Excellent electromagnetic interference shielding effectiveness of chemically reduced graphitic oxide paper at 101 GHz

摘要

Graphitic oxide (GO) was synthesized by oxidation of graphite powder using Hummer's method and the formed GO is solution processed into paper-like macroscopic form. Subsequently, chemically reduced graphitic oxide paper (CRGOP) is prepared by hydrazine vapours induced reduction of formed GO precursor based paper. The formation of GO and its successful reduction to RGO phase is confirmed by FTIR, Raman Spectroscopy and X-ray diffraction. It has been observed that due to high electrical conductivity similar to 200 micron thick CRGOP display excellent EMI shielding performance at very high frequency of 101 GHz frequency with total shielding effectiveness (SE) value of -35.49 dB (i.e. > 99.97% blocking of incident EM radiation) which is much higher compared to pristine GO paper (-1.55 dB) or comparable to expanded graphite (EG) sheet (-35.61 dB). Due to their lightweight nature, these freestanding CRGOPs display average specific SE value of -221.8 dB cm(3)/g. Besides, their excellent flexibility and makes them potential candidate for lightweight EMI gasketing material compared to other forms of flexible carbons like EG.