Abstract
Here, we study the self-aligned asymmetric electrically conductive composite thin film prepared via casting of graphene oxide (GO)/poly (vinylidene-hexafluoropropylene) (PVDF-HFP) dispersion, followed by low temperature hydriodic acid reduction. The results showed that composite thin film revealed the high orientation of graphene sheets along the direction of film surface. However, graphene sheets are asymmetrically distributed along the film thickness direction in the composite film. Both sides of as prepared composite film showed different surface characteristics. The asymmetric surface properties of composite film induced distinction of surface resistivity response; top surface resistivity (21 Ohm) is ∼ 4 times higher than bottom surface resistivity (5 Ohm). This asymmetric highly electrically conducting composite film revealed efficient electromagnetic interference (EMI) shielding effectiveness of ∼ 30 dB. This study could be crucial for achieving aligned asymmetric composite thin film for high-performance EMI shielding radiation.
Highlights
The recent development in information technology and fast portable devices packed with highly integrated circuits generates severe electromagnetic radiation
Polymer composite materials with enhanced electrical conductivity can be used as an alternative to conventional electromagnetic interference (EMI) shielding materials because of their lightweight, resistance to corrosion, flexibility, good processability and low cost compared to the metal based materials.[1,2]
The results indicate that asymmetric composite film exhibited EMI shielding effectiveness of ∼ 30 dB, which can shield up to 99.9% of incident radiation
Summary
Great progress has been made in the development of graphene/polymer composite including sandwich, foam, segregated and porous structured materials for shielding application, but further progress is still needed for the implementation of these materials and their viable and cheap manufacturing.[12,17,18,19] Wen and co-workers reported lightweight composites of 20 wt% rGO reaches EMI shielding of -38 dB.[20] In further study, ultrathin graphene composites with absorption value of ∼ -15 dB and reflection loss of -30 dB has been reported.[21] In another study by Cao et al, magnetic nanoparticles decorated reduced graphene oxide (NiFe2O4/r-GO) composite would have good tuneable EMI attenuation capacity.[22] Improvements are needed in the fabrication process to develop new lightweight and flexible composite materials such as film, which can give very high EMI shielding efficiency due to their high electrical conductivity. It is challenge to get high electrical conductivity in composite thin films due to either insufficient in situ reduction process or poor dispersion and interconnectivity of rGO sheets within the polymer matrix. First time we report dispersion casting approach for aligned asymmetric conducting rGO/PVDFHFP composite thin film with high-performance EMI shielding. This study could be crucial in the field of flexible composite thin films for high-performance EMI shielding application
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
