Graphene nanosheets‐filled epoxy composites prepared by a fast dispersion method

Abstract

Graphene nanosheets‐filled epoxy composites (GNS/Epoxy) were prepared at different filler loading levels from 0.25 to 3.00 wt %. A fast dispersion method as short as 5 min is employed to disperse GNS in epoxy matrix, which was enough for the homogeneous dispersion of GNS with the help of high ultrasonic frequency of 100 kHz and power of 200 W and high heat treatment temperature of 70 °C. The maximum electrical conductivity and thermal conductivity of the composites achieved 0.058 S m−1 and 0.57 W m−1 K−1, respectively, with a low electrical percolation threshold of 1.50 wt %. The electrical conductivities were further predicted by percolation theory and found to agree well with the experimental results, which indicated that the graphene nanosheets dispersed very well in the matrix even at very short processing time. The results showed that the microstructures, thermal, electrical, and mechanical properties of epoxy polymer were significantly improved by adding a low amount of graphene nanosheets. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45152.

Enhancing electrical conductivity of multiwalled carbon nanotube/epoxy composites by graphene nanoplatelets

“…Such high experimental percolation threshold value could be attributed to the uneven distribution and large aggregates of GNPs in the polymer matrix. Similar percolation threshold values were already observed in GNP/epoxy composites [23,24]. At low filler concentrations aggregated particles do not form a conductive path.…”

Tailored interphase and thermal interface resistance of self‐assembled thermally reduced graphene oxide–polyamide hybrid/epoxy composites with enhanced thermal conductivity

“…Many methods have been attempted to facilitate graphene dispersion in an epoxy (EP) matrix, such as mechanical blending with ultrasonication and high‐shear mixing, which was able to break the van der Waals interactions among graphene nanosheets and retain the distinct structure of graphene. However, the enhancement in phonon scattering and mismatch led to a increase in the thermal interface resistance of the resulting composites.…”

“…7,8 Therefore, graphene dispersion in an epoxy matrix and interface compatibility between graphene and the epoxy matrix are the key issues for the application of thermally conductive composites. 9,10 Many methods have been attempted to facilitate graphene dispersion in an epoxy (EP) matrix, such as mechanical blending with ultrasonication and high-shear mixing, [11][12][13][14] which was able to break the van der Waals interactions among graphene nanosheets and retain the distinct structure of graphene. However, the enhancement in phonon scattering and mismatch led to a increase in the thermal interface resistance of the resulting composites.…”

Mechanochemically Carboxylated Multilayer Graphene Nanoplatelets as Functionalized Carbon Nanofillers for Electrically Conductive Epoxy Spray Coatings

“…[20][21][22][23] In an alternative singlestep top-down process, Jeon et al obtained selectively edgefunctionalized multilayer graphene by grinding graphite in a planetary ball mill in the presence of carbon dioxide, nitrogen, sulfur, or phosphorous which react with carbon during the milling process [24][25][26][27] whereas a large variety FG/epoxy nanocomposites have been established during the last decade, little is known with respect to the impact of FG nanofillers on epoxybased spray coatings. [9,28,29] For instance, Sue et al examined the gas permeability of FG/epoxy spray coatings. In their process a solvent-based epoxy system was blended together with chemically reduced graphite oxide and the resulting graphene oxide dispersion was coated onto a polyimide film by means of spraying.…”