Solid phase functionalization of MWNTs: an eco-friendly approach for carbon-based conductive inks

A green approach for the functionalization of multiwalled carbon nanotubes (MWNTs) with hydrophilic groups and their use for the development of an ecofriendly conductive ink are described here. A known organic functionalization of MWNTs, 1,3 dipolar cycloaddition of catechol substituted azomethine ylide, is performed here for the first time, in the solid phase. The functionalized MWNTs were then mixed with graphene nanosheets in ethanol to produce a hydrophilic and highly conductive all-carbon hybrid. The end product was finally mixed with resin to produce a water based conductive ink. In the total procedure, a solid state reaction and non-toxic and eco-friendly solvents like water or alcohols have been used to produce a totally green conductive ink for industrial printing techniques like flexography or gravure printing.