Size effects of graphene nanoplatelets on the properties of high-density polyethylene nanocomposites: morphological, thermal, electrical, and mechanical characterization

Abstract

High-density polyethylene (HDPE)-based nanocomposites incorporating three different types of graphene nanoplatelets (GnPs) were fabricated to investigate the size effects of GnPs in terms of both lateral size and thickness on the morphological, thermal, electrical, and mechanical properties. The results show that the inclusion of GnPs enhance the thermal, electrical, and mechanical properties of HDPE-based nanocomposites regardless of GnP size. Nevertheless, the most significant enhancement of the thermal and electrical conductivities and the lowest electrical percolation threshold were achieved with GnPs of a larger lateral size. This could have been attributed to the fact that the GnPs of larger lateral size exhibited a better dispersion in HDPE and formed conductive pathways easily observable in scanning electron microscope (SEM) images. Our results show that the lateral size of GnPs was a more regulating factor for the above-mentioned nanocomposite properties compared to their thickness. For a given lateral size, thinner GnPs showed significantly higher electrical conductivity and a lower percolation threshold than thicker ones. On the other hand, in terms of thermal conductivity, a remarkable amount of enhancement was observed only above a certain filler concentration. The results demonstrate that GnPs with smaller lateral size and larger thickness lead to lower enhancement of the samples’ mechanical properties due to poorer dispersion compared to the others. In addition, the size of the GnPs had no considerable effect on the melting and crystallization properties of the HDPE/GnP nanocomposites.

Influence of Graphene Platelet Aspect Ratio on the Mechanical Properties of HDPE Nanocomposites: Microscopic Observation and Micromechanical Modeling

“…However, several reports have been reported on the preparation method of PE/graphene nanocomposites [ 10 , 11 , 12 , 13 , 14 ], the improvement in the interfacial interaction between PE-functionalized GNPs [ 15 , 16 , 17 , 18 , 19 ], the dispersion and alignment of graphene in the composite samples [ 20 , 21 ], and the construction of the hybrid network structures of graphene with other conductive fillers [ 10 , 22 , 23 ]. Although the GNPs size is an important factor, only a few works have studied the GNP’s size effect on the mechanical properties of High-Density Polyethylene (HDPE) nanocomposites [ 24 , 25 , 26 ].…”

Preparation and Characterization of New Electrically Conductive Composites Based on Expanded Graphite with Potential Use as Remote Environmental Detectors

“…The signal decrease to 50% for this sample (GFG 5) occurs after around 3 min, which is two times faster than for the largest particle size (GFG 500). This could be explained by better distribution of smaller particles than the larger ones [24][25][26]. All of the measured data exhibit a sigmoid shape of the curve with a fast decrease of the electric current in the initial part, followed by a slower decrease in an exponential decay pattern.…”

In vitro elution characteristics of gentamicin-impregnated Polymethylmethacrylate: premixed with a second powder vs. liquid Lyophilization

“…Both LG-PMMA and PG-PMMA spacers were analyzed with a scanning electron microscope [ver. Quanta 400 (SEM-Quanta)] for surface evaluation [10].…”