阅读说明：本技术 一种制备木质基微纳米空心树脂球和炭球的方法 (Method for preparing wood-based micro-nano hollow resin balls and carbon balls ) 是由 马晓军 杨昭昭 吕春飞 于 2021-09-18 设计创作，主要内容包括：本发明公开了一种木质基微纳米空心树脂球和炭球的制备方法。包括以下步骤：以木材粉末、苯酚和磷酸为原料制备木材液化物,将木材液化物、六次甲基四胺、无水乙醇混合物作为炭前驱体,将其分散于聚乙烯醇溶液中制备微纳米树脂球,将微纳米树脂球经过初次固化、甲醇溶解、二次固化以及在通氮气下炭化、活化得到微纳米空心树脂球和炭球。本发明技术制备的微纳米空心树脂球和炭球,其比表面积可达到1029～1610m～(2)/g,球径在20～40μm；该技术在制备过程中不添加醛类物质,防止有毒物质产生；该技术以生物质材料制备微纳米空心树脂球和炭球,减少化石资源的消耗,有利于保护环境；该技术操作过程简单、周期短、树脂球和炭球的空腔大小可调。(The invention discloses a preparation method of a wood-based micro-nano hollow resin ball and a carbon ball. The method comprises the following steps: preparing a wood liquefied product by taking wood powder, phenol and phosphoric acid as raw materials, dispersing a mixture of the wood liquefied product, hexamethylenetetramine and absolute ethyl alcohol as a carbon precursor in a polyvinyl alcohol solution to prepare micro-nano resin spheres, and performing primary curing, methanol dissolution, secondary curing, carbonization under nitrogen and activation on the micro-nano resin spheres to obtain micro-nano hollow resin spheres and carbon spheres. The specific surface area of the micro-nano hollow resin ball and the micro-nano hollow carbon ball prepared by the technology can reach 1029-1610 m 2 The diameter of the sphere is 20-40 mu m; the technology does not add aldehydes in the preparation process, thereby preventing toxic substances from being generated; the technology uses biomass materials to prepare micro-nano hollow resin balls and carbon ballsThe consumption of fossil resources is reduced, and the environment is protected; the technology has simple operation process and short period, and the size of the cavities of the resin ball and the carbon ball can be adjusted.)

1. A method for preparing a wood-based micro-nano hollow resin ball is characterized by comprising the following steps:

the method comprises the following steps: after the biomass material is ground into powder, the powder is mixed with phenol and phosphoric acid, and liquefaction is carried out to obtain a liquefied substance.

Step two: adding the curing agent and the concentration regulator into the liquefied substance, stirring for 1h at room temperature, and taking the mixture as a carbon precursor solution after the mixture is completely dissolved.

Step three: the polyvinyl alcohol powder is dissolved in deionized water under stirring and heating to form a polyvinyl alcohol solution which is used as a dispersing agent.

Step four: adding the carbon precursor solution into a dispersing agent, stirring and heating to prepare the micro-nano resin ball.

Step five: and (3) carrying out primary curing on the micro-nano resin balls in a mixed solution of formaldehyde and hydrochloric acid, filtering and drying to obtain the primary cured resin balls.

Step six: and fully dissolving the primarily cured resin balls by using a dissolving agent, filtering and drying to obtain the hollow resin balls.

2. The preparation method of the micro-nano hollow resin ball according to claim 1, wherein in the first step, the biomass material is wood, bamboo, straw and plant fiber, the fineness of the powder is 20-80 meshes, the amount of the phenol is 4-7 times of the weight of the biomass powder, the addition amount of the phosphoric acid is 6-8% of the weight of the phenol, the concentration of the phosphoric acid is 85%, and the liquefaction is carried out at the temperature of 150-160 ℃ and at the speed of 300rpm for 150-180 min.

3. The method for preparing micro-nano hollow resin spheres of claim 1, wherein in the second step, the curing agent and the concentration regulator are hexamethylenetetramine and absolute ethyl alcohol respectively, and the amounts of the curing agent and the concentration regulator are 7.5% -17.5% and 7% -8.5% of the amount of the liquefied substances respectively.

4. The method for preparing the micro-nano hollow resin ball according to claim 1, wherein in the third step, the polyvinyl alcohol solution is prepared by dissolving polyvinyl alcohol powder in deionized water at 80-95 ℃ and 300-800 rpm, and the mass fraction of the polyvinyl alcohol solution is 4-12%.

5. The method for preparing the micro-nano hollow resin spheres of claim 1, wherein in the fourth step, the micro-nano resin spheres are prepared by reacting at 130 ℃ and 350-650 rpm for 40-120 min.

6. The preparation method of the micro-nano hollow resin ball according to claim 1, wherein in the fifth step, the concentration of the formaldehyde and hydrochloric acid mixed solution is 18.5%, and the time and the temperature of the primary curing are respectively 3-30 min and 80-100 ℃.

7. The preparation method of the micro-nano hollow resin ball according to claim 1, wherein in the sixth step, the dissolving agent is methanol, glycerol or acetone, and the hollow resin ball is prepared by dissolving the resin ball with 20-40 ml of the dissolving agent by standing at 50-65 ℃ for 30-90 min.

8. A method for preparing a wood-based micro-nano hollow carbon sphere is characterized by comprising the following steps:

the method comprises the following steps: and (3) carrying out secondary curing on the hollow resin spheres in a water bath kettle by using a mixed solution of formaldehyde and hydrochloric acid, filtering and drying to obtain the secondary cured hollow resin spheres.

Step two: and (3) activating and carbonizing the secondary cured hollow resin ball in a vacuum tube furnace under the condition of introducing nitrogen and water vapor to obtain the hollow carbon ball.

9. The preparation method of the micro-nano hollow carbon sphere according to claim 8, wherein in the first step, the concentration of the formaldehyde and hydrochloric acid mixed solution is 18.5%, the use amount of the formaldehyde and hydrochloric acid mixed solution is 30-50 ml, and the time and the temperature of the secondary curing are 2-4 h and 95 ℃.

10. The preparation method of the micro-nano hollow carbon sphere according to claim 8, wherein in the second step, the flow of the nitrogen is 100mL/min, the carbonization temperature is 600-900 ℃, the carbonization and activation time is 30-60 min, and the water vapor output rate during activation is 5-10 g/min.

11. A micro-nano hollow resin ball characterized by being prepared by the preparation method of any one of claims 1 to 7.

12. A micro-nano hollow carbon sphere which is characterized by being prepared by the preparation method of any one of claims 1 to 10.

Technical Field

The invention relates to the field of micro-nano resin ball and carbon ball preparation, in particular to a micro-nano hollow resin ball and a preparation method of a carbon ball.

Background

The hollow carbon sphere has a larger specific surface area and a cavity structure, when the hollow carbon sphere is used as a cathode material of a super capacitor, the larger specific surface area provides more active sites for charges, and the cavity structure is favorable for storage and transmission of the charges, so that larger specific capacitance can be provided. Meanwhile, the element-doped hollow carbon ball can adsorb harmful gas in the air and toxic substances in water, and can also store gas by utilizing a larger cavity of the element-doped hollow carbon ball.

At present, carbon sources for preparing micro-nano hollow carbon spheres comprise asphalt, phenolic resin and the like. The phenolic resin is a promising polymer material for preparing the activated carbon spheres with high specific surface area due to low impurity content. The main raw materials of the activated carbon ball prepared by taking phenolic resin as a carbon precursor are phenols and aldehydes, and the activated carbon ball is synthesized by coal tar and petroleum residues. With the gradual depletion of petroleum resources and the continuous deterioration of ecological environment, people are eagerly looking for a biomass material to replace petroleum resources to prepare a carbon material. The wood is a natural biomass material, has wide resource source, can be continuously used and is a good source for preparing the carbon balls. If the excess wood is fully processed and utilized, the method has very important significance for protecting the environment and improving the effective utilization of the biomass material.

In addition, the synthesis of the hollow carbon spheres mainly comprises methods such as a hard template and a soft template. The hard template synthesis is to synthesize the hollow carbon spheres by selecting carbon precursors to gradually wrap the template, then removing the template and the like. Although this method is effective and reliable, the preparation process is complex, the time period is long, and it is not easy to obtain a rich porous structure on the shell, thus limiting its application. Soft templates do not require template removal, which typically requires a specific templating agent, and its use is limited because of the poor self-assembly ability of the carbon precursor and the high propensity to crosslink, which is not easily achieved.

Disclosure of Invention

The invention aims to provide a micro-nano hollow resin ball with an adjustable cavity size and a preparation method of the carbon ball by taking a biomass liquefied substance as a carbon source, so as to overcome the defects of the prior art.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention comprises the following steps:

the invention provides a preparation method of micro-nano hollow resin spheres and carbon spheres, which specifically comprises the following steps:

preparing solid resin balls:

the method comprises the following steps: adding biomass powder, phenol and phosphoric acid into a three-neck flask, and stirring at a stirring speed of 300rpm and a temperature of 150-160 ℃ for 150-180 min to obtain a wood liquefaction product.

Step two: and weighing a curing agent and a concentration regulator according to the weight of 7.5-17.5% and 7-8.5% of the liquefied substance, adding the curing agent and the concentration regulator into the wood liquefied substance, and stirring at a constant speed (400rpm) for 1h at room temperature to obtain a completely dissolved carbon precursor solution.

Step three: adding the carbon precursor mixed solution into a dispersing agent with the mass fraction of 4-12%, stirring (350-650 rpm), heating to 130 ℃, reacting for 40-120 min, filtering, and drying to obtain the solid resin balls.

In the first step of preparing the solid resin ball, the biomass powder is wood, bamboo, straw and plant fiber, the fineness of the powder is 20-80 meshes, the phenol content is 4-7 times of the weight of the biomass powder, the adding amount of the phosphoric acid is 6-8% of the weight of the phenol, and the concentration of the phosphoric acid is 85%.

In the second step of preparing the solid resin ball, the curing agent is hexamethylenetetramine, the concentration regulator is absolute ethyl alcohol, and the dispersing agent is polyvinyl alcohol aqueous solution.

Primary curing of resin balls:

the method comprises the following steps: and (3) mixing 18.5% formaldehyde and hydrochloric acid (the volume is 30-50 ml) to prepare a curing solution.

Step two: and adding the solid resin balls into a curing solution at the temperature of 80-100 ℃ for primary curing, wherein the curing time is 3-30 min, and filtering and drying to obtain the primary cured resin balls.

Dissolving the resin balls:

and adding the primarily cured resin balls into methanol (20-40 ml), standing and dissolving for 30-90 min at 50-65 ℃, filtering, and drying to obtain the hollow resin balls.

Secondary curing of resin balls:

and adding the hollow resin balls into a mixed solution of formaldehyde and hydrochloric acid with the concentration of 18.5%, heating to 95 ℃ at the heating rate of 35 ℃/h, continuously preserving the heat (for 2-4 h) when the temperature reaches 95 ℃, filtering, and drying to obtain the secondary cured resin balls.

Hollow carbon spheres:

the twice-cured resin pellets were poured into a crucible and sent into a vacuum tube furnace in N₂Under protection (N)₂The flow rate is 100mL/min), the mixture is uniformly heated (600-900 ℃) at the heating rate of 5 ℃/min for carbonization (30-60 min), and then carbonized and activated (30-60 min) by water vapor (the output rate is 5-10 g/min), so that the micro-nano hollow carbon sphere is obtained.

The wood-based micro-nano hollow carbon sphere prepared by the method has the following characteristics:

average sphere diameter: 20 to 40 (mu m) in thickness,

specific surface area: 1029 to 1610 (m)²/g)，

Average shell thickness: 5 to 20 (mu m),

the yield is as follows: 8 to 20 percent of the total weight of the mixture,

the inventor prepares waste biomass China fir wood powder, phenol and phosphoric acid into a wood liquefied substance, and prepares hollow resin balls and carbon balls by a method of 'primary curing-dissolving-secondary curing-carbonizing' by using the wood liquefied substance as a carbon source. The carbon ball prepared by the method has the following advantages: the biomass material existing in large quantity in the nature is used as the carbon source, so that the consumption of non-renewable resources is saved, no aldehyde is added in the process, the production cost is reduced, and the generation of toxic substances is avoided; the method for preparing the hollow resin ball and the carbon ball is simple to operate and short in period; the resin ball and the carbon ball with variable cavity sizes can be prepared by a first solidification-second dissolution method, and have strong competitiveness in the market.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for the embodiments will be described below. It should be apparent that the following drawings are only a few of the embodiments of the present invention, and that other drawings may be derived from those drawings by those skilled in the art.

FIG. 1 is an optical photograph of a solution after resin beads are dissolved at different primary curing times according to an embodiment of the present invention;

FIG. 2 is a scanning electron microscope image of a ground hollow resin sphere according to an embodiment of the present invention;

FIG. 3 shows N of the wood-based micro-nano hollow carbon sphere provided by the embodiment of the invention₂Adsorption-desorption graph and pore size distribution graph;

fig. 4 is a constant current charge-discharge curve and a cyclic voltammetry curve of the wood-based micro-nano hollow carbon sphere provided by the embodiment of the invention;

detailed description of the invention

The invention firstly provides a preparation method of a wood-based micro-nano hollow resin ball and a carbon ball, which comprises the following steps: preparing micro-nano hollow resin balls:

step 1: crushing the cedar into 20-80-mesh powder, adding the wood powder, phenol 4-7 times of the weight of the wood powder and phosphoric acid (the concentration is 85%) 6-8% of the weight of the phenol into a three-neck flask, and reacting for 150-180 min at the stirring speed of 300rpm and the stirring temperature of 150-160 ℃ to obtain the wood liquefied product.

Step 2: mixing the wood liquefied substance and 7.5-17.5 percent of hexamethylene tetramine and 7-8.5 percent of hexamethylene tetramine by weight of the wood liquefied substance with absolute ethyl alcohol, stirring at constant speed (400rpm) for 1h at room temperature, and completely dissolving to obtain the carbon precursor mixed solution.

Step 3: preparing PVA and deionized water, and adding the PVA into the deionized water for three times under the condition that the stirring speed is 400r/min at the temperature of 85-95 ℃ to obtain a polyvinyl alcohol solution with the mass fraction of 4-12%.

Step 4: adding the carbon precursor mixed solution into a polyvinyl alcohol solution preheated to 65 ℃, reacting for 40-120 min at a stirring speed of 350-650 rpm and a temperature of 130 ℃, filtering, and drying to obtain the micro-nano solid resin balls.

Step 5: adding the micro-nano solid resin balls into a curing solution obtained by mixing 18.5% of formaldehyde (30-50 ml) and hydrochloric acid (30-50 ml), primarily curing for 5-30 min at 80-100 ℃, filtering, and drying to obtain the primarily cured resin balls.

Step 6: and adding the primarily cured resin balls into 20-40 ml of methanol solution, standing and dissolving for 30-90 min at 50-65 ℃, filtering, and drying to obtain the hollow resin balls.

Preparing micro-nano hollow carbon spheres:

step 1: and adding the hollow resin balls into a curing solution obtained by mixing 18.5% formaldehyde (30-50 ml) and hydrochloric acid (30-50 ml), heating to 95 ℃ at a heating rate of 35 ℃/h, keeping the temperature for 2-4 h when the temperature reaches 95 ℃, filtering, and drying to obtain the secondary curing resin balls.

Step 2: and (3) sending the secondary cured resin balls into a vacuum tube furnace under the protection of nitrogen for carbonization and activation, carbonizing for 30-60 min at 600-900 ℃, introducing 5-10 g/min of water vapor after carbonization, and then carbonizing and activating for 30-60 min to obtain the micro-nano hollow carbon balls.

In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention will be further described with reference to the following embodiments and the accompanying drawings.

Example 1

Preparing micro-nano hollow resin balls:

step 1: pulverizing lignum seu ramulus Cunninghamiae Lanceolatae into 80 mesh powder, adding 20g of wood powder and 6 times of wood powder weight of phenol and 8% phosphoric acid (concentration 85%) into a three-neck flask, and reacting at 160 deg.C for 2.5 hr at stirring speed of 300rpm to obtain wood liquefied product.

Step 2: 10.00g of wood liquefied product, 1.50g of hexamethylenetetramine and 7.67g of absolute ethyl alcohol are mixed, stirred at a constant speed (400rpm) for 1 hour at room temperature, and completely dissolved to obtain a carbon precursor mixed solution.

Step 3: 20g of PVA and 180g of deionized water are weighed, and the PVA is added into the deionized water for three times under the condition that the temperature is 85 ℃ and the stirring speed is 400r/min to obtain a polyvinyl alcohol solution.

Step 4: adding the carbon precursor mixed solution into a polyvinyl alcohol solution preheated to 65 ℃, reacting for 1h at the stirring speed of 550rpm and the temperature of 130 ℃, filtering and drying to obtain the micro-nano solid resin balls.

Step 5: adding the micro-nano solid resin balls into a curing solution obtained by mixing formaldehyde (40ml) and hydrochloric acid (40ml) with the concentration of 18.5%, primarily curing for 5min at 95 ℃, filtering, and drying to obtain the primarily cured resin balls.

Step 6: and adding the primarily solidified resin balls into 25ml of methanol solution, standing and dissolving for 90min at 55 ℃, filtering and drying to obtain the hollow resin balls.

Preparing micro-nano hollow carbon spheres:

step 1: adding the hollow resin ball into a curing solution obtained by mixing 18.5% formaldehyde (40ml) and hydrochloric acid (40ml), heating to 95 ℃ at a heating rate of 35 ℃/h, keeping the temperature for 4h when the temperature reaches 95 ℃, filtering, and drying to obtain the secondary curing resin ball.

Step 2: and (3) sending the secondary cured resin balls into a vacuum tube furnace under the protection of nitrogen for carbonization and activation, carbonizing for 30min at 800 ℃, introducing 5g/min of water vapor after carbonization, and carbonizing and activating for 30min to obtain the micro-nano hollow carbon balls.

Optical photo of solution in preparation of hollow resin ball by using method of the invention, scanning electron microscope of wood-based micro-nano hollow carbon ball, and N₂Adsorption-desorption, pore size distribution, constant current charge and discharge and linear cyclic voltammetry. The detection results are shown in FIGS. 1 to 4.

Example 2

Preparing micro-nano hollow resin balls:

step 1: pulverizing lignum seu ramulus Cunninghamiae Lanceolatae into 80 mesh powder, adding 20g of wood powder and 6 times of wood powder weight of phenol and 8% phosphoric acid (concentration 85%) into a three-neck flask, and reacting at 160 deg.C for 2.5 hr at stirring speed of 300rpm to obtain wood liquefied product.

Step 2: 10.00g of wood liquefied product, 1.50g of hexamethylenetetramine and 7.67g of absolute ethyl alcohol are mixed, stirred at a constant speed (400rpm) for 1 hour at room temperature, and completely dissolved to obtain a carbon precursor mixed solution.

Step 3: 20g of PVA and 180g of deionized water are weighed, and the PVA is added into the deionized water for three times under the condition that the temperature is 90 ℃ and the stirring speed is 500r/min to obtain a polyvinyl alcohol solution.

Step 4: adding the carbon precursor mixed solution into a polyvinyl alcohol solution preheated to 65 ℃, reacting for 1h at the stirring speed of 550rpm and the temperature of 130 ℃, filtering and drying to obtain the micro-nano solid resin balls.

Step 5: adding the micro-nano solid resin balls into a curing solution obtained by mixing formaldehyde (50ml) and hydrochloric acid (50ml) with the concentration of 18.5%, primarily curing for 10min at 95 ℃, filtering, and drying to obtain the primarily cured resin balls.

Step 6: and adding the primarily solidified resin balls into 25ml of methanol solution, standing and dissolving for 90min at 55 ℃, filtering and drying to obtain the hollow resin balls.

Preparing micro-nano hollow carbon spheres:

step 1: adding the hollow resin ball into a curing solution obtained by mixing 18.5% formaldehyde (50ml) and hydrochloric acid (50ml), heating to 95 ℃ at a heating rate of 35 ℃/h, keeping the temperature for 4h when the temperature reaches 95 ℃, filtering, and drying to obtain the secondary curing resin ball.

Step 2: and (3) sending the secondary cured resin balls into a vacuum tube furnace under the protection of nitrogen for carbonization and activation, carbonizing at 800 ℃ for 40min, introducing 5g/min of water vapor after carbonization, and carbonizing and activating for 40min to obtain the micro-nano hollow carbon balls.

Optical photo of solution in preparation of hollow resin ball by using method of the invention, scanning electron microscope of wood-based micro-nano hollow carbon ball, and N₂Adsorption-desorption, pore size distribution, constant current charge and discharge and linear cyclic voltammetry. The test results were similar to those of example 1.

Example 3

Preparing micro-nano hollow resin balls:

step 1: pulverizing lignum seu ramulus Cunninghamiae Lanceolatae into 80 mesh powder, adding 20g of wood powder and 6 times of wood powder weight of phenol and 8% phosphoric acid (concentration 85%) into a three-neck flask, and reacting at 160 deg.C for 2.5 hr at stirring speed of 300rpm to obtain wood liquefied product.

Step 2: 10.00g of wood liquefied product, 1.50g of hexamethylenetetramine and 7.67g of absolute ethyl alcohol are mixed, stirred at a constant speed (400rpm) for 1 hour at room temperature, and completely dissolved to obtain a carbon precursor mixed solution.

Step 3: 20g of PVA and 180g of deionized water are weighed, and the PVA is added into the deionized water for three times under the condition that the temperature is 90 ℃ and the stirring speed is 500r/min to obtain a polyvinyl alcohol solution.

Step 4: adding the carbon precursor mixed solution into a polyvinyl alcohol solution preheated to 65 ℃, reacting for 1h at the stirring speed of 550rpm and the temperature of 130 ℃, filtering and drying to obtain the micro-nano solid resin balls.

Step 5: adding the micro-nano solid resin balls into a curing solution obtained by mixing formaldehyde (50ml) and hydrochloric acid (50ml) with the concentration of 18.5%, primarily curing for 30min at 95 ℃, filtering, and drying to obtain the primarily cured resin balls.

Step 6: and adding the primarily solidified resin balls into 25ml of methanol solution, standing and dissolving for 90min at 55 ℃, filtering and drying to obtain the hollow resin balls.

Preparing micro-nano hollow carbon spheres:

step 1: adding the hollow resin ball into a curing solution obtained by mixing 18.5% formaldehyde (50ml) and hydrochloric acid (50ml), heating to 95 ℃ at a heating rate of 35 ℃/h, keeping the temperature for 4h when the temperature reaches 95 ℃, filtering, and drying to obtain the secondary curing resin ball.

Step 2: and (3) sending the secondary cured resin balls into a vacuum tube furnace under the protection of nitrogen for carbonization and activation, carbonizing at 800 ℃ for 40min, introducing 5g/min of water vapor after carbonization, and carbonizing and activating for 40min to obtain the micro-nano hollow carbon balls.

Optical photo of solution in preparation of hollow resin ball by using method of the invention, scanning electron microscope of wood-based micro-nano hollow carbon ball, and N₂Adsorption-desorption, pore size distribution, constant current charge and discharge and linear cyclic voltammetry. The test results were similar to those of example 1.

Some exemplary embodiments of the invention have been described above by way of illustration only, and it goes without saying that the described embodiments may be modified in different ways by a person skilled in the art without departing from the scope of the invention. Accordingly, the drawings and description are illustrative in nature and should not be construed as limiting the scope of the invention.