Poly(methyl methacrylate)‐functionalized reduced graphene oxide‐based core–shell structured beads for thermally conductive epoxy composites

Abstract

Thermally conductive epoxy nanocomposite with core-shell structured filler beads has been prepared. The core represents plasma-treated poly(methyl methacrylate) bead, and the shell, amine-functionalized reduced graphene oxide (frGO) sheets. The negatively charged core and the positively charged shell form core-shell unified structure through electrostatic attraction and the conductive bridges are formed among neighboring filler particles in the composite mass. The epoxy composite prepared with these core-shell structured filler shows a thermal conductivity of 0.72 W m −1 K −1 for an overall frGO concentration of as low as 0.96 wt %. Pal model has been applied to evaluate the effective thermal conductivity of frGO sheets that have been realized in the epoxy composition. Assuming the maximum possible volume packing fraction of the spherical beads for random jamming to be equal to 0.63, the effective thermal conductivity has been estimated as 280 W m −1 K −1 . Evaluation of the effective thermal conductivity is a step forward to in-depth study of real contribution of the highly conductive fillers in the polymer composites.

Fabrication of BaTiO3-Loaded Graphene Nanosheets-Based Polyarylene Ether Nitrile Nanocomposites with Enhanced Dielectric and Crystallization Properties

“…Figure 3 shows the intensity of light scattering as a function of the zeta potential of GO, BT@ZnPc-1 and BT@ZnPc-1 after modified by Ca 2+ particles at pH = 7. Zeta potential refers to the potential of the Shear Plane, which is related to the total charge carried by the particles in a particular medium and the peak of the zeta potential represents the type and intensity of charge present after dispersed in solution [23]. It can clearly be seen that the highest light scattering of GO is observed at the zeta potential of −17.29 mV, which is mainly owing to the ionization of oxygenated functional groups in a high polar solvent like water, and the pristine GO would assume slightly negative charge.…”

3D printing of copper particles and poly(methyl methacrylate) beads containing poly(lactic acid) composites for enhancing thermomechanical properties

“…27 Polymeric beads have been used to provide volume exclusion effect that leads to an effective continuous filler network in polymer matrix. [29][30][31][32] Grunlan et al 29 reported a significant improvement in electrical and thermal conductivity of polymer matrix with a low content of carbon nanotubes (CNT) using spherical polymer particles of poly(vinyl acetate). They claimed that the improved conductivity was attributed to the segregated network by the formation of CNT-CNT connection.…”

“…The thermally conductive nanoparticles were formed the segregated structure in the presence of polymer beads in the epoxy matrix using hot-press method. 32 The polymer beads were also utilized as a core template for coating a shell layer of multiwall carbon nanotubes (MWCNTs), then the embedded core-shell structure of MWCNTs@polymer beads resulted in thermal conductivity of 0.95 W m −1 K −1 at 1 wt% of MWCNTs loading. 25 To the best author's knowledge, most of researchers have been concentrating to improve the properties of 3D printed composites by loading higher amount of fillers.…”

“…In our previous studies, 25,33 the polymer beads have been utilized to improve the thermal conductivity and thermal properties of polymer composites. The thermally conductive nanoparticles were formed the segregated structure in the presence of polymer beads in the epoxy matrix using hot‐press method 32 . The polymer beads were also utilized as a core template for coating a shell layer of multiwall carbon nanotubes (MWCNTs), then the embedded core‐shell structure of MWCNTs@polymer beads resulted in thermal conductivity of 0.95 W m −1 K −1 at 1 wt% of MWCNTs loading 25 .…”

Effect of aspect ratio of vertically aligned copper nanowires in the presence of cellulose nanofibers on the thermal conductivity of epoxy composites

“…[3][4][5] The polymer-based composites with various thermally conductive fillers are in high demand as thermal management materials because of their easy processability, low production cost, and lightweight. [6][7][8] In general, the thermally conductive composites are prepared by a random dispersion of the fillers in polymer matrix and the composites require a high filler loading to reach a high thermal conductivity. [9][10][11] However, the high filler loading leads to a deterioration of mechanical properties, the difficulty of processing, and heavyweight.…”