Low Defect Planar Graphene Exfoliation by Sonication in Polypropylene Carbonate and 5 Sec Microwaving

Abstract

This is an exceptional process on low cost, low defect and high-quality graphene which is produced by sonication in PPC and microwaving for just 5sec. Low energy arc-discharging process expands electrolytic graphite rods into hierarchical-like 3D-graphene retaining the basal plane carbon crystalline order and chemical purity [1-2]. Sonication in Polypropylene Carbonate causes non-covalent PPC-π bonding at graphene basal plane, aligning the graphene sheets in directions that allows efficient transmission of cavitation pressures and exfoliation; while microwave treatment for 5s separates any layered graphene, utilizing thermally induced lattice vibrations without changes on surface properties. Produced graphene (XRD 2θ = 26 ⁰C) has low defect (0.05 < ID/IG < 0.2), retainment of chemical purity (0~2.5% O2 content), with optimized effective graphene sizes (ranging from 350nm to 35 um), for diverse applications, dispersibility in diverse solvent, conformability to flat semi-transparent surfaces; storable in concentrated slurry (>50 mg mL−1). Planar graphene is suitable as 2D electronic materials applications [3], composites [4] and energy materials applications [5-10].