Morphological changes on graphene nanoplatelets induced during dispersion into an epoxy resin by different methods

A structural analysis demonstrating how the manufacturing method of graphene nanoplatelets (GNPs) into a polymer matrix can strongly modify the GNPs morphology and, consequently, their properties, was carried out. Three different methods based on sonication and high shear forces were used to elucidate defects induction and possible size diminution. Manufacturing methods including high shear forces caused the extension of the GNPs while sonication induces wrinkling of the sheets. Residual stresses are induced in the nanoplatelets structure showing an increase in the Raman intensities ratios I-D/I-G and I-D/I-G when a major cycles number of calendering are applied. (C) 2014 Elsevier Ltd. All rights reserved.