A comparative study of graphite and graphene sheets employed in polymer‐based electromagnetic shielding materials

Abstract

AbstractIn this work, the comparative properties of graphite (GT) and graphene (GE) sheets for use in polymer‐based electromagnetic (EM) shielding materials were explored. To accomplish this, GT and GE were individually combined with polyvinylidene fluoride (PVDF) as composite films and each was later attached to a nonwoven fabric to produce nonwoven‐reinforced (NR) films. The microtopography showed that GT was easily wrapped by the PVDF matrix in the composite film, whereas GE was partially exposed on the film surface because of its complete contact with PVDF. Addition of the carbon materials appeared to increase the EM shielding effectiveness (SE) of the films in the X‐band. The SE of the PVDF/GE films was significantly higher than the PVDF/GT films, up to 50.4 dB, which was mainly affected by electronic conductivity. The internal loss of the EM wave in PVDF/GE films was dominated by internal reflection because of the more regular arrangement of GE, whereas the loss in the PVDF/GT films contained greater EM absorption. Although the SE at 1–18 GHz of NR PVDF/GT film was significantly lower than the NR PVDF/GE film, the internal loss at high frequency was higher due to the better absorption loss in its surface layer.Highlights GT and GE sheets were compared as functional materials. GT and GE sheets showed different distribution states in the films. The EM SE of the PVDF/GE films was up to 50.4 dB. The EM shielding mechanism was analyzed and compared.