Surface Engineering Division, CSIR-National Aerospace Laboratories, Bengaluru 560017, India.
Phys Chem Chem Phys. 2019 Feb 27;21(9):5068-5077. doi: 10.1039/c8cp06943c.
A manganese based spinel ferrite, chemically modified with polymethyl methacrylate (PMMA) and polyaniline (PANI) are synthesized and their composites are used as electromagnetic interference (EMI) shielding materials. X-ray diffraction studies show that the as-prepared manganese ferrite crystallizes in a cubic spinel structure. The particles are highly agglomerated and nanocrystalline as indicated by transmission electron microscopy. Manganese exists in +2 and +4 oxidation states and Fe in +2 and +3 oxidation states. Modified manganese ferrite and polyaniline composites in different weight ratios are evaluated for their EMI shielding properties. It is observed that composites containing the PMMA modified ferrite show enhanced total shielding effectiveness (SET) compared to those containing the unmodified ferrite in the X band frequency range (8-12 GHz). The optimized ratio of the PMMA modified ferrite and PANI demonstrates SET values as high as ∼44 dB in the X band frequency range.
一种锰基尖晶石铁氧体，经聚甲基丙烯酸甲酯（PMMA）和聚苯胺（PANI）化学修饰，并将其复合材料用作电磁干扰（EMI）屏蔽材料。X 射线衍射研究表明，所制备的锰铁氧体在立方尖晶石结构中结晶。透射电子显微镜表明，颗粒高度团聚且为纳米晶。锰以+2 和+4 价态存在，铁以+2 和+3 价态存在。以不同的重量比评估了修饰后的锰铁氧体和聚苯胺复合材料的 EMI 屏蔽性能。结果表明，与未修饰的铁氧体相比，在 X 波段（8-12GHz）频率范围内，含有 PMMA 修饰的铁氧体的复合材料具有更高的总屏蔽效能（SET）。在 X 波段频率范围内，优化的 PMMA 修饰的铁氧体和聚苯胺的比例表现出高达约 44dB 的 SET 值。
