Mechanochemically Carboxylated Multilayer Graphene Nanoplatelets as Functionalized Carbon Nanofillers for Electrically Conductive Epoxy Spray Coatings

Abstract

Dry ball milling of graphite under CO2 pressure in a planetary ball mill affords carboxylated multilayer graphene nanoplatelets as carbon nanofillers (MFG‐CO2) for carbon/epoxy spray coatings combining electrical conductivity up to 0.09 S cm−1 with excellent adhesion and improved toughness. As confirmed by µCT‐imaging, the two‐stage homogenization by means of a speed mixer with subsequent shearing in a three‐roll mill uniformly disperses up to 60 wt% MFG‐CO2 in aqueous emulsions of epoxy resins and hardener without impairing spray coating. The MFG‐CO2 content governs surface roughness, as determined by 3D laser microscopy, gloss, electrical conductivity, and toughness without adversely affecting excellent adhesion. Mechanochemical tailoring MFG nanofillers holds great promise for the development of advanced epoxy spray coatings exhibiting an improved balance of thermooxidative, chemical and environmental stability, electrical and thermal conductivity, toughness, corrosion, and barrier resistance.

Influence of Curing Agents Molecular Structures on Interfacial Characteristics of Graphene/Epoxy Nanocomposites: A Molecular Dynamics Framework

“…Adding nano‐fillers to the epoxy matrix has been shown to be efficacious in enhancing the overall properties of the final nanocomposite. [ 7–10 ] Among the numerous candidates, carbon allotropes like graphenes are appropriate candidates to improve epoxy's thermal and mechanical characteristics due to their attractive mechanical properties and excellent compatibility with the epoxy matrix. [ 11 ]…”