石墨烯基三维组装体的可控制备及其在导热复合材料中的应用研究

发布时间：2018-06-04 15:09

本文选题：导热复合材料 + 石墨烯　；参考：《宁波大学》2017年硕士论文

【摘要】：导热复合材料作为填充于热源与散热器之间用于热传输的材料,对电子元器件的正常运行和使用寿命有着重要影响,因此具有高热导率的导热复合材料的制备成为导热领域的重要研究课题。石墨烯的热导率高达5300 W/(m·K),是目前已知材料中热导率最高的,同时其拥有质轻、比表面积高、结构稳定、机械性能好等优点成为目前最理想的导热填料之一。然而,采用传统共混方法难以实现石墨烯在高分子基体中的均匀分散,不利于构建高效的导热网络。同时,共混方法也难以控制石墨烯导热网络的结构,无法发挥石墨烯各向异性的导热特性。针对上述问题,本论文提出了通过自组装预先构筑基于石墨烯的三维导热网络,以制备具有高热导率的导热复合材料的研究思路。论文的主要研究工作如下:1、通过乙醇和水混合溶剂挥发诱导石墨烯自组装,构建石墨烯三维导热网络,进而通过树脂灌注,获得具有高热导率的导热复合材料。研究了在石墨烯三维组装体的制备过程中石墨烯的浓度、混合溶剂中乙醇和水的体积比、挥发温度等条件对三维组装体结构的影响,以及三维组装体的微观结构、密度等对复合材料导热性能的影响。结果表明,该方法不仅保证了石墨烯良好的分散,而且能够在一定程度上实现石墨烯在高分子基体中的定向排列,从而可以获得具有优异导热性能的石墨烯基导热复合材料2、以氧化石墨烯和氮化硼为前驱体,通过水热方式构筑石墨烯与六方氮化硼复合三维导热网络。研究了制备过程中石墨烯与氮化硼的质量比对导热网络结构的影响,同时探索了石墨烯与氮化硼之间的协同效应,以及氧化石墨烯与氮化硼的质量比对复合材料的导热性能和绝缘性能的影响。结果表明,石墨烯与氮化硼的复合并用提升了体系的导热性能,同时与单纯使用石墨烯相比,赋予了导热复合材料更好的绝缘性能。
[Abstract]:Thermal conductivity composite material, which is used for heat transfer between heat source and radiator, has an important effect on the normal operation and service life of electronic components. Therefore, the preparation of thermal conductive composites with high thermal conductivity has become an important research topic in the field of thermal conductivity. The thermal conductivity of graphene is as high as 5300 W / m Ke, which is the highest among known materials. At the same time, it has the advantages of light weight, high specific surface area, stable structure, good mechanical properties and so on. It has become one of the most ideal thermal conductivity fillers at present. However, it is difficult to realize the uniform dispersion of graphene in polymer matrix by traditional blending method, which is not conducive to the construction of efficient thermal conductivity network. At the same time, it is difficult to control the structure of graphene heat conduction network by blending method, and it is unable to display the anisotropic thermal conductivity of graphene. In order to solve the above problems, this paper proposes a new method to fabricate thermal conductivity composites with high thermal conductivity by constructing a three dimensional heat conduction network based on graphene by self assembly. The main work of this paper is as follows: 1. Through ethanol and water mixed solvent volatilization induced graphene self-assembly, the three-dimensional thermal conductivity network of graphene was constructed, and then the high thermal conductivity composite was obtained by resin perfusion. The effects of the concentration of graphene, the volume ratio of ethanol and water in the mixed solvent, the volatilization temperature on the structure of the three-dimensional assembly and the microstructure of the three-dimensional assembly were studied. The effect of density on the thermal conductivity of composites. The results show that this method not only ensures the good dispersion of graphene, but also realizes the directional arrangement of graphene in polymer matrix to a certain extent. Therefore, graphene based thermal conductive composites with excellent thermal conductivity can be obtained. Using graphene oxide and boron nitride as precursors, a three-dimensional thermal conductivity network of graphene and hexagonal boron nitride can be constructed by hydrothermal method. The effect of the mass ratio of graphene to boron nitride on the thermal conductivity network was studied, and the synergistic effect between graphene and boron nitride was explored. The effect of the mass ratio of graphene oxide to boron nitride on the thermal conductivity and insulation properties of the composites was also discussed. The results show that the composite of graphene and boron nitride can improve the thermal conductivity of the composites, and the thermal conductivity of the composites is better than that of the simple use of graphene.
【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33

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