石墨烯粉体及石墨烯水分散液的制备研究

发布时间：2018-01-11 16:24

本文关键词：石墨烯粉体及石墨烯水分散液的制备研究　出处：《深圳大学》2017年硕士论文　论文类型：学位论文

【摘要】：自从2004年单原子厚度二维平面结构的石墨烯在实验室被发现后,就吸引了人们的广泛关注。石墨烯所表现出来的诸多优异特性,及其在各领域的潜在应用,也引起了世界范围内广泛的研究热潮。如何实现石墨烯高质量、大规模的生产,是目前亟需解决的一大难题。所以如何对石墨烯的制备技术进行创新,或者在原有的基础上对制备技术进行改进,以提高石墨烯的产量和质量也就势在必行了。本论文的内容主要包括以下几个部分:(1)通过改进原有的制备方法,获得了高产量、高质量的石墨烯粉体。本文将原本在空气气氛条件下进行的LPAN预烧结过程改进为在氮气气氛保护下进行,防止了在预烧结过程中LPAN分子链上氧化反应的发生,减少了烧结过程中碳量的损失,以及石墨烯平面结构上缺陷的产生,提高了最终产物的质量和产量。这无疑对石墨烯的工业化生产研究有着重要的意义。(2)设计了一种简单、有效的球磨方法:机械分裂与化学修饰法相结合,使石墨烯粉体与KOH在球磨过程中发生反应,制备出了浓度可达0.5 mg/ml的高质量的石墨烯水分散液。其机理就是通过球磨过程中的机械力,使石墨烯片层分裂,在其分裂的边缘部位,断裂的C-C键形成了活性碳物种(离子,自由基等),非常易于与羟基化合物发生反应,从而在石墨烯片层边缘的位置引入羟基官能团,这种球磨方法既增加了石墨烯的分散性也没有破坏石墨烯的基面。将所得样品分散在不同的溶剂中后可以发现,球磨方法制备的石墨烯水分散液在大多数的极性溶剂中均具有良好的分散效果。(3)对石墨烯水分散液进行热还原处理,通过拉曼、紫外、红外等表征手段,对还原前后的产物进行了分析,进一步验证了本文所提出的的球磨反应的机理。此外,本文利用所得到的石墨烯水分散液抽滤制膜,对其薄层电阻进行测试,结果发现石墨烯又可以恢复到其原有的导电性能。这说明通过球磨方法,不仅制备出了较高浓度的石墨烯水分散液,同时很好的保留了石墨烯的本征结构,并基本保全了其优异的性能。这对石墨烯材料在实际领域中的应用有着非常重大的意义。
[Abstract]:Since the discovery of graphene with monoatomic thickness and two-dimensional planar structure in the laboratory in 2004, it has attracted much attention. And its potential applications in various fields have also caused a worldwide wide range of research upsurge. How to achieve high quality graphene production on a large scale. Therefore, how to innovate the preparation technology of graphene, or improve the preparation technology on the basis of the original. It is imperative to improve the yield and quality of graphene. The main contents of this paper include the following parts: 1) by improving the original preparation method, the high yield has been obtained. High quality graphene powder. In this paper, the pre-sintering process of LPAN under the condition of air atmosphere was improved to be carried out under the protection of nitrogen atmosphere. The oxidation reaction on LPAN molecular chain during pre-sintering process was prevented, and the loss of carbon content and the formation of planar defects in graphene structure were reduced. The quality and yield of the final product are improved, which is undoubtedly of great significance to the study of the industrial production of graphene.) A simple and effective ball milling method is designed, which is the combination of mechanical splitting and chemical modification. A high quality graphene aqueous dispersion with concentration up to 0.5 mg/ml was prepared by the reaction between graphene powder and KOH in the process of ball milling. The mechanism is the mechanical force in the process of ball milling. At the edge of the cleavage, the C-C bond breaks into active carbon species (ions, free radicals, etc.), which is very easy to react with hydroxyl compounds. Therefore, hydroxyl functional groups were introduced into the edge of graphene lamellar. The ball milling method not only increased the dispersion of graphene, but also did not destroy the base surface of graphene. The samples were found to be dispersed in different solvents. The graphene aqueous dispersion prepared by ball milling has good dispersion effect in most polar solvents. The products before and after reduction were analyzed, and the mechanism of ball milling reaction was further verified. In addition, the thin layer resistance of the film was tested by using the obtained graphene aqueous dispersion to filter the film. The results show that graphene can recover to its original electrical conductivity, which indicates that through ball milling method, not only high concentration of graphene aqueous dispersion was prepared, but also the intrinsic structure of graphene was well preserved. It is of great significance to the application of graphene materials in the practical field.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ127.11

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