【作者】 唐海涛；

【导师】 陈国华；

【作者基本信息】 华侨大学 ， 材料物理与化学， 2006， 硕士

【摘要】 由石墨层间化合物经过膨化制得的纳米石墨微片具有高的电导率和比表面积，从而赋予它较好的电磁屏蔽性能。根据Schelkoff的电磁屏蔽理论可知，具有优良电磁屏蔽性能的电磁屏蔽材料应具有较高的相对电导率和相对的磁导率。但纳米石墨微片本身是反铁磁性的，为了进一步增强纳米石墨微片的屏蔽性能，希望能将一些磁性微粒包覆到纳米石墨微片表面，得到一种兼有导电性和导磁性的新型复合材料。 本论文以Fe²⁺和Fe³⁺的混合溶液为覆层前驱液，通过湿化学共沉淀包覆法使具有亚铁磁性的四氧化三铁微粒包覆到纳米石墨微片的表面。详细研究了影响Fe₃O₄在包覆过程中转化生成的四个主要因素：铁离子总浓度、Fe²⁺与Fe³⁺之比、反应温度以及晶化时间。通过研究这些因素对纳米石墨微片／四氧化三铁复合粉末的物相组成、磁性能和电性能的影响，获得了制备纳米石墨微片／四氧化三铁复合粉末的最佳工艺条件，并运用XRD、SEM、FT-IR、TG-DSC、VSM等仪器表征分析了最佳条件下制备的纳米石墨微片／四氧化三铁复合粉末。研究表明，包覆层粒子为纳米级的四氧化三铁微粒，而且四氧化三铁微粒和纳米石墨微片表面是通过分子间力和化学键结合在一起。 本论文还研究了纳米石墨微片／四氧化三铁复合粉末在磁场作用下的自组装行为。研究表明，分散在聚合物基体中的改性纳米石墨微更多还原

【Abstract】 Graphite nanosheets prepared by the intercalated and expanded method have the high conductivity and surface area, thus entrusted it with the good electromagnetic shielding performance. According to Schelkoff’s electromagnetic shielding theory, electromagnetic shielding materials with good electromagnetic shielding performance should have higher relative conductivity and relative magnetic conductivity. Graphite nanosheets itself are anti-ferromagnetic, in order to further strengthens the shielding properties of graphite nanosheets, we hope coat some magnetic particle to the surface of graphite nanosheets to enhance the magnetic performance of graphite nanosheets.Taking the Fe and Fe mixing solution as coating premonitory solution, magnetite particles with ferromagnetism were coated to the surface of graphite nanosheets by the wet-chemical co-precipitation method. In a detailed study of four main impact factors during the forming and coating process of magnetite particles: the total concentration of iron ions, the ratio of Fe²⁺/Fe³⁺, the crystallization temperature and the reaction time, the optimum preparation condition of graphite nanosheets/magnetite compound powder were obtained through researching the effect of these factors on the phase composition, magnetic更多还原