Graphene-reinforced carbon composite foams with improved strength and EMI shielding from sucrose and graphene oxide

Abstract

Graphene-reinforced carbon composite foams were prepared by thermo-foaming of graphene oxide (GO) dispersions in molten sucrose to form solid organic foams followed by carbonization at 900°C. The hydrogen bonding interactions between sucrose hydroxyls and functional groups on GO decreased the melting point of sucrose from 185 to 120°C when the GO concentration increased from 0 to 1.25 wt%. The viscosity of GO dispersions in molten sucrose increased gradually with an increase in GO concentration up to 0.75 wt% and then rapidly up to 1.25 wt%. The foaming time and foam setting time decreased drastically from 6 to 1 h and 34 to 9 h, respectively, when the GO concentration increased from 0.15 to 1.25 wt% due to the catalytic effect of GO toward -OH to -OH condensation. The density and cell size of the carbon composite foams depended on the GO concentration. A maximum compressive strength and specific compressive strength of 5.2 MPa and 21.3 MPa g -1 cm -3 , respectively, achieved at a very low GO concentration of 0.25 wt% corresponded to an increase of 189 and 133 %. The electrical conductivity and EMI shielding effectiveness (SE) of the graphene-reinforced carbon composite foams increased with an increase in the GO concentration up to 0.15 wt% and then decreased. The decrease was due to a decrease in foam density and GO agglomeration at higher GO concentrations. The maximum SE and specific SE of 38.6 dB and 160 dB g -1 cm -3 were achieved at GO concentrations of 0.15 and 1 wt%, respectively.

Multifunctional Aramid Nanofiber/Carbon Nanotube Hybrid Aerogel Films

“…(a) Proposed EMI shielding mechanism of FC-ANF/CNT aerogel films. (b) Comparison the EMI shielding performance of FC-ANF/CNT aerogel films with other shielding materials, including conducting polymers, metals, and nanoscale carbons at the X-band. ,,− ,− (c) Plots of thickness-specific shielding effectiveness (SSE/t) versus density, where the SSE/t values of FC-ANF/CNT aerogel films are among the highest, compared to those of previously reported shielding materials. − ,− …”

Recent progress in graphene based ceramic composites: a review

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Thermal and electrical properties of phenol formaldehyde foams reinforcing with reduced graphene oxide

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