Powdery carbon aerogel, as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of an aerogel material and discloses a powdery carbon aerogel, as well as a preparation method and an application thereof. The powdery carbon aerogel is formed by carbon nanometer ball building units with a grain size of 20-300 nm by cross-linking and stacking; lots of micropores are formed on the surface of the carbon nanometer balls, and the specific surface area is 294-2472 m<2> / g. The powdery carbon aerogel disclosed by the invention is micron-level powder, can be directly used without being ball-milled in lots of application fields, and contributes to simplification of an application technique. The powdery carbon aerogel disclosed by the invention has a high specific surface area which is as high as 2472m<2> / g at most, and has wide potential application in preparation of electrode materials, medicine release control materials and adsorbing materials. Moreover, the building unit of the powdery carbon aerogel has good sphericity degree and grain size uniformity, and is benefit for precise building of a nanometer structure. The preparation method of the powdery carbon aerogel is simple, realizes moderate and easily controlled reaction condition, and is beneficial to industrialization amplification.

Description

technical field [0001] 本发明属于气凝胶材料技术领域,特别涉及一种粉末状炭气凝胶及其制备方法和应用。 Background technique [0002] 炭气凝胶材料一经出现,即引起世界各国研究工作者的浓厚兴趣。近年来,人们已经在廉价原料开发、工艺简化(尤其是干燥工艺)、结构控制、性能表征和应用开发等方面进行了大量的研究工作。但时至今日,气凝胶材料无论是在基础理论研究方面,还是在实际生产应用方面,都仍然处于探索阶段。 [0003] 目前这类材料的合成通常基于酚醛溶液的溶胶-凝胶反应。这种制备方法存在多种问题:(1)由溶胶反应得到酚醛树脂纳米颗粒单元,紧接着利用凝胶化反应将这些单元交联形成三维纳米网络再炭化后形成的纳米炭颗粒单元都是无孔的或准无孔的。(2)溶胶-凝胶化反应通常是在静置的密闭容器内完成,导致聚合过程中的热量难以迅速导出,工艺放大过程中会发生危险的爆聚。(3)大部分溶胶-凝胶化反应后得到的炭气凝胶前驱体力学强度低,无法承受常压下溶剂干燥过程中所产生的强烈的毛细管收缩力,因此通常需采用工艺繁琐、成本昂贵的超临界干燥或冷冻干燥等技术去除溶剂。(4)经过溶胶-凝胶化反应得到的气凝胶材料一般呈块状,无法满足应用的多样化需求。例如,炭气凝胶经常被用作超级电容器电极材料,这时就得把块状气凝胶球磨成微米级粉末(~10μm),不仅费时费力,还费钱。 Contents of the invention [0004] 为了克服上述现有技术的缺点与不足,本发明的首要目的在于提供一种粉末状炭气凝胶。 [0005] 本发明另一目的在于提供一种上述粉末状炭气凝胶的制备方法。 [0006] 本发明再一目的在于提供上述粉末状炭气凝胶在制备电极材料、药物控释材料和吸附材料中的应用。 [0007] 本发明的目的通过下述方案实现: [0008] 一种粉末状炭气凝胶,由粒径为20~300nm的炭纳米球构筑单元交联堆叠而成,炭纳米球表面有大量微孔,其比表面积为294~2472m 2 / g. [0009] 上述粉末状炭气凝胶的炭纳米球球间交联与堆叠形成大量中孔与大孔,各孔道间相互贯穿连通,形成具有独特的、三维相连通的层次化纳米网络孔道结构,各层次纳米孔道之间具有协同效应。 [0010] 上述粉末状炭...

AI Technical Summary

Problems solved by technology

There are many problems in this preparation method: (1) The phenolic resin nanoparticle units are obtained by the sol reaction, and then these units are cross-linked by gelation reaction to form a three-dimensional nano-network and then carbonized to form nano-carbon particle units. porous or quasi-nonporous

(2) The sol-gelation reaction is usually completed in a static closed container, which makes it difficult to quickly extract the heat during the polymerization process, and dangerous explosions will occur during the process of process amplification

(3) Most of the carbon airgel precursors obtained after the sol-gelation reaction have low mechanical strength and cannot withstand the strong capillary contraction force generated during the solvent drying process under normal pressure. Expensive techniques such as supercritical drying or freeze drying to remove solvents

(4) The airgel materials obtained by sol-gelation reaction are generally in the form of blocks, which cannot meet the diverse needs of applications

For example, carbon aerogels are often used as electrode materials for supercapacitors. At this time, it is necessary to grind the bulk airgel balls into micron-sized powders (~10 μm), which is not only time-consuming and labor-intensive, but also expensive.

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