In this investigation, the mechanical properties such as compression, impact, and flexural properties of graphene decorated with graphene quantum dots (GDGQD) epoxy composites with concentration of GDGQD ranging from 0.25 to 1 wt % were studied. Ideal mechanical properties are obtained by systematically varying the filler weight in the epoxy matrix. The morphological studies of GDGQD have been characterized using transmission electron microscope, X-ray diffraction, and Fourier transform infrared technique. The compression, impact, and flexural strengths were enhanced effectively by the GDGQD loading. With the addition of 0.75 wt % of GDGQD, the compressive strength, compressive modulus, flexural strength, and flexural modulus of the composites were improved by 22, 29, 31, and 63%, respectively. Also an improvement in impact strength of 102% for 0.75 wt % GDGQD epoxy sample was also obtained. Examination of fractured test specimens was performed with scanning electron microscope. The enhancement in the mechanical properties is due to the better stress transfer that is attributed by enhanced interfacial bonding between GDGQDs and the epoxy. Using the GDGQD aspect ratio in the two-dimensional randomly oriented filler modified Halpin-Tsai model, the theoretical flexural modulus for the GDGQD/epoxy composites has been established.

The article explores viscoelastic and mechanical property analysis of graphene decorated with graphene quantum dots (GDGQD) reinforced epoxy composite. Tensile, nanoindentation, and nano‐dynamic mechanical analysis (DMA) tests were conducted on the composite with 0 to 1 wt% filler variation (an interval of 0.25 wt% maintained). The hardness and elastic modulus for two different loading conditions under a frequency range of 10 to 250 Hz were performed. The viscoelastic properties described through loss tangent and storage modulus graphically and the various factors such as modulus and depth of penetration were influenced by force frequency and mobility of the molecular chain. The results revealed the role of GDGQDs as filler material for enhancing the nanomechanical and tensile properties of the epoxy matrix. The differences in the properties can be ascribed to the filler interfacial bonding with the polymer matrix at the molecular level. The macro‐level properties like tensile properties following the same trend as that of the micro‐level properties like nano‐indentation and nano‐DMA results. Further, with the GDGQD aspect ratio, and assuming three‐dimensionally filled randomly orientation of filler, the Halpin‐Tsai model was satisfied with the experimental tensile modulus values.

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The paper discusses about the wear and micro hardness behavior of Graphene Decorated with Graphene Quantum Dots (G-D-GQD) reinforced epoxy composites. The samples were prepared by open mold casting method by adding 0.25–1 wt. % (in an interval of 0.25%) of GDGQD and evaluated on a reciprocating wear tester configuration for wear and coefficient of friction properties. The micro-hardness testing of the G-D-GQD particles embedded epoxy composites has been performed and the hardness value results were compared with neat epoxy to find the improvement in hardness. Significant improvements in the hardness and wear resistance of the epoxy nanocomposites was obtained by the embedding of G-DGQD fillers, which is due to the efficient bonding of GDGQD filler with the epoxy matrix. Scanning Electron Microscope (SEM) images of the worn composites were analysed to get an insight into the morphology of the surfaces. Furthermore, the coefficient of friction of the composites got increased with the wt. % of fillers in the base material, but due to the superior bond strength and lesser agglomeration of the particles, the Vicker's hardness improved and the wear loss reduced. Hence the surface area coverage of G-D-GQDs got a significant role in the reduced wear loss and thereby coming to a threshold value. The study concludes by suggesting that 0.25 wt. % GDGQD/epoxy composites shown a least wear rate and increased hardness of 0.023% and 26%, respectively thereby suggesting application involving reduced wear rates.

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