Figure 6 that the pore distribution is 1-2nm micropores, mainly 2nm micropores, and there are a large number of 5-50nm mesopores and 50-100nm macropores, and its specific surface area is 69.97m ² /g.

Claims (4)

1. A preparation method of porous carbon microspheres is characterized in that: mixing resin and a curing agent into a whole, adding deionized water, stirring at a high speed to form emulsion, adding the emulsion into silicone oil, stirring at a high speed to form water-in-resin microdroplets, heating to cure the resin to form water-in-resin microcapsules, and performing high-temperature pyrolysis carbonization on the water-in-resin microcapsules to finally prepare the porous carbon microspheres;

the preparation method of the porous carbon microsphere comprises the following steps:

(1) Mixing resin and curing agent to form a uniform phase; the resin is one of epoxy resin and phenolic resin; the curing agent is one of ethylenediamine, diethylenetriamine, triethylenetetramine and p-toluenesulfonic acid; the mass ratio of the resin to the curing agent is 100:7-100:13;

(2) Adding deionized water into the resin homogeneous phase, and stirring at high speed to form emulsion;

(3) Dripping the emulsion into silicone oil, and stirring at high speed to form a complex phase emulsion; the silicone oil is methyl silicone oil;

(4) Heating the multiphase emulsion to solidify the resin, and preparing the water-in-resin microcapsule;

(5) Placing the filtered, washed and dried resin water-in-resin microcapsule under the protection of inert gas, and performing high-temperature pyrolysis carbonization to finally obtain the porous carbon microsphere; the technological conditions of the high-temperature pyrolysis carbonization are as follows: heat-preserving at 80-90deg.C for 20-40min, then heating to 350-450deg.C, heat-preserving for 50-90min, heating to 600-1000deg.C, heat-preserving for 60-180min, and heating at 1-5deg.C/min;

the methyl silicone oil has the viscosity of 100ps-2000ps and the mass ratio of the resin to the silicone oil of 1:3-1:6;

in the step (2), the mass ratio of the resin to the deionized water is 100:50-100:70.

2. The method for preparing the porous carbon microsphere according to claim 1, wherein: in the step (4), the heating temperature is 60-150 ℃, the heating rate is 1-5 ℃/min, and the heat preservation time is 1-24h.

3. The method for preparing the porous carbon microsphere according to claim 1, wherein: in the step (5), the drying temperature is 40-80 ℃ and the time is 1-8h.

4. The method for preparing the porous carbon microsphere according to claim 1, wherein: in the step (5), the inert gas is argon.

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