Microwave assisted synthesis and characterization of graphene nanoplatelets

Abstract

Graphene Nanoplatelets were fabricated from expandable graphite by rapid microwave exfoliation. Expandable graphite was irradiated in microwave in full power for 3 min, then was soaked in mixed nitric acid and sulphuric acid at volume ratio of 1:1 for 24 h and re-irradiated, thus graphene nanoplatelets (GNPs) were obtained. Extensive characterization techniques showed that GNPs synthesized using this technique are highly pure with traces of oxide groups and without serious unrecoverable oxidation damage. GNPs synthesized by microwave technique have high crystallinity, with variable size and little layer thickness.

Study on epoxy resin-based thermal adhesive filled with hybrid expanded graphite and graphene nanoplatelet

“…XRD pattern of 35GNP + 65Ep shows peak broadening due to the smaller size of GNPs. These values of d-spacing are slightly higher than that of expanded graphite (d002 = 3.34162 Å) [5,6,44]. This is due to exfoliation and intercalation of epoxy chains between graphitic layers during mixing which increases the slight distance between graphene nanoplatelet layer units.…”

“…However, they are prone to brittleness behavior and poor crack propagation resistance which restrict their application. It has some inherent thermal conductivity (~ 0.2 W/m K) and further increased by incorporation of commercially available silver, aluminum nitride, boron nitride and graphite-based micro and nanofillers by our researchers [4][5][6]. Many commercial thermal adhesives and pastes are available in the market.…”

Biomedical Applications of Graphene Nanomaterials and Beyond

“…There are several reported synthesis procedures for the synthesis of graphene, including mechanical exfoliation, chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PE-CVD), cleavage of natural graphite, hydrogen arc discharge, epitaxial growth of electrically insulating material like boron nitride, solution-processable methods, − and the microwave synthesis method (see Figure ). , …”

“…There are several reported synthesis procedures for the synthesis of graphene, including mechanical exfoliation, 7 chemical vapor deposition (CVD), 27 plasma-enhanced chemical vapor deposition (PE-CVD), 28 cleavage of natural graphite, 29 hydrogen arc discharge, 5 epitaxial growth of electrically insulating material like boron nitride, 30 solution-processable methods, 31−33 and the microwave synthesis method (see Figure 1). 34,35 Graphene was first synthesized by mechanical exfoliation in 2004. 7 This simple cost-effective synthesis procedure created an explosive growth in the research field of graphene and consequently demands graphene flakes, which are valuable for research to clarify graphene properties.…”

Variable-Angle Spectroscopic Ellipsometry of Graphene-Based Films

“…In Ref. [62], it was stated that GNPs show an index of refraction n of 1.42 at 482 nm. Therefore, GNPs thin films display lower optical constants than GO [32] and graphene [36].…”