阅读说明：本技术 一种大尺寸多孔碳材料的制备方法 (Preparation method of large-size porous carbon material ) 是由 张展 穆春丰 张大奎 贾楠楠 张馨予 姚君 王晓楠 于 2019-09-06 设计创作，主要内容包括：本发明涉及一种大尺寸多孔碳材料的制备方法,1)将二氧化硅磨成粉末,烘干；2)加入表面活性剂聚乙烯吡咯烷酮PVP和正硅酸乙酯TEOS,充分搅拌,二氧化硅粉末完全浸润液体后取出,干燥将表面活性剂蒸干,形成碳氮复合小球；3)将碳氮复合小球加入反应釜中,以乙二醇为溶剂,聚合生成小球聚合物；4)将小球聚合物和氨腈混合,形成碳氮复合材料前驱体,煅烧,形成碳氮复合材料；5)在碳氮复合材料中加入溶剂乙醇,在负压条件下进行搅拌,使二氧化硅为核心的碳氮复合小球脱离碳氮复合材料,碳氮复合小球抽滤排出,抽滤后的残留物干燥去除乙醇,完成大尺寸多孔碳材料的制备。本发明保证碳材料结构强度的基础上,降低碳材料15％以上的重量。(The invention relates to a preparation method of a large-size porous carbon material, which comprises the following steps of 1) grinding silicon dioxide into powder and drying; 2) adding surface active agents of polyvinylpyrrolidone PVP and tetraethyl orthosilicate TEOS, fully stirring, taking out after silicon dioxide powder completely soaks liquid, drying and evaporating the surface active agents to dryness to form carbon-nitrogen composite balls; 3) adding the carbon-nitrogen composite pellets into a reaction kettle, and polymerizing by using ethylene glycol as a solvent to generate pellet polymers; 4) mixing the pellet polymer and cyanamide to form a carbon-nitrogen composite material precursor, and calcining to form a carbon-nitrogen composite material; 5) adding ethanol serving as a solvent into the carbon-nitrogen composite material, stirring under a negative pressure condition to separate the carbon-nitrogen composite balls taking silicon dioxide as a core from the carbon-nitrogen composite material, carrying out suction filtration on the carbon-nitrogen composite balls, discharging, drying residues obtained after the suction filtration to remove ethanol, and completing preparation of the large-size porous carbon material. The invention reduces the weight of the carbon material by more than 15 percent on the basis of ensuring the structural strength of the carbon material.)

1. A preparation method of a large-size porous carbon material is characterized by comprising the following steps:

(1) grinding silicon dioxide into powder with diameter of 5-8 μm, drying at 80-100 deg.C for 2-4 hr, and completely discharging water;

(2) adding a surfactant, namely polyvinylpyrrolidone (PVP) and Tetraethoxysilane (TEOS), into silicon dioxide powder in a mass ratio of 1:0.3-0.8:2-3, fully stirring, taking out the silicon dioxide powder after the silicon dioxide powder is completely soaked in liquid, drying for 6-8h at the temperature of 100-120 ℃, evaporating the polyvinylpyrrolidone (PVP) to dryness, and coating the Tetraethoxysilane (TEOS) on the surface of the silicon dioxide to form a carbon-nitrogen composite pellet;

(3) adding the carbon-nitrogen composite pellets into a reaction kettle, using ethylene glycol as a solvent, wherein the adding amount of the ethylene glycol is 4-6 times of the mass of the nitrogen composite pellets, controlling the temperature between 180 ℃ and 220 ℃, controlling the stirring rate between 45-60r/min, and continuing the polymerization reaction for 2-4h to generate pellet polymers;

(4) mixing the small ball polymer with cyanamide, wherein the addition amount of the cyanamide is 2-3 times of the mass of the small ball polymer,stirring at 60-80 deg.C to make cyanamide completely infiltrate into small ball polymer to form carbon-nitrogen composite material precursor, calcining at 1800-2000 deg.C to remove ethylene glycol andis left behindPolyvinylpyrrolidone (PVP) to form a carbon-nitrogen composite material;

(5) adding ethanol serving as a solvent into the carbon-nitrogen composite material, wherein the adding amount of the ethanol is 8-10 times of the mass of the carbon-nitrogen composite material, stirring under a negative pressure condition to separate the carbon-nitrogen composite balls taking the silicon dioxide as the core from the carbon-nitrogen composite material, carrying out suction filtration and discharge along with the solvent under the negative pressure condition, drying residues after the suction filtration at the temperature of 60-80 ℃ to remove the ethanol, and completing the preparation of the large-size porous carbon material.

2. The method according to claim 1, wherein the large-size porous carbon material has a pore diameter of more than 50 nm.

Technical Field

The invention relates to the field of coking, in particular to a preparation method of a large-size porous carbon material.

Background

Carbon fiber materials were first used in the past 70 s and have been used as high performance materials in the aerospace and luxury goods industries. In recent years, with commercialization of aerospace technology and an increase in the consumer level of the public, general-purpose carbon fibers (polyacrylonitrile-based carbon fibers) are widely used in household automobiles, high-end sports products, and the conventional industry. However, high performance carbon fibers have been affected by both performance and cost, and commercialization has progressed slowly.

Compared with common carbon materials, the carbon fiber has the advantages of high strength, light weight, high price and complex production process. If the weight of the carbon material can be reduced as much as possible while maintaining the strength of a common carbon material, the goal of commercializing the carbon material can be achieved. At present, the most mainstream technical scheme is to construct holes in the carbon material, so that the overall quality of the carbon material is reduced.

The current popular process technology mainly adopts a physical processing mode, and the physical punching or ball milling mode is easy to damage the microstructure of the existing carbon material, so that the overall strength is reduced. Therefore, if a chemical processing mode can be developed, the weight of the carbon material can be reduced on the basis of not influencing the microstructure, and the aim of commercializing the carbon material can be quickly achieved.

Patent CN201710247691.9 is a method for preparing small-size porous carbon nanospheres, mixing surfactant, organic hydrocarbon and ammonia water into a clear and transparent solution, adding a mixture of resorcinol and formalin, and stirring to form a reverse microemulsion system; transferring the system into a hydrothermal kettle containing a polytetrafluoroethylene lining, sealing, and carrying out heat treatment at 80-120 ℃ for 10-24 h; and (3) adding a demulsifier into the reaction liquid after cooling, and carrying out ultrasonic treatment, centrifugation, washing, drying, grinding and high-temperature roasting in an inert atmosphere to obtain the carbon nanospheres. The preparation method of the small-size carbon nanosphere has simple and economical process, and the size of the carbon nanosphere can be controlled by changing reaction conditions. The patent adopts a mode of combining chemical and physical methods, and finally adopts a grinding mode to carry out modeling. Grinding affects the structural strength of the material, unlike pure chemical treatment processes.

The invention discloses a preparation method of a black titanium dioxide nanorod visible light photocatalyst, and aims to solve the technical problems that titanium dioxide prepared by the existing method is low in sunlight utilization rate and low in charge transmission efficiency when the titanium dioxide is used as a catalyst. The method comprises the following steps: firstly, preparing a mixed solution; secondly, preparing reaction liquid; thirdly, washing and drying; fourthly, ball milling; fifthly, calcining; and sixthly, washing and drying to obtain the black titanium dioxide nanorod visible light photocatalyst. The advantages are that: the degradation rate of the black titanium dioxide nanorod visible-light-driven photocatalyst prepared by the method for degrading the rhodamine B is more than 94%; the black titanium dioxide nanorod visible light photocatalyst prepared by the method is rod-shaped, and the size of the black titanium dioxide nanorod visible light photocatalyst is 150 nm-300 nm. This patent adopts the mode of ball-milling to process, and physical processing can influence the structural strength of material finally.

Disclosure of Invention

The invention aims to solve the technical problem of providing a preparation method of a large-size porous carbon material, which reduces the weight of the carbon material by more than 15% on the basis of not influencing the structural strength of the carbon material. In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of a large-size porous carbon material specifically comprises the following steps:

(1) grinding silicon dioxide into powder with diameter of 5-8 μm, drying at 80-100 deg.C for 2-4 hr, and completely discharging water;

(2) adding a surfactant, namely polyvinylpyrrolidone (PVP) and Tetraethoxysilane (TEOS), into silicon dioxide powder in a mass ratio of 1:0.3-0.8:2-3, fully stirring, taking out the silicon dioxide powder after the silicon dioxide powder is completely soaked in liquid, drying for 6-8h at the temperature of 100-120 ℃, evaporating the polyvinylpyrrolidone (PVP) to dryness, and coating the Tetraethoxysilane (TEOS) on the surface of the silicon dioxide to form a carbon-nitrogen composite pellet;

(3) adding the carbon-nitrogen composite pellets into a reaction kettle, using ethylene glycol as a solvent, wherein the adding amount of the ethylene glycol is 4-6 times of the mass of the nitrogen composite pellets, controlling the temperature between 180 ℃ and 220 ℃, controlling the stirring rate between 45-60r/min, and continuing the polymerization reaction for 2-4h to generate pellet polymers;

(4) mixing the small ball polymer with cyanamide, stirring at 60-80 deg.C to make cyanamide completely infiltrate the small ball polymer to form carbon-nitrogen composite material precursor, calcining at 1800-2000 deg.C to remove glycol and nitrileIs left behindPolyvinylpyrrolidone (PVP) to form a carbon-nitrogen composite material;

(5) adding ethanol serving as a solvent into the carbon-nitrogen composite material, wherein the adding amount of the ethanol is 8-10 times of the mass of the carbon-nitrogen composite material, stirring under a negative pressure condition to separate the carbon-nitrogen composite balls taking the silicon dioxide as the core from the carbon-nitrogen composite material, carrying out suction filtration and discharge along with the solvent under the negative pressure condition, drying residues after the suction filtration at the temperature of 60-80 ℃ to remove the ethanol, and completing the preparation of the large-size porous carbon material.

The diameter of the pore diameter of the large-size porous carbon material is larger than 50 nm.

Compared with the prior art, the invention has the beneficial effects that:

the invention is a chemical method for preparing a large-size porous carbon material, and reduces the weight of the carbon material by more than 15% on the basis of not influencing the structural strength of the carbon material.

The pore-forming principle of the carbon material of the invention is as follows: silica is taken as a core, and is polymerized by a coating material to form a polymer of silica powder, namely, microscopically, a small ball aggregate. The voids in the pellet aggregates are filled with cyanamide, and then the pellets are removed and the holes are formed in situ.

Drawings

FIG. 1 is a flow chart of the preparation process of the present invention.

Detailed Description

The invention is further illustrated by the following examples:

the following examples describe the invention in detail. These examples are merely illustrative of the best embodiments of the present invention and do not limit the scope of the invention.