将经酸化处理的可膨胀石墨浸渍在二茂铁的有机溶剂中,充分搅拌并静置5h~8h,经快速加热后制得表面沉积磁性铁颗粒的膨胀石墨。利用扫描电镜观察了不同工艺条件下产物的显微形貌与元素组成。由振动磁强计测试出这种石墨蠕虫在室温静态条件下的磁化曲线及磁化率,并结合工艺条件进行了对比分析。同时,还考核了掺杂磁性铁颗粒膨胀石墨对8mm电磁波信号发生装置的干扰作用。结果表明:铁氧化物沉积在膨胀石墨表层,随着二茂铁投入量的增大,膨胀石墨磁性能提高越明显,在0A/m~7.958×10^5A/m磁场强度下测得其平均磁化强度≥8emu/g,在军用毫米波雷达频段的衰减率最高可达-10dB,质量消光系数大于1.0g/m^2,遮蔽效果优于现役毫米波干扰剂。
Magnetic iron particle-doped expanded graphite was prepared by dipping, stirring and standing an expandable graphite for 5-8 h in ferrocene then expanding at 500℃. The surface morphology and composition of the expanded graphite were characterized by SEM and elemental analysis while the magnetization curves, magnetic susceptibility and the attenuation properties for an 8 mm wavelength electromagnetic signal were characterized by a vibration magnetometer. Results showed that ferric oxide was deposited on the surface of the expanded graphite. The average magnetic intensity of the expanded graphite prepared is higher than 8 emu/g under a magnetic field intensity of 0-7.958 × 105 A/m. The largest attenuation is over-10dB and its mass extinction coefficient is over 1.0 g/m^2 in the wave length of military radar, which is better than a current millimeter wave radar shielding material.