Effects of Size and Functionalization on the Structure and Propertiesof Graphene Oxide Nanoflakes: An in Silico Investigation

摘要

Graphitic nanoparticles, specifically, graphene oxide(GO) nanoflakes, are of major interest in the field of nanotechnology,with potential applications ranging from drug delivery systems toenergy storage devices. These applications are possible largely becauseof the properties imparted by various functional groups attached to theGO surface by relatively simple production methods compared topristine graphene. We investigated how varying the size and oxidationof GO flakes can affect their structural and dynamic properties in anaqueous solution. The all-atom modeling of the GO nanoflakes ofdifferent sizes suggested that the curvature and roughness of relativelysmall (3×3nm) GO flakes are not affected by their degree ofoxidation. However, the larger (7×7nm) flakes exhibited an increasein surface roughness as their oxidation increased. The analysis of waterstructure around the graphitic nanoparticles revealed that the degree ofoxidation does not affect the water dipole orientations past the first hydration layer. Nevertheless, oxygen functionalizationinduced a well-structured first hydration layer, which manifested in identifiable hydrophobic and hydrophilic patches on GO.The detailed all-atom models of GO nanoflakes will guide a rational design of functional graphitic nanoparticles for biomedicaland industrial applications.