Non-Covalent Functionalization of Graphene Using Self-Assembly of Alkane-Amines

Abstract

A simple, versatile method for non-covalent functionalization of graphene based on solution-phase assembly of alkane-amine layers is presented. Second-order Møller–Plesset (MP2) perturbation theory on a cluster model (methylamine on pyrene) yields a binding energy of ≈220 meV for the amine–graphene interaction, which is strong enough to enable formation of a stable aminodecane layer at room temperature. Atomistic molecular dynamics simulations on an assembly of 1-aminodecane molecules indicate that a self-assembled monolayer can form, with the alkane chains oriented perpendicular to the graphene basal plane. The calculated monolayer height (≈1.7 nm) is in good agreement with atomic force microscopy data acquired for graphene functionalized with 1-aminodecane, which yield a continuous layer with mean thickness ≈1.7 nm, albeit with some island defects. Raman data also confirm that self-assembly of alkane-amines is a non-covalent process, i.e., it does not perturb the sp² hybridization of the graphene. Passivation and adsorbate n-doping of graphene field-effect devices using 1-aminodecane, as well as high-density binding of plasmonic metal nanoparticles and seeded atomic layer deposition of inorganic dielectrics using 1,10-diaminodecane are also reported.