石墨烯的多尺度组装及其性能研究

发布时间：2018-05-12 21:06

本文选题：石墨烯 + 氧化石墨烯　；参考：《大连理工大学》2015年博士论文

【摘要】：石墨烯是碳原子以六角形密堆积形成的二维原子晶体,具有独特的物理化学性质,在电子器件、能源环境和生物医学等诸多领域展现出广阔的应用前景。石墨烯的可控制备和组装是其实际应用的基础。本论文以水溶性氧化石墨烯(GO)为前驱体,基于胶体和界面化学基本原理和技术策略,成功实现了石墨烯在不同尺度上的可控制备和组装,并研究了石墨烯片层结构的组装机制。在微纳米尺度上,制备得到了石墨烯基微球和一维(1D)石墨烯纳米带；在宏观尺度上,实现了厘米级二维(2D)石墨烯薄膜和三维(3D)石墨烯组装体的可控构筑。并对各种石墨烯组装结构的特异性能和应用领域进行了探索。主要研究结果如下： 1.氧化石墨烯液晶乳液的制备及其控制组装：通过调节界面张力,控制氧化石墨烯纳米片在油/水界面的自组装行为形成氧化石墨烯液晶乳液。二维氧化石墨烯纳米片在界面上的定向排列形成液晶的各向异性。得到的液晶乳液结构稳定,可作为软模板构筑孔道规则可控(1.7～31.6μm)的三维的石墨烯组装体结构。 2.石墨烯纳米带的制备及其功能化：利用限域空间内的结冰过程诱导石墨烯片层折叠,形成具有超弹性(弹性形变恢时间小于35ms)的新型一维石墨烯带状结构。提出制备石墨烯包覆过渡金属氧化物复合结构的通用技术,包覆四氧化三铁的石墨烯折叠纳米带作为锂离子电池负极材料表现出优异的倍率特性能(10C)和长达600次的稳定循环寿命。 3.绿色还原法石墨烯制备及其柔性高强度二维宏观薄膜构筑：提出基于柠檬酸钠作为还原剂的绿色还原新技术制备石墨烯。采用XRD特征峰比值法系统研究了氧化石墨烯的柠檬酸钠还原进程。将化学还原石墨烯真空诱导自组装构筑柔性石墨烯薄膜结构,考察了不同干燥方式对于薄膜形成过程和力学强度的影响,制备得到了抗拉强度高达83MPa的石墨烯薄膜材料。 4.超快共价交联组装多功能石墨烯三维组装体：发展超快制备(1min)氧化石墨烯三维组装体的化学交联策略。利用商业化环氧树脂固化剂(聚醚胺-D400)作为交联剂,基于分子动力学计算和实验结果提出氧化石墨片层组装过程中存在的三种结构模型：环型构型,桥型构型和尾形构型。得到的三维组装体是一种低毒性支撑体材料,细胞培养测试表明人体成纤维细胞(L929)能够顺利在其孔道上生长繁殖,24h后细胞存活率高达99%。
[Abstract]:Graphene is a two-dimensional atomic crystal formed by hexagonal dense stacking of carbon atoms. It has unique physical and chemical properties. Graphene has been widely used in many fields such as electronic devices, energy environment and biomedicine. The controlled preparation and assembly of graphene is the basis of its practical application. Based on the basic principles and technical strategies of colloid and interfacial chemistry, the controllable preparation and assembly of graphene at different scales were successfully realized in this thesis, and the assembly mechanism of graphene lamellar structure was studied. Graphene based microspheres and one-dimensional (1D) graphene nanobelts were prepared at the micro- and nano-scale, and the controllable construction of centimeter-scale 2D / 2D) graphene thin films and 3D / 3D) graphene assemblies were achieved. The specific properties and application fields of various graphene assembly structures were also explored. The main findings are as follows: 1. Preparation and controlled assembly of graphene oxide liquid crystal emulsion: graphene oxide liquid crystal emulsion was formed by adjusting the interfacial tension and controlling the self-assembly behavior of graphene oxide nanoparticles at the oil / water interface. The orientation of graphene oxide nanocrystals at the interface formed the anisotropy of liquid crystal. The obtained liquid crystal emulsion has a stable structure and can be used as a soft template to construct a three-dimensional graphene assembly structure with a regularly controlled pore structure of 1.7 ~ 31.6 渭 m. 2. Preparation and functionalization of graphene nanobelts: a novel one-dimensional graphene strip structure with hyperelastic (elastic deformation recovery time less than 35 Ms) was formed by inducing graphene lamellar folding by ice formation in confined space. A general technique for preparing graphene coated transition metal oxide composite structure is presented. The graphene folded nanobelts coated with iron trioxide as anode materials for lithium ion batteries show excellent rate characteristic of 10C) and stable cycle life of 600 times. 3. The preparation of graphene by green reduction method and the construction of flexible high strength two-dimensional macro film: a new green reduction technology based on sodium citrate was proposed to prepare graphene. The process of sodium citrate reduction of graphene oxide was studied by XRD characteristic peak ratio method. The structure of flexible graphene thin films was constructed by vacuum induced self-assembly of chemically reduced graphene. The effects of different drying methods on the formation process and mechanical strength of the films were investigated. The graphene thin films with tensile strength up to 83MPa were prepared. 4. Ultrafast covalent crosslinking assembly of multifunctional graphene: development of chemical crosslinking strategy for ultrafast preparation of graphene oxide three-dimensional assembly. The commercial epoxy resin curing agent (polyether amine D400) was used as crosslinking agent. Based on the molecular dynamics calculation and experimental results, three structural models of graphite oxide lamellar assembly were proposed: ring configuration, bridge configuration and tail configuration. The results of cell culture test showed that human fibroblasts (L929) could successfully grow and reproduce on their channels for 24 hours and the cell survival rate was as high as 99g.
【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TQ127.11

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