Optimization of electromagnetic shielding and mechanical properties of reduced graphene oxide/polyurethane composite foam

Abstract

Reduced graphene oxide (RGO) is an effective polymer filler for shielding against electromagnetic interference (EMI). Its shielding efficiency rises as its concentration in polymer matrices increases. However, higher filler loading impedes polymer foaming and deteriorates the mechanical properties of the resulting foam. The goal of this work is to determine the optimal RGO concentration that can be loaded into polyurethane (PU) matrix to produce a composite foam with a high level of electromagnetic shielding along with good mechanical properties. To that end, different PU foam samples containing varying amounts of RGO were synthesized. The synthesized samples were characterized by scanning electron microscope (SEM), thermogravimetric analysis (TGA), Fourier transform infra-red (FT/IR) and universal testing machine. Furthermore, the shielding efficiency of the samples was measured using a vector network analyzer over the frequency range of 8-12 GHz. The results revealed that the increase in RGO concentration enhances the mechanical and thermal properties of the prepared composite foam materials. The shielding effectiveness reached À23 dB at 5 wt% RGO concentration. The polyurethane-RGO composite foam materials have been identified as potentially viable materials for use in electromagnetic shielding applications.

Recent advances in structural design of conductive polymer composites for electromagnetic interference shielding

“…The polymer foams (including polyurethane foam, melamine foam, PDMS foam, polyimide foam, and formaldehyde resin foam) were highly suitable as the framework and template for the deposition of nanofillers due to their continuous 3D skeleton and porous structure 238–242 . The porous polymers have been utilized for the large‐scale fabrication of porous conductive foams and CPCs, which possessed the advantages of high porosity, low modulus, excellent mechanical properties, durability and low price 243–245 .…”

“…The polymer foams (including polyurethane foam, melamine foam, PDMS foam, polyimide foam, and formaldehyde resin foam) were highly suitable as the framework and template for the deposition of nanofillers due to their continuous 3D skeleton and porous structure. [238][239][240][241][242] The porous polymers have been utilized for the large-scale fabrication of porous conductive foams and CPCs, which possessed the advantages of high porosity, low modulus, excellent mechanical properties, durability and low price. [243][244][245] For example, Shen et al 243 prepared the porous and compressible conductive PU/graphene (PUG) composite foam by impregnating the commercial porous PU sponge into GO solution and then chemical reduction, where a 3D conductive rGO network around the PU F I G U R E 8 (A-C) SEM images of GA, unfoamed TPU/GA and foamed TPU/GA composites; (D) EMI SEs of unfoamed TPU/GA and foamed TPU/GA composites in X-band frequency; (E) Schematic of attenuation mechanism of incident EMWs for TPU/CRGO composite foams.…”

Flexible and durable conductive nickel/graphene‐coated polyethylene terephthalate fabric for highly efficient electromagnetic shielding

“…In recent years, textiles coated with nanomaterials are principally promising because of their lightweight, high electrical conductivity, superior EMI shielding efficiency, flexibility, and comfort. Various nanomaterials have been used such as Ag nanowires, 1,13 carbon nanotubes (CNTs), 4 MXene, 14,15 reduced graphene oxide (rGo), 16,17 and graphene aerogel 18 . The rGo two‐dimensional (2D) sheets are superior for electronic applications due to their high modulus, good chemical stability, and better electrical properties than other nanomaterials 6,19,20 .…”

Determination of electromagnetic traveling path in polymer/multi‐walled carbon nanotube nanocomposite foams and analysis by Taguchi technique

“…19 This phenomenon could dissipate microwave energy in the shield because EM wave reflected and scattered numerous times into cellular structure of nanocomposite foams, as well as the EM wave traveling path into the shield were prolonged. 20 Furthermore, the introduction of microcellular structure could optimize impedance match which permits EM beam penetrates into the shield, therefore absorption mechanism is dominant mechanism compared to reflection. 21 According to the mentioned tips, structural properties, for instance, cell density and cell size have irrefutable effect on the dissipation of EM energy.…”