石墨烯的改性及石墨烯增强银基复合材料的研究

发布时间：2018-04-03 21:57

  本文选题：石墨烯　切入点：银基复合材料　出处：《西安理工大学》2017年硕士论文

【摘要】：本文分别采用化学还原法和水热法合成了负载银石墨烯(Ag-doped graphene)及掺氮石墨烯(N-doped graphene)复合粉末,并通过粉末冶金法制备了负载银石墨烯增强的银基块体复合材料和掺氮石墨烯增强的银基块体复合材料。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和拉曼光谱仪(Raman)及X射线光电子能谱仪(XPS)对负载银石墨烯及掺氮石墨烯复合粉末进行表征。通过光学显微镜(OM)、扫描电子显微镜(SEM)、能谱分析(EDS)及透射电子显微镜(TEM)对负载银石墨烯增强银基块体复合材料和掺氮石墨烯增强银基块体复合材料的组织进行了分析,并对其密度、硬度和电导率进行了测试。通过以上研究可得到以下结论。(1)采用水合肼在90℃保温2h条件下可有效还原氧化石墨烯(GO)和AgN03,并去除了氧化石墨烯中的大量含氧官能团,银纳米粒子成功地负载到石墨烯上,阻碍了石墨片层的有序堆叠,有效地重建石墨烯的共轭结构。(2)在160℃保温6h水热条件下,掺氮石墨烯被有效的还原,且在石墨烯中成功地引入氮元素,掺氮量为4.74at%。除了局部区域出现堆叠和褶皱外,合成的掺氮石墨烯由于氮元素在石墨烯晶面内的替代导致形貌呈现较大程度的扭曲。(3)负载银石墨烯的添加显著增强了银基块体复合材料的性能。与纯银相比,添加0.5wt%负载银石墨烯的银基块体复合材料硬度与电导率分别提高了 55.4%和2.78%。但是过量的负载银石墨烯导致银基块体复合材料的硬度和电导率显著降低。随着银粉粒度的增大,银基块体复合材料的硬度降低,而电导率呈现升高的趋势。采用100nm银粒制备的0.5wt%负载银石墨烯增强的银基块体复合材料硬度和电导率分别为89.4HV和95.68%IACS。(4)负载银石墨烯增强银基块体复合材料的硬度和电导率随着烧结温度的升高先增大后减小。600℃烧结制备的银基块体复合材料的硬度和电导率均达到最大,分别为89.4HV 和 95.68%IACS。(5)少量掺氮石墨烯的添加显著提高了银基块体复合材料的性能。但是过多掺氮石墨烯的添加显著降低了块体银基复合材料的硬度和电导率。当掺氮石墨烯的量为0.1wt%时,银基块体复合材料硬度和电导率与纯银相比分别提高了 64.8%和3.71%。(6)细小的银粉有利于掺氮石墨烯增强的银基块体复合材料硬度的提高,但降低了电导率。当银粒径为100nm时,银基块体复合材料的硬度为94.6HV。采用不同粒径的银粉制备的掺氮石墨烯增强的银基复合材料的电导率均保持在96%IACS以上。
[Abstract]:In this paper, Ag-doped graphene and N-doped graphene (N-doped graphene) composite powders were synthesized by chemical reduction method and hydrothermal method, respectively.Silver bulk composites reinforced by silver graphene and silver matrix bulk composites reinforced by nitrogen-doped graphene were prepared by powder metallurgy method.The composite powders of silver graphene and nitrogen-doped graphene were characterized by X-ray diffractometer, scanning electron microscope (SEM), transmission electron microscope (TEM), Raman spectrometer (Raman) and X-ray photoelectron spectroscopy (XPS).The microstructure of silver-supported graphene-reinforced silver-based bulk composites and nitrogen-doped graphene-reinforced silver-based bulk composites were analyzed by optical microscope, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM).The density, hardness and electrical conductivity were tested.Through the above study, we can get the following conclusion: 1) under the condition of holding hydrazine hydrate for 2 hours at 90 鈩，

本文编号：1707070